Higher Intellectual functions of brain
- 2. Presented to: Presented by: Dr. Tehseen Ahmed Ali 48 Ahmar Raza 14 Ahsan Raza 16 Qamar Shah 71 M. Rizwan 79
- 3. HIGHERINTELLECTUALFUNCTIONS: • Higher intellectual functions are very essential to make up the human mind. These functions are also called higher brain functions or higher cortical functions. • The extensive outer layer of gray matter in cerebral cortex is responsible for higher intellectual functions. Conditioned reflex forms the basis of all higher intellectual functions.
- 9. Sensitization is a process by which the body is made to become more sensitive to a stimulus. When a stimulus is applied repeatedly, habituation occurs. But, if the same stimulus is combined with another type of stimulus, which may be pleasant or unpleasant, the person becomes more sensitive to original stimulus. Sensitization
- 10. For example: a woman is sensitized to crying sound of her baby. She gets habituated to different sounds around her and sleep is not disturbed by these sounds. However, she suddenly wakes up when her baby cries because of sensitization to crying sound of the baby.
- 11. Associative learning is a complex process. It involves learning about relations between two or more stimuli at a time. Classic example of associative learning is the conditioned reflex ASSOCIATIVELEARNING
- 12. Conditioned reflex is the acquired reflex that requires learning, memory and recall of previous experience. It is acquired after birth and it forms the basis of learning. Conditioned reflex is different from unconditioned reflex . Unconditioned reflex is the inborn reflex, which does not need previous experience. CONDITIONED REFLEX
- 13. Classical conditioned reflexes are those reflexes, which are established by a conditioned stimulus, followed by an unconditioned stimulus. CLASSICAL CONDITIONED REFLEXES
- 14. Instrumental conditioned reflexes are those reflexes in which the behavior of the person is instrumental. This type of reflexes is developed by the conditioned stimulus, followed by a reward or a punishment. The instrumental conditioned reflexes are also called operant conditioned reflexes or Skinner conditioning. INSTRUMENTAL CONDITIONED REFLEXES
- 17. Memory is defined as the ability to recall past experience or information. It is also defined as retention of learned materials. MEMORY
- 18. Long term.
- 19. Short-term memory is the recalling events that happened very recently, i.e. within hours or days. It is also known as recent memory. For example, telephone number that is known today may be remembered till tomorrow. But if it is not recalled repeatedly, it may be forgotten on the third day. Short-term memory
- 20. Long-term memory is the recalling of events of weeks, months, years or sometimes lifetime. It is otherwise called the remote memory. Examples are, recalling first day of schooling, birthday celebration of previous year, picnic enjoyed last week, etc. Long-term memory is more resistant and is not disrupted easily. LONG TERM MEMORY
- 21. Implicit memory is defined as the memory in which past experience is utilized without conscious awareness. It helps to perform various skilled activities properly. Implicit memory is otherwise known as non-declarative memory or skilled memory. Examples of implicit memory are cycling, driving, playing tennis, dancing, typing, etc. Implicit memory involves the sensory and motor pathway. IMPLICIT MEMORY
- 26. SPEECHDEFINITION: Speech is defined as the expression of thoughts by production of articulate sound, bearing a definite meaning. It is one of the highest functions of brain. When a sound is produced verbally, it is called the speech. If it is expressed by visual symbols, it is known as writing. If visual symbols or written words are expressed verbally, that becomes reading MECHANISM OF SPEECH: Speech depends upon coordinated activities of central speech apparatus and peripheral speech apparatus with the influences of motor impulses from respective motor areas of the cerebral cortex. Central speech apparatus consists of the cortical and subcortical centers in brain. Peripheral speech apparatus includes larynx or sound box, pharynx, mouth, nasal cavities, tongue and lips.
- 28. DEVELOPMENT OF SPEECH First Stage First stage in the development of speech is the association of certain words with visual, auditory and other sensations, aroused by objects in the environment. Second Stage When a definite meaning has been attached to certain words, pathway between the auditory area (Heschl area; area 41) and motor area for the muscles of articulation, which helps in speech (Broca area 44) is established . The child attempts to formulate and pronounce the learnt words. Role of Cortical Areas in the Development of Speech Development of speech involves integration of three important areas of cerebral cortex: 1. Wernicke area 2. Broca area 3. Motor area.
- 29. Role of Wernicke area – Speech understanding Understanding of speech begins in Wernicke area that is situated in upper part of temporal lobe. It sends fibers to Broca area through a tract called arcuate fasciculus. Wernicke area is responsible for understanding the visual and auditory information required for the production of words. After understanding the words, it sends the information to Broca area. Role of Broca area – Speech synthesis Speech is synthesized in the Broca area. It is situated adjacent to the motor area (responsible for the movements of tongue, lips and larynx, which are necessary for speech). By receiving information required for production of words from Wernicke area, the Broca area develops the pattern of motor activities required to verbalize the words. The pattern of motor activities is sent to motor area Role of motor area – Activation of peripheral speech apparatus By receiving the pattern of activities from Broca area, motor area activates the peripheral speech apparatus. It results in initiation of movements of tongue, lips and larynx required for speech. Later, when the child is taught to read, auditory speech is associated with visual symbols (area 18). Then, there is an association of the auditory and visual areas with the motor area for the muscles of hand. Now, the child is able to express auditory and visual impressions in the form of written words.
- 31. NERVOUS CONTROL OF SPEECH Speech is a well-coordinated motor phenomenon. So, many parts of cortical and subcortical areas are involved in the mechanism of speech. Subcortical areas are controlled by cortical areas of dominant hemisphere. In about 95% of human beings, the left cerebral hemisphere is functionally dominant and those persons are right handed. Following are the motor and sensory cortical areas concerned with speech. A. Motor Areas Broca area is also called speech center, motor speech area or lower frontal area and It includes area 44. It controls the movements of structures (tongue, lips and larynx) involved in vocalization. Upper frontal motor area is situated over the medial surface of cerebral hemisphere. It controls the coordinated movements involved in writing. B. Sensory Areas Secondary auditory area or auditopsychic area includes area 22. It is concerned with the interpretation of auditory sensation and storage of memories of spoken words. Secondary visual area or visuopsychic area includes area 18. This area is concerned with the interpretation of visual sensation and storage of memories of the visual symbols.
- 33. Wernicke area is situated in the upper part of temporal lobe. This area is responsible for the interpretation of auditory sensation. It also plays an important role in speech. It is responsible for understanding the auditory information about any word and sending the information to Broca area . C. Wernicke Area Aphasia Acquired disorder of language due to damage to one or more speech centres. In form of impaired ability to use or comprehend words. It impairs a person’s ability to process language. Class of aphasia ranges from having difficulty remembering words to being completely unable to speak, read and write. Causes of aphasia Aphasia is caused by vascular lesions, traumatic brain injury, tumors of left hemisphere, infection of nervous system, epileptic seizures and central nervous system diseases. In short, any factor that effects speech areas is cause of aphasia
- 34. Types pf aphasia 1. Broca’s aphasia 2. Wernicke’s aphasia 3. Global nominal and others types of aphasia Broca’s aphasia It is the non fluent speech problem. It occurs due to lesions in left frontal lobe of cerebral cortex. The affected persons can comprehend the words but do not complete the sentences because of their inability to construct the sentences. They often talk in short phrases by omitting small words such as ‘and’, ‘is’, ‘for’, etc. They make great efforts even to initiate speech. Wernicke’s aphasia Wernicke aphasia is the speech without any meaning. It occurs due to lesion in left temporal lobe. It is characterized by fluent speech. The affected persons speak long sentences but without any meaning. This type of speech is known as jargon speech. These individuals are unable to understand others’ speech. Because of this weakness, they are unaware of their own mistakes
- 36. Treatment of Aphasia The recommended treatment for aphasia is usually speech and language therapy. Sometimes aphasia improves on its own without treatment. This treatment is carried out by a speech and language therapist (SLT). If you were admitted to hospital, there should be a speech and language therapy team there. How speech and language therapy can help? For people with aphasia, speech and language therapy aims to: •help restore as much of your speech and language as possible (reduce impairment) •help you communicate to the best of your ability (increase activity and participation) •find alternative ways of communicating (use compensatory strategies or aids)