PSY 3E 04: COGNITIVE DEVELOPMENT:
INFANCY THROUGH CHILDHOOD
UNIT–I: WHAT BABIES DO
TOPIC: Visual Perception
Visual perception, put simply, refers to how the brain perceives and processes visual stimuli. It consists
of various aspects:
i) Visual Figure Ground
The ability to focus one’s visual attention on one object or figure, against a complex background.
ii) Visual Discrimination
The ability to perceive the similarities and differences between objects, shapes and symbols. This aspect
of visual perception enables us to categorize, match and sort things.
iii) Visual analysis & synthesis
The ability to combine parts of a unit to form a whole, or alternatively, to divide the whole into its
iv) Visual closure
The ability to complete figures, words or sentences, which are perceived as incomplete, in order to give
v) Visual memory
The ability to memories information received from the eyes. Visual memory is important for accurate and
efficient reading and spelling.
vi) Visual motor integration
The ability to integrate the functions of the visual system and the motor skills.
DEFECTS IN VISUAL PERCEPTION
A visual processing or perceptual disorders refers to a hindered ability to make sense of information taken
in through the eyes. Difficulties with visual processing affect how visual information is interpreted, or
processed by the brain. The defects in visual perception include the following:
Defects in visual location
Defects in visual orientation
Stereopsis and depth perception
Defect in the perception of movement.
i) Defects in visual location
The perceptual ability of the brain damaged subjects to assess the visual location of the
stimulus gets affected. The patient has to compare the location of a dot on each two cards and he has to
judge whether the dots are on identical or different locations. Patients with right hemisphere lesion perform
poorly on this test.
ii) Defect in visual orientation
Brain lesions could disrupt man’s perception of the horizontal and vertical. The widely used test is the
Benton Line Orientation Test. The subject is shown on each item a stimulus line and is asked to select the
corresponding slope from a multiple choice array. Defective performance is associated with right posterior
lesion. No defective performance is found for anterior and very few for left posterior lesion.
iii) Stereopsis and depth perception
Bilateral occipital lesions produce disturbances of depth perception. Patients describe their experience of
the world as two rather than three dimensional and are unable to discriminate which of the two similar
objects is near or far.
This term signifies an acquired difficulty in perceiving color. The patient perceives well i.e., has normal
acuity (Snellen chart), form and depth perception but sees only shades of grey. The defect may affect any
one but often both visual fields. The cause is the damage to the inferior visual association cortex.
iv)Defect in the perception of movement
It is characterized by loss of movement perception. The results of the other test of visual function appeared
normal. Patients could discriminate colors, recognize objects and read and write.
For e.g., difficulty pouring tea into a cup because the fluid appears to be frozen.
Damage to the visual cortex can cause a category of deficits known as” visual agnosia, the term coined by
Sigmund Freud. It is the inability to recognize objects or their pictorial representations or the inability to
draw or copy them. The visual agnostic fails to name a whistle presented visually but identifies it
immediately by its noise or feel. Visual agnosia refers to the deficits in visual perception in the absence of
blindness caused by brain damage.
People with visual agnosia cannot identify common objects by sight, even though they have relatively
normal visual acuity. In some cases, they can read small print but fail to recognize a common object, such
as wrist watch. However, if they are permitted to hold the object (say, the wrist watch), they can