Psychology Ch. 5 & 6

Psychology Ch. 5 & 6Sensation & Perception and States of Consciousness

SensationSensationour sensory receptors and nervous system receive and represent stimulus energyPerceptionorganizing and interpreting sensory information, enabling us to recognize meaningful objects and events

Sensation

SensationBottom-Up Processinganalysis that begins with the sense receptors and works up to the brains integration of sensory informationTop-Down Processinginformation processing guided by higher-level mental processesSensation - Basic PrinciplesPsychophysicsstudy of the relationship between physical characteristics of stimuli and our psychological experience of themLight- brightnessSound- volumePressure- weightTaste- sweetnessSensation - ThresholdsAbsolute Threshold minimum stimulation needed to detect a particular stimulus 50% of the timeDifference Thresholdminimum difference between two stimuli required for detection 50% of the timejust noticeable difference (JND)Perceptual OrganizationGestalttendency to integrate pieces of information into meaningful wholes

7Perceptual OrganizationFigure and Ground--organization of the visual field into objects (figures) that stand out from their surroundings (ground)

8Perceptual Organization- GestaltGroupingthe perceptual tendency to organize stimuli into coherent groupsGrouping Principlesproximity--group nearby figures togethersimilarity--group figures that are similarcontinuity--perceive continuous patternsclosure--fill in gapsconnectedness--spots, lines, and areas are seen as unit when connected9Perceptual Organization- ClosureGestalt grouping principles are at work here.

10Perceptual Organization- Grouping PrinciplesGestalt grouping principles are at work here.

11Perceptual InterpretationPerceptual Adaptation(vision) ability to adjust to an artificially displaced visual fieldprism glassesPerceptual Seta mental predisposition to perceive one thing and not another12Perceptual Set- SchemasWhat you see in the center is influenced by your perceptual set

13Waking ConsciousnessConsciousnessour awareness of ourselves and our environmentsSelective Attentionfocusing of conscious awareness on a particular stimulus

Sleep and DreamsCircadian Rhythm the biological clockregular bodily rhythms, such as of wakefulness and body temperature, that occur on a 24-hour cycleSleep and DreamsREM (Rapid Eye Movement) Sleep recurring sleep stage vivid dreamsparadoxical sleep muscles are generally relaxed, but other body systems are activeSleepperiodic, natural, reversible loss of consciousnessSleep DeprivationEffects of Sleep Lossfatigueimpaired concentrationdepressed immune systemgreater vulnerability to accidents

Sleep DisordersInsomniapersistent problems in falling or staying asleepNarcolepsyuncontrollable sleep attacksSleep Apneatemporary cessation of breathing during sleepmomentary reawakeningsNight Terrors and NightmaresNight Terrorsoccur within 2 or 3 hours of falling asleep, usually during Stage 4high arousal - appearance of being terrifiedseldom rememberedDreams: FreudSigmund Freud--The Interpretation of Dreams (1900)wish fulfillment discharge otherwise unacceptable feelingsManifest Contentremembered story lineLatent Contentunderlying meaningDreams: FreudDreamssequence of images, emotions, and thoughts passing through a sleeping persons mindhallucinatory imagerydiscontinuitiesincongruitiesdelusional acceptance of the contentdifficulties rememberingDreamsAs Information Processinghelps facilitate memoriesAs a Physiological Functionperiodic brain stimulationREM ReboundREM sleep increases following REM sleep deprivationHypnosisHypnosisa social interaction in which one person (the hypnotist) suggests to another (the subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occurDrugs and ConsciousnessPsychoactive Druga chemical substance that alters perceptions and moodPhysical Dependence physiological need for a drugmarked by unpleasant withdrawal symptomsPsychological Dependencea psychological need to use a drugfor example, to relieve negative emotionsPsychoactive DrugsDepressantsdrugs that reduce neural activity alcohol, barbiturates, opiatesslow body functions Psychoactive DrugsAlcoholaffects motor skills, judgment, and memoryreduces self awarenessBarbituratesdrugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgmentPsychoactive DrugsOpiatesopium and its derivatives (morphine and heroin)opiates depress neural activity, temporarily lessening pain and anxietyhighly addictivePsychoactive DrugsStimulantsdrugs that excite neural activity caffeine, nicotine, amphetamines, cocaine speed up body functionsPsychoactive DrugsAmphetaminesdrugs that stimulate neural activity, causing speeded-up body functions and associated energy and mood changesPsychoactive DrugsCocaineeffects depend on dosage, form, expectations, personality and situationcoca leavespowdercrack Cocaine Euphoria and Crash

Psychoactive DrugsEcstasyMDMA (methylenedioxymethamphetamine)stimulant and mild hallucinogendangerous short and long term effectsPsychoactive DrugsHallucinogenspsychedelic (mind-manifesting) drugs that distort perceptions and evoke sensory images in the absence of sensory inputLSDMDMA (Ecstasy)Psychoactive DrugsLSD lysergic acid diethylamidea powerful hallucinogenic drugalso known as acidTHCthe major active ingredient in marijuanatriggers a variety of effects, including mild hallucinationsPsychoactive Drugs