Chapter One The Major Issues

1
Chapter OneThe Major Issues
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
1 of 26
2
Biological Psychology
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
2 of 26

• Study of the physiological, evolutionary, and
  developmental mechanisms of behavior and
  experience
• emphasis on the study of areas and sub-areas of
  the brain
• brain areas function depends on communication
  among neurons, the building blocks of behavior
• neuron activity somehow produces behavior and
  experience

3
Figure 1.1
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
3 of 26

• Figure 1.1  A dorsal view (from above) and a
  ventral view (from below) of the human brain. The
  brain has an enormous number of divisions and
  subareas the labels point to a few of the main
  ones that are visible from outside.

4
Biological Explanations of Behavior
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
4 of 26

• Physiological relates a behavior to the activity
  of the brain and other organs (area of brain
  enables bird to sing)
• Ontogenetic describes the development of the
  structure or behavior (why genes and environment
  both necessary for bird to sing)
• Evolutionary examines a structure or a behavior
  in terms of evolutionary history (two different
  species of birds with similar songs have same
  ancestor)
• Functional describes why a structure or behavior
  evolved as it did (singing improves birds
  chances of mating)

5
Mind-Body Problem
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
5 of 26

• Dualism mind and body are different kinds of
  substances, that exist independently but somehow
  interact
• René Descartes proposed that mind and brain
  interact in the pineal gland
• Monism there is only one kind of existence
• materialism everything is material or physical
• mentalism only the mind exists
• identity mental processes are the same thing as
  certain kinds of brain processes, but described
  in different terms (e.g., fear is the same as the
  accompanying pattern of neural activity in the
  brain)

6
Mind-Body Problem cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
6 of 26

• What is consciousness and how is it produced?
• Hard problem the question of why and how any
  kind of brain activity is associated with
  consciousness
• Chalmers (1995) consciousness is a fundamental
  property of matter and cannot be reduced further
• Easy problems determining the difference between
  wakefulness and sleep, or identifying brain
  mechanisms that enable us to focus our attention
• Dennet (1991, 1996) When we answer all of the
  easy problems, the hard problem will go away

7
Mind-Body Problem cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
7 of 26

• Research may not solve problem soon because
  consciousness is not directly observable
• I know that I am conscious but I can only infer
  that you have conscious experience
• solipsism the belief that only I exist
• Where and when does consciousness occur?
• do all animals have conscious experiences?
  plants? rocks?
• when does the human embryo experience
  consciousness?
• could we build a robot that experiences
  consciousness?

8
Genetics of Behavior
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
8 of 26

• Mendel (19th century) inheritance occurs through
  genes
• chromosomes are strands of genes, normally in
  pairs
• genes are units of heredity that maintain their
  structural identity across generations
• a genotype is an expression of a gene pair (e.g.,
  BB, Bb, or bb)
• Deoxyribonucleic acid (DNA)
• when DNA exists as a double strand in a helix, it
  makes up a chromosome
• when DNA exists in a single strand, it serves as
  a template for the synthesis of RNA

9
Figure 1.6
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
9 of 26

• Figure 1.6  How DNA controls the development of
  an organism. The sequence of bases along a strand
  of DNA determines the order of bases along a
  strand of RNA RNA in turn controls the sequence
  of amino acids in a protein molecule.

10
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
10 of 26

• Genotype expression (Bbrown eyes bblue eyes)
• homozygous having an identical pair of genes on
  two chromosomes (BB or bb)
• heterozygous having an unmatched pair of genes
  on two chromosomes (Bb)
• dominant gene expressed in either the homozygous
  or heterozygous condition (Bb or BB will be
  expressed as brown eyes)
• recessive gene only expressed in the homozygous
  condition (bb is the only condition where blue
  eyes will be expressed)

11
Figure 1.7
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
11 of 26

• Figure 1.7  Four possible 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).

12
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
12 of 26

• When genes are close together on the same
  chromosome they are usually inherited together,
  e.g., BC or bc
• crossing over occurs during reproduction when a
  pair of chromosomes exchange parts with each
  other, e.g., BC and bc become Bc and bC
• Sex-linked genes on X and Y chromosomes
• male (XY) has only one X chromosome and will
  always express X-linked recessive genes (8 have
  red-green color blindness)
• female (XX) will express a recessive gene only if
  it occurs on both of her X chromosomes (1 have
  color blindness)

13
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
13 of 26

• Sex-limited genes
• present in both sexes but effect is limited or
  almost limited to one sex (chest hair, breast
  size)
• genes expressed only after activation by sex
  hormones
• Sources of variation
• recombination some genes from two parents
  combine to yield characteristics not found in
  either parent
• mutation a random change in a single gene
• crossing over creates unique characteristics not
  found in either parent

14
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
14 of 26

• Heritability
• an estimate of how much of the variance in a
  population characteristic is due to heredity
  (ranges from 0 to 1)
• if 0, heredity accounts for none of the observed
  variations in that characteristic (e.g., in a
  population with similar genes, most differences
  are due to environment)
• if 1, heredity accounts for all of the variations
  in that characteristic (e.g., in identical
  environments most differences are due to genes)
• if 0.5, both components contribute

15
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
15 of 26

• How heritability is determined
• compare similarities in monozygotic twins versus
  dizygotic twins
• compare adopted children with their biological
  and adoptive parents
• findings support high heritability in many areas
  but we may underestimate the effect of
  environment and interaction between geneotype and
  environment

16
Genetics of Behavior cont.
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
16 of 26

• Can heritability be modified?
• PKU, caused by genetic inability to metabolize
  phenylalanine, can be minimized with proper diet

17
Figure 1.8
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
17 of 26

• Figure 1.8  Prenatal development of monozygotic
  and dizygotic twins. In most cases, monozygotic
  (identical) twins develop in a single placenta
  and have the same blood supply. Dizygotic
  (fraternal) twins develop in separate placentas.
  Therefore, monozygotic twins have the sane
  prenatal environment as well as the same genetic
  inheritance, and dizygotic twins differ in both
  respects.

18
Evolution of Behavior
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
18 of 26

• Change over generations in the frequencies of
  various genes in a population
• Change occurs through mutations, recombinations
  and any new genes that are successfully
  reproduced
• Artificial selection limits reproduction to
  animals that possess a desired trait, ensuring
  its survival

19
Misunderstandings about Evolution
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
19 of 26

• Lamarckian evolution is mistaken belief that we
  acquire characteristics through use and lose them
  through disuse.
• If survival of fittest no longer applies, has
  evolution stopped?
• no, reproduction, not survival is key
• Does evolution mean improvement?
• maybe your genes got you here but they may not
  be advantageous tomorrow
• Does evolution act to benefit the individual or
  the species?
• neither it acts to spread the genes

20
Sociobiology/Evolutionary Psychology
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
20 of 26

• Seeks functional explanations for why a behavior
  is useful and is favored by natural selection
• why some animals have better color or peripheral
  vision
• why we cycle through stages of sleep
• why mammals and birds use most of their energy to
  stay warm
• why different species have different eating
  habits
• why people die at different rates
• why more men than women enjoy casual sex with
  multiple partners

21
Sociobiology/Evolutionary Psychology cont
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
21 of 26

• How does sociobiology explain altruistic
  behavior?
• a gene that encourages altruism would help others
  survive to reproduce
• humans exhibit altruism but uncommon in
  non-humans
• reciprocal altruism and kin selection may help
  spread gene
• Sociobiology can be criticized when practitioners
  assume that a behavior is adaptive and then
  propose an explanation without testing it

22
Reasons for Animal Research
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
22 of 26

• Underlying mechanisms of behavior are similar
  across species and sometimes a nonhuman species
  is easier to study
• We are interested in animals for their own sake
• Learning about animals sheds light on human
  evolution
• Legal or ethical restrictions prevent the use of
  human participants in certain experiments

23
Figure 1.12
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
23 of 26

• Figure 1.12  Brains of several species. The
  general plan and organization of the brain are
  similar for all mammals, even though brain size
  varies from species to species.

24
The Ethical Debate on Animal Research
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
24 of 26

• Some experiments subject animals to brain damage,
  electrode implantation, injections for drugs or
  hormones
• Minimalists agree that some animal research is
  acceptable, but wish to minimize it
• Abolitionists want all research on animals to
  stop
• Principles of moderation and compromise are now
  the legal standard in the US

25
Careers in Biological Psychology for
Psychologists (PhDs)
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
25 of 26

• Behavioral neuroscientist investigates how
  functioning of the brain and other organisms
  affect behavior
• Neuroscientist studies anatomy, biochemistry,
  and physiology of the nervous system
• Neuropsychologist conducts behavioral tests to
  determine what brain damaged people can and
  cannot do
• Psychophysiologist measures heart rate,
  breathing rate brain waves, and other body
  processes that change as a function of peoples
  activities and information processing

26
Careers in Biological Psychology for Physicians
(MDs)
James W. Kalat
Biological Psychology, 8th Edition
Chapter 1 The Major Issues
26 of 26

• Neurologist treats people with brain damage or
  diseases of the brain
• Neurosurgeon performs brain surgery
• Psychiatrist helps people with emotional
  distress or troublesome behaviors, sometimes
  using drugs or other medical procedures