Introduction to biopsychology 2.0
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Dr. Suresh Kumar Murugesan is a professor of psychology heading the department at The American College in Madurai, India. His areas of specialization include psychometry, positive psychotherapy, and cyber psychology. He is interested in conducting new research in behavioral sciences. The presentation provides an overview of the history and development of biopsychology, from ancient Greek philosophers' ideas about the brain and mind, to modern understandings informed by anatomical discoveries and experiments challenging past theories.
Introduction to biopsychology 2.0
- 1. Dr.Suresh Kumar Murugesan PhD Biopsychology
- 2. About the Presenter ● Dr.Suresh Kumar Murugesan is a passionate Professor, Researcher and Behavioural Scientist from Madurai, Tamil Nadu, India ● At present he is Heading the department of Psychology, The American College, Madurai and Adjunct Professor of School of Behavioural Sciences and Education at TAU ● He is very keen in new research studies in behavioural Sciences and open to learn. ● His area of specializations are Psychometry, Positive Psychotherapy and Cyber Psychology Yellow Pond
- 3. Disclaimer ● This presentation is prepared for learning purpose only and all the images and pictures used in this presentation are taken from google image search. ● Due recognition was given to all the material collected from the various sources. ● Any name or reference is missed kindly bring it to the notice of the presenter for inclusion. ● Email - sureshkumar800@yahoo.com Thank you Yellow Pond
- 4. What is Biopsychology? • the branch of psychology concerned with its biological and physiological aspects. • biopsychology is the study of the brain and how it influences and develops behaviour and mental processes. Yellow Pond
- 5. Biopsychology Other names of biopsychology are a.Neuropsychology b.Biological Psychology c.Physiological Psychology d.Clinical Neuropsychology e.Behavioural Neuroscience Yellow Pond
- 6. What is Biopsychology? ● A multidisciplinary study of nervous system and the role it plays in behavior! ● It is a branch of psychology that studies relation between brain and behavior Yellow Pond
- 7. What is Biopsychology? Biopsychology is merging of several disciplines: • anatomy and physiology • Biology and chemistry • Philosophy • Psychology: Behavioral, social and cognitive areas, in particular Yellow Pond
- 8. History of Biopsychology – Plato and Aristotle • Among the first people to realise that the brain was the organ of the mind and behaviour were the ancient Greeks. • For instance, Plato (429–348 BC) proposed that the brain was the organ of reasoning – although others disagreed, including his student Aristotle, who believed that the heart served this function and that the brain merely served to cool blood. Yellow Pond
- 9. Human Brain - Animal Dissection The ancient Greeks were aware of the basic shape of the brain mainly through animal dissection, and of its ventricles Yellow Pond
- 10. Human Brain - Leonardo da Vinci ● Throughout most of the ancient world the human body was considered sacred and autopsies were prohibited. ● The first drawings of the human brain were not undertaken until the late fifteenth century AD, by Leonardo da Vinci. Yellow Pond
- 11. Galen • One of the first writers to propose a theory of brain function based on the ventricles was Galen (AD 130– 200) • He was the most important physician of the Roman imperial period. Yellow Pond
- 12. Galen - Anatomical Discoveries • Galen made many important anatomical discoveries, including the cranial nerves that pass between the brain and the body. • Galen believed that the heart was the crucial organ of the body because it contained the vital spirit that gave the spark of life to the person. Yellow Pond
- 13. Galen - Heart and Mind • The vital spirit was also thought to provide the ‘substance’ of the mind, and was transported to a large group of blood vessels at the base of the brain called the rete mirabile (‘wonderful net’). • Here the vital spirit was mixed with air that had been inhaled through the nose, and transformed into animated spirit that was stored in the ventricles. When needed for action, the animated spirit was then believed to enter nerves resembling hollow tubes, that passed into the body where it pneumatically moved muscles to produce behaviour. Yellow Pond
- 14. Galen - Ventricles • Galen knew that the brain had four main ventricles (the first two are now called the lateral ventricles and they form a symmetrical pair inside the cerebral cortex, which then feed into the third ventricle located in the mid-part of the brain, that joins with the fourth ventricle in the brain stem). • Others who followed Galen extended his ideas and gave the ventricles different functions. Yellow Pond
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- 16. Galen and Animal Dissection Galen, who had not been allowed to perform human dissection in Rome, had inferred its human existence by observing it in cattle and ox on. Yellow Pond
- 17. Nemesius In the fourth century AD, Nemesius, Bishop of Emesa, hypothesized that 1. the lateral ventricles were the site of sensory and mental impressions; 2. the third ventricle the site of reason; and 3. the fourth ventricle the site of memory. Yellow Pond
- 18. Augustine • Augustine of Hippo (354–430) who was one of the founding fathers of the Christian religion. • With respected spiritual authority behind it, the ventricular concept of brain function became the most popular theory in the brain’s written history and was accepted as the truth for nearly 1,500 years. Yellow Pond
- 19. Vesalius - Anatomical work • The concept of rete mirabile began to be doubted only in the Renaissance when Vesalius in his great anatomical work De humani corporis fabrica (1543) showed that the human brain does not actually contain a rete mirabile. Yellow Pond
- 20. René Descartes René Descartes (1596–1650) was a French philosopher and mathematician Yellow Pond
- 21. René Descartes His famous quote Cogito; ergo sum (‘I think, therefore I am’), which refers to Descartes’s doubt of all things except his own existence, is often seen as heralding a new age of reason. Yellow Pond
- 22. René Descartes The importance of Descartes in the development of psychology lies largely with his attempt to resolve the mind–body problem. Yellow Pond
- 23. René Descartes He believed, as did Plato, that mind and body are two entirely different things (a theory known as dualism), with the body composed of physical matter, and the mind or soul being non-physical and independent of the material world. Yellow Pond
- 24. Pineal gland A problem with dualism, however, lies in trying to explain how the non-material mind can control the physical or mechanical workings of the body. In his attempt to provide an answer, Descartes proposed that mind and body interacted in the pineal gland. Yellow Pond
- 25. René Descartes - Pineal gland Descartes chose the pineal gland as it was a singular structure (most other brain areas are bilateral, or ‘paired’) and because he believed that the soul had to be a unified indivisible entity. Yellow Pond
- 26. René Descartes - Pineal gland The pineal gland was located close to the third ventricle and bathed by cerebrospinal fluid. This provided the pineal gland with a means by which its minute movements could influence the animated spirits of the brain. In other words, the pineal gland provided an ideal site where the soul could act upon the body (Mazzolini 1991). Yellow Pond
- 27. René Descartes and Royal Garden Descartes also realised that a great deal of behaviour was mechanical and did not require mental intervention.
- 28. René Descartes and Royal Garden • During a visit to the Royal Gardens in Paris as a young man that he began to develop the idea. • The gardens exhibited mechanical statues that moved and danced whenever they were approached, which was caused by hydraulic pressure-sensitive plates hidden under the ground. This led Descartes to speculate that the human body might work according to similar principles.
- 29. René Descartes He developed the concept of the automatic reflex which occurs, for example, when a limb is quickly moved away from a hot source such as a fire. Yellow Pond
- 30. René Descartes Descartes hypothesised that a sensory nerve composed of a hollow tube containing vital spirit conveyed the message of heat to the ventricles of the brain; these in turn directed animal spirit to flow out through the nerves from the brain, back to the muscles of the affected limb thereby causing its withdrawal. Yellow Pond
- 31. René Descartes • Prior to Descartes, it had generally been accepted that the soul controlled all the actions of the human body. • But Descartes showed that the human body worked according to mechanical principles – not unlike the internal workings of a watch – and did not need a soul to make it operate once it had been put into motion. Yellow Pond
- 32. René Descartes Descartes proposed that not only the functions such as digestion and respiration were reflexive, but also were a number of mental functions, including sensory impressions, emotions and memory. Yellow Pond
- 33. René Descartes • He believed that animal had no soul • Animal were capable of sensory processing along with emotion and memory. • The sensory processes did not need the involvement of a soul (or mind) in animals
- 34. René Descartes • The one exception was reasoning and pure thought which Descartes believed was the exclusive property of the soul and unique to humans. • This was a position that allowed his theory to be in accordance with the religious teachings of the time. Yellow Pond
- 35. René Descartes (Dualism) • Descartes’s theory helped lay the foundations for the modern development of physiology and psychology. • His theory was based on a dualist view of the mind, it helped shift attention towards the practical problem of how reflexes might underlie behaviour without fear of contradicting religious dogma. Yellow Pond
- 36. René Descartes (Dualism) • His theory encouraged others to think more deeply about how the brain worked. • Descartes provided a great impetus for experimental research – not least because some of his ideas could be tested. Yellow Pond
- 37. René Descartes - Experiment • Descartes believed that the nervous system controlling reflexes was a hydraulic system consisting of hollow tubes through which animal spirits flowed from the ventricles to the muscles. Yellow Pond
- 38. René Descartes - Experiment • If the idea of Descaes was correct then it followed that muscles should increase in volume as they ‘swelled’ with spirit during contraction. • When investigators tested this theory by flexing a person’s arm in a container of water, however, no increase in the water level occurred. Yellow Pond
- 39. René Descartes - Experiment • Descartes had paved a way for a scientific and non-secular approach to understanding human physiology that included the brain. Yellow Pond
- 40. Luigi Galvani (The discovery of ‘animal’ electricity) • In 1791, the idea of animal spirit as the cause of nervous activity was challenged by the Italian Luigi Galvani who undertook a series of experiments on amputated frog legs which included the exposed ends of their severed nerves. Yellow Pond
- 41. Luigi Galvani (The discovery of ‘animal’ electricity) • Galvani found that he could induce a leg to twitch in a number of ways – as indeed shown in one famous case where, during a thunderstorm, he connected a nerve stump to a long metallic wire that pointed to the sky and obtained strong muscular contractions in the detached leg (Galvani was obviously unaware of the great dangers of such a demonstration). Yellow Pond
- 42. Luigi Galvani (The discovery of ‘animal’ electricity) • He found that similar movements were produced when he suspended a frog’s leg between two different metals. • Although he did not know it at the time, Galvani had shown that when dissimilar metals make contact through a salt solution an electrical current is produced. Yellow Pond
- 43. Luigi Galvani (The discovery of ‘animal’ electricity) • The first demonstration of the battery later formally invented by Volta in 1800. These discoveries led Galvani to conclude that nerves are capable of conducting electricity and that their ‘invisible spirit’ must be electrical in nature. Yellow Pond
- 44. Luigi Galvani (The discovery of ‘animal’ electricity) • Nerve conduct electricity was finally proved beyond reasonable doubt in 1820 when the German Johann Schweigger invented the galvanometer (named in honour of Galvani) Yellow Pond
- 45. Luigi Galvani (The discovery of ‘animal’ electricity) • It measured the strength and direction of an electrical current. Indeed, this invention soon showed that nervous tissue contained intrinsic electrical energy. Yellow Pond
- 46. Luigi Galvani (The discovery of ‘animal’ electricity) • The twitching frogs’ legs marked the end to hydraulic theories of nervous action and the start of a new chapter in understanding how nerve cells work (Piccolino 1997). Yellow Pond
- 47. Johannes Müller (Speed of nerve impulse is of light speed) • One question that fascinated neurophysiologists during this time was the speed of the nervous impulse that flowed down the fibre (axon). • Although the galvanometer could detect electrical activity, the nerve impulse appeared to be instantaneous and too fast to be measured. Yellow Pond
- 48. Johannes Müller (Speed of nerve impulse is of light speed) • The famous physiologist Johannes Müller wrote somewhat despairingly in 1833 that the speed of the nerve impulse was comparable to the speed of light and would never be accurately estimated. Yellow Pond
- 49. Hermann von Helmholtz (Speed of nerve impulse= 98 km/hr) • However, Müller was soon proved wrong by the work of Hermann von Helmholtz who managed, in 1850, to extract long motor nerves (some 50–60 mm in length) that were still attached to muscles taken from frogs’ legs. Yellow Pond
- 50. Hermann von Helmholtz (Speed of nerve impulse= 98 km/hr) • Helmholtz recorded the delay between the onset of electrical stimulation and the resulting muscle twitch, and calculated the speed of the impulse to be about 90 feet per second, which translates to around 98 kilometres per hour. Yellow Pond
- 51. Hermann von Helmholtz (Speed of nerve impulse= 98 km/hr) • We now know that Helmholtz was fairly accurate in his estimation. Moreover, while the nerve impulse was fast, it was not comparable with the speed of light. • In fact, neurophysiologists have now established that speed of nerve conduction varies depending on the type of axon Yellow Pond
- 52. Hermann von Helmholtz (Speed of nerve impulse= 98 km/hr) • the impulse being quicker in large-diameter myelinated axons (for example, the fastest neuron can conduct action potentials at a speed of 120 metres per second, or 432 kilometres per hour), and slowest in small- diameter unmyelinated axons (at 35 metres per second). Yellow Pond
- 53. Camillo Golgi (Stain - Silver Nitrate) In 1875, a major breakthrough occurred when the Italian anatomist Camillo Golgi (1843– 1926) discovered a new stain that allowed individual nerve cells to be observed. Yellow Pond
- 54. Camillo Golgi (Stain - Silver Nitrate) • He found that when nervous tissue was exposed to silver nitrate, the nerve cells would turn black. • This caused them to stand out in bold relief so they could clearly be seen under a microscope. But, more importantly, Golgi’s technique only stained around 2 percent of the cells in any given slice of nervous tissue. • This was a great advance as it made individual neurons, and all their various components such as dendrites and axons, much more clearly observable Yellow Pond
- 55. Ramón Y Cajal • Ramón y Cajal’s most important contribution to neuroanatomy was his discovery that nerve cells were separate and individual units. • Previously, it had been believed that nerve cells were joined together in a network of tubes which allowed the direct passage of information from cell to cell. Yellow Pond