Biological Bases of Behaviour Chapter 2 PDF

Biological Bases of Behaviour CHAPTER 2  Both hemispheres share the work in performing most tasks. Language dominance is associated with handedness (Hopkins & Cantalupo, 2008). The left hemisphere is dominant for language functions in about 95 percent of right-handed people a...

Biological Bases of Behaviour CHAPTER 2  Both hemispheres share the work in performing most tasks. Language dominance is associated with handedness (Hopkins & Cantalupo, 2008). The left hemisphere is dominant for language functions in about 95 percent of right-handed people and about 70 percent of left-handed people (Pinker, 1994; Springer & Deutsch, 1993). For about 15 percent of left-handed people, the right hemisphere is dominant for language functions. The other 15 percent of left-handers show patterns of mixed dominance.  Broca’s discovery 1824-1880 His most important discovery involved a male patient, 51 years old, who was admitted to the ward suffering from gangrene in his leg. The patient was also nearly unable to speak. He understood clearly what he heard, but his verbal utterances were limited primarily to one meaningless sound (tan). The patient died a few days after being admitted. While conducting an autopsy, Broca found that an egg- shaped part of the left frontal lobe of the patient’s brain had degenerated. The surgeon concluded that this area of the brain, now known as Broca’s area in his honor, is essential to the production of speech  SPLIT BRAIN STUDIES Nobel Prize winner Roger Sperry and his colleague Michael Gazzaniga  SPLIT BRAIN STUDIES Nobel Prize winner Roger Sperry and his colleague Michael Gazzaniga  SPLIT BRAIN STUDIES Nobel Prize winner Roger Sperry and his colleague Michael Gazzaniga PHINEAS GAGE (1848)  GAGE IS NO LONGER GAGE He was helped home, where his wounds were bandaged. Gage’s wounds healed within two months, and he was able to function despite the massive head injury he had suffered. Then, however, changes in his personality began to appear, which suggests to us that he suffered from subtle forms of brain damage. The formerly polite and conscientious worker became irritable, rude, and irresponsible (Holden, 2009). He started brawling and drinking heavily. Those who knew him before the accident said, “Gage is no longer Gage.” Gage’s skull is now on display at Harvard University.  PFC one-third of the entire cerebral cortex behaviors that make up what it is to be “human” the “seat of intelligence” or the “executive control center” of the brain because it is involved is so many higher mental functions, including reasoning, decision making, weighing the consequences of our actions, creative thinking, planning, problem solving, and control of impulsive behavior Damage to the PFC, as in the case of Phineas Gage, may impair the person’s ability to follow moral and social codes of conduct. Contemporary research also links damage to the PFC of the type suffered by Phineas Gage to changes in how people make moral decisions or judgments (Koenigs et al., 2007).  Brain plasticity Surgical removal of certain parts of the brain- if done before 13 years of age, patients are able to function normally Until 13, functions of the left and right hemispheres appear to be flexible The ability of the brain to adapt and reorganize itself following trauma or surgical alteration is called plasticity When one part of the brain is damaged by injury or disease, another part of the brain may take over its functions to a certain extent. Stroke patients- stimulation of healthy neurons Highest plasticity in children Find out and tell me about Gabrielle Giffords PART 2 Cerebral Cortex CEREBRAL CORTEX CEREBRAL CORTEX CEREBRAL CORTEX Adolescent Brain Pruning Social Perspective Pleasure seeking High Risk Behaviour  Adolescent Brain- Pruning Getting rid of synapses which are not being used Can be about 50% loss in grey matter in certain areas Adolescent Brain- Social Perspective Adolescent Brain- Social Perspective Lab experiment on social perspective, University of Cambridge, UK Adolescent Brain- Social Perspective Lab experiment on social perspective, University of Cambridge, UK Adolescent Brain- PLEASURE SEEKING LIMBIC SYSTEM Adolescent Brain- High risk behaviour LIMBIC SYSTEM and PRE-FRONTAL CORTEX Nature or Nurture? Nature or Nurture? The relationship between the innateness of an attribute (whether it is part of our nature) and the environmental effects on that attribute (whether it is influenced by our environment, or nurture). This is often referred to as the nature vs. nurture debate Epigenetics- the study of how your behaviors and environment can cause changes that affect the way your genes work Eg. Heritability of depression is about ~40% - what does this mean?