Slides on perception

1. Perception
• It is a complex mental process and unlike sensation, it provide
the meaning
• It refers to the activity of sensing, interpreting and appreciating
social and physical objects and reacting to them.
• It is the identification of sensation.
• It provide the immediate knowledge of environmental stimulus.
• It is organizing process by which we interpret our sensory input.
• The impression received by brain are organized in meaningful
pattern.

2. Some definitions
• Perception is process of obtaining knowledge of external objects
and events by means of senses - Stagner and Karwoski, 1952.
• Perception is the first event of a chain which leads from stimulus
to action. –E.G. Boring and H.S. langfield
• Perception may be defined as the process by which sensory
input is interpreted. Chapman et al.
• Perception is the individual’s awareness aspect of behaviour, for
it is the way each person processes the raw data he or she
receives from environment, into meaningful pattern.- R.E.
Silverman.
• Perception is the organizing process by which we interpret our
input.- E. Fantino and G.S Renolds 1975.

3. Conclusions
• Perception is process.
• Perception is information extractor.
• Perception is preparation to response.
• Perception involve sensation.
• Perception provides organization.
• Perception is highly individualized.

4. Sensation Vs Perception
Sensation
• It is the primary mental process
and Ist step in the process of
knowledge.
• It meaningless.
• Sense organs have greater role
• Past experience is not involved.
• Awareness of immediate
knowledge.
• It is abstract mental process
Perception
• It is the complex process and 2nd
step in the process of
knowledge.
• It is meaningful.
• Brain is more active in sensation.
• Past experience is must.
• immediate knowledge is
interpreted
• It is concrete mental process.

5. Top down and bottom up processing
• Perception involves bottom up and top down
process
 Bottom up.
The first step of perception or sensory analysis is to
receive the stimulus.
The sensory receptors receive the stimulus, in
response to stimulus, the sensory impulse are
formed.
The impulses transfer to higher brain centre where
it is processed.
The process of sensory analysis with basic
elements and working toward higher complex level
is known as bottom up process.
The cycle goes on: stimulus receptors Brain

6. Top down and bottom up processing
 Top down
 After receiving the sensory impulses, it goes through several stages
of analysis.
 Past experiences, expectation, aim , interest etc process the
information that are received from receptors.
 It is higher level of processing which give the identity and knowledge
of stimulus.
 Finally, whole object, place and event are recognized in complex form.
 This is called top down process by psychologist.
 The process goes like:
stimulus receptors brain effectors perception

7. Process of perception
• Perception is process of obtaining knowledge of
external objects and events by means of senses.
• The mechanism involved in perceiving the
behaviour , experience and response.
• The process of perception involves:
• Receptor process
• Symbolic process
• Affective process
• Unification process

8. Process of perception
Receptor process
 Receptors cells specialized cells located in eyes, ear, nose, skin,
tongue.
 These cells are sensitive to stimulus and give the knowledge of
sensory stimulation.
 Whenever information reaches the receptors, the receptor cells
response to it, it is called receptor process.
 When you see your best friend calling you, seeing her, your rods
and cones becomes active, hearing the sound sensory receptor
of basilar membrane are stimulated.
 When you shake hands, your cutaneous receptor stimulated and
smell of her perfume stimulate the olfactory receptors.
 These receptor activate simultaneously but the perception
process is limited to particular process.
 For example, when your friend call you, at the same time mobile
rings….
 You give the any one which is you think more important

9. Process of perception
Symbolic process
 In the substitution of actual objects, mental image of different
smell, ideas, signs, symbols, shapes, memories, language etc in
the brain are also used in perception.
 The mental activity help in symbolic way to process selective
response.
 The past experiences are also used in symbolic process.
 Symbolic images are formed by the neural activity of sense
organ in the absence actual stimuli.
 For example you have lost pen.
 You try to remember all the activities you have carried during
whole day through symbolic process.


10. Process of perception
affective process
 In perception , there is not only images of the object but also
impression like pleasant-unpleasant; liked –disliked; interesting –
uninteresting; love –hate etc.
 Affective process is the feeling and sentiments attached to an
objects or person.
 Affective process overlaps the recall of past experiences of receptor
and symbolic functions.
 Affective process are also related to the situation, if is favorable
individual take pleasure if not he may be against to it.
 The pleasantness unpleasantness may be related to physical
condition of the individual.
 For example, if a person is hungry situation is pleasant and it is
related to organic process as salivation, gastric secretion etc
 If he is sick, it may be highly unpleasant.
 Affective process also involve aesthetic experiences which may be
perceived as beautiful, ugly or indifferent

11. Process of perception
Unification Process
 Meaningful interpretation of something we have perceived is
not only possible by receptor, symbolic and affective process
alone.
 It is possible only through their combined effort.
 Unification process states that all the process needed to
understand clearly what we have perceived.
 For example; when you shake hand with a friend, there is
arousal of different sensation like visual, auditory, cutaneous,
and particular odor, it is receptor process
 At the same you just recall your first meeting , which is
symbolic process.
 You like him and want to meet him time to time ( affective
process)
 All these process work together to give you knowledge and
understanding about your friend, and it is unification process.

12. Principles of perception
Koffka, Kohlar
• It is based on Gestalt means whole or totality.
• A/c gestalt, Individuals have tendency to perceive sensory
patterns as well organized wholes rather than separate or
isolate parts.
• Some principles are
Principle of figure ground relationship.
Principle of closure.

13. Principle of grouping.(organised
meaning full pattern by grouping them).
• Similarity
Proximity
• .

14. •
• Continuiy
Principle of simplicity. ( information about parts
provide knowledge
Principle of counter.
Principle of context. ( A word or phrase mean
different )
Principle of contrast

15. • Principle of contrast

16. Subliminal perception
• Subliminal stimuli are any sensory stimuli below an individual's threshold for
conscious perception.
• Subliminal perception is supposed to occur when a stimulus is too weak to be
perceived yet a person is influenced by it.
• A recent review of functional magnetic resonance imaging (fMRI) studies
shows that subliminal stimuli activate specific regions of the brain
despite participants being unaware.]
• Visual stimuli may be quickly flashed before an individual can process them,
or flashed and then mask, thereby interrupting the processing.
• Audio stimuli may be played below audible volumes or masked by other
stimuli.
• Recent experiment showed that under certain condition they influence us
though we are unaware of them.
• Prakanis (1956 ) demonstrated an experiment to study subliminal perception
in movie theater. The movie audiences were presented an ads of popcorn
and soft drinks for fraction of a second. However movie viewer were
unaware of ads, still the sale of popcorn and soft drinks was found to be
higher. This was because subliminal perception had unconscious attraction to
these stumli and also had extra ordinary suggestive powers.

17. Extrasensory perception
• ESP is most commonly called the "sixth sense”
• It is sensory information that an individual receives
which comes beyond the ordinary five senses sight,
hearing, smell, taste, and touch.
• It is the perception without sensation.
• ESP is also called ‘psi’ means transfer of unusual
energy which have no scientific basis.
• It can provide the individual with information of the
present, past, and future; as it seems to originate in
a second, or alternate reality.
it seems to originate in a second, or alternate
reality.
• In function, ESP is dissimilar to the ordinary senses.

18. Extrasensory perception
• ESP includes
 telepathy, or thought transference between
persons
 clairvoyance, or supernormal awareness of
objects
 precognition, or knowledge of the future

19. Illussion
 It is the false interpretation about stimulus.
 It is the incorrect perception or misjudgment.
 Misperception or misinterpretation of stimuli do not
correspond the sensation received by sense organs.
 Wrong interpretation fail to correspond with reality.
 Illusion is caused due to physical process eg mirrage.
 Or may be caused due to cognitive processes eg illusion of
shape and size.

20. TYPES
• Personal or temporary.
 It is limited to individual
 It is of short duration.
 It appears infrequently.
 Imagination, wishful thinking, fear lead to this type of illusion as
the result of mental state.
• Universal illusion.
 It is permanent also called general illusion
 It occurs to all individual.
 Eg . Geometrical illusion.

21. TypesIllusion of size
Illusion of length ( Muller –layer).
Illusion of perspectives. ( Ponzo Illusion)

22. Illusion of curvature.
Horizontal vertical illusion.
Movement of illusion (Auto kinetic illusion)

23. Perception distortion
• Perception distortion is an abnormality in sensory or
psychological perception.
• It is Self-perception, the identification of the self
• IT is due to psychological disorders, damage to the brain, medications.
• A number of factors are involved in perception, making it very different
between individuals.
• People can see, hear, smell, taste, and feel phenomena that are not there.
• play a role in the cognitive processes behind some mental health
conditions. people may experience a decreased sense of self worth, for
example, as part of depression or anxiety disorders
• a care provider can explore the topic to learn more about its origins.
• If the problem is medical in nature, it may be correctable with measures
like changing the dose of medication.
• For psychological conditions, the patient may need therapy

24. Delusion
• Delusion is a mistaken belief or false belief that have no
real basis.
• These are unusual subjectively determined belief.
• And are out of harmony with the individuals education
and surrounding.
• Frequent delusion indicates a sign of abnormality.
• Persistent and systematic delusion lead to
psychotic state.

25. Classsification
• 1. Delusion of persecution(maltreatment). (indiduals are
following or poisoning his food or taking advantage from him.).
• Delusion of grandeur ( wants to ruler of universe. I have a divine
power).
• Hypochondrial delusions. (usually interpreted as having physical and
mental disease.).
• Self condemnatory(critical) delusion ( concerned with
condemning for different activities. Eg fighting and other social crime.).
• Ideas of reference ( refer himself as an ideal . Eg. Back biting. and is
suspicious.
• Nihilistic delusion. ( Thinking that: will no exist in the earth after death.
Either ghost or evaporated in the sky.

26. hallucination
• It is the false perception.
• Hallucinations are the sensory perception in
the absence of external stimuli.
• The various sensory experiences have no basis
in physical reality.
• Psychotic hallucination can occur for longer
duration.
• Hallucinogenic chemical can produce
hallucination among normal people.

27. Classification.
• Auditory – individual hear bt no sound.
• Visual - see non existed object.
• Olfactory – smell non existed odour.
• Kinestic - non existed stimuli.

28. Hallucination and delusion Vs illusion
Hallucination and delusion
• Abnormal reaction to
perception.
• These are regarded as neurotic
and psychotic symptoms.
• These varies with the individual
in same situation.
• Stimulus is in the individual
himself
illusion
• Normal phenomenon to
perception.
• Such symptoms are not found.
• It identical to normal person.
• Stimulus is external

29. Errors in perception
Visual receptors
Auditory receptors
Olfactory receptors
Lingual receptors
Cutaneous receptors
Other errors
Age
Selection of stimuli
Health
distance