Donald Olding Hebb

Donal Olding Hebb B. Sümeyye Meylani 215312459 His life and Academic Life Donal Olding Hebb lived years between 1904-1985. His parents both were doctor and her mother influenced education approach Of Maria Montessori which gives more importance education of the sense before development of the intellect. Thus, his raised and had his early education from his mother in home schooled system until the age of eight. (Wikipedia alıntı). He started his journey of psychology by entering master’s degree at McGill University. Then he started University of California under supervision of Professor Karl S. Lashley. In 1937 he attended a research fellow at the Montreal Neurological Institute where he was able to study and search brain activity and neuroscience. His focus was on role of the brain in the behavior. (Milite 2001). Hebb became professor at McGill University in 1947. He won the APA Distinguished Scientific Contribution Award in 1961which was for the first time given non U.S citizen. Adams pointed that Hebb`s book is one of two most significant books in the biology. It is greeted actively as “a breath of fresh air” since Darwin’s Origin of Species (1998). His famous book is The Organization of Behaviour that published at 1946. Frank A. Beach claims that this book is known as an extremely significant, and innovative contribution for theoretical psychology. Also, he called his way of studies “a biological understanding of mind.” Such as, intelligence, learning, memory, perception, emotion, and motivation so on. Thus, his approach was combination of behavioural as well as neuro psychology. (1987). However, the time when Hebb’s book was published there was famous and growing approached in psychology to against cognitive construct which was behavioural psychology (Skinner 1938). That is why The Organization of Behaviour singed a turning point away from behavioural psychology trend. Hebb concluded that “the problem of understanding behaviour is the problem of understanding the total action of the nervous system and vice versa” (1949, p.14). Hebb’s another famous book is A Textbook of Psychology that first published at 1958. This book interested in the biological approach to mental phenomena as well as dealt with personality, structure, development of intelligence, mental illness (Beach 1987). Learning Before the Donald Hebb behavioural psychology approach was pretty much famous. However, Hebb went beyond of behaviourist in two features. First, he claimed that an association could not be localized to a single synapse despite of that neurons are grouped in cell assemblies. Second, he refused idea of stimulus- response association by explanation of necessarily to postulate a central neural mechanism to account for the delay hence there must be between stimulation and response are characteristic of thought (Seung 200). In cognitive science and computational neuroscience referred to like “Hebb rule” that delivers learning algorithm to regulate connection weights at neural, and insincere network models (Trappenberg, 2002). Hebb’s main principle of learning and remembering is stated as “Neurons that fire together, wire together” which means that repetition strengthens the connections between neurons (Whitmore 2009). To sum up, images, ideas or any other activation representation or assemblies of the neurons that tend to be active at the same time. The neurones firing in cell assembly would persist after triggering event.as well as form of memory emergence (Milner, 1986). Synapses in the brain Hebb “When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased. (p. 62) These words mean that the conditions for synaptic plasticity rely on coincidence detection which is reinforces on the depolarization of the postsynaptic cell (Hinton & Anderson, 1981). Long Term Potential LTP controls by the NMDA receptors, it can call “Hebb molecule”, which activation needs the binding of the neurotransmitter glutamate to depolarization of the postsynaptic neuron (Rieke, Warland, de Ruyter van Steveninck, & Bialek, 1998). Also, Hebb found that cell assemblies, formation of them both external and internal, are dynamic. That means whenever a cell assembly fires in the nonexistence of object person experience thought. Serial of assembly creates amounts of stream of thoughts. Synaptic Plasticity “Hebb in perspective” aims at presenting theoretical and experimental functions of spike timing relied synaptic plasticity (van Hemmen & Senn 2002). According to Hebb early life is important to develop their perception by enriched environment and large experiences. Also, lack of early experiences compromises perception (Von Senden, 1932). In his restricted environment study rats has been examined. Twi rats were in his home with great opportunity to play and experiences variety of experiments, the other rats were in laboratory with no enriched environment. Then Hebb compared these two group of rats. Thus, the result of study was that rats that are were in enriched environment became fast learners and their brain activation were improved and their axons were enriched compared to rats were in laboratory (Rosenzweig et al., 1964). Thus, we can say that after this study and knowledge’s intelligence comes from experiences and from genetics both. Children early experiences are more significant in determination of intelligence specially at the time ot development if the brain. Not only intelligence but also perceptions, emotions are learnt at early developmental stages, Infant are born with random and interconnections of neural networks. Enriched environment and large variety of different experiences become networks organized and provides effective association with the environment. On the other hand, due to the fact that little experiences lead to permanent damage or lose of inborn functions. Memory and Arousal Theory As known that there are two type of memories which are long term and short term; however, Hebb called them as transient and permanent memories. Transient memory refers to ongoing actively in cell assemblies as well as phase sequences what traditionally short-term memory. Permanent Memory means that structural changes ın the synapses (long term memory). Also, transition from transient memory to the permanent memory called as consolidation. Hebb pointed that “dual trace mechanism” of memory which is reverberatory neural activity in short term memory while synaptic associations are the trace of long term memory (Seung 200). When Hebb was working under Lashley supervision he was able to study fear in the monkeys, so he developed Reticular Activation System RAS. It examines sleep, attention, fear. These are cue function which is stimulus provides sensory knowledge as well as arousal function that is activates the RAS. The performance depends on cue and arousal functions. Such as, Low sleep lead to deficient performance, also high degree of deteriorate concentration (Hebb & Donderi, 2013). It works as U curve which means if arousal level is too high, drops it reinforcement and if arousal is too low, rises its reinforcement Thus, reinforcement either increase performance or decrease (Hergenhahn & Olson, 2005). Moreover, Hebb examined the sources of fear arousal. He studied fear in chimps result was no fear until four months both in presence of familiar or unfamiliar objects; however, only when familiar object shown in unfamiliar way the fear has emerged. Hebb claims that the fear of monkeys emerged due to the fact that disruption of learnt phase about shown stimulus. Sensory Deprivation Hebb and his colleagues pointed that experiment to investigate, when restriction of sensory experience during adulthood results in similar issues observed in later life who had raised under restrict perceptual conditions throughout of their life (1957). The experiment was that “. College students were given $20.00 a day to lay in bed where they were deprived of sensory and motor activity. Food and water was given on demand along with use of the washroom”. The result of experiment is majority of participants can stand in conditions for 2-3 days the longest period was 6 days only, and suffered a variety of mental and personality problems. Such as, Incoherent thinking, having difficulty solving simple problems, and hallucinations etc. All in all, Hebb found that sensory stimulation is significant during development. If sensory stimulation is blocked, destruction of psychological and mental functions can be seen. Sensory stimulation is important as much as hunger, thirsty, and sleep. Referances Adams, P. (1998) Hebb and Darwin. Journal of Theoretical Biology, 195, 419–438. Beach, F. A. (1987). Donald Olding Hebb (1904–1985) p 6, 12. Hebb, D. O., & Donderi, D. C. (2013). Textbook of Psychology (Psychology Revivals). Psychology Press. Hebb, D. O. (1949). The organization of behavior: A neuropsychological theory. Hebb, D. (1980). Donald O. Hebb. A history of psychology in autobiography, 7, 273-303. Hergenhahn and Olson, 2005 Hergenhahn, B.R., & Olson, M.H. (2005). An introduction to theories of learning. (7th ed.). New Jersey: Prentice Hall. Hinton, G. E., & Anderson, J. A. (Eds.). (1981). Skeleton filters in the brain, in parallel models of associative memory (pp. 189-212). Hillsdale, NJ: Lawrence Erlbaum Associates. Milite, George A. “Hebb, Donald O. (1904-1985).” Encyclopedia of Psychology. 2001. Milner, P. M. (1986). Donald Olding Hebb (1904–1985). Trends in Neurosciences, 9, 347-351. Rieke, F. M., Warland, D., de Ruyter van Steveninck, R., & Bialek, W. (1997). Spikes: Exploring the neural code. Cambridge, MA: MIT Press. Salinas, E., & Sejnowski, T. J. (2000). Impact of correlated synaptic input on output firing rate and variability in simple neuronal models. Journal of Neuroscience, 20, 6193-6209. Sejnowski, T. J. (2003). The once and future Hebb synapse. Canadian Psychology/Psychologie canadienne, 44(1), 17. Seung, H. S. (2000). Half a century of Hebb. nature neuroscience, 3, 1166-1166. Skinner, B. F. (1938). The Behavior of Organisms: An Experimental Analysis New York: Appleton-Century. Trappenberg, T. P. (2002) Fundamental of computational neuroscience. Oxford: Oxford University Press. Whitmore P. G. (2009) A New Mindnest For A New Mınd van Hemmen, J. L., & Senn, W. (2002). Hebb in perspective. 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