Gottfried Leibniz  “Why is there something rather than nothing”

 Mind-body problem (mind-brain problem)

  • If universe is composed of matter and energy, how is there consciousness? How did brain activity become conscious? What is the relationship between mental experience and brain activity?
  • Consciousness as fundamental property: can’t be reduced to something else

 Biological psychology

  • study of physiological, evolutionary and developmental mechanisms of behaviour and experience; relate biology to psychology. Think/act as we do because brain mechanisms survived and reproduced better than animals with other mechanisms
  • Biological psychology concerns brain functioning; two kinds of cells:
    1. ieurons: convey messages to one another and to muscles/glands
    2. Glia: smaller; functions without message transmission Biological Explanations of Behaviour
  • Explanations refer to intentional goals, don’t always know reasons for their own behaviours
  • Biological explanations of behaviour 4 categories:
    1. Physiological: relates behaviour to brain activity and other organs; deals with machinery of the body
    2. Ontogenic: how a structure of behaviour develops, influence of: genes, nutrition, experiences, interactions
    3. Evolutionary: reconstructs evolutionary history of a structure/behaviour; characteristics of animals are modifications found in ancestral species.
    4. Functional: describes why a structure/behaviour evolved as it did. A gene that is prevalent in a large population provides some advantage; gene can spread through process called genetic drift

GEiETICS AiD BEHAVIOUR  Mendellian Genetics

  • Before 19th C, scientists thought inheritance occurred by a blending of the sperm and egg
  • Gregor Mendel: inheritance occurs through genes (units of heredity, maintain structural identity from one generation to another)
  • Genes come in pairs because aligned along chromosomes (strands of genes). Gene is part of chromosome, composed of Some genes overlap between chromosomes, other outcome depends on 2+ genes.
  • DNA serves as template for RiA, single stranded molecule, that codes for protein
  • DNA contains 4 bases – A, G, C, T; order of bases determines order of bases along an RNA molecule, which determines amino acids that compose a protein.
  • Proteins consist of 20 amino acids.
  • Some proteins part of body structures, others enzymes (biological catalyzes that regulates chemical rxns in body)
  • Homozygous: identical pair of genes on 2 chromosomes
  • Heterozygous: unmatched pair of genes
  • Dominant: strong effect in a homozygous or heterozygous

 Recessive: effects only in homozygous conditions Sex-Linked and Sex-Limited Genes  Sex-linked genes

  • Present in both sexes, genes on sex chromosomes (X and Y), all other chromosomes are autosomal chromosomes
  • Females (two X chromosomes); Males (X and Y chromosome)

 Sex-limited genes

  • Present in both sexes, generally on autosomal chromosomes, but active mainly in one sex (sex hormones activate in one sex or other) Genetic Changes
  • Genes change in several ways
  • Mutation: heritable change in a DNA molecule. Evolution selected best makeup of every gene, new mutation is rarely advantageous
  • Duplication/deletion: part of a chromosome that should appear once, appears twice or not at all o When this happens to just a tiny portion of a chromosome, it’s called microduplication or microdeletion

 Can be a possible explanation of schizophrenia

  • Epigenetics: changes in gene expression without modification of DNA sequence; certain genes active in certain types of cells, or only at a particular time of life
  • Various experiences can also turn a gene on or off
  • Changes in gene expression are also central to learning and memory and to brain changes resulting from drug addiction
  • Epigenetics is new, growing field that will play increasingly important role in our understanding of behavior
  • An experience can modify gene expression; proteins called histones bind DNA into a shape that’s like a string around a ball; the loose ends allow chemical groups to attach. To activate a gene, the DNA must partially unwind from the histones.
  • Result of experience  new proteins into cells/alter chemical environment
  • Removal of acetyl group causes histone to tighten grip on DNA  turns gene off
  • Adding methyl group to promotes  turns genes off; removing them  turns gene on

 Heredity and Environment

  • To determine contributions of heredity and environment, rely on:
  • Monozygotic: from one egg (identical twins)  same gene
  • Dizygotic: from two eggs (twins)  not same gene
  • Adopted children: if children resemble their biological parents, there is high heritability. If children are similar to adopted parents, any similarity is due to environmental influences.
  • Virtual twins: children of the same age, adopted at the same time into a single family; grow up in same environment from infancy, but without any genetic similarity

 Genes linked to a behaviour

  • Evidence for heritability for almost every behaviour; estimate of heritability for a trait is specific to the population

Environmental Modification: a trait with high heritability can be modified by environmental interventions; the effect of a gene depends on the person’s environment

  • How genes affect behaviour: hard to explain how gene increases probability for given behaviour; some directly control brain chemicals, others have indirect affect.

 The Evolution of Behaviour

  • Evolution: change over generations in the frequencies of various genes in a population
  • Any change in gene frequencies
  • Do species evolve? Offspring resemble parents; recombination’s, microduplications, and mutations introduce new heritable variations that help or harm chance of survival; certain individuals reproduce more successfully then others, so the new generations will more closely resemble them.
  • Artificial selection: choose individuals with desired trait, make them parents to the next generation.
  • Charles Darwin  nature also selects

Common misunderstandings about evolution

  • Failing to use some body structure doesn’t change the genes
  • Lamarckian Evolution: inheritance of acquired characteristics; evidence not found for theory
  • Evolution depends on reproduction, not just survival
  • Evolution doesn’t mean improvement; fitness means number of genes that survive to the next generation – this can be positive and one point, but negative in the future
  • Genes of current generation evolved because they were fit for previous generations
  • Evolution doesn’t benefit the individual, it benefits the genes

Evolutionary Psychology

  • How behaviours evolved
  • Presumed genes of ancestors and why natural selection might favour genes that promote certain behaviours
  • Assume any behaviour arose through natural selection and provided some advantage.
  • BUT some characteristics of species have less relationship to natural selection
  • Altruistic behaviour: action that benefits someone else; help other individuals spread genes
  • Common among humans, less in animal world; may cost little, but still has cost & altruistic behaviour may benefit species, but not gene in the individual.
  • Group selection: altruistic groups survive better  but this is unstable
  • Kin selection: select for a gene that benefits the individual’s relatives  Helpful behaviour is more common towards relatives
  • Reciprocal altruism: individuals help those that will return the favour

THE USE OF AiIMALS Ii RESEARCH

  • Debate about the use of animals in research
  • Research on animals is responsible for a lot of knowledge on brain and behaviour but we want to minimize animal distress Reasons for Animal Research  Study non-humans:
    1. Underlying mechanisms of behaviour similar across species, easier to study o Brains and behavior of nonhuman vertebrates resemble those of humans in chemistry and anatomy
    2. Interested in animals for own sakeo Wider variety of species, relating behaviors of each animal
    3. What is learnt about animals sheds light on human evolution o Comparing species
    4. Legal or ethical restrictions prevent certain types of research on humanso If research unacceptable with humans, is it also unacceptable with other species? The Ethical Debate
  • In some cases, researchers just observe animals. in others, animals are subject to brain damage, injections that aren’t for their own benefit
  • In many areas, there wouldn’t be as much advancement without animal research

Degrees of Opposition  “Minimalists”

  • Tolerate some animal research but not others, depends on value of research, amount of distress to animal, type of animal
  • Favour firm research regulations

 

Legal Standard Emphasizes:

  1. Reduce animal numbers
  2. Replace animals with substitutes (using computers)
  3. Modify procedures to reduce pain/discomfort

 Every institution that performs animal research must have committee to evaluate proposed experiments, suggests changes, ensure there are standards of cleanliness and animal care

 “Abolitionists”

  • Animals have same rights as humans; killing is murder, animals in cages are slaves. humans have no rights to use animals for research, even if useful

Because animals can’t give informed consent, abolitionists insist it’s wrong to use them regardless of circumstances