5 Variations in Conscious.ppt

Chapter5,VariationsinConsciousness,Consciousness:PersonalAwareness,AwarenessofInternalandExternalStimuliLevelsofawarenessJamesstreamofconsciousnessFreudunconsciousSleep/dreamingresearch,TheElectroencephalograph:APhysiologicalIndexofConsciousness,EEGmonitoringofbrainelectricalactivityBrain-wavesAmplitude(height)Frequency(cyclespersecond)Beta(13-24cps)Alpha(8-12cps)Theta(4-7cps)Delta(retina-suprachiasmaticnucleusofhypothalamus-pinealgland-secretionofmelatoninMelatoninandcircadianrhythms,Sleep/WakingResearch,Instruments:ElectroencephalographbrainelectricalactivityElectromyographmuscleactivityElectrooculographeyemovementsOtherbodilyfunctionsalsoobserved,SleepStages:CyclingThroughSleep,Stage1:brief,transitional(1-7minutes)alpha-thetahypnicjerksStage2:sleepspindles(10-25minutes)Stages3&4:slow-wavesleep(30minutes)Stage5:REM,EEGsimilartoawake,vividdreaming(initiallyafewminutes,progressivelylongerascyclethroughthestages)DevelopmentaldifferencesinREMsleep,Fig5.5Anoverviewofthecycleofsleep.Thewhitelinechartshowatypical,healthy,youngadultmovesthroughthevariousstagesofsleepduringthecourseofanight.ThisdiagramalsoshowshowdreamsandrapideyemovementstendtocoincidewithREMsleep,whereasposturechangesoccurbetweenREMperiods(becausethebodyisnearlyparalyzedduringREMsleep).NoticehowthepersoncyclesintoREMfourtimes,asdescentsintoNREMsleepgetshallowerandREMperiodsgetlonger.This,slow-wavesleepisprominentearlyinthenight,whileREMsleepdominatesthesecondhalfofanightssleep.Althoughthesepatternsaretypical,keepinmindthatsleeppatternsvaryfromonepersontoanotherandthattheychangewithage.,TheNeuralBasesofSleep,BrainStructures:AscendingreticularactivatingsystemPons,medulla,thalamus,hypothalamus,limbicsystemNeurotransmitters:AcetylcholineandserotoninAlsonorepinephrine,dopamine,andGABA,Fig5.7Theascendingreticularactivatingsystem(ARAS).Anumberofbrainareasandstructuresinteracttoregulatesleepandwaking.ParticularlyimportantistheARAS(representedbythewhitearrows),whichconveysneuralstimulationtomanyareasofthecortex.,WhyDoWeSleep?,Hypothesis1:SleepevolvedtoconserveorganismsenergyHypothesis2:ImmobilizationduringsleepisadaptivebecauseitreducesdangerHypothesis3:Sleephelpsanimalstorestoreenergyandotherbodilyresources,SleepDeprivation,Completedeprivation3or4daysmaxPartialdeprivationorsleeprestrictionimpairedattention,reactiontime,coordination,anddecisionmakingaccidents:Chernobyl,ExxonValdezSelectivedeprivationREMandslow-wavesleep:reboundeffect,Fig5.8-Effectofsleepdeprivationoncognitiveperformance.ExperimentalsubjectsinthePilcherandWalters(1997)studyunderwent24hoursofsleepdeprivationpriortotakingtheWatson-GlaserCriticalThinkingAppraisal.Asyoucansee,theirperformanceonthiscognitivetestwasclearlyinferiortothatofthecontrolsubjects,whohadnotexperiencedsleepdeprivation.,SleepProblems,InsomniadifficultyfallingorstayingasleepNarcolepsyfallingasleepuncontrollablySleepApneareflexivegaspingforairthatawakensNightmaresanxietyarousingdreams-REMNightTerrorsintensearousalandpanic-NREMSomnambulismsleepwalking,Fig5.10Theviciouscircleofdependenceonsleepingpills.Becauseofthebodysabilitytodeveloptolerancetodrugs,usingsedativesroutinelyto“cure”insomniacanleadtoaviciouscircleofescalatingdependencyaslargerandlargerdosesofthesedativeareneededtoproducethesameeffect.,Fig5.11-Sleepproblemsandthecycleofsleep.Differentsleepproblemstendtooccuratdifferentpointsinthesleepcycle.Whereassleepwalkingandnightterrorsareassociatedwithslow-wavesleep,nightmaresareassociatedwiththeheighteneddreamactivityofREMsleep.,DreamsandDreaming:ContentandSignificance,DreamsmentalexperiencesduringsleepContentusuallyfamiliarCommonthemesWakinglifespilloverdayresidueWesternvs.Non-Westerninterpretations,Fig5.12Threetheoriesofdreaming.Dreamscanbeexplainedinavarietyofways.Freudstressedthewish-fulfillingfunctionofdreams.Cartwrightemphasizestheproblem-solvingfunctionofdreams.HobsonandMcCarleyassertthatdreamsaremerelyabyproductofperiodicneuralactivation.Allthreetheoriesareratherspeculativeandhavetheircritics.,Hypnosis:AlteredStateofConsciousnessorRolePlaying?,Hypnosis=asystematicprocedurethatincreasessuggestibilityHypnoticsusceptibility:individualdifferencesEffectsproducedthroughhypnosis:AnesthesiaSensorydistortionsandhallucinationsDisinhibitionPosthypnoticsuggestionsandamnesia,Meditation,Meditation=practicesthattrainattentiontoheightenawarenessandbringmentalprocessesundergreatervoluntarycontrolYoga,Zen,transcendentalmeditation(TM)PotentialphysiologicalbenefitsSimilartoeffectiverelaxationprocedures,PrincipalAbusedDrugsandTheirEffects,6categoriesofpsychoactivedrugsNarcotics(opiate