Chapter 1 Introduction to Biopsychology How Biopsychologists Think about Behavior This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or in part, of any images; any rental, lease, or lending of the program. Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Chapter 1 Overview What is Biopsychology? Human Evolution Fundamental Genetics Thinking about the Biology of Behavior: Mind-Brain and Nature-Nurture Issues Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Consider this.. Does the brain have the capacity to understand something as complex as itself? Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Four Major Themes Thinking Clearly about Biopsychology Connecting the text to real life Clinical Implications The Evolutionary Perspective The comparative approach – what can we learn from other species? Cognitive Neuroscience Connecting brain activity and cognition Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon What is Biopsychology? “the scientific study of the biology of behavior” Also known as behavioral neuroscience, behavioral biology, psychobiology Psychology: the scientific study of behavior Hebb (1949) proposed that psychological phenomena might be produced by brain activity Copyright © 2007 by Allyn and Bacon

Biopsychology is an integrative discipline Knowledge from other disciplines of neuroscience is applied to the study of behavior Each discipline studies a different aspect of the nervous system that informs our understanding of what produces and controls behavior Copyright © 2007 by Allyn and Bacon

Other Disciplines of Neuroscience Neuroanatomy Structure of the nervous system Neurochemistry Chemical bases of neural activity Neuroendocrinology Interactions between the nervous system and the endocrine system Copyright © 2007 by Allyn and Bacon

Other Disciplines of Neuroscience Neuropathology Nervous system disorders Neuropharmacology Effects of drugs on neural activity Neurophysiology Functions and activities of the nervous system Copyright © 2007 by Allyn and Bacon

Behavior is the Product of Interactions Among: Genes (“genetic endowment”, nature) Experience (nurture) Perception of the current situation The brain – where these 3 factors interact Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Human Evolution While Darwin was not the 1st to propose that species evolve, he was the 1st to compile supporting evidence and to suggest how evolution works Darwin presented 3 kinds of evidence The most convincing evidence comes from direct observation of evolution in progress Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Human Evolution Darwin’s evidence Fossil evidence of evolution Noted structural similarities among living species, suggesting common ancestors Impact of selective breeding Copyright © 2007 by Allyn and Bacon

Evolution and Behavior Just as physical features can contribute to “fitness”, so do behaviors The ability to find food, avoid predation, etc. Social dominance and courtship displays Copyright © 2007 by Allyn and Bacon

Thinking about Human Evolution Evolution does not proceed in a single line Humans have only been around for a brief period of time Rapid evolutionary changes do occur < 1% of all known species are still in existence Copyright © 2007 by Allyn and Bacon

Evolution of the Human Brain There is no relationship between brain size and intelligence Brain size is generally correlated with body size More informative to look at relative size of different brain regions Copyright © 2007 by Allyn and Bacon

Evolution of the Human Brain Brain stem regulates reflex activities that are critical for survival Cerebrum is involved in complex adaptive processes such as learning, perception, and motivation Copyright © 2007 by Allyn and Bacon

Evolution of the Human Brain The human brain has increased in size during evolution Most of the increase in size has occurred in one region - the cerebrum Increased convolutions in the cerebrum have increased the volume of the cerebral cortex Copyright © 2007 by Allyn and Bacon

Evolution of the Human Brain Copyright © 2007 by Allyn and Bacon

Biopsychological Research Involves Both Human and Nonhuman Subjects Why would we look at rats, mice, and nonhuman primates to further our understanding of the human brain? How different are you and a rat? Copyright © 2007 by Allyn and Bacon

Why use nonhuman subjects? While some questions about behavior can only be addressed using human subjects, much can be learned from studying the brains of other species Differences are more quantitative (relating to size) than qualitative (relating to function) Copyright © 2007 by Allyn and Bacon

Why use nonhuman subjects? Simpler brains makes it more likely that brain-behavior interactions will be revealed Comparative approach – gain insight by making comparisons with other species Fewer ethical restrictions Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Fundamental Genetics Dichotomous traits – occur in one form or another, not normally in combination True-breeding lines – interbred members always produce offspring with the same traits Mendel studied dichotomous traits in true-breeding lines of pea plants Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Mendel’s Experiments Crossed a line bred true for brown seeds with one bred true for white First generation offspring all had brown seeds When the first generation were bred, the result was ¾ brown and ¼ white seeds Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Mendel’s Experiments True-breeding lines White (ww) Brown (BB) Brown was the dominant trait, appearing in all of the 1st generation offspring (Bw) Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Mendel’s Experiments Phenotype – observable traits Genotype – traits present in the genes If the dominant trait is present in the genotype (Bw), it will be observed in the phenotype (brown seeds) Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Mendel’s Experiments Each inherited factor is a gene Two genes that control the same trait are called alleles Homozygous – 2 identical alleles (BB, ww) Heterozygous – 2 different alleles (Bw) Copyright © 2007 by Allyn and Bacon

Chromosomes and Reproduction Genes are located on chromosomes in the nucleus of each cell. Humans have 23 pairs of chromosomes, with an allele on each chromosome Meiosis – a process of cell division that yields cells with just 23 chromosomes Copyright © 2007 by Allyn and Bacon

Chromosomes and Reproduction Gametes, eggs and sperm, are produced by meiosis When egg and sperm combine to form a fertilized egg (zygote), 23 pairs of chromosomes are again present Mitosis – a form of cell division that yields daughter cells that have 23 pairs of chromosomes Copyright © 2007 by Allyn and Bacon

Sex Chromosomes and Sex-Linked Traits Sex chromosomes, X and Y, look different and carry different genes Female = XX, Male = XY Sex-linked traits - influenced by genes on the sex chromosomes Dominant traits on the X chromosome will be seen more commonly in females, recessive ones in males Copyright © 2007 by Allyn and Bacon

Sex Chromosomes and Sex-Linked Traits Color-blindness – a recessive sex-linked trait Who is more likely to be color-blind? Males Why? Copyright © 2007 by Allyn and Bacon

Chromosome Structure and Replication Each chromosome is a double-stranded molecule of deoxyribonucleic acid (DNA) Each strand consists of a sequence of nucleotide bases – their sequence constitutes the genetic code Copyright © 2007 by Allyn and Bacon

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Human Genome Project: What’s Next? Why don’t we now have all the answers? How genes interact with one another and experience is still not clear. Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Thinking about the Biology of Behavior: Mind-Brain and Nature-Nurture Issues The mind-brain issue Are the mind and brain one and the same? The nature-nurture issue What makes you how you are – genes or environment? The genetics of individual differences Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon The Mind-Brain Issue Dualism – human brain and mind are separate While we generally accept that mind and brain are really one today, there are some who still believe that some components of the mind are not just products of brain activity Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Consider this.. What evidence is there that mind and brain are one? Copyright © 2007 by Allyn and Bacon

The Nature-Nurture Issue Is it inherited or is it learned? Watson – father of behaviorism – believed that all behavior was the product of learning (nurture) Ethology – the study of animal behavior in the wild – focused on instinctive behaviors, emphasizing nature Copyright © 2007 by Allyn and Bacon

Copyright © 2007 by Allyn and Bacon Consider this.. Is the “nature-nurture” debate alive today? Copyright © 2007 by Allyn and Bacon

The Nature-Nurture Issue Behavior is impacted by factors other than genetics (nature) or learning (nurture) “Nurture” now encompasses learning and environment While it is generally accepted that behavior is a product of nature and nurture, many still ask how much is determined by each But genetic and experiential factors do not merely combine in an additive fashion Copyright © 2007 by Allyn and Bacon

The Heritability of Individual Differences What conclusions can be made, if any about the heritability of individual differences? What would a biological psychologist say about what makes you who and how you are? Copyright © 2007 by Allyn and Bacon