Transcript 6-Slides
Nature vs. Nurture-6 What makes us human? Nurturist position: Beyond Human Nature by Jesse J. Prinz -- Norton Fall 2016 D.D. Reeder 1 Experience (Life) Life = Interaction with the environment Homeostasis (equilibrium) might be termed our “comfort zone” If we are perturbed from our comfort, we do what is necessary to try to restore homeostasis. All our genes, all our cells, all our behaviors are regulated to restore homeostasis. Interactions which perturb us from comfort can be termed STRESS A common and general form of stress is physical harm (threat or actual) Behavioral response– “flight or fight” Fall 2016 2 Stress Stress perturbs the equilibrium Equilibrium is restored by the autonomous nervous system QUICK - Stimulates the sympathetic nervous system – e.g. “flight or fight” blood pressure rises breathing becomes more rapid digestive system slows down heart rate (pulse) rises Immune system goes down muscles become tense no sleep (heightened state of alertness) temperature is regulated Parasympathetic nervous system returns the organism to Homeostasis Fall 2016 3 Stress Response Brain adrenal glands Hypothalamus (releases neurotransmitters) (releases CRH) adrenal glands (release steroid – cortisol) Cortisol increase available energy suppress immune system Glucocorticoids (GR) Cortisol binds to a GR (receptor) Fall 2016 D.D. Reeder 4 Apes Physical closest living relatives of human Chimpanzee 3-4% difference in DNA ~1-2% difference in genes Bonobo Similar Behavioral e.g. Chimps -- male dominated Bonobos – female dominated In the ‘50’s and ‘60’s Harlow (at UW) studied rhesus monkeys • maternal neglect and/or abuse • induced fearful responses (stress) • led to abnormal or bad behavior as adults Fall 2016 D.D. Reeder 5 Rats Meaney et al. at McGill U Quantified maternal behavior as licking and grooming (LG) Variations; Hi LG mothers --- Low LG mothers Observation: pups (Low LG moms) Poor tolerance mild stress Was it inherited or the result of rearing? Cross fostered not genetic (rearing important) Female rates became Hi LG moms when fostered by a Hi LG mom even if biological (DNA) mom was Low LG. Connect to GR levels in the brain cells (methylation in DNA) Fall 2016 D.D. Reeder 6 Apes reprise Following Harlow better designed experiments examined epigenetic effects of maternal neglect • Increased methylation levels in many places in brain and in many cells (neurons and immune system) Other patterns were observed caused by change in social status • Gene expression patterns were elastic • Rank causes different patterns Fall 2016 D.D. Reeder 7 Neuropsychological Stress (short term and long term) (physical or mental) Inter-related, complex, Fetal Development Maternal drug use Zika virus (microcephaly) Maternal Diet Alcohol Tobacco Narcotics Infant Development Diet - breast feeding Parental abuse War, terrorism (PTSD) Sexual Physical Emotional neglect Later Development Divorce/parental conflict War, terrorism (PTSD) Parental abuse Behavior Reading, dyslexia ADD Correlation or Causation (or a complex mixture) Fall 2016 8