PSYCH100H FINAL EXAMIntro-Psych as the study of the human organism-Psych as the study of the human mind-Psych as the study of the human personalityThe Biological Basis of BehaviorHistorical Issues-Descartes = mind-body dualism theory refuted!Pineal body = “the seat of the soul”All other parts of body act in automatic reflexesMvmt of cerebrospinal fluid moved body through hydraulic action-Gall and Spurzheim proposed localization of function in the brainLocalization = accurate, but theory of skull features to deduce personality was refuted-Broca showed left inferior frontal lobe = expression of spoken languageSupports localization theory-Cajal = neuron doctrineElectrophysiological Studies-Muscle contraction & nerve action can be electronically stimulated-Realized nerve conduction was not instantaneous-Alpha rhythm (10Hz) = relaxed waking state, increases when eyes are closed-Beta waves = desynchronized, fast, during intense mental activity, especially when eyes open-Delta waves (2Hz) = mostly during sleepPeriodically become desynchronized during dreams in REM sleepEvolution by Natural Selection-Theory credited to Darwin & Wallace-More individuals are born into a generation than can survive-There is variability in characteristics; some traits more successful than others-Natural selection = “enhanced reproductive success due to heritable phenotypic traits”-Interaction btw genes and environment-Behaviors may be based on inherited genetic traits-Adaptions = genetically based traits (including behaviors) that promote reproductive success-Application of evol theory to social behavior = SociobiologyProximate v. Ultimate Causation-Proximate causation = immediate casual sequences yielding behaviors“How” behaviors come aboutEx. Learning, motivation, neurological variables-Ultimate causation = long term casual sequences yielding behaviors“Why” behaviors work the way that they doEx. Evolution of behaviorEpigenesis-Phenotypic expression due to environmental stimulation-Actual heritability can be inferred using twin studies and adoption studiesMonozygotic = same original egg, same DNADizygotic = two diff fertilized eggs, share 50% DNA like regular siblingsCompare concordance rates for trait expressionConcordance rates will be higher for monozygotic if traits are based geneticallySexual v. Asexual Reproduction-Most species reproduce sexually Genetic diversityResistance to diseaseCapacity to adaptDilute harmful recessive mutations-More gene copies are transmitted asexually-Males produce sperm, females produce eggs-Eggs are more expensive to produce, so females are choosier than males in mate selection-Males compete for access to femalesMating Systems-Competition for females is greater if males do not provide parenting or resources-Exaggerated characteristics (sexual dimorphisms) = good genes-Monogamous species show little sexual dimorphism, males help females-Polyandry = females mate with multiple males, rareIn human systems, usually fraternal polyandryAltruism-Performing unselfish acts-Kin selection = pass on genes by helping close relatives, prominent in social insects-Reciprocal altruism = genetically based tendency to help others expecting reciprocationMust be able to recognize individualsNeurons & Neurotransmitters-Neurons generate the electrical activity of the brain-Neuron doctrine = neurons are the structural and functional units of the nervous system-Glial cells = supporters-Soma = cell bodyContains cytoplasm where proteins are madeNucleus contains DNA-Neutrites extend from the somaDendrites receive infoAxons send infoAxon ends with a bouton / nerve terminal-Resting potential:Inside is negativeMembrane pumps Na+ out and K+ inMembrane is more permeable to K+, resulting in an excess of + outside (resting pot)Approx. 60-70mv-Action PotentialDepolarization = inside becomes less negativeIf depolarization exceeds threshold, voltage-dependent sodium channels openOpening of channels depolarizes membrane furtherAscending Phase = sodium channels opening, voltage dependent, to reach +55mvDescending Phase = sodium channels close, potassium channels open, time dependentAbsolute refractory period = sodium channels inactivated, no action no matter whatRelative refractory period = after absolute, action can be triggered when over thresholdMyelin sheaths insulate axons and increase speed of action potential -Release of NeurotransmitterArrival of action potential depolarizes the terminalCa++ ion channels open, calcium flows inNeurotransmitter vesicles migrate toward the presynaptic membraneVesicles and membrane fuse; neurotransmitters enter synaptic cleftInteractions with receptive sites cause ion channels to open or close, depol or hyperpolDepolarization = excitatory postsynaptic potential (EPSP)Hyperpolarization = inhibitory postsynaptic potential (IPSP)-Temporal Summation = two action potentials invading synapse close together in time can addPostsynaptic potential increases as presynaptic firing increases-Spatial Summation = combination of inputs from many synapses, both EPSPs and IPSPsTrigger zone = axon hillockNervous System Organization-Central nervous system = brain and spinal cord-Peripheral nervous system = somatic and autonomicSomatic = voluntary muscles and sense organsAutonomic = internal organs-Sensory neurons receive input from skin, muscles, and internal organs-Motoneurons project axons directly to muscle fibers causing them to contract-Interneurons form a web of interconnections and make up the bulk of all neurons-Vertebrate brain has 5 basic subdivisions:Telencephalon = largest, processes sensory info, includes olfactory bulbs and cerebrumDiencephalon = thalamus(relay sensory info to telen.) & hypothalamus(control pituitary)Mesencephalon = midbrain, basic visual & auditory reactions. Roof = “optic tectum”Metencephalon = pons and cerebellum, balance and movementMyelencephalon = medulla, controls vital reflexes like breathing & heart rate-Organization of the CerebrumFrontal Lobe = mvmt, planning of behaviors, Broca’s area (speech)Parietal Lobe = sense of touch, primary somatosensory areaOccipital Lobe = visionTemporal Lobe = hearing, Wernicke’s area (understanding language)Organized contralaterallyCentral Sulcus binds frontal and parietal lobesPrecentral Gyrus / primary motor cortex lies anterior to central sulcusPostcentral gyrus / primary somatosensory cortex lies posterior to central sulcusSylvian Fissure binds temporal lobe to frontal and parietal lobesLeft