Sensation is the initial response of an individual to a stimulus and precedes perception. Perception is the interpretation of sensory stimuli reaching the sense organs and the brain. When our sense organs come in contact with the world, are stimulated by external stimuli and receive sensations it results in perception. Interpretation gives meaning to sensation thereby making us aware of objects.

1. PERCEPTION
BY PAHARI SHARMA

2. INTRODUCTION
• Sensation is the initial response of an individual
to a stimulus and precedes perception.
• Perception is the interpretation of sensory stimuli
reaching the sense organs and the brain.
• When our sense organs come in contact with the
world, are stimulated by external stimuli and
receive sensations it results in perception.
• Interpretation gives meaning to sensation thereby
making us aware of objects.

3. DEFINITIONS
• Perception is the experience of objects, events or relationships
obtained by extracting information from and interpreting
sensations.
-JH Jackson, O Desiderato and DB Howieson (1976)
• Perception is an individual's awareness aspect of behavior, for
it is the way each person processes the raw data he receives
from the environment into meaningful patterns.
-RE Silverman (1976)

4. PRINCIPLES

5. 1. PRINCIPLES OF FIGURED- GROUND RELATIONSHIP:
According to principle of figure-ground relationship, a
figure is perceived in relation-ship to its background. The
perception of the object or figure in terms of color, size, shape
and intensity, etc. depends upon the figure ground relationship.

6. 2. Principle of Grouping: The main founder of Gestalt
psychology is Max Wertheimer.
 Principle of proximity: Proximity means nearness. The
objects which are nearer to each other can be perceived
meaningfully by grouping them.

7.  Principle of similarity: There is a tendency to perceive objects
of a similar size and shape or color as a unit or figure.

8. Principle of continuity: Any stimulus which extends in the
same direction or shape is perceived as a whole. Our attention
is held more by continuous patterns rather than discontinuous
ones.

9.  Principle of closure: While confronting an incomplete pattern
one tends to complete or close the pattern or fill in sensory
gaps and perceive it as a meaningful whole. This type of
organization is extremely helpful in making valuable
interpretation of various incomplete objects, patterns or
stimuli present in our environment.

10. Principle of symmetry: Objects having symmetrical shape are
perceived as groups.

11. 3. Principle of Context: Perceptual organization is also governed
by the principle of context, i.e., an examiner may award higher
marks to the same answer book in a pleasant context than in an
unpleasant one.
4. Principle of Contrast: Perceptual organization is much
affected through contrast effects as the stimuli that are in sharp
contrast to nearby stimuli may draw our maximum attention and
carry different perceptual affects.

12. 5. Principle of Adaptability: Perceptual organization for some
stimuli depends upon the adaptability of the perceiver to
perceive similar stimuli. An individual who adapts himself to
work before an intense bright light will perceive normal sunlight
as quite dim.

13. FACTORS AFFECTING PERCEPTION
• Sense Organs : Perception depends upon the sense organs or
receptors on which the stimuli act and the sensory neurons
that transmit the nerve current from the receptors to the
sensory area of the brain.
• Brain: Perception depends upon the functioning capacity of
both the sensory and association areas of the brain.
• Memory Images of the Past Experience: Memory images help
us in the comprehension of the object or stimulus before us.
Generally, perception involves the integration of sensory
experience in the light of past experience and present
psychological conditions.

14. • Needs and Desires: Our needs or desires also modify our
perceptions. Besides these our beliefs, opinions and cultural
ideals also modify our perception of things, situations and
objects.
• Nature of the Stimuli: In addition to the above functional
factors, structural factors that affect perception are nature of
physical stimuli such as size, background, novelty, motion and
proximity of the stimuli and their arrangements and the neural
effects they evoke in the nervous system of the individual.
• Situational Factors: The context in which we see objects may
influence our perception. These factors include time of the
day, social or organizational setting.

15. ERRORS IN PERCEPTION
• Perceptual processes enable an individual to perceive things
accurately and facilitate smooth functioning. However, some
errors creep into this process under certain circumstances
leading to impaired perceptions. These are-illusions and
hallucinations.
1. Illusion: It is a misinterpretation of actual perception. When
the interpretation of a particular stimulus goes wrong, it
gives rise to a wrong perception or illusion.
2. Hallucination: Hallucination is identified as one of the major
errors of perception. It is a sensory perception that occurs in
the absence of any corresponding external sensory stimuli.

16. CAUSES FOR INACCURATE PERCEPTION:
1. Defective functioning of sense organs: Sensory defects like
myopia, deafness and anesthesia can cause inaccurate
perception.
2. Inadequate stimulus: Our receptors may not be stimulated
adequately if the stimuli are vague, indefinite or not strong
enough. A very weak light or soft sound will make it difficult
to perceive correctly.
3. Too many stimuli at one time: When too many stimuli are
present at one given time, perceiving each stimulus
separately is difficult.
4. Poor health: Sense organs cannot function correctly and
adequately as a result of illness. For this reason perceptions
of patients may be inaccurate.

17. 5. Limited attention: If we try to apprehend more things than
we can at a time, we are liable to have an inaccurate perception.
6. Figure merges in the ground: Some-times objects are
perceived with difficulty because they resemble their
surroundings.
7. Guidance: Perception is inaccurate when we do not know
what to perceive.