1. Biological Level of Analysis Physiology and Behavior

2. Principles There are physiological origins of many behaviors Human beings should be studied as biological systems Consider how the environment and cognition may interact with biological systems and affect physiology Biology can affect cognition and vice versa 3. Physiology Some physiological factors which can affect behavior: Brain processes Neurotransmitters Hormones Genes Physiology responds to environmental stimuli 4. Physiology Nature versus nurture debate: Is human nature the result of environmental factors or biological factors? Interactionist approach: Mix of the two arguments Holistic picture of human behavior This is the goal of I.B. Psychology 5. Principles Behavior can be innate because it is genetically based Thus, evolution plays a key factor in behavior Animal research can provide insight into human behavior There are biological correlates of behavior Should be possible to find links between biological factors and specific behaviors 6. Principles Reductionist approach is commonly used Micro-level of research Breaks down complex human behavior into its smallest parts Could be overly simplistic, but it is detailed 7. Neurotransmission Neurotransmission underlies behavior: NEUROTRANSMITTER EFFECT ON BEHAVIOR Acetylcholine Muscle contraction Affects memory in hippocampus Dopamine Voluntary movement Learning Pleasure Noradrenaline Arousal Alertness Stimulation of sympathetic nervous system Serotonin Sleep Arousal levels Emotion 8. Kasamatsu and Hirai (1999) Aim: See how sensory deprivation affects the brain Method: Studied Buddhist monks on a 3-day pilgrimage No food or water, no speaking, cold weather Started hallucinating after 48 hours Blood samples before and after pilgrimage: Serotonin levels heightened Serotonin activated hypothalamus and frontal cortex = hallucinations Sensory deprivation = release more serotonin 9. Martinez and Kesner (1991) Aim: Determine the role of the neurotransmitter acetylcholine on memory Method: Rats in a maze One group of rats given scopolamine to block acetylcholine from being transmitted Second group given physostigmine which keeps cholinesterase from monitoring levels of acetylcholine Third group as control 10. Martinez and Kesner (1991) Results: (First group) Inhibited acetylcholine = rats were slow and made errors (Second group) Inhibited physostigmine = rats were fastest (Third group) Control = average speed (between the first and second group) Conclusion: Acetylcholine is important in creating memory Experiment was well designed, but it is unclear how much this relates to human physiology 11. Drugs Drugs can simulate a certain neurotransmitter When there is not enough of the neurotransmitter When the site needs to be blocked 12. Brain & Behavior Brain is the command center of activity Case studies of brain damage help understand how the brain affects behavior Often longitudinal studies (carried out over a long period of time) to see short-term and long-term affects of damage 13. Phineas Gage Famous case study of brain damage and behavior Phineas Gage was studied by Dr. John Harlow Metal pole through skull (but still managed to survive???) Ruined the balance between his intellect and his emotional control Impatient, indulgent, profane, agitated, vulgar Shows that the brain affects personality and social behaviors 14. Localization of Brain Function Paul Broca (1861) found people with damage to the left frontal lobe couldnt understand or make grammatically complex sentences Brocas aphasia: Problems producing speech, but still able to understand it Famous patient called Tan because thats the only word he could say 15. Localization of Brain Function Carl Wernicke (1874) found area of brain crucial for language comprehension Described as left posterior superior temporal gyrus Wernickes aphasia: Patients could produce speech, but could not understand it 16. Localization of Brain Function Language processing is localized Meaning it is possible to trace the origin of the behavior to a specific part of the brain Desire to map out brains functions Localization doesnt explain all human behavior, but its a start! 17. Robert Heath (1950s) Found that electrically stimulating parts of the brain caused pleasure in patients with depression Patients could press the button themselves to experience the pleasure Patient B-19 pressed it 1500 times in 3 hours Had to be disconnected despite protests 18. Dopamine & Serotonin Dopamine produces desire Serotonin promotes satiety and inhibition All drugs increase production of dopamine and reduce production of serotonin Both D&P play central roles in feelings produced by drugs like cocaine and nicotine James Olds: Rats would walk over electrified grids to get to a lever that would stimulate the pleasure centers in their brains 19. Technology in Brain Research Allows researchers to see where specific brain processes take place (localization) Invasive techniques: removing/scarring brain tissue in order to study behavioral changes to compare the effect Raise ethical concerns (DUH!) Cant undo it Cant foresee the potential harm Hurting poor little defenseless animals!!!!!! 20. EEG (Electoencephalogram) Often thought of as recording brain waves Registers patterns of voltage change in the brain Provides limited information Cannot reveal what is happening in deeper brain regions Cant show the actual functioning of the brain 21. PET (Positron Emission Topography) Monitors glucose metabolism in the brain Used to diagnose abnormalities i.e. tumors, Alzheimers progression, comparisons in sexes or disorders Can record ongoing activity in the brain such as thinking 22. fMRI (Functional Magnetic Resonance Imaging) 3D pictures of the brain structures using magnetic fields and radio waves Shows brain activity and indicates which areas are active when engaged in a behavior Higher resolution than PET scans Easier to carry out than PET scans Used super frequently today 23. Brain Plasticity Brain can change as a response to environmental input Demonstrated by Hubel and Wiesel (1965) Brain plasticity: brains ability to rearrange connections between neurons Changes that occur in the structure of the brain as a result of learning or experience More stimulation and learning opportunities = denser neural connections 24. Dendritic Branching When we learn something new the neurons connect to create a new trace in the brain This is called Dendritic branching Dendrites of the neurons grow in numbers and connect with other neurons 25. Rosenzweig & Bennett (1972) Enriched environments vs. deprived environments & their effects on rats Enriched = toys Deprived = no toys Enriched environment created thicker cortex and heavier frontal lobe in rats Rat + toys + other rat friends = biggest growth in cortical thickness 26. Richard Davidson (2004) Meditation of Buddhist monks and 10 volunteers Monks and 2 volunteers had an increase in gamma waves during meditation Gamma waves = higher reasoning faculties After meditating for 10,000+ hours, the monks did not go back to normal gamma wave production afterwards Therefore meditation can have long-term effects and the brain adapts to stimulation 27. Mirror Neurons People can learn by observing others and imitating their actions Mirror neurons fire when someone performs an action or when someone else performs the same action May play a vital role in learning from and empathizing with someone It mirrors the behavior of another 28. Gallese et al. (1996) Could hear crackle of electrical signal caused by activated neurons Monkeys neurons crackled when it reached for a peanut to eat Heard crackling noise again when researcher reached for a peanut to eat Monkeys brain acted as though the monkey had carried out the behavior just because it saw someone else carry out the behavior 29. Marco Iacoboni (2004) Tested mirror neurons in humans Supported Galleses findings Observing a happy face activates pleasure centers in the brain Could explain how we feel the hit a football player feels when they get tackled Mirror Ns may have evolved to make us capable of understanding/interacting with others 30. Endocrine System Hormones affect behavior too Produced by the glands that make up the endocrine system 31. Hormones & their Functions Hormone Glands Function Adrenaline Adrenals Fight or flight response Arousal Melatonin Pineal Regulation of sleep Testosterone and Oestrogen Gonads Development Emotion Oxytocin Pituitary Hypothalamus Mother-child attachment 32. Oxytocin Induces labour contractions and lactation Released with touches and hugs Bond between mother & child, and lovers Called the love hormone Affects fear regulation in brain; increases trust and generosity 33. Melatonin Researchers study melatonin in hopes of helping insomnia and jet lag Production of melatonin is stimulated by darkness and inhibited by light Levels peak in the middle of the night Earlier onset of darkness in winter makes us feel tired earlier Melatonin pills may help with falling asleep 34. Seasonal Affective Disorder (SAD) Rosenthal (1987) Subcategory of depression with sleepiness and lethargy Winter darkness disrupts circadian rhythm in people (biological clock) which leads to depression Exposure to sunlight and bright light may improve symptoms