Chapter 4Chapter 4

Sensation and PerceptionSensation and Perception

Sensation and Perception: Sensation and Perception: The basicsThe basics

Sensation:Sensation: the stimulation of the stimulation of sensory receptors & transmission sensory receptors & transmission of information to the central of information to the central nervous system.nervous system.

Perception:Perception: psychological psychological process through which we process through which we interpret sensory stimulationinterpret sensory stimulation

ThresholdsThresholds Absolute Threshold:Absolute Threshold: the weakest the weakest

amount of stimulus that can be amount of stimulus that can be sensed.sensed.

Difference Threshold:Difference Threshold: the minimum the minimum amount of difference that can be amount of difference that can be detected between two stimuli.detected between two stimuli.

Detection and Detection and AdaptationAdaptation

Signal–Detection Theory:Signal–Detection Theory: your your environment, physical state, environment, physical state, mood, and your attitude can mood, and your attitude can affect sensitivity to stimuli.affect sensitivity to stimuli.

Sensory Adaptation:Sensory Adaptation: process by process by which we become more sensitive which we become more sensitive to weak stimuli and less to weak stimuli and less sensitive to unchanging stimuli.sensitive to unchanging stimuli.

Vision:Vision: Light:Light: is electromagnetic energy is electromagnetic energy We only see ROY G BIV, this is only a We only see ROY G BIV, this is only a

fraction of all the possible colors in fraction of all the possible colors in the electromagnetic spectrum. the electromagnetic spectrum. (infrared & ultraviolet light)(infrared & ultraviolet light)

Afterimages:Afterimages: the color’s the color’s complementary colorcomplementary color

Color Blindness:Color Blindness: only seeing light only seeing light and dark, no color. (rare)and dark, no color. (rare)

The EyeThe Eye The Eye:The Eye: The Pupil:The Pupil: lets in light (like a lets in light (like a

camera)camera) Pupil size is sensitive to light & Pupil size is sensitive to light &

emotions.emotions. Allows dark & light adaptation for up Allows dark & light adaptation for up

to 45 minutesto 45 minutes

Eye continued…Eye continued… Lens:Lens: adjusts to the distance of adjusts to the distance of

objects by changing its thickness.objects by changing its thickness. (when people squint, they are (when people squint, they are

adjusting the thickness of the lenses adjusting the thickness of the lenses in their eyes) in their eyes)

Eye continued…Eye continued… Retina:Retina: sensitive surface- acts like sensitive surface- acts like

the film of the camerathe film of the camera Photoreceptors make it possible for Photoreceptors make it possible for

the optic nerve to carry the message the optic nerve to carry the message to the brainto the brain

Eye continued…Eye continued… Blind Spot:Blind Spot: spot where optic nerve spot where optic nerve

leaves the eyeleaves the eye this is how the information gets to the this is how the information gets to the

brain.brain. Rods & Cones:Rods & Cones: Located in the retinaLocated in the retina

Rods= black & white, Cones= colorRods= black & white, Cones= color

Hearing:Hearing: Pitch:Pitch: how high or low a sound is. how high or low a sound is. Human ear can hear sound waves Human ear can hear sound waves

from 20 to 20,000 cycles per second.from 20 to 20,000 cycles per second. Loudness:Loudness: determined by determined by

amplitude=sound wavesamplitude=sound waves Loudness measured by decibels Loudness measured by decibels

(0 dB is the lowest we can hear)(0 dB is the lowest we can hear)

Ear:Ear: shaped to capture sound. shaped to capture sound. Made up of outer, middle, and inner ear.Made up of outer, middle, and inner ear. Eardrum:Eardrum: gateway for outer to middle ear gateway for outer to middle ear As it vibrates it sends it to 3 small bones: As it vibrates it sends it to 3 small bones:

hammerhammer, , anvilanvil, & , & stirrupstirrup The bones then vibrate sending the The bones then vibrate sending the

sound to the inner earsound to the inner ear Inner ear-cochlea:Inner ear-cochlea: fluid filled bony fluid filled bony

tube=sends to the auditory nerve.tube=sends to the auditory nerve.

Deafness:Deafness:

Conductive deafness:Conductive deafness: damage to damage to middle ear.middle ear. Usually older people (can be helped with Usually older people (can be helped with

hearing aids)hearing aids) Sensorineural deafness:Sensorineural deafness: damage to damage to

inner earinner ear Usually caused by damage to the auditory Usually caused by damage to the auditory

nerve through disease or prolonged exposure nerve through disease or prolonged exposure to very loud noises.to very loud noises.

NoseNose Smell:Smell: Olfactory nerve, connection to the Olfactory nerve, connection to the

brain.brain. Adaptive:Adaptive: we lose awareness of smells around we lose awareness of smells around

us.us. If we could not smell then we could not taste.If we could not smell then we could not taste.

Tongue Tongue Taste:Taste: Sweet, Sour, Salt, & Bitter. Sweet, Sour, Salt, & Bitter. Taste is sensed through receptor neurons Taste is sensed through receptor neurons

located on taste buds.located on taste buds. Scraping your tongue or burning it kills taste Scraping your tongue or burning it kills taste

buds.buds. Taste buds can renew themselves in a week.Taste buds can renew themselves in a week.

TouchTouch Touch:Touch: pressure, temperature, pain pressure, temperature, pain Pressure:Pressure: receptors around your hair roots detect receptors around your hair roots detect

pressurepressure Different parts of the body are more sensitive than others.Different parts of the body are more sensitive than others.

Temperature:Temperature: sensors help you to adapt to temp sensors help you to adapt to temp changeschanges

Pain:Pain: point of contact-spinal cord-thalamus-cerebral point of contact-spinal cord-thalamus-cerebral cortex = prostaglandins (chemicals that tell the brain cortex = prostaglandins (chemicals that tell the brain of pain)of pain)

Gate theoryGate theory- rub or scratch the area to help pain go - rub or scratch the area to help pain go away= flooding the neurons away= flooding the neurons

Body Senses:Body Senses: Vestibular sense:Vestibular sense: tells you whether you are tells you whether you are

physically upright or upside down.physically upright or upside down. Sensory organs located in the ear monitor Sensory organs located in the ear monitor

body’s motion, balance, tells you whether body’s motion, balance, tells you whether you’re upside down, falling, etc…you’re upside down, falling, etc…

Kinesthesis:Kinesthesis: “to move” & “perception” “to move” & “perception” Info is fed to the brain from sensory organs in the Info is fed to the brain from sensory organs in the

joints, tendons, & muscles.joints, tendons, & muscles.

PerceptionPerception Gestalt: “whole”Gestalt: “whole”

Closure: tendency to perceive a complete Closure: tendency to perceive a complete or whole figure even when there are gaps or whole figure even when there are gaps

in what your senses tell youin what your senses tell you

Similarity: people think of similar Similarity: people think of similar objects as belonging together.objects as belonging together.

Depth PerceptionDepth Perception

MovementMovement

Proximity: if something is close Proximity: if something is close together we perceive it as together we perceive it as

grouped togethergrouped together

ConnectednessConnectedness

IllusionsIllusions

Ponzo IllusionPonzo Illusion

Chapter 5Chapter 5

Levels of ConsciousnessLevels of Consciousness

Selective attention:Selective attention: focusing on a particular focusing on a particular stimulus.stimulus.

Usually involves our 5 sensesUsually involves our 5 senses Direct Inner Awareness:Direct Inner Awareness: thoughts, images, thoughts, images,

emotions, or memories.emotions, or memories. Examples: being angry, remembering a friend, Examples: being angry, remembering a friend,

concepts like fairness or love.concepts like fairness or love.

Levels of Awareness:Levels of Awareness: Consciousness:Consciousness: Aware of inner and exterior Aware of inner and exterior

stimulistimuli Preconscious:Preconscious: not aware right now but could not aware right now but could

recall them if needed.recall them if needed. Unconscious/Subconscious:Unconscious/Subconscious: unavailable to unavailable to

awareness. awareness.

Altered States of Consciousness:Altered States of Consciousness: Examples include:Examples include: sleeping, under the sleeping, under the

influence of drugs/alcohol, meditation, influence of drugs/alcohol, meditation, biofeedback, hypnosis, etc.biofeedback, hypnosis, etc.

Sleep & DreamsSleep & Dreams Circadian Rhythms:Circadian Rhythms: Cycle occurring in people, Cycle occurring in people,

animals, & plants. (every 24 hrs)animals, & plants. (every 24 hrs) Examples: body temp, blood pressure, Examples: body temp, blood pressure,

sleepiness, & wakefulness.sleepiness, & wakefulness.

Stages of Sleep:Stages of Sleep: Stage 1Stage 1: lightest sleep, if awakened we feel like we : lightest sleep, if awakened we feel like we

haven’t been to sleep yet.haven’t been to sleep yet. Lasts about 30-40 minutes, we then move to stages Lasts about 30-40 minutes, we then move to stages

2,3, & 42,3, & 4 Stage 2, 3, & 4:Stage 2, 3, & 4: Moving deeper and deeper into sleep. Moving deeper and deeper into sleep. After about 30 mins of stage 4 we move back to stage After about 30 mins of stage 4 we move back to stage

3, then 2, then 1 (takes about 90 min)3, then 2, then 1 (takes about 90 min) Stage 5:Stage 5: REMREM- breathe more irregularly, blood - breathe more irregularly, blood

pressure rises, heart beats faster.pressure rises, heart beats faster.

Why do we need sleep?Why do we need sleep? Rand Gardner experiment:Rand Gardner experiment: no sleep for 11 no sleep for 11

days= irritable, could not focus eyes, speech days= irritable, could not focus eyes, speech difficulties, & memory lapses.difficulties, & memory lapses.

REM deprived:REM deprived: makes people & animals learn makes people & animals learn more slowly & forget quicklymore slowly & forget quickly

Sleep problemsSleep problems Insomnia:Insomnia: inability to sleep inability to sleep *Racing minds & worrying can cause this*Racing minds & worrying can cause this *Coping: relaxing when trying to sleep (good) *Coping: relaxing when trying to sleep (good)

& sleeping pills (not good!)& sleeping pills (not good!)

Nightmares:Nightmares: anxiety can cause nightmares to anxiety can cause nightmares to occur more oftenoccur more often

*Occurs during REM sleep & usually in the *Occurs during REM sleep & usually in the morningmorning

Night Terrors:Night Terrors: severe nightmares with a racing severe nightmares with a racing heart & gasping for air.heart & gasping for air.

*most people don’t remember exactly what *most people don’t remember exactly what happenshappens

*Occur during 3*Occur during 3rdrd & 4 & 4thth stage of sleep stage of sleep *Most common in children*Most common in children

Sleep Walking:Sleep Walking: *usually children, usually don’t remember the *usually children, usually don’t remember the

next day, & usually grow out of it.next day, & usually grow out of it.

Sleep Apnea:Sleep Apnea: breathing interruption breathing interruption *Occurs when air passages are blocked*Occurs when air passages are blocked *Usually caused by obesity & snoring*Usually caused by obesity & snoring *People may feel tired during the day*People may feel tired during the day

Narcolepsy:Narcolepsy: suddenly fall asleep no matter suddenly fall asleep no matter what time it is or where they are.what time it is or where they are.

*Believed to be a genetic functioning problem*Believed to be a genetic functioning problem

Meditation, Biofeedback, & Meditation, Biofeedback, & HypnosisHypnosis

Meditation:Meditation: narrowing consciousness to narrowing consciousness to relieve stress of the outside world.relieve stress of the outside world.

Biofeedback:Biofeedback: controlling certain bodily controlling certain bodily functions, such as heart rate. functions, such as heart rate.

* Treats things like tension headaches & high * Treats things like tension headaches & high blood pressureblood pressure

Hypnosis:Hypnosis: altered state of consciousness altered state of consciousness during which people respond to suggestions & during which people respond to suggestions & behave as though they are in a trance.behave as though they are in a trance.

*Has been used in trials, for pain prevention, *Has been used in trials, for pain prevention, & quitting bad habits& quitting bad habits

AddictionAddiction Physical addiction: your body craves it after a Physical addiction: your body craves it after a

while.while.

DepressantsDepressants Depressants:Depressants: slows the activity of the nervous slows the activity of the nervous

systemsystem * gives people a sense of relaxation* gives people a sense of relaxation Alcohol:Alcohol: low doses= relaxation, high doses= low doses= relaxation, high doses=

sleep or worsesleep or worse Intoxication:Intoxication: another word for drunkenness , another word for drunkenness ,

root being the word toxicroot being the word toxic

Effects of drinking:Effects of drinking: 1) slurred speech, blurred vision, clumsy1) slurred speech, blurred vision, clumsy 2) affects judgment2) affects judgment 3) lowers inhibitions 3) lowers inhibitions * cause of more than half of all fatal car * cause of more than half of all fatal car

accidents in the U.S.accidents in the U.S.

Narcotics:Narcotics: relieves pain & induce sleep relieves pain & induce sleep Examples: morphine, heroin, and codeine Examples: morphine, heroin, and codeine

(derived from the poppy plant)(derived from the poppy plant)

Effects:Effects: 1) 1) Morphine:Morphine: very addictive (the soldier’s very addictive (the soldier’s

disease)disease) 2) 2) Heroin:Heroin: gives feelings of pleasure, also gives feelings of pleasure, also

depression, impairs judgment, memory, AIDS, depression, impairs judgment, memory, AIDS, death. death.

StimulantsStimulants Stimulants:Stimulants: increase activity of the nervous increase activity of the nervous

systemsystem Effects:Effects: speeds up the heart & breathingspeeds up the heart & breathing includes nicotine, amphetamines, & cocaineincludes nicotine, amphetamines, & cocaine

EffectsEffects 1) 1) Nicotine:Nicotine: causes release of adrenaline causes release of adrenaline * causes alertness, reduces appetite * causes alertness, reduces appetite * as addictive as heroine* as addictive as heroine * 400,000 people a year die from smoke * 400,000 people a year die from smoke

related illnessesrelated illnesses

2) 2) Amphetamines:Amphetamines: helps to stay awake & reduces helps to stay awake & reduces appetiteappetite

* 1st used in WWII* 1st used in WWII * produces feelings of pleasure* produces feelings of pleasure * causes hallucinations & delusions* causes hallucinations & delusions 3) 3) Cocaine:Cocaine: causes feelings of pleasure, reduces causes feelings of pleasure, reduces

hunger, deadens pain, and boosts self-confidencehunger, deadens pain, and boosts self-confidence Overdose symptoms include restlessness, Insomnia, Overdose symptoms include restlessness, Insomnia,

trembling, headaches, nausea, etc… trembling, headaches, nausea, etc…

Hallucinogens:Hallucinogens: Hallucinogen:Hallucinogen: causes hallucinations, causes hallucinations,

relaxation, pleasure, or feelings of panicrelaxation, pleasure, or feelings of panic Effects:Effects: 1) 1) Marijuana:Marijuana: impairs perceptions, impairs perceptions,

coordination, memory, & learningcoordination, memory, & learning * can cause anxiety & confusion* can cause anxiety & confusion 2) 2) LSD:LSD: (acid) produces hallucinations (acid) produces hallucinations * most injure themselves in a panic* most injure themselves in a panic

TreatmentTreatment Detoxification:Detoxification: removal of a harmful removal of a harmful

substance from the bodysubstance from the body 1) 1) Maintenance Programs:Maintenance Programs: given controlled given controlled

dosesdoses 2) 2) Counseling:Counseling: treats stimulant & depressant treats stimulant & depressant

abuseabuse 3) 3) Support Groups:Support Groups: people help because they people help because they

know what you’re going through know what you’re going through