PSYCH100H EXAM 1 Intro Psych as the study of the human organism Psych as the study of the human mind Psych as the study of the human personality The Biological Basis of Behavior Historical Issues Descartes mind body dualism theory refuted Pineal body the seat of the soul All other parts of body act in automatic reflexes Mvmt of cerebrospinal fluid moved body through hydraulic action Gall and Spurzheim proposed localization of function in the brain Localization accurate but theory of skull features to deduce personality was refuted Broca showed left inferior frontal lobe expression of spoken language Supports localization theory Cajal neuron doctrine Electrophysiological 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 sleep Periodically become desynchronized during dreams in REM sleep Evolution 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 Sociobiology Proximate v Ultimate Causation Proximate causation immediate casual sequences yielding behaviors How behaviors come about Ex Learning motivation neurological variables Ultimate causation long term casual sequences yielding behaviors Why behaviors work the way that they do Ex Evolution of behavior Epigenesis Phenotypic expression due to environmental stimulation Actual heritability can be inferred using twin studies and adoption studies Monozygotic same original egg same DNA Dizygotic two diff fertilized eggs share 50 DNA like regular siblings Compare concordance rates for trait expression Concordance rates will be higher for monozygotic if traits are based genetically Sexual v Asexual Reproduction Most species reproduce sexually Genetic diversity Resistance to disease Capacity to adapt Dilute 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 females Mating 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 rare In human systems usually fraternal polyandry Altruism 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 reciprocation Must be able to recognize individuals Neurons 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 body Contains cytoplasm where proteins are made Nucleus contains DNA Neutrites extend from the soma Dendrites receive info Axons send info Axon ends with a bouton nerve terminal Resting potential Inside is negative Membrane pumps Na out and K in Membrane is more permeable to K resulting in an excess of outside resting pot Approx 60 70mv Action Potential Depolarization inside becomes less negative If depolarization exceeds threshold voltage dependent sodium channels open Opening of channels depolarizes membrane further Ascending Phase sodium channels opening voltage dependent to reach 55mv Descending Phase sodium channels close potassium channels open time dependent Absolute refractory period sodium channels inactivated no action no matter what Relative refractory period after absolute action can be triggered when over threshold Myelin sheaths insulate axons and increase speed of action potential Release of Neurotransmitter Arrival of action potential depolarizes the terminal Ca ion channels open calcium flows in Neurotransmitter vesicles migrate toward the presynaptic membrane Vesicles and membrane fuse neurotransmitters enter synaptic cleft Interactions with receptive sites cause ion channels to open or close depol or hyperpol Depolarization excitatory postsynaptic potential EPSP Hyperpolarization inhibitory postsynaptic potential IPSP Temporal Summation two action potentials invading synapse close together in time can add Postsynaptic potential increases as presynaptic firing increases Spatial Summation combination of inputs from many synapses both EPSPs and IPSPs Trigger zone axon hillock Nervous System Organization Central nervous system brain and spinal cord Peripheral nervous system somatic and autonomic Somatic voluntary muscles and sense organs Autonomic 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 cerebrum Diencephalon thalamus relay sensory info to telen hypothalamus control pituitary Mesencephalon midbrain basic visual auditory reactions Roof optic tectum Metencephalon pons and cerebellum balance and movement Myelencephalon medulla controls vital reflexes like breathing heart rate Organization of the Cerebrum Frontal Lobe mvmt planning of behaviors Broca s area speech Parietal Lobe sense of touch primary somatosensory area Occipital Lobe vision Temporal Lobe hearing Wernicke s area understanding language Organized contralaterally Central Sulcus binds frontal and parietal lobes Precentral Gyrus primary motor cortex lies anterior to central sulcus Postcentral gyrus primary somatosensory cortex lies posterior to central sulcus Sylvian Fissure binds temporal lobe to frontal and parietal lobes Left hemisphere language right hemisphere spatial relations Learning Conditioning Learning permanent change in behavior as a result of experience Non associative