Psyc4130 1nd EditionExam # 3 Study Guide Lectures: 15 - 21Lecture 15, 16, 17, 18 (2/24, 2/26, 2/28, 3/3)Sleep and Biological RhythmsChapter 9 A Physiological and Behavioral Description of Sleep- Stages of sleepo 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 closedo 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 infoo 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; SWSo Stage 4 Contains more than 50% of delta activity; SWSo Delta Activity Regular, synchronous electrical activity of less than 4 Hz recorded from the brain; occurs during the deepest stages of slow-wave sleepo Down State Period of inhibition during slow oscillation during SWS; neurons in neocortexare silent and restingo Up State Period of excitation during a slow oscillation during SWS; neurons in the neocortex briefly fire at a high rateo 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 sleepo Mental activity can accompany slow wave sleep too, but most narrative dreams occur during REM sleep-Section Summary- pg 294 Disorders of Sleep- Insomniao Sleep Apnea A particular form of insomnia, caused by an inability to sleep and breath at the same time. Cessation of breathing while sleeping- Narcolepsyo A sleep disorder characterized by periods of irresistible sleep, attacks of cataplexy, sleep paralysis, and hypnagogic hallucinationso Sleep attacks Symptom of narcolepsy; an irresistible urge to sleep during the day, after which the person awakens feeling refreshedo Cataplexy A symptom of narcolepsy where complete paralysis occurs during wakingo Hypnagogic Hallucination Vivid dreams that occur just person a person falls asleep; accompanied by sleep paralysiso 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 Disordero A neurological disorder in which the person doesn't become paralyzed during REM sleep and thus acts out dreams - Problems Associated with Slow-Wave Sleepo Bedwetting, sleepwalking, night terrors. Most common in children who usually outgrow them.-Section Summary- pg 298 Why Do We Sleep?- Functions of SWSo Sleep serves as an adaptive response and provides a period of restorationo Permits the brain to rest and recover from its daily activityo Memory consolidation, facilitates declarative learning - Functions of REM Sleepo Rebound phenomenon Increased frequency or intensity of a phenomenon after it has been temporarily suppressed; for example, the increase in REM sleep seen after aperiod of REM sleep deprivation; suggests that there is a need for a certain amount of REM sleepo 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 sleepo 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 arousalo 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 environmento 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, theneurons temporarily became very active againo 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 SWSo 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 Sleepo 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 Zeitgeberso Circadian Rhythm A daily rhythmical chance in behavior or physiological processo Zeitgber  A stimulus (usually the light of dawn) that resets the biological clock that is responsible for circadian rhythms - The Suprachiasmatic Nucleuso 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 Melatonino Pineal gland secretes a hormone called melatonin which plays a role in circadian