Completed handout for lecture 4b Ian - Brain and Behaviour PDF

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Completed handout for lecture 4b Ian - Brain and Behaviour...

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PS10086: MIND & BEHAVIOUR Lecture 4b: The brain and behaviour 2 Objectives • • • • •

Describe & understand the functions of various parts of the brain. Define hemispheric lateralization & discuss what functions are located in the left versus right hemispheres. Describe the results of Sperry’s split brain research. Describe the concept of neural plasticity & explain what factors can play a role in it. Describe the functions of the endocrine & immune systems.

Association Cortex Involved in many important mental functions, including perception, language, and thought Stimulation does not cause specific sensory or motor reactions Damage can cause disruption or loss of speech, understanding, thinking, & problem solving The more association cortex an organism has the more complex behaviours they posess Agnosia: the inability to identify familiar objects e.g. can recognize that bananas as yellow and curved but wouldn’t recognize what it is even though they could verbally say this is a yellow curved fruit etc. e.g. the man who thought his wife was a hat.

The Frontal Lobes 29% of human brain; less in all other mammals e.g. chimps 17% dogs 7% etc. Least understood part of the brain Damage can result in an inability to plan and carry out a sequence of actions e.g. make the same mistakes over and over, IQ is often unaffected Involved in emotional experience

Prefrontal Cortex

The seat of the “executive functions” (mental abilities that allow people to direct their behaviour in an adaptive fashion) Problems planning strategically, struggling to control impulses, setting goals and poor judgement. Damage results in an inability to understand & anticipate future consequences make drastic gestures based on whims e.g. shotgun weddings and quitting jobs Most famous historical case: Phineas Gage

Activity Identifying Injured Brain Structures There are a number of clients in the Shady Pines Nursing Home who have suffered neurological damage. Given the limited, and admittedly oversimplified, information provided below, make an educated guess as to the part of the brain that has been damaged. 1.

Anna is very placid and easy to get along with, but she seems to live only in the moment, with no ability to think ahead or make plans that she can then follow. _____________________frontal lobe

2. Lucia displays considerable paralysis on the right side of her body. ___________________motor cortex______________ 3. Leona has difficulty walking and performing other routine and daily tasks because she experiences jerks and spasms and a lack of coordination in her arms and legs. She also has trouble maintaining her balance. _______________cerebellum___________________ 4. Ben shows extremely confused thinking and disordered attention of the sort that characterises schizophrenia. _____________________thalamus_____________

Hemispheric Lateralisation The two cerebral hemispheres are connected by the corpus callosum, a large band of myelinated nerve fibres

Most information is transmitted between the two hemispheres via these nerve fibres enabling them to work effectively as a single unit. Lateralisation: the relatively greater localization of a function in one hemisphere or another

Left hemisphere: mathematical and logical abilities are localised here, as are most aspects of verbal abilities and speech Aphasia: the partial or total loss of the ability to communicate; results from damage to Broca’s or Wernicke’s areas in the left hemisphere Right hemisphere: perceiving and understanding spatial relations recognizing faces, perceiving emotion mental imagery and certain aspects of musical and artistic abilities

The Split Brain Split brain research is conducted on people who have undergone severance of the corpus callosum. Demonstrates that visual input is not unified in these individuals Input on right side is sent to left hemisphere & vice-versa

Writing exercise (Try summarising the results of these experiments in your own words below & later check with the textbook…)

Neural Plasticity The ability of neurons, brain areas & networks to change in structure & function

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Effects of experience include: –

Stimulating environment (e.g. massage, & music)

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Cultural factors (e.g. Chinese speakers)

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Your job/career (e.g. taxi drivers)

Healing the Nervous System Neurons can modify themselves in two ways: – Structurally: sprouting enlarged networks of dendrites; extending axons from surviving neurons – Biochemically: increasing neurotransmitter volume Neurogenesis: the production of new neurons in the nervous system

Neural Stem Cells: immature “uncommitted” cells that can mature into any type of neuron or glial cell needed by the brain

Endocrine & Immune System Endocrine System: numerous hormone-secreting glands distributed throughout the body Hormones: chemical messengers that are secreted from the glands into the bloodstream

Adrenal Glands: twin structures that serve as hormone factories, producing and secreting about 50 different hormones • They produce several stress hormones

Immune System: • Antigens: foreign substances that trigger a biochemical response from the immune system • Antibodies: biochemical weapons needed to destroy the antigens Psychosocial factors can influence immune system functioning

A Useful Reminder? http://www.youtube.com/watch?v=snO68aJTOpM

Course Text Holt, N., Bremner, A., Sutherland, E., et al. (2019). Psychology: the Science of Mind & Behaviour (Chapter 4). Berkshire: McGraw-Hill....