Presentation on theme: "PSY460 Biological Bases of Behavior Introduction to the Class Chapter 1: The Major Issues Mind-Brain Relations Nature & Nurture."— Presentation transcript:
PSY460 Biological Bases of Behavior Introduction to the Class Chapter 1: The Major Issues Mind-Brain Relations Nature & Nurture
Slide 2: The Syllabus X Class & Labs- where and when X Reaching me & office hours X Resources XThe web page & resources XTextbook & Annual Editions XLaboratory Assignments XNature of lab assignments XLate Assignments XGrade Scale- a point system XParticipation XClass/Lab Participation XResearch Participation
Slide 3: Intro to Biological Psychology X Phineas Gage- Film X Biological Psychology- *the study of behavior and experience in terms of genetics, evolution and physiology (esp. nervous physiology… i.e., the brain and autonomic nervous system). X Names of Scientists of the field *Physiological psychologist *Biopsychologist *Behavioral Neuroscientist *Neurologists
Slide 4: Explaining Behavior and Experience X What is the job of psychology? Explain/Understand Behavior and Experience X Biopsychology (4 approaches to explanation) *Physiological explanation- explanations for psychology at the level of the the brain, organ structures and biochemical interactions. *Ontogenetic Explanations- contribution of genes, nutrition and experience on behavior (alcoholism). *Evolutionary Explanation- where (ancestors) the behavior evolved from (e.g., piloerection) *Functional Explanation- how is behavior of a functional value (useful) for survival (reproduction) (e.g., greed). Sociobiology (aka evolutionary psychology) = evolution of social behavior
Slide 5: Consequences of Biopsychological Perspective X A conscious understanding of “reasons” for behavior are not necessary to explain behavior! *We act because of nervous system wiring *We act because of genetic make-up could you ask someone to explain the reasons for their eye-color? *We act because of a distant ancestor did the same “fight/flight” activation to threat *We act because it has served us in the past to survive and reproduce. Jealousy, greed, helping, altruism, aggression
Slide 6: The Brain & Conscious Experience X Biological Psychology- An ambitious field…. X PHILOSOPHIES OF EXISTENCE: *The mind-body problem: what is the relation between mind and the body? *Dualism (2 kinds of existence) *Monism (1 kind of existence) Material Monism Mental Monism X METHODOLOGICAL LEAPS OF FAITH: *The problem of minds- How can we know others really experience what we do? Solipsism- “I alone am conscious/exist” Non-solipsists- can know by reason and analogy –but how far can you go…Monkeys, rats, roach, amoebas???
Slide 7: Summary X Our experiences and behaviors certainly exist. Biopsychologist attempt to explain these most frequently in terms of physiological and genetic processes. *“The physiology of human experience consciousness X What to expect- *mechanistic explanations *evolutionary (rather that cultural) explanation *references to animal research *the grounds of much of our experience (“body”)
Slide 8: The Language of Genetics X “We should not be amazed that almost every human behavior has some heritability (effected by genetic influence)” But how much is nature vs. nuture???? X Gene- a physiological unit of heredity that maintains its structural identity from one generation to another. (come in pairs) --- Examples? X Chromosomes- strands of genes (23 pairs) *Chromosome is Homozygous for a gene identical pair of genes on each chromosome pair *Chromosome is Heterozygous for a gene unmatched pair of genes of each chromosome pair
Slide 9: Language of Genetics (cont.) X Dominant Genes (A)- genes that show a strong effect in either the homozygous and heterozygous condition X Recessive Genes (a)- genes that show its effect only in homozygous conditions. X Homozygous pairings= AA (dominant trait expressed) or aa (recessive trait expressed) X Heterozygous pairings= Aa or aA (dominant expressed) X Common Example of and inherited trait: Taste and PTC *Dominant Gene- (T) can taste in moderate concentrations *Recessive Gene- (t) can taste only in high concentrations »(overhead 1)(overhead 1)
Slide 10: Passing on Traits X Quick & Dirty Exercise-gene for “ticklishness” (somatic sensitivity) *“A” (dominant)- highly sensitive to tickling *“a” (recessive)- modestly sensitive SCENARIOS: *Parents- Aa and Aa *Parents- AA and aa *Parents- aA and AA X What is the chance that their child will be highly sensitive in each case? If there are 4 children in each family, what is the likelihood of a hetero- or homozygous gene pairing?
Slide 11: Gene Expression…if the conditions are right! X Simple results of a dominant/recessive gene combinations *Eye color, Hair color, toes and finger size etc etc…. X More complicated cases involve combinations of other genes & environmental conditions to produce their effect. *Partial Penetrance- genes expressed (penetrate into one’s life) only under certain conditions. Genes and Alcohol risk- expression only apparent in certain environments. X Sex-Linked Genes- genes found exclusively on the male/female chromosomes *“X”- the female chromosome- loaded with genes (Rs & Dom) *“Y”- the male chromosome- virtually w/o genes..X is default *XX = female XY= male (fem. genes expressed)
Slide 12: Sex Linked & Sex Limited Genes X Red-Green Color Blindness- a condition that results from combination on the sex chromosomes *text example (not actual number) if 8% of women had recessive RG gene then 8% of all men but only 1% of women would be color blind X Sex-Limited Gene Expression- expression effects only one sex or it has a much stronger effect on one sex. examples- location of hair growth, breast growth
Slide 13: Sources of Variation X Why aren’t we clones of one another? *Recombination - receiving new combinations of genes from our parents.. –They might be Aa and Aa –We might be AA or aa or Aa *Mutation- a random change in a single gene. A gene for blue eyes-- become one for brown. Usually recessive, therefore rarely harmful because both parents would have to have recessive mutation to have gene expressed. Unless… “inbreeding” occurs. Why??? –Hemophilia (the disease of czars)-- Romanov Family
Slide 14: Measuring the Contribution of Genes X Heritability- estimate of variance (effect) due to heredity. *Scale- 0 to 1. e.g.,.15 = low.85 = high heritability PKU = 1, gene combination inhibits phenylalanine. *Key Point- in the cases of looking at the heritability of behavior, one cannot speak only only of genes or environment. Behaviors are clearly affected by both (while the contributions of each may not be be equal. X Measuring Heritability (of Depression, for example) *Identical Twin Studies- compare identical twin to fraternal twins *Adoption Studies are children more like adopted or biological parents?
Slide 15: Genes affecting Behavior X “They have a Gene for….” (depression in text) X KEY POINT: Genes don’t directly affect behavior genes affect physiological processes by affecting protein production which affect chemical production (for example). Depression (factors which affect serotonin or NE use at the neuronal level) X Even more indirect routes limitations of physiology due to genetic building –Dr. Craig = Michael Jordan? Ever? Nope!
Slide 16: Evolution of Behavior X Evolution - the changes over many generations of the frequencies of various genes in a population. *How did we evolve (from where?) evolutionary tree 98% shared genes with chimpanzee *How do species evolve (process of change) natural (vs. artificial) selection –Characteristics that lend themselves to survival assist an individual in surviving to reproductive age, therefore these “survival” genes are passed on to the next generation Process- mutations and recombination make animal more or less able to reproduce.
Slide 17: Misunderstandings of Evolution X Evolution=Improvement? *Maybe, maybe not… dependent on environment of the time… (e.g., peacock..) X Have human stopped evolving? *No. As long as we reproduce we evolve X Lack or excess use lead to change in that use area? (Lamarkian Evolution,… giraffe, lil’toe) *Not one that will be passed down to children X Does evolution act to benefit individuals/species? *Neither… it is a neutral event in which genes live on, but not you or necessarily the species as you know it.
Slide 18: Sociobiological Example: Evolutionary Explanations of Altruism X Sociobiology- the study of the evolution of social behavior *Functional explanations *Criticisms of the field Functional explanations are often speculative Sociobiological explanations sometimes imply that human behavior has evolved to be as it is, and therefore it should stay that X Altruistic Behavior *animal behaviors *human behavior X Class Discussion of the evolutionary and functional explanations for “Altruism” –(exercise?? See “Stop & Check” on pg. 16) X Common Explanations & Rebuttals *reciprocal altruism *kin selection
Figure 1.7 Four equally likely outcomes of a mating between parents who are heterozygous for a given gene (Tt) A child in this family has a 25% chance of being homozygous for the dominant gene (TT), a 25% chance of being homozygous for the recessive gene (tt), and a 50% chance of being heterozygous (Tt). Figure: Genetic combinations/outcomes [BACK]