Sensation and Perception

1. Welcome…
1A.S.Arul Lawrence, U.S.P.College of Education

2. 2A.S.Arul Lawrence, U.S.P.College of Education

3. 3A.S.Arul Lawrence, U.S.P.College of Education

4. Whether ghost is
present or not?
OK…
Come along with me to
find out the truth…
4A.S.Arul Lawrence, U.S.P.College of Education

5. A.S.Arul Lawrence M.Sc., M.Phil.(Zoo.), M.Ed., M.Phil.(Edn.), NET,
Principal, U.S.P.College of Education,
Tenkasi-627804, Tamil Nadu.
E-mail: [email protected],
Mobile: [phone]

6. Sensation: Meaning
Anyexperiencethattakesplacethrougha
senseorganiscalledSensation.
Sensationisalsocalledasthegatewaysof
knowledge,becauseallourknowledgeis
baseduponthefunctioningofsenseorgans.
Sensationisthesimpleandmostelementary
process,whichcreatesthedesiretoworkfor
somethingandhowtoknowsomethingbased
onpreviousexperiences.
Itispurelysensoryknowledge,whichdoesnot
haveanyrelationshipwithanyknowledgeor
awareness.
Asensationdoesnothelpusacquiring
completeknowledge.
6A.S.Arul Lawrence, U.S.P.College of Education

7. Definitions:
Theimpressionsreceivedthroughthesense
organsarecalledsensations–Mathur.
Asensationisanelementarycognitive
experience–Dr.Jalota.
Sensationsarefirstthingsinthewayof
consciousness–James.
Sensationisdefinedasthesimplestofall
consciousexperience–DuglasandHalland.
Sensationistheprocessofreceiving,
translatingandtransmittinginformationtothe
brainfromtheexternalandinternal
environment–Huffman.
7A.S.Arul Lawrence, U.S.P.College of Education

8. Types of Sensation:
Wecandivideeasilythesensation
processintofivecategoriesonthebasis
ofsenseorgans.
1.VisualSensation
2.AuditorySensation
3.OlfactorySensation
4.TasteSensation
5.TactualSensation
8A.S.Arul Lawrence, U.S.P.College of Education

9. Organs involved in
Sensation:
Eye
Ear
Nose
Tongue
Skin
9A.S.Arul Lawrence, U.S.P.College of Education

10. Sl.
No.
Type of Sensation
Sense
Organ
Senses
Knowledge
gaining
1.Visual Sensation Eye Sight 83%
2.Auditory SensationEar Hear 11%
3.
Olfactory
Sensation
Nose Smell 3.5%
4.Taste SensationTongue Taste 1.0%
5.Tactual SensationSkin Touch 1.5%
10A.S.Arul Lawrence, U.S.P.College of Education

11. Elements of Sensation:
Themainelementsofthesensationprocessare
givenbelow:
Quality:Thenatureofeachsensationisdifferent
fromother.Everytypeofsensationhasgotitsown
specialqualityorcharacteristics.Thisqualityofthe
sensationhelpsustodistinguishonefromother.For
example,greensensationofeye,coldsensationof
skin.
Intensity:Sensationdiffersinrespectofits
intensity.Iftwosoundsarecreatedatonce,onewill
betheintenserthanother.Itisdiffersinsametypeof
senseoramongthedifferenttypesofsensations.
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12. Elements…
Extensity:Extensityreferstheextensionin
space.Eachsensationhasitsextensity.The
vasterthestimulus,themoreextensivethe
sensation.Theextensityisnottrueforallthe
typesofsensation,butrestrictedtocertain.
Duration:Everysensationhasitsdurationor
lastsforcertaintime.Theauditorysensationof
aeroplanesoundismoreextensivethanthe
soundofthecallingbell.
Clarity:Everysensationhasgotclarity.The
sensationwhichlastsforlongerperiod
becomesclearerthanthesensationlastsfor
shorterperiod.
12A.S.Arul Lawrence, U.S.P.College of Education

13. Perception: Meaning
Whenthingscomeintocontactwithanyof
oursenseorgans,wefeelsensation.When
braincomestoknowtheformofthese
sensations,itcomestoknowthestimulus
fully.Thiscognitiveexperienceofthebrain
iscalledperception.
Perceptionistheprocessbywhichan
organisminterpretssensoryinputsothatit
acquiresmeaning.
Perception = Sensation + Meaning (interpretation).
13A.S.Arul Lawrence, U.S.P.College of Education

14. Definitions:
Perceptionistheprocessofgettingto
knowobjectsandobjectivefactsbyuse
ofsenses–Woodworth.
Perceptionreferstothecomplex
processeswhichbeginwiththe
stimulationofasenseorganandend
withaninterpretationoftheresulting
neuralactivitybytheorganismi.e.with
themeaningofthestimulus–JamesA.
Dyal.
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15. Perception:
Allknowledgeoftheworldisultimately
obtainedthoroughsensoryexperiences.
Sensationaloneismeaninglessanditwill
notresultinacquisitionofknowledge.
Sensationistobefollowedbyapplication
ofmind.Thenitresultsinperception.
Inotherwordswecansaythatthefirst
responsetoastimulusissensationand
perceptionisthenextresponsefollowing
sensation.
15A.S.Arul Lawrence, U.S.P.College of Education

16. Nature of Perception:
Perceptionismeaningful.
Perceptionisselective.
Perceptionisbasedonsensation.
Perceptionispreventiveandrepresentative
processofmind.
Perceptionneedsobservation/experience.
Perceptionmakesuseofimages.
Perceptionisbothanalyticandsynthetic.
Inperceptionsensorydatagetsenriched.
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17. Factors related to
Perception
Thereareseveralfactorsinvolvedin
perception.Theyarecategorizedunder
twotypesnamely,
Externaland
Internalfactors.
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18. External Factors:
Similarity:Similarelements
tendtobeperceivedas
belongtogetherandthey
areviewedaswholes.
Stimulithathavethesame
size,shapeandcolour
tendtobeperceivedas
partsofthepattern.
18A.S.Arul Lawrence, U.S.P.College of Education

19. External…
Proximity:Whenobjectsare
closetoeachother,the
tendencyistoperceivethem
togetherratherthanseparately.
Eveniftheindividualitemsdo
nothaveanyconnectionwith
eachothertheywillbegrouped
underasinglepatternor
perceivedasameaningful
picture.
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20. External…
Continuity:Anything which
extendsitselfintospaceinthe
sameshape,sizeandcolour
withoutabreakisperceivedasa
wholefigure.
Forexample,severaldotsfroma
curvedline,anindividualmay
perceivethefigureastwodifferent
continuouslinesirrespectiveofthe
factorslikeproximityandsimilarity
ofthedots.Thus,thewholefigure
isorganizedintoacontinuum
thoughthedotsareunconnected.
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21. External…
Inclusiveness:Thepatternwhich
includesalltheelementspresent
inagivenfigurewillbeperceived
morereadilythantheother
figures.
Thehexagonalfigureformedby
allthedotsmaybeperceived
morereadilythanthesquare
formedbythefourmiddledots.
Singledotsateitherendactasa
fenceorenclosurewithinwhich
alltheotherelementsare
included.
21A.S.Arul Lawrence, U.S.P.College of Education

22. External…
Closure:Closedareasmorereadilyformin
group.Theillusionoffigurewascausedby
closurewhichdidnotallowtheattentionto
dwellonbygaps,sothatthefigures
appearedorganized.
22A.S.Arul Lawrence, U.S.P.College of Education

23. Internal Factors:
Familiarity:Anorganisationwithwhichthe
personisaquatinted,isperceivedeasily
andwithenthusiasm.Seeingafamiliar
picturequiz,weatonceunderstandits
realityandsolutionandtheremaining
figureformsnoobstacleinthis.Butifthe
aquatintedpersonisaffectedbysome
otherpartofthepicture,hewillbe
incapableofrecognizingit,not
withstandinghisfamiliarity.
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24. Internal…
MentalSet:Mentalsethasabynomeans
insignificanteffectupontheorganizationofthe
sensation.Oneofthecausesofmentalsetis
habit.Forexample,aphilosopherlooksatthe
truthsoftheuniverse,whileatraderisalways
involvedinworthythings.
ReinforcingFactors:Theseincludegoodfigure.
Thesupplementingoftheincompleteisamental
tendency,whichdivertsourattentionfromgaps
andpresentsawhole.Theideaofgoodfigureis
explainedbythepicture,inthedescriptionof
closure.
24A.S.Arul Lawrence, U.S.P.College of Education

25. Perceptual Errors:
Itisquitepossiblethatthesameobject
maybeperceiveddifferentlybydifferent
peopleorbythesamepersonondifferent
occasions.
Therearetwoerrorsofperceptionnamely
illusionandhallucination.
25A.S.Arul Lawrence, U.S.P.College of Education

26. Illusion:
Awrongperceptioniscalledillusion.
Astateinwhicherrorsofperceptionare
immediatelyconfirmedbyexperienceis
calledanillusion.
Inillusionwetakeawrongmeaningof
thestimuluspresentbeforeus.Itis
relatedwiththestimulus.
26A.S.Arul Lawrence, U.S.P.College of Education

27. Forexample,atdimlighttheropethatwe
findonthewayistakenforasnake.Error
mayresultfrominadequatestimulation,
poorlyfunctioningsenseorgansorincorrect
interpretationofsensations.
27A.S.Arul Lawrence, U.S.P.College of Education

28. Common types of
illusions:
Illusionregardingdistance
Illusionregardingsizeandshapeofthe
things
Illusionregardingcolour
Illusionregardingmovementandspeed
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34. Causes for Illusion:
Irregularorunusualconditionsinthe
externalworld
Defects in sensory organs
Anticipation expectation and suggestions
Interest and habits
Previous experience and present
selfishness
Present aptitudes
34A.S.Arul Lawrence, U.S.P.College of Education

35. Hallucination:
Hallucinationisfalseperception.Here,a
personexperiencesofthestimuluseveninthe
absenceofit.
Ahallucinationisamentalstateinwhicha
personbeginstoperceivesomethinginspite
oftheabsenceofanyexternalstimulus.
Forexample,atnightapersonmayseea
ghostwhenpracticallythereisnostimulus
eitherintheformofahumanfigureor
anythingresemblingit.Thisisacaseof
hallucination.Thereisnostimulusin
hallucinationandmemoryimageistakenfor
perception.
35A.S.Arul Lawrence, U.S.P.College of Education

36. Types of Hallucination:
Therearetwokindsofhallucinations.
VisualHallucination:Ahallucinationwhich
occursinthesphereofvisioniscalleda
visualhallucination,anditmeansseeingan
objectwhichisnotinfrontofeyesatall.
AuditoryHallucination:Thehallucination
whichoccursinthesphereofhearingis
calledauditoryhallucination.Forexample,
whilesittinginsolitudeorloneliness,wemay
suddenlyfeel,thatsomeoneiscallingus,
through,inrealitynoonehascalledus.
36A.S.Arul Lawrence, U.S.P.College of Education

37. Causes for Hallucination:
More but vague and irrelevant continuous
thinking
Excessive imagination or day-dreaming
The will and desire in the unconscious
mind
Hysteria / madness, schizophrenia and
other related mental diseases.
37A.S.Arul Lawrence, U.S.P.College of Education

38. Difference: Sensation &
Perception
Sl. No Sensation Perception
1.
Sensation is a normal,
simplest, initial mental
process
Perception is a complex and
developed mental activity
2.It begins with stimulus
It begins with some object /
fringe of meaning
3.
It is based on external
stimuli, conditions
It is associated with internal
mental conditions
4.
There is passivity in
sensation
There is activity in perception
5.
The basis of sensation is
mental analysis
The processes of perception
linked with actual life
experience.
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39. Review
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40. Evaluation
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