Psyc4130 1nd Edition Exam 3 Study Guide Lectures 15 21 Lecture 15 16 17 18 2 24 2 26 2 28 3 3 Sleep and Biological Rhythms Chapter 9 A Physiological and Behavioral Description of Sleep Stages of sleep o Alpha Activity Smooth electrical activity of 8 12 Hz recorded from the brain generally associated with a state of relaxation Person is resting quietly Can occur when a persons eyes are open but mostly occur when they are closed o Beta Activity Irregular electrical activity of low amplitude waves 13 30 Hz recorded from the brain generally associated with a state of arousal Shows desynchrony reflects the fact that many different neural circuits in the brain are actively processing info o Theta Activity EEG activity of 3 5 7 5 Hz that occurs intermittently during early stages of slow wave sleep and REM sleep Stage 1 sleep is marked by the presence of some theta activity Firing of neurons in neocortex is becoming more synchronized transition between sleep and wakefulness o Stage 1 Sleep spindles theta activity o Stage 2 K complexes sudden sharp waveforms usually found only during stage 2 sleep o Stage 3 Signaled by the occurrence of high amplitude delta activity contains 20 50 of delta activity SWS o Stage 4 Contains more than 50 of delta activity SWS o Delta Activity Regular synchronous electrical activity of less than 4 Hz recorded from the brain occurs during the deepest stages of slow wave sleep o Down State Period of inhibition during slow oscillation during SWS neurons in neocortex are silent and resting o Up State Period of excitation during a slow oscillation during SWS neurons in the neocortex briefly fire at a high rate o REM Sleep A period of desynchronized EEG activity during sleep at which time dreaming rapid eye movements and muscular paralysis occur also called paradoxical sleep stage 4 Mental activity during sleep o Mental activity can accompany slow wave sleep too but most narrative dreams occur during REM sleep Section Summary pg 294 Disorders of Sleep Insomnia o Sleep Apnea A particular form of insomnia caused by an inability to sleep and breath at the same time Cessation of breathing while sleeping Narcolepsy o A sleep disorder characterized by periods of irresistible sleep attacks of cataplexy sleep paralysis and hypnagogic hallucinations o Sleep attacks Symptom of narcolepsy an irresistible urge to sleep during the day after which the person awakens feeling refreshed o Cataplexy A symptom of narcolepsy where complete paralysis occurs during waking o Hypnagogic Hallucination Vivid dreams that occur just person a person falls asleep accompanied by sleep paralysis o Orexin A peptide also known as hypocretin produced by neurons whose cell bodies are located in the hypothalamus their destruction causes narcolepsy REM Sleep Behavior Disorder o A neurological disorder in which the person doesn t become paralyzed during REM sleep and thus acts out dreams Problems Associated with Slow Wave Sleep o Bedwetting sleepwalking night terrors Most common in children who usually outgrow them Section Summary pg 298 Why Do We Sleep Functions of SWS o Sleep serves as an adaptive response and provides a period of restoration o Permits the brain to rest and recover from its daily activity o Memory consolidation facilitates declarative learning Functions of REM Sleep o Rebound phenomenon Increased frequency or intensity of a phenomenon after it has been temporarily suppressed for example the increase in REM sleep seen after a period of REM sleep deprivation suggests that there is a need for a certain amount of REM sleep o May promote brain development promote learning Sleep and Learning o Slow wave sleep and REM sleep was an improvement seen in the subjects performance on non declarative visual discrimination task Section Summary pg 303 Physiological Mechanisms of Sleep and Walking Chemical control of sleep o Adenosine Neuromodulator that is released by neurons engaging in high levels of metabolic activity may play a primary role in the initiation of sleep Neural control of arousal o Acetylcholine Levels of Ach were high during both waking and REM sleep periods but low during slow wave sleep o Norepinephrine Locus Coeruleus Dark colored group of noradrenergic cell bodies located in the pons near the rostral end involved in arousal and vigilance Give rise to axons that branch widely releasing norepinephrine Increases an animals vigilance and its ability to pay attention to stimuli in the environment o Serotonin Raphe Nuclei Causes locomotion and cortical arousal Firing rate declined during slow wave sleep and became virtually zero during REM However once the period of REM sleep ended the neurons temporarily became very active again o Histamine A neurotransmitter synthesized from the amino acid histidine plays an important role in maintenance of wakefulness and arousal Tubermammillary Nucleus TMN A nucleus in the ventral posterior hypothalamus contains histaminergic neurons involved in cortical activation and behavioral arousal o Orexin Has an excitatory effect Fired at high rates during alert or active waking and low rate during quiet waking SWS and REM Neural control of SWS o Sleep is controlled by three factors homeostatic allostatic and circadian o SWS occurs when neurons in the vIPOA become active These neurons inhibit the system of neurons that promote wakefulness in turn the vIPOA is inhibited by these same wakefulness promoting regions thius forming a kind of flip flop that keeps us either awake or alseep Neural control of REM Sleep o Sublaterodorsal nucleus SLD serves as the REM on region and the ventrolateral periaqueductal grey region vIPAG serves as the REM off Section Summary pg 314 Biological Clocks Circadian Rhythms and Zeitgebers o Circadian Rhythm A daily rhythmical chance in behavior or physiological process o Zeitgber A stimulus usually the light of dawn that resets the biological clock that is responsible for circadian rhythms The Suprachiasmatic Nucleus o A nucleus situated atop to optic chiasm Contains a biological clock that is responsible for organizing many of the bodies circadian rhythms Control of Seasonal Rhythms The Pineal Gland and Melatonin o Pineal gland secretes a hormone called melatonin which plays a role in circadian and seasonal rhythms Section Summary pg 321 Lecture 18 19 20 21 3 3 3 5 3 7 3 17 Reproductive Behavior Chapter 10 Sexual Development Production of Gametes and Fertilization o Sexually dimorphic behavior A behavior that has different forms