Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Introduction to Psychology Neurology Plan for Today • • • • Biological bases of behavior Communication in the nervous system Organization of the nervous system Researching the brain Components of the Neuron – Dendrites: receive information from other neurons – Cell body: creates transmitter molecules – Axon • Myelin insulates the nerve cell, speeds up conduction of nerve messages • Terminal buttons of the axon release transmitter Graded Potentials • Stimulation of the nerve membrane can open ion channels in the membrane • NA+ ions flowing in will depolarize the membrane (movement from -70 mV to say -60 mV • K+ ions flowing out of membrane will hyperpolarize the membrane (-70 mV to say -90 mV) The Action Potential • Graded potentials are generated at the dendrites and are conducted along the membrane to the axon hillock • If the summated activity at the axon hillock raises the membrane potential past threshold, an action potential (AP) will occur • During the AP, NA+ ions flow into the cell raising the membrane potential to +40 mV, producing the spike – The restoration of the membrane potential to -70 mV is produced by an opening of channels to K+ – The AP is conducted along the axon toward the terminals Details of the Synapse Neurotransmitters • Acetylcholine (Ach) • Monoamines: - epinephrine and norepinephrine - serotonin - dopamine • GABA • Glutamate Autonomic Nervous System • The Autonomic Nervous System (ANS) has two divisions: – Sympathetic: Emergency system – Parasympathetic: Vegetative functions (e.g. digestion) • The two systems often act in opposition (as in the control of heart rate) • Can act in concert (as in the control of sexual reflexes) Autonomic Nervous System Midline View of Human Brain Medulla: Controls heart rate, respiration Cerebellum: Coordinates smooth movements, balance, and posture Pons: Involved in the control of sleep Limbic System Functions • Septal area is involved in pleasure and in relief from pain • Amygdala is involved in learning and recognition of fear • Hippocampus is involved in memory Cerebral Cortex • Functions of cerebral cortex: – Provides for flexible control of patterns of movement – Permits subtle discrimination among complex sensory patterns – Makes possible symbolic thinking • Symbolic thought is the foundation of human thought and language The Cortical Lobes of the Human Brain Frontal Lobe Damage and Personality • Frontal lobes are involved in movement, attention, planning, memory, and personality. • Frontal lobe function in personality is evident in the case of Phineas Gage – Gage suffered frontal lobe damage after an accident involving a dynamite tamping rod – Gage was a railroad supervisor prior to the damage; after the damage he became childish and irreverent, could not control his impulses, and could not effectively plan. Cerebral Lateralization • The structures of the cortex and sub-cortex appear to specialize in function: – Hemispheric Specialization • Left hemisphere is dominant for language, logic, and complex motor behavior. • Right hemisphere is dominant for non-linguistic functions including recognition of faces, places, and sounds (music) • The hemispheric specializations are evident from studies of – Damage to one hemisphere (I.e. Broca’s area) – Split-brain subjects The Split-Brain Study • Information from the one visual field is usually transmitted to the opposite visual cortex • The corpus callosum serves to integrate the two hemispheres • Cutting the corpus callosum can result in information reaching only one hemisphere – Language is a left-hemisphere function – Information reaching the left hemisphere will be reported by the subject, but not information reaching the right hemisphere Split-Brain Studies (Figure adapted from Gazzaniga, 1967) The Endocrine System • Glands that secrete hormones into the bloodstream to help control bodily functioning • Hypothalmus connected to pituitary gland (master gland) - adrenal glands = fight or flight - Gonads = secondary sex characteristics Endocrine Systems • Endocrine glands release hormones into blood stream – Have effects at diffuse target sites throughout the body – Hormones bind to receptors – Hormones can have organizational effects (permanent change in structure and function) – Hormones can have activational effects: • Lack of testosterone reduces sexual behavior