Sensa&on(and(Percep&on( Sensa&on:(your(window(to(the(world(( Percep&on:(interpre&ng(what(comes(in(your(window.((

Transcription

1 Sensa&on(and(Percep&on( Sensa&on:(your(window(to(the(world(( Percep&on:(interpre&ng(what(comes(in(your(window.((

2 Bo:om;Up(Processing( Also(called(feature( analysis.( We(use(the(features(on( the(object(itself(to(build( a(percep&on.( Takes(longer(that(top; down(but(is(more( accurate.( ( Click(to(see(an(example(of( bo:om( up(processing.((

3 Top;Down(Processing( We(perceive(by(filling(the( gaps(in(what(we(sense.( I(_ant(ch_co_ate(ic_( cr_am.( Based(on(our(experiences( and(schemas.( If(you(see(many(old(men( in(glasses,(you(are(more( apt(to(process(a(picture(of( an(old(man((even(when( you(may(be(in(error).(

4 Psychophysics8 A$study$of$the$relationship$between$physical$ characteristics$of$stimuli$and$our$psychological$ experience$with$them.8 8 Physical$World8 Light8 Psychological$ World8 Brightness8 Sound8 Pressure8 Sugar8 Volume8 Weight8 Sweet8 6(

5 Signal(Detec&on(theory( Absolute(thresholds(are( not(really(absolute.( Things(like(mo&va&on(or( physical(state(can(effect( what(we(sense.( False(Posi&ves( False(Nega&ves( If(a(baby(whimpers(in(the(night,(mom(is(up(and( listening.((other(noises(don t(even(phase(mom.((

6 Thresholds8 Absolute$Threshold:$Minimum$stimulation$needed$ to$detect$a$particular$stimulus$50%$of$the$time.8 Proportion$of$ Yes $Responses8 0.00$$$$$$$$$$$$$$$$$0.50$$$$$$$$$$$$$$$$1.008 $$$$$$$$$$$$$0$$$$$$$$$$$$5$$$$$$$$$$$$10$$$$$$$$$$$15$$$$$$$$$$20$$$$$$$$$$258 $$$$$$$$$$$$$$$$$$$$$$$$$$$Stimulus$Intensity$(lumens)8 10(

7 Subliminal$Threshold8 Subliminal$Threshold:$ When$stimuli$are$below$ one s$absolute$threshold$for$ conscious$awareness.8 Kurt Scholz/ Superstock 11(

8 Difference$Threshold8 Difference$Threshold:$Minimum$difference$ between$two$stimuli$required$for$detection$50%$ of$the$time,$also$called$just$noticeable$difference$ (JND).( Difference8 Threshold8 No8 No8 Yes8 Observer s Response Tell$when$you$(observer)$detect$a$difference$in$the$light.7 13(

9 Weber s(law( Computes(the(Just( No&ceable(Difference.( The(change(needed(is( propor&onal(to(the(original( intensity(of(the(s&mulus.( The(more(intense(the( s&mulus(the(more(change( is(needed(to(no&ce(the( difference.( 8%(for(vision.(

10 Sensory(Adapta&on( Decreased( responsiveness(to( s&muli(due(to(constant( s&mula&on.( Do(you(feel(your(underwear(all(day?(

11 Cocktail;party(phenomenon( The(cocktail%party%effect( describes(the(ability(to( focus(one's(listening( a:en&on(on(a(single(talker( among(a(mixture(of( conversa&ons(and( background(noises,( ignoring(other( conversa&ons.( Form(of(selecBve%aCenBon.(

12 Ina;entional$Blindness! to$see$an$object$or$a$person$in$our$midst.$ Simmons$&$Chabris$(1999)$showed$that$half$ of$the$observers$failed$to$see$the$gorillav suited$assistant$in$a$ball$passing$game.$8 Daniel Simons, University of Illinois

13 Transduc&on( Transforming(signals( into(neural(impulses.( Informa&on(goes(from( the(senses(to(the( thalamus(,(then(to(the( various(areas(in(the( brain.( Remember(Ethan(in(Sky(High.((He(changes(his( body(to(slime.((solid(form(to(liquid(form.((( Change(from(one(form(of(energy(to(another.(( Click(the(picture(to(watch(power(placement.((

14 Phase(One:(Gathering(Light( The(height(of(a(wave(gives(us(its(intensity((brightness).(( The(length(of(the(wave(gives(us(its(hue((color).( ROY(G(BIV( The(longer(the(wave(the(more(red.( The(shorter(the(wavelength(the(more(violet.((

15 Energy v. Chemical senses Energy%Senses% Chemical%Senses%

16 Vision Our(most(dominant(sense.( % Visual%Capture%

17 Phase(Two:(Gejng(the(light(in(the(eye(

18 Parts$of$the$eye8 1. Cornea:$Transparent$tissue$where$light$enters$ the$eye.8 2. Iris:$Muscle$that$expands$and$contracts$to$ change$the$size$of$the$opening$(pupil)$for$light.8 3. Lens:$Focuses$the$light$rays$on$the$retina.8 4. Retina:$Contains$sensory$receptors$that$process$ visual$information$and$sends$it$to$the$brain.8 25(

19 The$Lens8 Lens:$$Transparent$ structure$behind$the$ pupil$that$changes$shape$ to$focus$images$on$the$ retina.8 8 Accommodation:$The$ process$by$which$the$ eye s$lens$changes$ shape$to$help$focus$near$ or$far$objects$on$the$ retina.8 26(

20 Nearsightedness:$A$ condition$in$which$ nearby$objects$are$seen$ more$clearly$than$ distant$objects.8 8 Farsightedness:$A$ condition$in$which$ faraway$objects$are$ seen$more$clearly$than$ near$objects.$8 The$Lens8 27(

21 Retina8 Retina:$The$lightV sensitive$inner$ surface$of$the$eye,$ containing$receptor$ rods$and$cones$in$ addition$to$layers$of$ other$neurons$ (bipolar,$ganglion$ cells)$that$process$ visual$information.8 28(

22 Optic$Nerve,$Blind$Spot$&$Fovea8 Optic$nerve:$Carries$neural$impulses$from$the$eye$to$the$ brain.$blind$spot:$point$where$the$optic$nerve$leaves$the$ eye$because$there$are$no$receptor$cells$located$there.$$this$ creates$a$blind$spot.$fovea:$central$point$in$the$retina$ around$which$the$eye s$cones$cluster (

23 Test$your$Blind$Spot8 Use$your$textbook.$Close$your$left$eye,$and$fixate$ your$right$eye$on$the$black$dot.$move$the$page$ towards$your$eye$and$away$from$your$eye.$at$ some$point$the$car$on$the$right$will$disappear$due$ to$a$blind$spot.8 30(

24 Phase(Three:(Transduc&on(

25 Transduc&on(Con&nued( Order(is(Rods/Cones(to( Bipolar(to(Ganglion(to(Op&c( Nerve.( Sends(info(to(thalamus;( area(called(lateral% geniculate%nucleus%(lgn).( Then(sent(to(cerebral( cortexes.( Where(the(op&c(nerves( cross(is(called(the(opbc% chiasm.(

26 Visual$Information$Processing8 Optic$nerves$connect$to$the$thalamus$in$the$ middle$of$the$brain,$and$the$thalamus$connects$to$ the$visual$cortex.8 34(

27 Feature$Detection8 Nerve$cells$in$the$visual$cortex$respond$to$ specific$features,$such$as$edges,$angles,$and$ movement.8 Ross Kinnaird/ Allsport/ Getty Images 35(

28 Visual$Information$Processing8 Processing$of$several$aspects$of$the$stimulus$ simultaneously$is$called$parallel$processing.$the$ brain$divides$a$visual$scene$into$subdivisions$such$ as$color,$depth,$form$and$movement$etc.8 36(

29 Color(Vision( Two Major Theories

30 Trichroma&c(Theory( Three(types(of(cones:( Red( Blue( Green( These(three(types(of( cones(can(make(millions( of(combina&ons(of( colors.( Does(not(explain( anerimages(or(color( blindness(well.(

31 Color$Blindness8 Genetic$disorder$in$which$people$are$blind$to$ green$or$red$colors.$$this$supports$the$ Trichromatic$theory.8 Ishihara$Test8 39(

32 Opponent$Colors8 Gaze$at$the$middle$of$the$flag$for$about$308 Seconds.$When$it$disappears,$stare$at$the$dot$and$report8 whether$or$not$you$see$britainks$flag.8 40(

33 Color$Constancy8 Color$of$an$object$remains$the$same$under$ different$illuminations.$however,$when$context$ changes$the$color$of$an$object$may$look$different.8 R. Beau Lotto at University College, London 41(

34 Constancy( Objects(change(in(our( eyes(constantly(as(we( or(they(move.but(we( are(able(to(maintain( content(percep&on( Shape(Constancy( Size(Constancy( Brightness(Constancy(

35 Opponent;Process(theory( The(sensory(receptors( come(in(pairs.( Red/Green( Yellow/Blue( Black/White( If(one(color(is( s&mulated,(the(other(is( inhibited.(

36 Hearing( Our auditory sense (audition)

37 We(hear(sound(WAVES( The(height(of(the(wave(gives(us(the(amplitude(of(the( sound.( The(frequency(of(the(wave(gives(us(the(pitch(if(the(sound.(

38 The(Ear(

39 Transduc&on(in(the(ear( Sound(waves(hit(the(eardrum(then( anvil%then(hammer(then(sbrrup(then( oval%window.( Everything(is(just(vibra&ng.( Then(the(cochlea(vibrates.( The(cochlea(is(lined(with(mucus( called(basilar%membrane.( In(basilar%membrane%there(are(hair( cells.( When(hair(cells(vibrate(they(turn( vibra&ons(into(neural(impulses(which( are(called(organ%of%corb.( Sent(then(to(thalamus(up(auditory( nerve.( It(is(all(about(the(vibra&ons!!!(

40 Pitch(Theories( Place(Theory(and(Frequency(Theory(

41 Place(Theory( Different(hairs(vibrate( in(the(cochlea(when( they(different(pitches.( So(some(hairs(vibrate( when(they(hear(high( and(other(vibrate(when( they(hear(low(pitches.(

42 Frequency(Theory( All(the(hairs(vibrate(but( at(different(speeds.( ( (

43 Deafness( ConducBon%Deafness% Something(goes(wrong(with( the(sound(and(the(vibra&on( on(the(way(to(the(cochlea.( You(can(replace(the(bones( or(get(a(hearing(aid(to(help.( Nerve%(sensorineural)%Deafness% The(hair(cells(in(the(cochlea( get(damaged.( Loud(noises(can(cause(this( type(of(deafness.( NO(WAY(to(replace(the(hairs.( Cochlea(implant(is(possible.(

44 Hearing$Deficits8 Older$people$tend$to$hear$low$frequencies$well$but$suffer$ hearing$loss$when$listening$for$high$frequencies.8 53(

45 Deaf$Culture8 Cochlear$implants$are$electronic$devices$that$ enable$the$brain$to$hear$sounds.$8 Deaf Musician EG Images/ J.S. Wilson Cochlear Implant Wolfgang Gstottner. (2004) American Scientist, Vol. 92, Number 5. (p. 437) 54(

46 Biopsychosocial$Influences8 56(

47 Gate%Control%Theory%of%Pain% pain(messages(start(from( nerves(associated(with(the( damaged(&ssue(and(flow( along(the(peripheral(nerves( to(the(spinal(cord(and(on(up( to(the(brain.( before(they(can(reach(the( brain(these(pain(messages( encounter( nerve(gates (in( the(spinal(cord(that(open(or( close(depending(upon(a( number(of(factors( Touch(

48 Taste( We(have(bumps(on(our( tongue(called(papillae.( Taste(buds(are(located( on(the(papillae((they( are(actually(all(over(the( mouth).( Sweet,(salty,(sour(and( bi:er.(

49 Taste8 Traditionally,$taste$sensations$consisted$of$sweet,$ a$fifth$taste$have$been$discovered$called$ Umami.3 Sweet Sour Salty Bitter Umami (Fresh Chicken) 59(

50 Smell$and$Memories8 The$brain$region$for$ smell$(in$red)$is$closely$ connected$with$the$ brain$regions$involved$ with$memory$(limbic$ system).$that$is$why$ strong$memories$are$ made$through$the$sense$ of$smell.8

51 Sensory$Interaction8 When$one$sense$affects$another$sense,$sensory$ interaction$takes$place.$so,$the$taste$of$strawberry$ interacts$with$its$smell$and$its$texture$on$the$ tongue$to$produce$flavor.3

52 Ves&bular(Sense( Tells(us(where(our(body( is(oriented(in(space.( Our(sense(of(balance.( Located(in(our( semicircular(canals(in( our(ears.(

53 Kinesthe&c(Sense( Tells(us(where(our(body( parts(are.( Receptors(located(in( our(muscles(and(joints.( Without(the(kinesthe&c(sense(you( could(not(touch(the(bu:on(to(make( copies(of(your(bu:ocks.(

54 Percep&on( The(process(of(organizing(and(interpre&ng( informa&on,(enabling(us(to(recognize(meaningful( objects(and(events.(

55 Perceptual$Organization8 When$vision$competes$with$our$other$senses,$ vision$usually$wins$ $a$phenomena$called$visual$ capture.8 8 How$do$we$form$meaningful$perceptions$from$ sensory$information?8 8 We$organize$it.$Gestalt$psychologists$showed$that$ a$figure$formed$a$ whole $different$than$its$ surroundings.8

56 Gestalt(Psychology( Gestalt(psychologists(focused(on(how(we( GROUP(objects(together.( We(innately(look(at(things(in(groups(and( not(as(isolated(elements.( Proximity((group(objects(that(are(close( together(as(being(part(of(same(group)( Similarity((objects(similar(in(appearance( are(perceived(as(being(part(of(same( group)( ConBnuity((objects(that(form(a( con&nuous(form(are(perceived(as(same( group)( Closure%(like(top;down(processing we(fill( gaps(in(if(we(can(recognize(it)(

57 Grouping8 After$distinguishing$the$figure$from$the$ground,$ our$perception$needs$to$organize$the$figure$into$ a$meaningful$form$using$grouping$rules.8

58 Grouping$&$Reality8 Although$grouping$principles$usually$help$us$construct$ reality,$they$may$occasionally$lead$us$astray.8 Both photos by Walter Wick. Reprinted from GAMES Magazine PCS Games Limited Partnership

59 Figure(Ground(Rela&onship( Our(first(perceptual(decision( is(what(is(the(image(is(the( figure(and(what(is(the( background.(

60 Depth(Cues( Eleanor(Gibson(and(her( Visual%Cliff%Experiment.( If(you(are(old(enough(to( crawl,(you(are(old(enough( to(see(depth(percep&on.( We(see(depth(by(using( two(cues(that(researchers( have(put(in(two( categories:(( Monocular(Cues( Binocular(Cues((

61 Binocular(Cues( We(need(both(of(our( eyes(to(use(these(cues.( ReBnal%Disparity%(as(an( object(comes(closer(to(us,( the(differences(in(images( between(our(eyes( becomes(greater.( Convergence((as(an( object(comes(closer(our( eyes(have(to(come( together(to(keep(focused( on(the(object).(

62 Binocular$Cues8 Retinal$disparity:$Images$from$the$two$eyes$differ.$Try$ looking$at$your$two$index$fingers$when$pointing$them$ towards$each$other$half$an$inch$apart$and$about$5$inches$ directly$in$front$of$your$eyes.$you$will$see$a$ finger$ sausage $as$shown$in$the$inset.8

63 Binocular$Cues8 Convergence:$Neuromuscular$cues.$When$two$ eyes$move$inward$(towards$the$nose)$to$see$near$ objects$and$outward$(away$from$the$nose)$to$see$ faraway$objects.8

64 Monocular$Cues8 Relative$Size:$If$two$objects$are$similar$in$size,$we$ perceive$the$one$that$casts$a$smaller$retinal$image$ to$be$farther$away.8

65 Monocular$Cues8 Interposition:$Objects$that$occlude$(block)$other$ objects$tend$to$be$perceived$as$closer.8 Rene Magritte, The Blank Signature, oil on canvas, National Gallery of Art, Washington. Collection of Mr. and Mrs. Paul Mellon. Photo by Richard Carafelli.

66 Monocular$Cues8 Relative$Clarity:$Because$light$from$distant$objects$ passes$through$more$light$than$closer$objects,$we$ perceive$hazy$objects$to$be$farther$away$than$ those$objects$that$appear$sharp$and$clear.8

67 Monocular$Cues8 Texture$Gradient:$Indistinct$(fine)$texture$signals$ an$increasing$distance.8 Eric Lessing/ Art Resource, NY

68 Monocular$Cues8 Relative$Height:$We$perceive$objects$that$are$higher$in$our$ field$of$vision$to$be$farther$away$than$those$that$are$lower.8 Image courtesy of Shaun P. Vecera, Ph. D., adapted from stimuli that appered in Vecrera et al., 2002

69 Monocular$Cues8 Relative$motion:$Objects$closer$to$a$fixation$point$ move$faster$and$in$opposing$direction$to$those$ objects$that$are$farther$away$from$a$fixation$point,$ moving$slower$and$in$the$same$direction.$8

70 Monocular$Cues8 Linear$Perspective:$Parallel$lines,$such$as$railroad$ tracks,$appear$to$converge$in$the$distance.$the$ more$the$lines$converge,$the$greater$their$ perceived$distance.8 The New Yorker Collection, 2002, Jack Ziegler from cartoonbank.com. All rights reserved.

71 Monocular$Cues8 Light$and$Shadow:$Nearby$objects$reflect$more$light$into$ our$eyes$than$more$distant$objects.$given$two$identical$ objects,$the$dimmer$one$appears$to$be$farther$away.8 From Perceiving Shape From Shading by Vilayaur S. Ramachandran by Scientific American, Inc. All rights reserved.

72 Apparent$Motion8 Phi$Phenomenon:$When$lights$flash$at$a$certain$ speed$they$tend$to$present$illusions$of$motion.$ Neon$signs$use$this$principle$to$create$motion$ perception.8 Two lights flashing one after the other. One light jumping from one point to another: Illusion of motion.

73 Perceptual$Constancy8 Perceiving$objects$as$unchanging$even$as$ illumination$and$retinal$images$change.$perceptual$ constancies$include$constancies$of$shape$and$size.8 Shape$Constancy8

74 Size$Constancy8 Stable$size$perception$amid$changing$size$of$the$ stimuli.8 Size$Constancy8

75 SizeVDistance$Relationship8 The$distant$monster$(below,$left)$and$the$top$red$ bar$(below,$right)$appear$bigger$because$of$ distance$cues.8 Alan Choisnet/ The Image Bank From Shepard, 1990

76 SizeVDistance$Relationship8 Both$girls$in$the$room$are$of$similar$height.$ However,$we$perceive$them$to$be$of$different$ heights$as$they$stand$in$the$two$corners$of$the$ room. Both photos from S. Schwartzenberg/ The Exploratorium

77 Ames$Room8 The$Ames$room$is$designed$to$demonstrate$the$sizeV distance$illusion.8

78 Perceived(Mo&on( Stroboscopic(effect((flip( book(effect)( Phi(phenomenon(( Autokine&c(Effect((if( people(stare(at(a(white( spotlight(in(a(dark( room,(it(appears(to( move.)(

79 Monocular(Cues( You(really(only(need( one(eye(to(use(these( (used(in(art(classes(to( show(depth).( Linear(Perspec&ve( Interposi&on( Rela&ve(size( Texture(gradient( Shadowing(

80 Perceptual$Adaptation8 Visual$ability$to$adjust$ to$an$artificially$ displaced$visual$field,$ e.g.,$prism$glasses.8 Courtesy of Hubert Dolezal

81 Perceptual$Set8 A$mental$predisposition$to$perceive$one$thing$ and$not$another.$what$you$see$in$the$center$ picture$is$influenced$by$flanking$pictures.8 From Shepard, 1990.

82 Perceptual$Set8 Other$examples$of$perceptual$set.8 Dick Ruhl Frank Searle, photo Adams/ Corbis-Sygma (a)$loch$ness$monster$or$a$tree$trunk;$$$$$$ (b)$flying$saucers$or$clouds?8

83 Schemas8 Schemas$are$concepts$that$organize$and$ interpret$unfamiliar$information.8 Courtesy of Anna Elizabeth Voskuil Childrenks$schemas$represent$reality$as$well$as$their$ abilities$to$represent$what$they$see.8

84 Claims$of$ESP8 1. Telepathy:$MindVtoVmind$communication.$One$ person$sending$thoughts$and$the$other$ receiving$them.$8 2. Clairvoyance:$Perception$of$remote$events,$ such$as$sensing$a$friend s$house$on$fire.8 3. Precognition:$Perceiving$future$events,$such$as$ a$political$leader s$death.8

85 Premonitions$or$Pretensions?8 Can$psychics$see$the$future?$Can$psychics$aid$ police$in$identifying$locations$of$dead$bodies?$ What$about$psychic$predictions$of$the$famous$ Nostradamus?8 8 The$answers$to$these$questions$are$NO!$ Nostradamus $predictions$are$ retrofi@ed $to$ events$that$took$place$after$his$predictions.8

86 In$an$experiment$with$28,000$individuals,$ can$psychically$influence$or$predict$a$coin$toss.$ People$were$able$to$correctly$influence$or$predict$a$ coin$toss$49.8%$of$the$time.8