PSY460 Biological Bases of Behavior

1
PSY460 Biological Bases of Behavior

• Introduction to the Class
• Chapter 1 The Major Issues
• Mind-Brain Relations
• Nature Nurture

2
Slide 2 The Syllabus

• Class Labs- where and when
• Reaching me office hours
• Resources
• The web page resources
• Textbook Annual Editions
• Laboratory Assignments
• Nature of lab assignments
• Late Assignments
• Grade Scale- a point system
• Participation
• Class/Lab Participation
• Research Participation

3
Slide 3 Intro to Biological Psychology

• Phineas Gage- Film
• 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).
• Names of Scientists of the field
• Physiological psychologist
• Biopsychologist
• Behavioral Neuroscientist
• Neurologists

4
Slide 4 Explaining Behavior and Experience

• What is the job of psychology? Explain/Understand
  Behavior and Experience
• 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

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 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

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 Monism
• Mental Monism
• 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 goMonkeys, rats, roach,
  amoebas???

7
Slide 7 Summary

• 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
• What to expect-
• mechanistic explanations
• evolutionary (rather that cultural) explanation
• references to animal research
• the 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 gene
• identical pair of genes on each chromosome pair
• Chromosome is Heterozygous for a gene
• unmatched pair of genes of each chromosome pair

9
Slide 9 Language of Genetics (cont.)

• Dominant Genes (A)- genes that show a strong
  effect in either the homozygous and heterozygous
  condition
• Recessive 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
  PTC
• Dominant Gene- (T) can taste in moderate
  concentrations
• Recessive 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 sensitive
• SCENARIOS
• Parents- Aa and Aa
• Parents- AA and aa
• Parents- aA and AA
• 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?

11
Slide 11 Gene Expressionif the conditions are
right!

• Simple results of a dominant/recessive gene
  combinations
• Eye 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 ones 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 default
• XX 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 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
• 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

13
Slide 13 Sources of Variation

• Why arent 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

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 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.
• 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?

15
Slide 15 Genes affecting Behavior

• They have a Gene for. (depression in text)
• KEY POINT Genes dont 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)
• Even more indirect routes
• limitations of physiology due to genetic building
• Dr. 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 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.

17
Slide 17 Misunderstandings of Evolution

• EvolutionImprovement?
• Maybe, maybe not dependent on environment of the
  time (e.g., peacock..)
• Have human stopped evolving?
• No. As long as we reproduce we evolve
• Lack or excess use lead to change in that use
  area? (Lamarkian Evolution, giraffe, liltoe)
• Not one that will be passed down to children
• 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.

18
Slide 18 Sociobiological Example Evolutionary
Explanations of Altruism

• 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
• Altruistic Behavior
• animal behaviors
• human behavior
• Class Discussion of the evolutionary and
  functional explanations for Altruism
• (exercise?? See Stop Check on pg. 16)
• Common Explanations Rebuttals
• reciprocal altruism
• kin 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).
20
Slide 20