Presentation on theme: "PSY460 Biological Bases of Behavior"— Presentation transcript:
1 PSY460 Biological Bases of Behavior Introduction to the ClassChapter 1: The Major IssuesMind-Brain RelationsNature & Nurture
2 Slide 2: The Syllabus Class & Labs- where and when Reaching me & office hoursResourcesThe web page & resourcesTextbook & Annual EditionsLaboratory AssignmentsNature of lab assignmentsLate AssignmentsGrade Scale- a point systemParticipationClass/Lab ParticipationResearch Participation
3 Slide 3: Intro to Biological Psychology Phineas Gage- FilmBiological 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).Names of Scientists of the fieldPhysiological psychologistBiopsychologistBehavioral NeuroscientistNeurologists
4 Slide 4: Explaining Behavior and Experience What is the job of psychology? Explain/Understand Behavior and ExperienceBiopsychology (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
5 Slide 5: Consequences of Biopsychological Perspective A conscious understanding of “reasons” for behavior are not necessary to explain behavior!We act because of nervous system wiringWe act because of genetic make-upcould 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 threatWe act because it has served us in the past to survive and reproduce.Jealousy, greed, helping, altruism, aggression
6 Slide 6: The Brain & Conscious Experience Biological Psychology- An ambitious field….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 MonismMental MonismMETHODOLOGICAL 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 analogybut how far can you go…Monkeys, rats, roach, amoebas???
7 Slide 7: SummaryOur experiences and behaviors certainly exist. Biopsychologist attempt to explain these most frequently in terms of physiological and genetic processes.“The physiology of human experienceconsciousnessWhat to expect-mechanistic explanationsevolutionary (rather that cultural) explanationreferences to animal researchthe grounds of much of our experience (“body”)
8 Slide 8: The Language of Genetics “We should not be amazed that almost every human behavior has some heritability (effected by genetic influence)” But how much is nature vs. nuture????Gene- a physiological unit of heredity that maintains its structural identity from one generation to another. (come in pairs) ---Examples?Chromosomes- strands of genes (23 pairs)Chromosome is Homozygous for a geneidentical pair of genes on each chromosome pairChromosome is Heterozygous for a geneunmatched pair of genes of each chromosome pair“Ultimately he ability of any biological organism to do anything at all…. depends on the genes.”- from previous Kalat text
9 Slide 9: Language of Genetics (cont.) Dominant Genes (A)- genes that show a strong effect in either the homozygous and heterozygous conditionRecessive Genes (a)- genes that show its effect only in homozygous conditions.Homozygous pairings= AA (dominant trait expressed)or aa (recessive trait expressed)Heterozygous pairings= Aa or aA (dominant expressed)Common Example of and inherited trait: Taste and PTCDominant Gene- (T) can taste in moderate concentrationsRecessive Gene- (t) can taste only in high concentrations(overhead 1)
10 Slide 10: Passing on Traits Quick & Dirty Exercise-gene for “ticklishness” (somatic sensitivity)“A” (dominant)- highly sensitive to tickling“a” (recessive)- modestly sensitiveSCENARIOS:Parents- Aa and AaParents- AA and aaParents- aA and AAWhat 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?
11 Slide 11: Gene Expression…if the conditions are right! Simple results of a dominant/recessive gene combinationsEye color, Hair color, toes and finger size etc etc….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.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 defaultXX = female XY= male (fem. genes expressed)
12 Slide 12: Sex Linked & Sex Limited Genes Red-Green Color Blindness- a condition that results from combination on the sex chromosomestext 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 blindSex-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
13 Slide 13: Sources of Variation Why aren’t we clones of one another?Recombination - receiving new combinations of genes from our parents..They might be Aa and AaWe might be AA or aa or AaMutation- 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
14 Slide 14: Measuring the Contribution of Genes Heritability- estimate of variance (effect) due to heredity.Scale- 0 to 1.e.g., .15 = low .85 = high heritabilityPKU = 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.Measuring Heritability (of Depression, for example)Identical Twin Studies-compare identical twin to fraternal twinsAdoption Studiesare children more like adopted or biological parents?
15 Slide 15: Genes affecting Behavior “They have a Gene for….” (depression in text)KEY POINT: Genes don’t directly affect behaviorgenes 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)Even more indirect routeslimitations of physiology due to genetic buildingDr. Craig = Michael Jordan? Ever? Nope!
16 Slide 16: Evolution of Behavior Evolution- the changes over many generations of the frequencies of various genes in a population.How did we evolve (from where?)evolutionary tree98% shared genes with chimpanzeeHow do species evolve (process of change)natural (vs. artificial) selectionCharacteristics that lend themselves to survival assist an individual in surviving to reproductive age, therefore these “survival” genes are passed on to the next generationProcess- mutations and recombination make animal more or less able to reproduce.
17 Slide 17: Misunderstandings of Evolution Evolution=Improvement?Maybe, maybe not… dependent on environment of the time… (e.g., peacock..)Have human stopped evolving?No. As long as we reproduce we evolveLack or excess use lead to change in that use area? (Lamarkian Evolution,… giraffe, lil’toe)Not one that will be passed down to childrenDoes 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.
18 Slide 18: Sociobiological Example: Evolutionary Explanations of Altruism Sociobiology- the study of the evolution of social behaviorFunctional explanationsCriticisms of the fieldFunctional explanations are often speculativeSociobiological explanations sometimes imply that human behavior has evolved to be as it is, and therefore it should stay thatAltruistic Behavioranimal behaviorshuman behaviorClass Discussion of the evolutionary and functional explanations for “Altruism”(exercise?? See “Stop & Check” on pg. 16)Common Explanations & Rebuttalsreciprocal altruismkin selection
19 Figure: Genetic combinations/outcomes [BACK]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).