Lecture 2 Chapter 2: Current Paradigms in PsychopathologyI. The Genetic ParadigmII. The Neuroscience ParadigmIII. The Cognitive Behavioral ParadigmIV. Factors That Cut Across the ParadigmsV. Diathesis-Stress: An Integrative Paradigm Notion of a Paradigm: Goal: Study abnormal behavior scientifically Science aims for objectivity Paradigm (Thomas Kuhn)• Perspective or conceptual framework from within which a scientist operatesWe can never be totally objective; subjective factors interfere No one paradigm sufficient to completely explain psychopathology Current Paradigms: Genetic Heredity plays a role in most behavior Genes • Carriers of genetic information (DNA)• Impacted by environmental influencese.g., stress, relationships, culture Relationship between genes and environment is bidirectional• Nature via nurture Important Genetic Terms: Gene expression• Proteins influence whether the action of a specific gene will occur  Polygenic transmission• Inheritance due to multiple gene pairs vs. single gene  Heritability• Extent to which variability in behavior is due to genetic factorsHeritability estimate ranges from 0.00 to 1.00Polygenetic inheritance: Psych 380 1st Edition Multiple alleles (more than two options) Genes spread over different locations or chromosomes Many different combinations and mixes Examples: Hair color Eye color Skin color Degrees of extremes (dark to light)Behavior Genetics: Study of the degree to which genes and environmental factors influence behavior Genotype• Genetic material inherited by an individual• Unobservable Phenotype• Expressed genetic material • Observable behavior and characteristics• Depends on interaction of genotype and environmentEpigenetics: Genes are not absolute determinants Study of how the environment can alter gene expression or function Cross-fostering adoptee method Rats from mothers with low parenting skills raised by mothers with high parenting skills showed lower levels of stress reactivity  Environment (mothering) was responsible for turning on (or turning up) the expression of a particular gene for stress resilienceCurrent Paradigms: Neuroscience Examines the contribution of brain structure and function to psychopathology• ASSUMPTION: Mental disorders are linked to aberrant processes in the brain. Three major components:• Neurons and neurotransmitters• Brain structure and function• Neuroendocrine systemThe Neuron: Basic Unit of the Nervous SystemNeurons Cells of the nervous system Four major parts Cell body Dendrites Axons Terminal buttonsNerve Impulse Dendrites or cell body stimulated Travels downs axon to terminalSynapse Gap between neuronsNeurotransmitters:Neurotransmitter Chemicals that allow neurons to send a signal across the synapse to another neuron Receptor sites on postsynaptic neuron absorb neurotransmitter Excitatory Inhibitory Reuptake Reabsorption of leftover neurotransmitter by presynaptic