Pleasure, Addiction, Technology Environment, Cognition, Mozart, Mirror Neurons, Hormones Animal studies, EEG, PET, fMRI

Role of the Nucleus Accumbens Robert Heath ▫Stimulated specific parts of the brain of depressed people ▫Some participants had to be forcible removed from the equipment James Olds ▫Used rats ▫Stimulated their pleasure centers when they pushed a lever ▫Found that they would cross electrified grids to push the lever ▫Preferred the stimulation to eating and drinking

Serotonin and Dopamine Electrical stimulation of the nucleus accumbens produces dopamine It promotes desire Electrical stimulation also produces serotonin Promotes satiety and inhibition

Addiction In animal studies ▫All drugs increase the production of dopamine and reduce the production of serotonin In humans both neurotransmitters play a central role in the feelings produced by ▫Cocaine ▫Nicotine Drugs increase dopamine levels which need to be maintained ▫Need more drug even when they know it is not good

Use of Technology in Brain Research Animal studies ▫invasive techniques ▫Scarring, removing parts of brain (ablation) Ethics ▫Animals are damaged and eventually die so that their brains can be studied ▫Should we continue to use animals for research?

Modern Technology EEG ▫Electroencephalogram ▫Brain waves ▫Patterns of the voltage change in the brain tissue ▫Sleep, emotions, and epilepsy have been studied using EEG’s PET ▫ positron emission topography ▫Monitors glucose metabolism ▫Use radioactive glucose ▫Tumors ▫Alzheimers ▫Schizoprenia ▫Can record ongoing processes like thinking

Modern Technology fMRI ▫funcional magnetic resonance imaging ▫Three dimensional pictures ▫Brain activity shows which areas are active and which are not Limitations ▫Not a natural environment ▫? Ecologically valid ▫Brain areas activate for various reasons- so it might be unrelated to the response being observed

Environments Affect The brain determines and changes behaviour Behaviour and environment can change the brain Plasticity Pre 1960 ▫brain only influenced by genetics ▫Unchangeable Post 1960 ▫Environmental enrichment can change the brain ▫Cerebral cortex- area of higher thinking ▫Brain is constantly changing as a result of experiences

Brain Plasticity Changes that occur due to learning or experiences Challenges of the environment will increase the size of various parts ▫Musicians have thicker cortex area than non-musicians Dendrite branching Rosenzweig and Bennett (1972) ▫Rat experiment showed that rats in an enriched environment had an increased thickness of cortex compared with rats in a deprived environment ▫The combination of company and toys created the best results

Generalizing to humans Can results from rat studies be generalized to humans? What is the importance of education in the growth of synapses? Human brains are different than rat brains ▫Genetically and environmentally (we don’t live in cages)

Effect of Cognition on Physiology Mediation ▫Davidson (2004) ▫8 monks, 10 volunteers who practices mediation for a week ▫PET scanned while meditating about love and compassion ▫Gamma waves increased ▫Volunteers gamma waves decreased quickly to normal ▫Monks remained high Conclusion ▫Meditation has long term effects ▫Humans adapt to stimulation from internal (thinking) as well as external sources

Mozart Effect Rauscher et al. (1993) ▫Listening to Mozart will temporarily increase spatial reasoning ability ▫Listening to music allows you to solve spatial problems Tompson el al. (2001) ▫The effect is not because of the music but because of arousal because people are doing something they like Majority of Mozart research is done in lab ▫Lacks ecological validity

Mirror Neurons Learning ▫Mirror neurons help us learn and empathize with others ▫Copying behavior/movement Limbic system also involved ▫Pleasure and pain- seeing a happy face activated pleasure centers in the brain Found by accident ▫Gallese et al. (1996) ▫Parma Italy ▫when watching a behaviour your brain acts like you are actually doing it

Ramachandran and Mirror Neurons Mirror Neurons play a role in peoples reactions to ▫Sport ▫Theatre ▫Video games When we see a player get crushed we “feel” the contact hit

Hormones and Behaviour Hormones- produced by specialized cells Endocrine system ▫Negative feedback loops ▫Positive feedback loops Released directly into the blood Take longer to change behaviour than neurons ▫Pituitary ▫Parathyroid ▫Thyroid ▫Adrenal glands ▫Pineal body ▫Hypothalamus ▫Thymus ▫Pancreas ▫Ovaries ▫Testes

Hormones Adrenaline: adrenal glands ▫fight or flight Cortisol: adrenal glands ▫Arousal, stress hormone, memory Melatonin: Pineal ▫Regulation of sleep Oxytocin: pituitary and hypothalamus ▫Mother-child attachment Testosterone and estrogen ▫Development, emotion

Oxytocin: the love hormone Induces labour contractions and lactation Released with hugs and touches Social recognition via facial expressions Increases trust and generosity Amygdala ▫Processes emotional stimuli

Melatonin: sleep regulator Insomnia Jet lag Pineal gland is affected by darkness ▫Melatonin levels increase at night and decrease in the morning ▫Suggested that taking melatonin at night will help you sleep Circadian rhythms ▫Biological clock Seasonal Affective Disorder ▫Subcategory of depression ▫Sleepiness, lethargy ▫Crave carbohydrates ▫Triggered by reduced levels of sunlight closer to the poles ▫Phototherapy works well

With reference to one empirical study (Rosenzweig and Bennett) explain how environmental factors can affect one physiological process. Note: command term “explain” requires detailed account with reasons and/or causes