Cognitive Psychology, memory and forgetting

7/23/2013
3rd
Year
1st
Semester
1st
Assignment
The Ways of Forgetting and the
Ways of Improving Memory
PSY 203-Cognitive Psychology
Name:D.K.D.Madhubhashini
Regno:A/BBA/09/068
Lecturer:Mrs.M.Gunasekara

Acknowledgement
I consider it is a great privilege to thank all those people who helped me to complete this assignment
I express my sincere thanks to Main lecturer Mrs.M.Gunasekaraand Assistant Lecturer
Miss.KokilaSubhashinifor giving me this opportunity to commence the project work and guidance
do so.
At for last not for least like to thank my parents who gave me a great deal of helping hand to make
this assignment a success.
D.K.D.Madhubhashini

Content
Acknowledgement .................................................................................................................................1
Content...................................................................................................................................................2
Table of Figures .....................................................................................................................................3
Introduction............................................................................................................................................4
Literature Review...................................................................................................................................5
Cognitive Psychology........................................................................................................................5
History of Cognitive Psychology...................................................................................................5
Memory and Forgetting .........................................................................................................................9
Memory..............................................................................................................................................9
Main Processors of Memory........................................................................................................10
Storage .............................................................................................................................................13
Special Situations in Recalling memeory ............................................................................................19
Hyperthymesia.................................................................................................................................19
Rebirth and Past life memory ..........................................................................................................20
Forgetting.........................................................................................................................................21
Why We Forget?..................................................................................................................................21
Elizabeth Loftus‟s key explanations for why forgetting occurs. .....................................................22
1. Retrieval Failure.......................................................................................................................22
The Ebbinghaus Forgetting Curve...............................................................................................22
2. Interferance ..............................................................................................................................23
3. Failure to Store.........................................................................................................................23
4. Motivated Forgetting ...............................................................................................................24
Memory Disorders ...........................................................................................................................25
Alzheimer's Disease.....................................................................................................................25
Dementia......................................................................................................................................26
Age Associated ............................................................................................................................27
Alcohol.........................................................................................................................................29

Amnesia .......................................................................................................................................30
Autism..........................................................................................................................................32
Huntington's Disease....................................................................................................................33
Korsakoff's Syndrome..................................................................................................................34
OCD.............................................................................................................................................35
Parkinson's Disease......................................................................................................................36
Schizophrenia...............................................................................................................................37
Tourette Syndrome.......................................................................................................................38
WAYS OF ENHANCING MEMORY................................................................................................38
Organization.....................................................................................................................................39
Concentration...................................................................................................................................39
Chunking Memory...........................................................................................................................39
Recoding: .........................................................................................................................................39
Use of schema..................................................................................................................................40
Mnemonic Strategies .......................................................................................................................40
Method of loci..............................................................................................................................40
SQ3R method...................................................................................................................................41
SURVEY......................................................................................................................................41
QUESTION..................................................................................................................................41
READ...........................................................................................................................................41
RECITE........................................................................................................................................42
REVIEW......................................................................................................................................42
Table of Figures
Figure 1 Memory and Brain.................................................................................................................11
Figure 2 Schematic Model of The Human Information Processing System. ......................................15
Figure 3 Ebbinghaus Forgetting Curve................................................................................................23
Figure 4 Aging.....................................................................................................................................27
Figure 5- Alcoholism...........................................................................................................................30
Figure 6 Source of amnesia..................................................................................................................32
Figure 7 OCD.......................................................................................................................................36
Figure 8 memory palace.......................................................................................................................41

Introduction
The chapters in this collection all reference causes of forgetting. But the variety of possible causes is
outstanding. Here we examine insights into trace decay, interference, and consolidation that have
emerged from recent computational and mathematical models of memory.
Two key theoretical issues support the contemporary discussion. The first of these concerns the
reputed distinction between two memory systems that are dedicated to the storage of information
over the short and the long term (STS and LTS respectively), and the second concerns the
importance of consolidation failure as a cause of forgetting. STS vs. LTS. Although the usefulness of
a theoretical distinction between STS and LTS has often been questioned (Crowder, 1989; Melton,
1963) only recently have specific models emerged that claim to account for both short-term and
long-term memory phenomena within a united framework.
There is no evidence that time based decay is the sole or even primary cause of forgetting over the
short term, thus undermining one piece of evidence from forgetting for the traditional distinction.
Other arguments that are consistent with our perspective can be found somewhere else.
In particular, we note that interference-based models such as those of Lewandowsky and others
(Lewandowsky& Farrell, 2008; Oberauer&Lewandowsky, 2008) and Brown (2007) can reason for
forgetting data that have previously been expected to connecta STS and LTS disunion, and that
experimental evidence that has been taken in support of temporal decay can be understood.
Consolidation is the second theoretical topic addressed that of consolidation as a primary factor
underpinning memory and forgetting.
Consolidation refers to the idea that memories continue to strengthen after they have been formed,
and that they thus become hardier to forgetting over time.As Wixted (2004b, 2005) notes,
“consolidation has featured prominently in theorizing on forgetting in the neurosciences for several
decades, whereas most cognitive approaches have relied exclusively on alternative notions such as
interference or decay”. Indeed, not a single recent formal model of memory within a cognitive
tradition assigns an important role to consolidation.
Conversely, models of memory that do emphasize consolidation (McClelland, McNaughton, &
O'Reilly, 1995; Meeter&Murre, 2005; Norman & O'Reilly, 2003) handle the data implicating
consolidation, but they typically do not address the rich data sets that are traditionally taken as the
path for cognitive models of memory.

Literature Review
Cognitive Psychology
Cognitive psychology is the scientific investigation of human cognition, that is, all our mental
abilities the way people think, perceive, remember and learn. As part of the larger field of cognitive
science, this is narrowly related to artificial intelligence, computer science, philosophy,
anthropology, linguistics, biology, physics, and neuroscience.
The fundamental concentration of cognitive psychology is on how people acquire, process and store
information. There are numerous practical applications for cognitive research, such as enlightening
memory, increasing decision-making accuracy etc.
History of Cognitive Psychology
Cognitive psychology in its contemporary practice includes a extraordinary set of new technologies
in psychological science. Although published inquiries of human cognition can be traced back to
Aristotle‟s „‟De Memoria‟‟ (Hothersall, 1984), the intellectual origins of cognitive psychology began
with cognitive approaches to psychological problems at the end of the 1800s and early 1900s in the
works of Wundt, Cattell, and William James (Boring, 1950).
Behaviorism school of thought
“Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and
I'll guarantee to take any one at random and train him to become any type of specialist I might select
-- doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his
talents, penchants, tendencies, abilities, vocations, and race of his ancestors.”
John Watson, Behaviorism, 1930
Till the year 1950 was the leading school of thought in psychology(Watson, 1913; Boring, 1950;
Skinner, 1950). Wilhelm Wundt's Influence The creation of a psychology lab established psychology
as a separate field of study with its own methods and questions. Wilhelm Wundt's support of
experimental psychology these issue led to the decline of behaviorism as the dominant branch of
scientific psychology and to the “Cognitive Revolution”.Cognitive psychology declined in the first
half of the 20th century with the rise of “behaviorism" the study of laws relating. It is a theory of
learning based upon the idea that all behaviors are acquired through conditioning. Conditioning
ensues through interaction with the environment. Behaviorists believe that our responses to
environmental stimuli forms our behaviors.There are two major types of conditioning:

Classical conditioning is a technique used in behavioral training in which a naturally occurring
stimulus is paired with a response.
Operant conditioning Operant conditioning /instrumental conditioning is a method of learning that
occurs through rewards and punishments for behavior.
Cognitive Revolution
The Cognitive Revolution began in the mid-1950s when researchers in couple of fields originated to
develop theories of mind based on compound representations and computational procedures (Miller,
1956; Broadbent, 1958; Chomsky, 1959; Newell, Shaw, & Simon, 1958). Cognitive psychology
became main theory in the use1960s (Tulving, 1962; Sperling, 1960).Unlike behaviorism, which
focuses only on observable behaviors, cognitive psychology is concerned with internal mental states.
The term "cognitive psychology" was first used in 1967 by the publication ofUlricNeisser‟s book,
„‟Cognitive Psychology‟‟, in 1967. According to Neisser, cognition involves
"All processes by which the sensory input is transformed, reduced, elaborated, stored, recovered,
and used. It is concerned with these processes even when they operate in the absence of relevant
stimulation, as in images and hallucinations... Given such a sweeping definition, it is apparent that
cognition is involved in everything a human being might possibly do; that every psychological
phenomenon is a cognitive phenomenon."
Major Topics in Cognitive Psychology
Cognitive psychology comprises human perception, attention, learning, memory, concept
formation, reasoning, judgment and decision-making, problem solving, and language
processing. For some, social and cultural factors, emotion, consciousness, animal cognition,
evolutionary approaches have also become part of cognitive psychology.
Perception
Learning perception pursue to recognize how we build subjective interpretations of proximal
information from the environment.
Cognitive psychologists have studied these properties empirically with psychophysical methods and
brain imaging. Perceptual systems are composed of separate senses like visual, auditory,
somatosensory and processing modules according to Livingston & Hubel,
(1988)Ungerleider&Mishkin, (1982)Julesz, (1971) “form, motion” and sub-modules as for Lu
&Sperling, 1995 that symbolizeunlike aspects of the stimulus information.

Contemporary research also focuses on how these separate demonstrations and modules cooperate
and are integrated into intelligible percepts. As per findings of Grossberg&Mingolla (1985) Marr
(1982) Wandell (1995) Computational models, grounded on physiological principles, have been
established for many perceptual systems.
Attention
As defined by Broadbent, (1957) Posner, (1980) and Treisman, (1969)Attention solves the problem
of information overload in cognitive processing systems by picking some information for additional
processing, or by handling resources useful to several sources of information sametime.
The theoretical analysis of attention has taken several major methods to categorize the mechanisms
of attention
1. The signal-detection approach by Lu &Dosher, (1998)
2. Similarity-choice approach byBundesen, (1990), Logan, (2004)
Experimental investigation conducted by Posner (1980) Weichselgartner&Sperling, (1987) Chun &
Potter,(1995) and Pashler, (1999)on attention has focused on how and why attention improves
performance, or how the lack of attention hinders performance. “Brain imaging studies” by
Kanwisher&Wojciulik in 2000 have documented effects of attention on activation in early visual
cortices, and have investigated the networks for attention control.
Learning
“Learning is never a matter of passive of passive absorbsion or registration but rather a complex of
activities which depend partly on what is being learned and partly on accomplishments brought by
the individual o the learning.”(Hunter I.M.L, 1964).and also says Learning improves the response of
the organism to the environment. Kandel‟s, (1976) Estes‟s, (1969) and Thompson‟s, (1986)studies
argue that The study of learning begins with an analysis of learning phenomena in animals
instrumental, contingency, habituation, conditioning, and, and
Studies of conceptual learning emphasize the nature of the processing of incoming information, the
role of elaboration, and the nature of the encoded representation (Craik, 2002). Those using
computational approaches have investigated the nature of concepts that can be more easily learned,
and the rules and algorithms for learning systems (Holland, Holyoak, Nisbett, &Thagard, 1986).
Those using lesion and imaging studies investigate the role of specific brain systems (e.g., temporal
lobe systems)

Memory
Memory study focuses on how memories are encored, stored, and retrieved. The study of human
memory is one of the most developed aspects of cognitive psychology. Memory domains have been
functionally divided into memory for facts, for procedures or skills, and working and short-term
memory capacity.
Anderson, (1996) Shiffrin&Steyvers, (1997) describe memory in Computational approaches as
“propositional networks, or as holographic or composite representations and retrieval processes.”
The experimental approaches have recognized dissociable memory types or capacity limited
processing systems such as short-term or working memory (Cowan, 1995; Dosher, 1999).
Concept Formation
The response to a precise stimulus is determined not by the precise occurrence but by classification
into the category and by association of knowledge with that category (Medin& Ross, 1992). Concept
or category creationrise to the ability to organize the perception and arrangement of experiences by
the construction of functionally relevant categories.
Definite concepts essentially reflect comparison of structures, but others may reflect function, or
conceptual theories of use (Medin, 1989). Computational models have been developed based on
aggregation of instance representations, similarity structures and general recognition models, and by
conceptual theories (Barsalou, 2003). Cognitive neuroscience has identified important brain
structures for aspects or distinct forms of category formation (Ashby, Alfonso-Reese, Turken, and
Waldron, 1998).
Judgment and decision
As for von Neumann & Morgenstern (1944 )and Luce, (1959)”The historic foundations of choice are
based in normative or rational models and optimality rules, beginning with expected utility theory”.
Extensive analysis identified failures of rational models due to differential assessment of risks and
rewards, the distorted assessment of probabilities. The limitations in human information processing
New computational approaches rely on dynamic systems analyses of judgment and choice
(Busemeyer& Johnson, 2004), and Bayesian belief networks that make choices based on multiple
criteria (Fenton & Neil, 2001) for more complex situations.
Problem Solving
This is the study of how humans follow goal directed behavior. Solving a problem is conceived as
finding operations to move from the initial state to a goal state in a problem space using either

algorithmic or heuristic solutions. The problem representation is critical in finding solutions (Zhang,
1997).
The computational state space analysis and computer simulation of problem solving of Newell and
Simon (1972) and the empirical and experiential analysis of Wickelgren (1974) together have set the
cognitive psychological approach to problem solving.
Language Processing
Psycholinguistics has studied encoding and verbal access of words, sentence level procedures of
describing and representation, and general representations of concepts, meaning, inference, and
semantic assumptions. While linguistic approaches focus on the formal structures of languages and
language use (Chomsky, 1965), Kintsch (1974)Pinker (1994) and Levelt, (1989) suggest cognitive
psychology has focused on language acquisition, language comprehension, language production, and
the psychology of reading The neuroscience of language has a long history in the analysis of grazes.
Computational models have been developed for all of these levels, including lexical systems, parsing
systems, semantic representation systems, and reading aloud.
Memory and Forgetting
Memory
According to Hunter I.M.L (1964) “Memory is an abstraction, a shorthand way of referring to
certain kind of activities.”Memory is a remarkable mental process and a mental system which
receives information from external or internal stimuli, recalls it and makes it obtainable on future
events. Though we talk about memory as a tangible it really is intangible and hypothetical store
house. It delivers continuity to our experiences across different time points. A moment‟s reflection
will tell you how difficult it will be if you do not have undamaged memory function. You would
perhaps lose your identity or the sense of what you are and will always remain a new learner because
the past learning experience will have no value orsignificance to you.
Whatever we experience now influenced by what we experience in past and our memory system
does perform this more dynamicallyand multipurposelike a tape recorder. It gives value byenabling
him to adjust to the present circumstances in the light of past events. But human memorydiffers from
a tape recorder in many important ways. For instance, we rememberhappen through various
forms, not only verbal material but visual experiences, tangible impressions, feelings of painand joy,
motor skills, events, activities and so on. Second, retrieval of informationcan be exactly in the
same way or in a different form. Third, the reception of newinformation depends a lot on what
information we already have. Fourth, we neitherreceive nor retain all the information presented

to us because there is great deal ofselectivity in receiving the information. Fifth, all tape
recorders have some limitation non recording but human memory can retain extremely large
amounts of information.
Finally, our memory system is an active system. It works on the information received. It may
mingle, enlarge, adapt, neglect or reorganize the information. It is not passivelike a tape recorder
which reproduces the information in its original form significance to you.
Main Processors of Memory
Encoding
It is the vital first step to creating a new memory. It permits the perceived article of attention to be
converted into a concept that can be stored within the brain, and then recalled later from short-term
or long-term memory. Encoding is a biological event beginning with perception through the senses.
The process of placing a memory originates with attentionregulated by the thalamus and the
frontal lobe, in which a memorable event causes neuronsto fire more frequently, making the
experience more intense and repetition the probability that the incident is encoded as a memory.
Emotion tends to increase attention, and the emotional element of an event is processed on an
unconscious pathway in the brain leading to the amygdala. Only then are the actual sensations
derived from an event processed.
The perceived sensations are decoded in the various sensory areas of the cortex, and then combined
in the brain’s hippocampus into one single experience. The hippocampus is then responsible for
analyzing these inputs and finallydetermining if they will be committed to long-term
memorywhichperformancesas likely of catalogingcentre where the novel sensations are compared
and associated with previously recorded ones. The different threads of information are then stored in
different parts of the brain, although the exact way in which these pieces are identified and recalled
later remains mostly unknown. The key role that the hippocampus plays in memory encoding has
been highlighted.
Ex: Individuals who have had their hippocampus damaged or removed and can no longer create new
memories (Anterograde Amnesia).
It is also one of the few areas of the brain where completely new neurons can grow. Human memory
is fundamentally associative, meaning that a new piece of information is remembered better if it can
be associated with previously acquired knowledge that is already firmly anchored in memory.

.
Figure 1 Memory and Brain
Different levels of Encoding occurs
Being the formation of short-term memory from the ultra-short term sensory memory,
followed by the conversion to a long-term memory by a process of memory consolidation.
The process begins with the creation of a memory trace or engram(or memory trace)in
response to the external stimuli. An engram is a hypothetical biophysical or biochemical
change in the neurons of the brain, hypothetical in the respect that no-one has ever actually
seen, or even proved the existence of, such a construct.

An organ called the hippocampus, deep within the medial temporal lobe of the brain,
receives connections from the primary sensory areas of the cortex, as well as from
associative areas and the rhinal and entorhinal cortexes.
While these anterograde connections join at the hippocampus, other retrograde pathways
arise from it, returning to the primary cortexes. A neural network of cortical synapses
effectively records the various associations which are linked to the individual memory.
Main types of encoding
1. Acoustic encoding is the processing and encoding of sound, words and other auditory input
for storage and later retrieval. This is assisted by the concept of the phonological loop, which
permits input within our echoic memory to be sub-vocally rehearsed in order to facilitate
remembering.
2. Visual encoding is the process of encoding images and visual sensory information. Visual
sensory information is temporarily stored within the iconic memory before being encoded
into long-term storage.
The amygdala fulfills an important role in visual encoding, as it admits visual input in
addition to input from other systems and encodes the positive or negative values of
conditioned stimuli.
3. Tactile encoding is the encoding of how something feels, generally through the sense of
touch. Physiologically, neurons in the primary somatosensory cortex of the brain react to
vibrotactile stimuli caused by the feel of an object.
4. Semantic encoding is the process of encoding sensory input that has precise meaning or can
be applied to a precise context, rather than originating from a precise sense.
Ways to Enrich Encording
As of the associative nature of memory, encoding can be upgraded by a strategy of
organization of memory called elaboration, in which new pieces of information are
associated with other information already recorded in long-term memory, thus integrating
them into a wider, rational narrative which is already familiar. W
When we use mnemonic devices while enording, (Mnemonic devices are techniques a
person can use to help them improve their ability to remember something. In other words, it‟s
a memory technique to help your brain better encode and recall important information. It‟s a
simple shortcut that helps us associate the information we want to remember with an image, a
sentence, or a word)we are effectively passing facts through the hippocampus several times,

so that it can keep strengthening the relations, and therefore increase the probability of
subsequent memory recall.
Storage
Storage is the more or less passive process of retaining information in the brain, whether in the
sensory memory, the short-term memory or the more permanent long-term memory. Each of these
diverse stages of human memory function as a sort of filter that helps to guard us from the flood of
information that meet us on a daily basis, avoiding an overload of information and helping to keep us
sane.
The more the information is repeated or used, the more likely it is to be retained in long-term
memory ex: studying helps people to perform better on tests.
Since the early neurological work of Karl Lashley and Wilder Penfield in the 1950s and 1960s, it has
become clear that long-term memories are not stored in just one part of the brain, but are widely
distributed throughout the cortex. After consolidation, long-term memories are stored throughout the
brain as clusters of neurons that are primed to fire together in the same design that created the
original experience, and each element of a memory is stored in the brain area that originated.
Certainly, it seems that they may even be encoded unnecessarily, several times, in various parts of
the cortex, so that, if one engram (or memory trace) is wiped out, there are duplicates, or alternative
pathways, in another place, through which the memory may still be retrieved.
Hence, opposing to the commonconcept, memories are not stored in our brains alike books on library
shelves, but necessity to be actively reconstructed from elements dispersedall over various areas of
the brain by the encoding process. Memory storage is therefore an ongoing process of
reclassification resulting from continuous changes in our neural pathways, and parallel processing of
information in our brains.
Richard Schiffrin and others have claimed, “ALL memories are stored somewhere in the brain,
and that it is only in the retrieval process that irrelevant details are “fast-forwarded” over or
expurgated”. It seems more likely that the memories which are stored are in some way edited and
sorted, and that some of the more peripheral details are never stored.
In the absence of disorders due to trauma or neurological disease, the human brain has the capability
to store almost unlimited amounts of information indefinitely. Forgetting, therefore, is more likely to

be result from incorrectly or incompletely encoded memories, and/or problems with the
recall/retrieval process. It is a mutual experience that we may try to remember something one time
and fail, but then remember that same item later. The information is therefore clearly still there in
storage, but there may have been some kind of a gap between retrieval cues and the original
encoding of the information. “Lost” memories recalled with the aid of psychotherapy or hypnosis
are other examples supporting this idea, although it is difficult to be sure that such memories are
real and not implanted by the treatment.
Key Aspects of Memory Storage
The stage model of memory is often used to explain the basic structure and function of memory that
also called “Information Processing Approach of Memory” , originally proposed in 1968 by
Atkinson and Shiffrin, this theory outlines three separate stages of memory, sensory memory, short-
term memory and long-term memory.
Sensory Memory
Sensory memory is the earliest stage of memory. During this stage, sensory information from
the environment is stored for a very brief period of time, generally for no longer than a half-
second for visual informationand 3 or 4 seconds for auditory information. We attend to only
certain aspects of this sensory memory, allowing some of this information to pass into the next stage
- short-term memory.
Short-Term Memory(STM)
Short-term memory, also known as active memory, is the information we are currently aware
of or thinking about. In Freudian psychology, this memory would be referred to as the conscious
mind. Paying attention to sensory memories generates the information in short-term memory. Most
of the information stored in active memory will be kept for approximately 20 to 30 seconds. While
many of our short-term memories are quickly forgotten, attending to this information allows it to
continue on the next stage long-term memory.
Long-Term Memory(LTM)

Long-term memory refers to the continuing storage of information. In Freudian psychology,
long-term memory would be call the preconscious and unconscious. This information is largely
outside of our awareness, but can be called into working memory to be used when needed. Some
of this information is fairly easy to recall, while other memories are much more difficult to
access.
, 1968
Figure 2 Schematic Model of The Human Information Processing System.
ADAPTED FROM ATKINSON & SHIFFRIN
Memory Recall/Retrieval
Recall or retrieval of memory refers to the subsequent re-accessing of events or information
from the past, which have been previously encoded and stored in the brain. In common jargon,
it is known as remembering. During recall, the brain "replays" a pattern of neural activity that was
originally generated in response to a particular event, echoing the brain's perception of the real event.
In fact, there is no real firmdifference between the act of remembering and the act of thinking.
These replays are not quite identical to the original otherwise we would not know the difference
between the genuine experience and the memory, but are mixed with an awareness of the present
situation. One consequence of this is that memories are not frozen in time, and new information and
suggestions may become incorporated into old memories over time. Thus, remembering can be
thought of as an act of creative re-imagination.

Since of the way memories are encoded and stored, memory recall is effectively rebuilding of
elements spread throughout many areas of our brains. Memories are not stored in our brains like
books on library shelves, or even as a collection of self-contained recordings or pictures or video
clips, but may be better thought of as a kind of collage or a jigsaw puzzle, involving different
elements stored in disparate parts of the brain linked together by associations and neural networks.
Memory retrieval therefore requires return to the nerve pathways the brain formed when encoding
the memory and the strength of those pathways controls how quickly the memory can be recalled.
Recall effectively returns a memory from long-term storage to short-term or working memory, where
it can be retrieved, in a kind of reflection of the encoding process. It is then restored in long-term
memory, thus re-amalgamating and solidification it.
The efficiency of human memory recall is astonishing. Most of what we remember is by direct
retrieval, where items of information are linked directly a question or cue, rather than by the kind of
in sequence scan. Other memories are retrieved quickly and efficiently by hierarchical implication,
where a specific question is linked to a class or subgroup of information about which certain facts are
known.
Also, the brain is usually able to determine in advance whether there is any point in searching
memory for a particular fact.
The evidence suggests that memory retrieval is a more or less automatic process. Thus, although
distraction or divided attention at the time of recall tends to slow down the retrieval process to some
extent, it typically has little to no effect on the accuracy of retrieved memories. Distraction at the
time of encoding, on the other hand, can severely impair subsequent retrieval success.
It is also possible that false or wrongly interpreted memories may be created during recall, and
carried forward thereafter. One can also, up to a point, choose to forget, by blocking out unwanted
memories during recall (a process achieved by frontal lobe activity, which inhibits the laying down
or re-consolidation of a memory

Main Methods of Accessing Memory
Recognition is the association of an event or physical object with one previously
experienced or encountered, and involves a process of comparison of information
with memory, e.g. recognizing a known face, true/false or multiple choice questions,
etc.
– Recognition is a largely unconscious process, and the brain even has a
dedicated face recognition area, which passes information directly through the
limbic areas (in brain) to generate a sense of familiarity, before linking up
with the cortical path,where data about the person's movements and intentions
are processed..
– Recognition is usually considered to be “superior” to recall (in the sense of
being more effective), in that it requires just a single process rather than two
processes. Recognition requires only a simple familiarity decisionamd
recognition only requires a relatively simple decision as to whether one thing
among others has been encountered before. Sometimes, however, even if a
part of an object initially activates only a part of the neural network concerned,
recognition may then suffice to activate the entire network.
Recall involves remembering a fact, event or object that is not currently physically
present (in the sense of retrieving a representation, mental image or concept), and
requires the straight exposure of information from memory, e.g. remembering the
name of a recognized person, fill in the blank questions, etc.
– A full recall of an item from memory requires a two-stage process (indeed,
this is often referred to as the two-stage theory of memory) in which the search
and retrieval of candidate items from memory is followed by a familiarity
decision where the correct information is chosen from the candidates
retrieved. Thus, recall involves actively reconstructing the information and
requires the activation of all the neurons involved in the memory in question,

Alternative theory totwo-stage process by EndelTulving.
This theory states that memory utilizes information both from the specific memory trace as well as
from the environment in which it is retrieved. Because of its focus on the retrieval environment or
state, encoding specificity takes into account context cues, and it also has some advantages over
the two-stage theory as it accounts for the fact that, in practice, recognition is not actually always
superior to recall.
Typically, recall is better when the environments are similar in both the learning (encoding) and
recall phases, suggesting that context cues are important. In the same way, emotional material is
remembered more reliably in moods that match the emotional content of these memories (e.g. happy
people will remember more happy than sad information, whereas sad people will better remember
sad than happy information).
Alternative theory to two-stage process by Fergus Craik and Robert Lockhart
This theory suggest that memory recall of stimuli is also a function of the depth of mental
processing, which is in turn determined by connections with pre-existing memory, time spent
processing the stimulus, cognitive effort and sensory input mode.
Thus, shallow processing as, naturally, that based on sound or writing leads to a relatively fragile
memory trace that is vulnerable to rapid decay, whereas deep processing as that based on semantics
and meanings results in a more durable memory trace.
This theory suggests, then, that memory strength is continuously variable, as opposed to the earlier
Atkinson-Shiffrin, or multi-store, memory model, which just involves a sequence of three discrete
stages, from sensory to short-term to long-term memory.
Main Types of Recall
1. Free recall is the process in which a person is given a list of items to remember and then is
asked to recall them in any order. This type of recall often displays evidence of either the
primacy effect of “Early Vs Late Selection”when the person recalls items presented at the
beginning of the list earlier and more often or when the person recalls items presented at the

end of the list earlier and more often, and also of “the contiguity effect”; the marked
tendency for items from neighboring positions in the list to be recalled successively.
Testing helps protect against "proactive interference" the familiar feeling of being
overwhelmed by too much information, and the studies suggest that a quick test is much more
effective than en extra hour of study or re-reading.
2. Cued recallis the process in which a person is given a list of items to remember and is then
tested with the use of cues or guides. When cues are provided to a person, they tend to
remember items on the list that they did not originally recall without a cue, and which were
thought to be lost to memory. This can also take the form of stimulus-response recall, as
when words, pictures and numbers are presented together in a pair, and the resulting
associations between the two items cues the recall of the second item in the pair.
3. Serial recall refers to our ability to recall items or events in the order in which they occurred,
whether chronological events in our autobiographical memories, or the order of the different
parts of a sentence in order to make sense of them. Serial recall in long-term memory appears
to differ from serial recall in short-term memory, in that a sequence in long-term memory is
represented in memory as a whole, rather than as a series of separate items.
Testing of serial recall by psychologists have yielded several general rules
– more recent events are more easily remembered in order;recall decreases as
the length of the list or sequence increases
– there is a tendency to remember the correct items, but in the wrong
order;where errors are made, there is a tendency to respond with an item that
resembles the original item in some way (e.g. “dog” instead of “fog”, or
perhaps an item physically close to the original item)
– repetition errors do occur, but they are relatively rare;if an item is recalled
earlier in the list than it should be, the missed item tends to be inserted
immediately after it; If an item from a previous trial is recalled in a current
trial, it is likely to be recalled at its position from the original trial.
Special Situations in Recallingmemeory
Hyperthymesia
Rare condition called“Hyperthymesia” (also known as hypermnesia or superior autobiographical
memory) in which a few people show an extraordinary capacity to recall detailed specific events
from a person‟s personal past, without relying on practised mnemonic strategies.
Although only a handful of cases of hyperthymesia have ever been definitively confirmed, some of
these cases are quite startling, such

 As a California woman who could recall every day in complete detail from the age of 14
onwards, a young English girl with an IQ of 191 who had a perfect photographic memory
spanning almost 18 years
 Russian man known simply as "S." who was only able to forget anything by a deliberate act
of will.
 One of the most famous cases, known as “A.J.”, described it as a burden rather than a gift,
but others seem to be able to organize and compartmentalize their prodigious memories and
do not appear to feel that their brains are "cluttered" with excess information.
Rebirth and Past life memory
According to Buddhist psychology “Rebirth, or samsara”mirror interest fat on memory in the
principle of rebirth has been greatlystimulated by the publicity given to several cases of people who
have remembered previous lives..Cases of this kind have from time to time appeared in the popular
press, particularly in Asia, mostly with sensational accounts of how the child's claims were verified.
Psychologists-and scholars in general-have paid almost no attention to these rare cases, with the
exception of Ian Stevenson, a psychiatrist at the University of Virginia. Stevenson (1 974, 1975,
1977a,
1977b, 1980, 1983, 1987, Stevenson and Samararatne, 1988) has studied cases of this kind for over
30 years and published numerous reports of his thorough and detailed investigations of individual
cases in various countries, most of them in Asia. Story (1975), a scholar of Theravada Buddhism,
has also investigated some cases in Sri Lanka as well as in India, Burma, and Thailand. The present
study can be considered an attempt to replicate Stevenson's (1977a) work in Sri Lanka.They have
ranged from chance coincidence, paramnesia, extrasensory perception by the child of life events of
a deceased person, to the theory of reincarnation, which is generally accepted by the Buddhists and
the Hindus of Sri Lanka.
For a long time past it has been known that under deep hypnosis events in very early infancy, outside
the normal range of memory could be recovered and this technique has been increasingly employed
for the treatment of personality disorders. It cannot be used with success on all patients because of
the involuntary resistance some subjects show to hypnotic suggestion, which in birth the cooperation
necessary to obtain deep trance. But where it can be applied, it has definite advantages over the usual
methods of deep psychoanalysis, one of them being the speed with which results are obtained.
The technique is to induce a state of hypnosis and thencarry the subject back in time to a particular
point in childhood or infancy at which it is suspected that some event of importance in the psychic
life may have occurred. In this state, known as hypermnesia the subject becomes in effect once more
the child he was, and re-lives experiences that have long been buried in the unconscious. Memories

of earliest infancy, and in some cases prenatal memories, have been brought to the surface in this
way
Cases relevant to this will be further explained in Annexes 01
Forgetting
Forgetting istemporary or permanent inability to retrieve a piece of information or a memory that
had previously been recorded in the brain. Forgetting normally follows a logarithmic curve, so that
information loss is quite hasty at the start, but becomes slower as time goes on. In particular,
information that has been learned very well will usually be very resistant to forgetting, especially
after the first three years.
Unlike amnesia, forgetting is usually regarded as a usual phenomenon involving specific pieces of
content, rather than relatively broad categories of memories or even entire segments of
memory.From forgetting where you left your keys to forgetting to return a phone call, memory
failures are an almost daily occurrence. Forgetting is so common that we typically rely on numerous
methods to help us remember important information such as jotting down notes in a daily planner or
scheduling important events on your phone's calendar.
As you are frantically searching for your missing car keys, it may seem that that the information
about where you left them is permanently gone from your memory. However, forgetting is generally
not about actually losing or erasing this information from your long-term memory. Forgetting
typically involves a failure in memory retrieval. While the information is somewhere in your long-
term memory, you are not able to actually retrieve and remember it.
Why We Forget?
Of course, many factors can help contribute to forgetting. Sometimes you might be distracted when
you learn new information, which might mean that you never truly retain the information long
enough to remember it later. Well-known memory researcher

Elizabeth Loftus’s key explanations for why forgetting occurs.
1. Retrieval Failure
Have you ever felt like a piece of information has just vanished from memory? Or maybe you know
that it's there, you just can't seem to find it. The inability to retrieve a memory is one of the most
common causes of forgetting.
So why are we often unable to retrieve information from memory? One possible explanation retrieval
failure is known as decay theory. Decay occurs when the passage of time causes us to forget.These
theories are popular because they appear to fit with common-sense views of the way memory works.
However, evidence suggests that they may not give a complete picture of how forgetting occurs.
They are also limited in terms of practical implications. According to this theory, a memory trace is
created every time a new theory is formed. Decay theory suggests that over time, these memory
traces begin to fade and disappear. If information is not retrieved and rehearsed, it will eventually be
lost.As mentioned in„The Ebbinghaus Forgetting Curve‟
The Ebbinghaus Forgetting Curve
Psychologist Hermann Ebbinghaus was one of the first to scientifically study forgetting. In
experiments where is used himself as the subject, Ebbinghaus tested his memory using three-letter
nonsense syllables. He relied on such nonsense words because relying on previously known words
would have made use of his existing knowledge and associations in his memory.
In order to test for new information, Ebbinghaus tested his memory for periods of time ranging from
20 minutes to 31 days. He then published his findings in 1885 in Memory: A Contribution to
Experimental Psychology.
His results, plotted in what is known as the Ebbinghaus forgetting curve, revealed a relationship
between forgetting and time. Initially, information is often lost very quickly after it is learned.
Factors such as how the information was learned and how frequently it was rehearsed play a role in
how quickly these memories are lost.
The forgetting curve also showed that forgetting does not continue to decline until all of the
information is lost. At a certain point, the amount of forgetting levels off. What exactly does this
mean? It indicates that information stored in long-term memory is surprisingly stable.

Figure 3Ebbinghaus Forgetting Curve
2. Interferance
Another theory known as interference theory suggests that some memories compete and interfere
with other memories. When information is very similar to other information that was previously
stored in memory, interference is more likely to occur. When such influences are adverse we call
them interference. It has been noted that more the similarity between two sets of materials to be
learned, the greater will be the degree of interference between them.
Basic Types of Interference:
1. Proactive interference is when an old memory makes it more difficult or impossible to
remember a new memory.
2. Retroactive interference occurs when new information interferes with your ability to
remember previously learned information.
3. Failure to Store
Sometimes, losing information has less to do with forgetting and more to do with the fact that it
never made it into long-term memory in the first place. Encoding failures sometimes prevent
information from entering long-term memory.
In one well-known experiment, researchers asked participants to identify the correct U.S. penny out
of a group of incorrect pennies (Nickerson & Adams). Try doing this experiment yourself by
attempting to draw a penny from memory, and then compare your results to an actual penny.

How well did you do? Chances are that you were able to remember the shape and color, but you
probably forgot other minor details. The reason for this is that only details necessary for
distinguishing pennies from other coins were encoded into your long-term memory.
4. Motivated Forgetting
Sometimes, we may actively work to forget memories, especially those of traumatic or disturbing
events or experiences. According to Freud, forgetting takes place because the event is unpleasant.
We forget because we do not want to remember something. We may exclude memories or push them
out of consciousness if we do not like them. Freud called this process repression. It’s a common
experience that we usually remember pleasant events more often than unpleasant ones. Also, we find
a strong tendency to remember incomplete tasks more than completed tasks. This has been termed as
“Zeigarnik effect”. The role of mood in human memory suggests that affective aspects of our lives
do shape our memory in significant ways.
Basic Forms of Motivated Forgetting
Suppression, a conscious form of forgettingand
Repression, an unconscious form of forgetting.
However, the concept of repressed memories is not universally accepted by all psychologists. One of
the problems with repressed memories is that it is difficult, if not impossible, to scientifically study
whether or not a memory has been repressed. Also note that mental activities such as rehearsal and
remembering are important ways of strengthening a memory, and memories of painful or traumatic
life events are far less likely to be remembered, discussed or rehearsed.
 One problem with this theory, however, is that research has demonstrated that even memories
which have not been rehearsed or remembered are remarkably stable in long-term memory.
Theorists disagree over exactly what becomes of material that is forgotten.
Some hold that long-term memories do actually decay and disappear completely over
time;
others hold that the memory trace remains intact as long as we live, but the bonds or
cues that allow us to retrieve the trace become broken, due to changes in the
organization of the neural network, new experiences, likewise. In the same way as a

misplaced book in a library is “lost” even though it still exists somewhere in the
library.
It seems not to be probable to intentionally delete memories at will, which can have negative
consequences.
ex: we experience traumatic events we would actually prefer to forget.
In fact, such memories tend to be imprinted even more strongly than normal due to their emotional
content, although recent research involving the use of beta blockers (such as propanonol) suggests
that it may be possible to tone down the emotional aspects of such memories, even if the
memories themselves cannot be erased. The way this works is that the act of recalling stored
memories makes them "malleable" once more, as they were during the initial encoding phase, and
their re-storage can then be blocked by drugs which inhibit the proteins that enable the emotional
memory to be re-saved.
Memory Disorders
Alzheimer's Disease
Alzheimer's disease (also known as just Alzheimer's or AD) is a progressive, degenerative and
ultimately fatal brain disease, in which cell to cell connections in the brain are lost. It is the most
common form of dementia, and is generally (though not exclusively) diagnosed in patients over the
age of about 65.
The disease was first identified by Alois Alzheimer as early as 1906, although up until the 1960s
it was usually referred to as "senile dementia" and considered a normal part of ageing. Scientific
interest in Alzheimer's was only re-awakened in the 1960s and 1970s as the consequences of an
ageing society began to be examined, and it was during the 1980s that research first focused on the
toxic proteins amyloid in plaques and tau in tangles.
The most commonly recognized symptom of AD is an inability to acquire new memories and
difficulty in recalling recently observed facts, but it is by no means the only symptom. As the disease
advances, symptoms include confusion, irritability and aggression, mood swings, language
breakdown, long-term memory loss, and ultimately a gradual loss of bodily functions and death

A number of non-invasive life-style habits, such as mental stimulation, physical exercise and a
balanced diet, have been suggested for the prevention or delayed onset of Alzheimer's disease, but no
effective treatments to delay or halt the progression of the disease are as yet available.
Alzheimer's does not affect all memory capacities equally. Episodic memory (memory of
autobiographical events) is the first to go; next comes short-term memory (the ability of hold
information in mind in an active, readily-available state for a short period of time); then semantic
memory (memory of the meanings of words and facts about the world), and finally procedural
memory (how to perform tasks and skills). However, as the disease advances, parts of memory which
were previously intact also become impaired, and eventually all reasoning, attention, and language
abilities are disrupted.
AD patients tend to display a loss of knowledge of the specific characteristics of semantic categories.
Initially, they lose the ability to distinguish fine categories, such as species of animals or types of
objects, but, over time, this lack of discrimination extends to broader, more general categories. Thus,
at first, an AD patient may see a spaniel and say, “that is a dog”; later, they may just say, “that is an
animal”
Dementia
Dementia is a general term for a large class of disorders characterized by the progressive
deterioration of thinking ability and memory as the brain becomes damaged. Essentially, when
memory loss is so severe that it interferes with normal daily functioning, it is called dementia. Less
severe memory loss is usually referred to as mild cognitive impairment.
It is sometimes estimated that dementia doubles in frequency about every 5 years from the age of 65,
which suggests that around 5% of those age 65 have dementia, and over 50% for those in the 85 to
90 year range.
Dementia is usually characterized by severe memory loss in conjunction with one or more of aphasia
(loss of the ability to produce or understand language), apraxia (the inability to make certain
movements, despite a healthy body), agnosia (problems recognizing familiar persons and objects,
even though the senses are functioning) or executive dysfunction (inability to plan, organize or
reason). Sufferers exhibit serious loss of cognitive ability, beyond what might be expected from
normal ageing, and particularly in the areas of memory, attention, language and problem solving.
The best known and most common type of dementia is Alzheimer’s disease, which accounts for 50-
75% of all dementias. The second most common type, accounting for up to 20% of dementia cases,
is vascular dementia, which has symptoms similar to Alzheimer’s but usually results from damage

done to the brain by a blood clot or a hemorrhage cutting off the brain's blood supply due to a stroke
or succession of strokes. Other types of dementia include Lowy body dementia, front temporal
dementia, Huntington's disease and Creutzfeldt-Jakob disease. Some types of dementia are
reversible (such as those caused by thyroid disease), while some (such as Alzheimer's disease) are
irreversible.
Dementia may be caused by specific events such as traumatic brain injury or stroke, or it may
develop gradually as a result of neurodegenerative disease affecting the neurons of the brain (thereby
causing gradual but irreversible loss of function of these cells) or as a secondary symptom of other
disorders like Parkinson‟s disease.
Age Associated
Figure 4 Aging
Age associated memory impairment is a label for the general degradation of memory which results
from ageing. It is a natural process, seen in many animals as well as humans, which often begins in
our 20s and tends to get noticeably worse as we reach our 50s. While some specific abilities do
decline with age, though, overall memory generally remains strong for most people through their
70s.
Episodic memory ;our memory of experiences and specific events in time in particular is impaired in
normal ageing. On the other hand, in the absence of specific neurological disorders, implicit or
procedural memory typically shows little or no decline with age, short-term memory shows only a
little decline, and semantic knowledge, such as vocabulary, actually tends to improve somewhat with
age.

Normal ageing is not responsible for causing memory disorders as such, but it is associated with a
general decline in cognitive and neural systems, including memory. As people age, the likelihood of
cholinergic dysfunction, beta-amyloid deposits, hippocampal neurofibrillary tangles or neuritic
plaques in the cortex of the brain increases, so that memory connections can become blocked,
memory functions decrease and the likelihood of memory disorders like dementia and Alzheimer’s
disease increases. Ageing is the single greatest risk factor for neurodegenerative diseases in general.
Recent research has identified a transitional state between the cognitive changes of normal ageing
and Alzheimer's disease, known as mild cognitive impairment, where some memory loss occurs, but
is not so severe that it interferes with normal daily functioning.
More severe memory loss is defined as dementia, of which Alzheimer's is just one common variant.
Those who experience mild cognitive impairment are at a significantly higher risk of developing
Alzheimer‟s disease or other types of dementia, especially after events like strokes.Although the
brain does not change its overall structure or grow whole new batches of neurons over time, the
connections between them change during the normal process of learning, as synapses are reinforced
and neural cells make more and stronger connections with each other. As we begin to age, however,
these connections begin to falter and weaken, in the same way as other biological processes
deteriorate and become more fragmented over time, and this begins to affect how easily we can
retrieve memories.
In particular, as the brain ages, the white matter which links together different parts of the brain,
begins to die off, largely because the blood flow supplied to the brain is not as healthy as in the
young, which causes memory to become impaired. Also, the production of the chemical messengers
(neurotransmitters) used to carry signals through the brain is also reduced, perhaps by as much as
50% between young adulthood and old age, which impairs our ability to think and perform memory
tasks.The decline theory of forgetting is illustrated by the order in which words tend to be forgotten
in old age: proper nouns, which are typically used less often, are usually the first words to go,
followed by common nouns, then adjectives, verbs and, lastly, exclamations and interjections
One theory for why this happens, at the cellular level, is that ageing cause‟s major cell loss in a tiny
region at the front of the brain that leads to a drop in the production of a neurotransmitter called
acetylcholine, which is vital to learning and memory. In addition, the brain itself shrinks in size to

some extent, and becomes less efficient as we age. In particular, the hippocampus, which is essential
to the proper functioning of the processes of memory, loses about 5% of its nerve cells with each
passing decade, up to a total loss of 20% by the age of about 80.
There are, however, several other environmental factors which may combine to speed up memory
decline, including the inheritance of unhealthy genes, exposure to toxins and poisons, or lifestyle
choices like smoking, drinking or bad diet. Physical exercise and mental stimulation can improve
mental function in general, and therefore help to slow memory decline, although there is no "magic
bullet" solution as some might claim
Alcohol
Alcohol, and the effects of alcohol on memory and general cognitive functioning, has been the
subject of much research over the years.
Alcohol acts as a general central nervous system depressant, but it affects some areas of the brain
more than others. Specifically, it leads to distraction and inattention and significantly inhibits
neuronal activity in the hippocampus, which impairs memory encoding since the hippocampus plays
an important role in the formation of new declarative memories. Because procedural memory
functions more or less automatically, retrieval of procedural memory (“remembering how”) is not as
severely impaired by alcohol as retrieval of declarative memory (“remembering what”).
Alcohol particularly impairs the encoding of episodic memory (that part of declarative memory that
relates to our personal experiences and specific events in time), especially for certain types of recall,
such as cued recall, the recognition of completed word fragments and free recall. A "blackout" is an
example of a difficulty in the encoding of episodic memories due to high doses of alcohol. It is
caused by a rapid increase in blood alcohol concentration, which in turn distorts the activity of
neurons in the hippocampus, thus impairing person's ability to form new episodic memories.
Alcohol also impairs short-term (working) memory, although mainly by affecting certain mnemonic
strategies and executive processes rather than by shrinking the basic holding capacity of working
memory or by physically altering the structure of the those parts of the brain which are critical for
working memory function. Although light to moderate drinking does not appear to impair long-term
cognitive functioning significantly (and according to some studies, may actually decrease the risk of
cognitive decline), heavy drinking and chronic alcoholism is associated with long-term impairment
in sustained attention and working memory function, especially visual working memory.

Serious over-consumption of alcohol, especially in comparison with the intake of other foods, can
cause a thiamine deficiency, leading to a much more serious form of amnesia known as Korsakoff‟s
syndrome.
Figure 5- Alcoholism
Amnesia
Amnesi Amnesia is the general term for a condition in which memory (either stored memories or the
process of committing something to memory) is disturbed or lost, to a greater extent than simple
everyday forgetting or absent-mindedness. Amnesia may result either from organic or neurological
causes (damage to the brain through physical injury, neurological disease or the use of certain drugs),
or from functional or psychogenic causes (psychological factors, such as mental disorder, post-
traumatic stress or psychological defence mechanisms).
Types of Amnesia
Anterograde amnesia (where the ability to memorize new things is impaired or lost because data
does not transfer successfully from the conscious short-term memory into permanent long-term
memory) Anterograde amnesia is the more common of the two.
Retrograde amnesia (where a person's pre-existing memories are lost to conscious recollection,
beyond an ordinary degree of forgetfulness, even though they may be able to memorize new things
that occur after the onset of amnesia).

Sometimes both these types of amnesia may occur together, sometimes called total or global
amnesia. Another type of amnesia is post-traumatic amnesia, a state of confusion and memory loss
that occurs after a traumatic brain injury. Amnesia which occurs due to psychological factors is
usually referred to as psychogenic amnesia.
Many kinds of amnesia are associated with damage to the hippocampus and related areas of the
brain which are used in the encoding, storage and retrieval of memories. If there is a blockage in the
pathways along which information travels during the processes of memory encoding or retrieval, or
if whole regions of the brain are missing or damaged, then the brain may not be able to form new
memories or retrieve some old ones.
The usual causes of amnesia are lesions to the brain from an accident or neurological disease, but
intense stress, alcohol abuse, loss of oxygen or blood flow to the brain such and such, can all also
cause amnesia, as sometimes can treatments such as electro-convulsive therapy.
ex: Intense stress can cause the sympathetic nervous system to activate the adrenal glands, which
then secrete certain hormones into the bloodstream which can significantly affect the plasticity of the
brain‟s neurons, especially those in the hippocampus.
In most cases, amnesia is a temporary condition, lasting from a few seconds to a few hours, but the
duration can be longer depending on the severity of the disease or trauma, up to a few weeks or even
months.
Although it is very rare for anyone to experience total (permanent) amnesia, one well-known case of
long-lasting and acute total (retrograde and anterograde) amnesia, perhaps the worst case of amnesia
ever recorded, is that of the British musician Clive Wearing, who suffered damage to his brain as a
result of an encephalitis virus in 1985. Because the damage was to an area of his brain required to
transfer memories from working memory to long-term memory, he is completely unable to form
lasting new long-term memories, and his memory is therefore limited to a short-term memory of
between 7 and 30 seconds, to the extent that he will greet his wife like a long-lost friend even if she
only left to go into the kitchen 30 seconds ago. However, Wearing still recalls how to play the piano
and conduct a choir, despite having no recollection of having received a musical education, because
his procedural memory was not damaged by the virus.
In general, memories of habits (procedural memory) are usually better preserved than memories of
facts and events (declarative memory), and the most distant long-term memories, such as those of
childhood, are more likely to be preserved. When memories return, older memories are usually
recalled first, and then more recent memories, until almost all memory is recovered.

Figure 6 Source of amnesia
Autism
Autism is a disorder of neural development, characterized by impaired social interaction and
communication and by restricted and repetitive behavior, which usually begins in childhood.
Autism spectrum disorders may range from individuals with severe impairments (who may be silent,
mentally disabled, and locked into hand flapping and rocking behaviors) to high-functioning
individuals who may have active but distinctly odd social approaches, narrowly-focused interests and
verbose or pedantic communication. Some individuals with autism spectrum disorder may even show
superior skills in perception and attention, relative to the general population. No cure is known.
In recent years, it has become increasingly apparent that autism affects the functioning of virtually
the entire brain, not just those brain areas involved with social interactions, communication
behaviors and reasoning abilities, as had been previously thought. It has been discovered that people
with autism have difficulty in many other areas, including balance, movement, memory and visual
perception skills, complex tasks which involve different areas of the brain working together. It is
perhaps better seen, then, as a disorder in which the various parts of the brain have difficulty working
together to accomplish complex (as distinct from basic) tasks.

Autism affects information processing in the brain by altering how nerve cells and their synapses
develop, connect and organize, although exactly how this occurs is not well understood, and there
does not appear to be a clear unifying mechanism at either the molecular, cellular or systems level. It
appears to result from developmental factors that affect many or all functional brain systems, and to
disturb the timing of brain development.
One popular theory, known as executive dysfunction, hypothesizes that autistic behavior results, at
least in part, from deficits in working memory, planning, inhibition and other forms of executive
function. Certainly, poor short-term memory (as opposed to long-term memory, which may actually
be normal or better than normal) is a common complaint among autism sufferers, although to what
extent this result from attention deficits is not clear.
Some studies have suggested that there may be selective damage to the limbic-prefrontal episodic
memory system in some people with autism, especially in the self-conscious memory of personally
experienced events.
Huntington's Disease
Huntington’s disease is an inherited progressive neurodegenerative disorder, which affects muscle
coordination and leads to general cognitive decline. If a parent carries the gene, there is a 50%
chance of the child inheriting it.
Early symptoms include a general lack of coordination and an unsteady gait, which develops into
involuntary and uncoordinated, jerky body movements (chorea) and a decline in mental abilities and
behavioral and psychiatric problems, and a gradual decline of mental abilities into dementia. The
memory decline symptoms, especially those affecting short-term memory, typically appear before
any motor function symptoms.
It typically becomes noticeable in middle age, affecting about 1 in every 10,000-20,000 people.
It results from a mutation of Htt proteins which is toxic to certain types of cells, particularly in the
brain. The mutation of specific gene codes leads to gradual damage to specific areas of the brain,
particularly the basal ganglia, although exactly how is not yet fully understood.
As the disease progresses, memory deficits tend to appear, ranging from short-term to long-term
memory difficulties, including deficits in episodic, procedural and working memory, ultimately
leading to dementia. Memory is affected by damage to the important brain pathways that help the

inner subcortical and prefrontal cortex parts of the brain to communicate. This damage occurs mainly
in the striatum, but other areas of the brain are also significantly affected as the disease progresses.
Korsakoff'sSyndrome
Korsakoff's syndrome, or Wernicke-Korsakoff syndrome, is a brain disorder caused by extensive
thiamine deficiency, a form of malnutrition which can be precipitated by over-consumption of
alcohol and alcoholic beverages compared to other foods.
It main symptoms are anterograde amnesia (inability to form new memories and to learn new
information or tasks) and retrograde amnesia (severe loss of existing memories), confabulation
(invented memories, which are then taken as true due to gaps in memory), meagre content in
conversation, lack of insight and apathy.
Individual Korsakoff's sufferers may exhibit wildly differing symptoms. In some cases, a patient
may just continue "living in the past", convinced that their life and the world around them is
unchanged since the onset of the condition (which may have been twenty or thirty years before).
Others may adopt a constant, almost frenzied, fever of confabulation (see box at right), constantly
inventing a series of new identities, often with detailed and convincing back-stories, in order to
replace the reality which has been forgotten and lost.
Much about the disorder has been gleaned from a sufferer known as “Patient X”, who wrote an
autobiography in 1979 and then developed the disease a short time later. Thus, his post-
Korsakoff memories could be directly compared with the details in his written autobiography.
Korsakoff‟s syndrome is caused by a deficiency of thiamine (vitamin B1), which is thought to cause
damage to the thalamus and to the mammillary bodies of the hypothalamus (which receives many
neural connections from the hippocampus), as well as generalized cerebral atrophy, neuronal loss
and damage to neurons.
Classically, the retrograde amnesia of Korsakoff‟s syndrome follows a distinct temporal curve: the
more remote the event in the past, the better it is preserved and the sharper the recollection of it. This
suggests that the more recent memories are not fully consolidated and therefore more vulnerable to
loss, indicating that the process of consolidation may continue for much longer than initially thought,
perhaps for many years

OCD
Obsessive-compulsive disorder (OCD) is a mental disorder characterized by intrusive thoughts that
produce anxiety (obsessions) and repetitive behaviours aimed at reducing the anxiety (compulsions).
Symptoms may include repetitive hand-washing, a generalized fear of contamination, extensive
hoarding, preoccupation with sexual or aggressive impulses or with particular religious beliefs,
aversion to odd numbers, and nervous habits such as repeated opening and closing of doors, constant
organizing of objects in certain ways, obsessive counting of events, etc.
OCD may be seen as a result of an imbalance between long-term memory and short-term memory
processes. A sufferer may be stuck in a mental loop where long-term memory is in control of the
subject's brain to such an extent that their reactions are solely based on memory without the
influence of the input (other than as a trigger for the memory).
Neuroimaging studies show, however, that OCD patients perform considerably better on procedural
memory tasks (memory of skills and how to do things) due to over-activation of the striatum brain
structures, specifically the front striatal circuit. Thus, the procedural memory in OCD patients may
actually be improved in its early learning stages.
Although there is no scientific evidence to suggest that people with OCD have any problems with
verbal memory (remembering information that has been stored verbally or in the form of words), it
has been consistently found that people with OCD show deficits in non-verbal, visual or special
memory. Also, people with OCD (particularly those whose symptoms involve compulsive
checking) tend to have less confidence in their memory than those without OCD, even if this level of
confidence is not actually related to their actual performance on memory tasks, and the worse the
OCD symptoms are, the worse this confidence in memory seems to be. This may explain to some
extent the repetitive nature of many OCD symptoms.
OCD has been linked to abnormalities with the neurotransmitter serotonin, and to miscommunication
between the different parts of the brain involved in problem solving. In normal usage, when a
problem or task is identified in the orbitofrontal cortex at the front of the brain, it is dealt with in the
cingulate cortex, and the caudate nucleus is then responsible for marking the problem as resolved and
removing any worry over it. In OCD sufferers, it is thought that the caudate nucleus may be
dysfunctional and so this resolution never occurs, leading to increased worry and a recurring and
ever-intensifying loop in behavior.

Recent improvements in the understanding of the neuroplasticity of the brain may lead to a potential
cure for the disorder.
Figure 7 OCD
Parkinson's Disease
Parkinson's disease is a chronic and progressive degenerative disorder of the central nervous
system that impairs motor skills, speech and other functions. It is usually characterized by muscle
rigidity, tremor, postural instability, and a slowing or loss of physical movement.
Ageing is an important risk factor, and the incidence of Parkinson's increases with age, although
about 4% are diagnosed before the age of 50. An estimated 7-10 million people worldwide (roughly
1 in 1,000 of the total population) are thought to be living with Parkinson's.
A high proportion of sufferers also experience mild cognitive impairment as the disease advances,
including executive dysfunction (impaired problem solving, fluctuations in attention, such and such),
slowed cognitive speed and memory problems, particularly with working memory, episodic memory
and with recalling learned information. In many cases (about 25-30% of cases), this eventually
develops into full-blown dementia, although memory problems in Parkinson's are typically milder
than in Alzheimer's disease. Non-motor symptoms such as memory loss remain the most under-
addressed area for research into Parkinson's disease.

Parkinson's disease is the result of decreased stimulation of the motor cortex by the basal ganglia,
usually due to the insufficient formation and action of the neurotransmitter dopamine in the neurons
in an area of the brain called the substantianigra. When cells that normally produce dopamine die
off, the symptoms of Parkinson‟s often appear. Its main cause is thought to be genetic, although the
exact mechanism is still unclear.
Schizophrenia
Schizophrenia is a mental disorder mainly characterized by abnormalities in the perception or
expression of reality, usually manifesting itself in hallucinations, "voices", paranoid delusions or
disorganized speech and thinking, often with significant social or occupational dysfunction. It does
not necessarily imply the "split mind" of dissociative identitydisorder (also known as multiple
personality disorder or split personality), but schizophrenia sufferers can experience severe
difficulty in distinguishing what is real from what is not. “Noise” in the brains of schizophrenics also
results in cognitive impairment, memory loss and attention deficits, resulting in difficulties in day to
day functioning and learning.
Both schizophrenia and multiple personality disorder chiefly affect biographical or episodic
memory, leaving semantic and procedural memory largely accessible (to all of the person‟s
identities). The disorder is believed to develop as a defense mechanism against childhood deprivation
or abuse or some other kind of psychic trauma. Elderly schizophrenia patients often also suffer from
Alzheimer’s disease, or some other form of dementia, in varying levels of severity.
Schizophrenics often have difficulty encoding, storing and recalling words, although recent advances
in the understanding of neuroplasticity have led to some promising new treatments. It has been
shown that schizophrenic symptoms can be improved by stimulation, particularly through the regular
repetition of some simple (although progressively more challenging) auditory and visual exercises.
As brains change physically through neuroplasticity, many of the abnormal patterns in the brain
which characterize schizophrenia are removed. In addition, levels of the protein BDNF (brain-
derived neurotropic factor), which is lower than normal in schizophrenics, are also increased to near
normal levels. Similar treatments may even be used to prevent the onset of schizophrenia in people
exhibiting early warning signs of the disorder.
Studies have shown that schizophrenic patients not currently taking related medication have a
smaller putamen (part of the striatum that plays a very important role in procedural memory), as
well as improper communication from the basal ganglia part of the brain. Although it is thought that
functional problems in the striatum of schizophrenic patients are not significant enough to seriously

impair procedural memory, the impairment may be significant enough to cause problems in the
improvement of performance on a task between practice intervals.
Tourette Syndrome
Tourette syndrome, also known as Gilles De La Tourette Syndrome or simply Tourette’s, is an
inherited neuropsychiatric disorder of the central nervous system with onset in childhood,
characterized by physical and vocal tics, which often wax and wane, and, less commonly but more
publicized, the spontaneous utterance of socially objectionable or taboo words or phrases, or the
repetition of others’ words.It has been described, by both patients and neurologists, as a lack of stop
signs in the brain. Obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder
(ADHD) are often (but not necessarily) associated with Tourette‟s.
Tourette's appears to be related to the skill-acquisition process that ties stimuli to responses during
the learning part of procedural memory (memory of skills and how things work). Physiologically, it
involves changes in the sub-cortical brain area known as the striatum, and its interaction with the
basal ganglia due to abnormalities in the way that hormones and neurotransmitters mediate
communication between nerve cells in the brain.
Although aspects of procedural memory may be abnormal in Tourette‟s, declarative memory
(memory of facts and events) remains largely spared. For example, “rule-governed” knowledge (used
in language, for example, to combine parts of words together according to the grammatical rules of
the language), which involves the procedural memory system, is affected, whereas “idiosyncratic”
knowledge (which allows us to learn that a word is linked to an object), which depends on
declarative memory and is learned and processed in the hippocampus and other temporal lobe areas
in the brain, is not. Indeed, children with Tourette’s are sometimes faster and better than typically
developing children at certain aspects of language.
WAYS OF ENHANCING MEMORY
It is a common experience that forgetting is usually a source of trouble for people.Everyday
conversation, class room participation, performance in examination,interview, presentation and
communication in meetings often put demands on us toremember information. Failure in doing so
has negative consequences which all ofus experience to different degrees in our lives. As a result
most of us are interested in improving our memory. The study of memory aids and related techniques
is called mnemonics. Some of the techniques used in improving memory are listed

Organization
While preparing for learning a learner needs to organize thematerial in some form. Such an
organization may help by creating a natural context and provide relevant cues while retrieving the
learned material. If thematerial lacks natural organization, an artificial organization may be created
bythe learner.
Concentration
One of the main reasons of forgetting is inadequate allocation attention resources to the material
while processing the same. As a result the material is not stored and we fail to recall when we need
it. Thus by focusing attention on the material while processing we can increase the probability of
storage and recall.
Chunking Memory
Chunking involves creating something more meaningful and therefore memorable from seemingly
random bits of information. One example is if you need to remember a list of things such as buying
figs, lettuce, oranges, apples, and tomatoes you can create a word out of the first letters (e.g.,
"FLOAT"), which is easier to remember than the individual items. If you've ever tried to remember a
phone number by making a word (or words) out of the letters on the phone's dial pad, you've used
chunking.
The Atlantic recently highlighted the value of chunking based on the ideas in the book The Ravenous
Brain by neuroscientist Daniel Bor. In one study, an undergraduate volunteer went from being able
to remember a 7-digit sequence to remembering an 80-digit sequence after 20 months of practice,
using chunking. The volunteer had been a track runner, so he grouped numbers as running times:
3492, for example, became 3 minutes and 49.2 seconds.
Assigning meaning to hard-to-remember things like numbers and letters is also what's at play behind
the strategies used by memory champions
Recoding: While dealing with non-meaningful material one may recode theitems to be
remembered in a more meaningful manner. Recoding may takemany forms. For example people may
use the first letter of all the items andmake a sentence. This kind of narrative structure works as a
cue. Acronyms(e.g., U.N.O., TV, CBI, WHO) are also used for the purpose in which all thefirst
letters are used. Using elaboration one may add more information whichmakes the material

distinctive. Chunking is a good example of recoding. If alarge serial of numbers is presented it
becomes difficult to remember. Thesame, however, may be divided in two or three chunks in some
meaningfulway using ingenuity. Using elaborative coding one may put many items in astory form
and recall the same easily
Use of schema
The efficiency of memory recall can be increased to some extent by making inferences from our
personal stockpile of world knowledge, and by schemata..A schema is an organized mental
structure or framework of pre-conceived ideas about the world and how it works, which we can
use to make realistic inferences and assumptions about how to interpret and process information.
Thus, our everyday communication consists not just of words and their meanings, but also of what is
left out and mutually understood. Such schemata are also applied to recalled memories, so that we
can often flesh out details of a memory from just a skeleton memory of a central event or object.
However, the use of schemata may also lead to memory errors as assumed or expected associated
events are added that did not actually occur.
Mnemonic Strategies
In the same way, associating words with visual imaginary is another commonly used mnemonic
device providing two alternative methods of remembering, and creating additional associations in the
mind. Taking this to a higher level, another method of improving memory encoding and
consolidation is the use of a so-called memory palace (also known as the method mention above as
of loci), a mnemonic techniques that relies on memorized spatial relationships to establish, order
and recollect other memories. Many top memorizers today use the memory palace method to a
greater or lesser degree. Similar techniques involve placing the items at different landmarks on a
favorite hike or trip (known as the journey method), or weaving them into a story.
Method of loci/memory palace
As the name implies, this technique uses associations with place or task. The visualization of the
same provides cues for recalling the task. By choosing any action properly one can use memory at
any point in the day. Use of such mnemonic codes allows one to have vivid and distinctive
associations between new information and prior knowledge. Being related to context the cues
become very effective. For instance one may have a clear visual image of a building, its rooms,
furniture and other details. These may be linked to different ideas and using these linkages, memory
of those ideas can be enhanced.

Figure 8 memory palace
SQ3R method
SURVEY
 Glance over the heading in the chapter to see the fee major points which will be developed.
This survey should not take more than a minute and will show the three to six central ideas
within the chapter. This survey helps you to organize the ideas as you read them later.
QUESTION
 Now begin to work. Turn the first heading into a question. This will arouse your curiosity
and increase comprehension. It will help bring to mind information already known and help
you to understand the section more quickly. The question will make important points stand
out from the explanatory detail. Turning the heading into a question can be done the instant
you read it, but it demands a conscious effort on the part of the reader.
READ

 Read to answer that question. Read to the end of the first section, not by passively plowing
along, but by conducting an active search for the answer to your question.
RECITE
 After reading the first section, look away from the book and try to briefly recite the answer to
your question. Use your own words and cite an example. If you can do this, you know what
is in the book; if you can't, glance over the section again. An excellent way to do this reciting
is to jot down very brief cue phrases in outline form on a sheet of paper.
 Now repeat steps 2, 3, and 4 for each heading in the section. That is, turn the next heading
into a question, and recite the answer by jotting down cue phrases in your outline. Read in
this way until you have completed the entire lesson.
REVIEW
 When you have completed the assignment in the manner described above, look over your
notes to get a bird's-eye view of the points and their relationships. Then check your memory
for content by reciting the major sub points under each heading. An excellent way to check
your memory is to cover your notes and try to recall the main points. Then uncover each
major point and try to recall the sub points listed under it.

Robert Kurzban (2007) Evolutionary psychology.Scholarpedia, 2(8):3161

Cognitive Psychology, memory and forgetting

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