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Presenter: Zain-ul-Abideen

PMAS Arid Agriculture University RWP.

Presentation On

perception.

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Topic of presentation: PERCEPTION

Sensation+ Meanings + Thinking + Memory

= “Perception”

Wundt Regards:

The process by which sensory information is actively organized and interpreted by the brain

The process of selecting, organizing, and interpreting raw sensory data into useful mental representations of the world.

Perception: 

Subjective factor

Objective factor

Factors of perception:

Subjective Factors

Motives or needs Interests and values Age Preparatory set Social and cultural factors

Motives or Needs

When people are motivated, they tend to see and hear what they want to hear.

Interests and Values

Interest and values have a great deal to do with perception

Age

Age brings a change in perception as well.

Preparatory set This refers to a person’s readiness to respond to one

kind sensory input, but not to other kinds.

Social and Cultural Factors

Social Factors The normal perceptual experiences of a culture may

lead its members to develop perceptual biases.

Cultural Factors:

Cultural factors have a great impact on the ways people from different societies view the world.

Intensity Size Movement Novelty Repetition Abrupt change

Objective factor:

The brighter a light, the more likely is to be in focus of perception.

Intensity

Size

A big size picture is more likely to be noticed than a smaller size.

Movement Bird sitting quietly on tree are not quickly

perceived as compared to ones about fly.

Novelty

A novel thing is perceived sooner than old and used things.

Duration Duration also affects the perception.

Repetition

Repetition causes us to adapt to repeated stimulus

Abrupt Changes

Any change in stimulus condition attracts our attention.

There are five kinds of perceptionThese are: Form Perception. Perception of Movement. Depth perception. Time Perception.

Kinds of Perception:

Perception depends on sensory information's. On the base of these information, different forms and patterns are perceived. According to wood worth, perceptual organization is based on two thinks:

Figure Ground

Form Perception:

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Figure Ground Perception:

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Law of Proximity or Nearness. Law of Similarity. Law of Good from or figure.

Law Of Perceptual Organizations:

Proximity means nearness. According to this law, the things situated nearer to each other; form a figure or a pattern and are perceived as a whole figure. This proximity may be in space and time. If different words are set nearer to each other, they form an organization. Consequently, we perceive them in a moment. As it is evident from the following figure

Laws of Nearness or proximity:

Our brain see objects near each other as groups.

Laws of proximity:

Law of similarity or likeness is the perceptual tendency to group together similar elements. If different objects are similar in shape, we classify them in a group; and perceive accordingly as shown in fig:

Law of similarity or Likeness:

In the law of good form, the stimuli having stimuli having similar ship are grouped together. This group[ may b of five types Good Continuation Symmetry Closure Common Direction Inclusiveness

Law of Good Form:

The perceptual tendency to see all the parts of a figure in “one whole” is called the whole good continuation. It make a picture of the grouping organization.

Good Continuation:

A symmetrical figure makes a perceptual organization and perceived sooner.

In the following figures we perceived circles, areas and lines as a single unit when uniformed and linked.

Symmetry:

It is our perceptual tendency to fill the gaps or closure fills the gaps in perceptual organization to help us to perceive it as a whole complete form, for example the following incomplete circle

Closure:

When the stimuli are presented in a straight line or a semi-circle form, their grouping in the perceptual organization is classified in two groups because of their common direction, for example

Common Direction:

Sometimes all the stimuli are include to form a pattern.Due to this inclusiveness in the following lines of similar pattern.

Inclusiveness:

Movement or Motion is perceived by following the progressive change of an object’s position in space with time. It has two types Real Movement: Apparent Movement:

Perception of Movement:

Real Movement: The perception of the actual

movement of objects in the world is termed as “real motion/movement “perception”.

Apparent Movement:It is movement perceived in the

absence of physical movement of an image across the retina. This can be produced by a rapid succession of motionless stimuli that minimize the changes that occur in real movement.

Apparent Movement:

The ability to view the world in three dimensions and to perceive distance is known as depth perception.

“This ability helps to perceive three dimensional space and to accurately

judge distance”

Depth Perception:

We perceive time in, seconds, minutes, and hours which pass into days weeks months and in years and even in centuries. Time is perceived in terms of Past, Present, and Future Perception of time is less in children than elders Several factors influence time perception: Subjective (age, activity, motivation, intelligence) Objective:

Time Perception:

Three types of constancy are explained briefly here:

Size Constancy Shape Constancy Color Constancy

Type of Perceptual Constancy:

Size constancy is the tendency to perceive objects in a consistent manner despite the changing sensations that are received by our senses. visual constancy plays an important role in helping us adapt to our environment successfully.

Size Constancy:

Size Constancy:

When we know that the object is a certain shape ,we tend to perceive it as the same shape, regardless of the viewing angle. We have learned to make corrections in our perception dependent on the angle from which we observe

Shape Constancy:

Shape Constancy:

Colors of objects tend to remain constant in perception when we know their true color. Visual objects also appear constant in their degree of whiteness, grayness and blackness.

Color Constancy:

Something that looks or seems different from what it is something that is false or not real but that seems to be true or real.

Illusion:

Physical causes. Habit & Familiarity. Expectancy & Mental Set. Momentary State of Mind or Mood. Incomplete analysis of the collective

impression. Apperception. Suggestion. Arrangement of stimuli.

Causes of Illusion:

There are two type of illusion: Illusion Of motion. The Illusion Of forms.

Type of Illusion:

When a stationary stimulus is perceive as moving, it is named as illusion of motion or movement.

Illusion Of motion.

The Illusion of Phi-phenomenon. The Illusion of Stroboscope. The Illusion of Gama phenomenon. The Illusion of Delta motion. The Illusion of Auto-Kinetic. The Illusion of Induced movement. The Illusion of negative after image of

movement.

Types of Illusion of motion:

Form perception is attained in relation to the figure and ground according to the law of perception Organization. As the figure is smaller then the ground according to perceptual.

The Illusion of form:

The illusion of distance occurs when the parallel lines seem to bend in different directions.

The Illusion of distance:

Psychologists have fail to understand this illusion. It seem that the curving line behind the spiral have become the cause of this illusion. The illusion is also known as the false spiral, or by its original name, the twisted cord illusion.

Spiral circle illusion:

The parallel lines seem to bend to each other instead of looking straight. The reason of this Illusion is the smaller diagonal lines cutting the parallel line.

The Zollner Illusion:

If two parallel line are dissected by another straight line separately, a large straight line seem cutting the parallel line instead of two partial line.

The Poggindorf’s Illusion:

The Herring illusion can also be induced by a background of optic flow. It is two horizontal line are cure by the line of different direction, will not look parallel. The distance between the two lines looks greater where the lines assemble from different direction as is found in fig

Herring’s Illusion:

A near object is near usually perceived larger and farther object is perceived smaller but in the moon illusion, moon is perceived larger on horizon where the earth and sky seem to meet.

The Illusion of size:

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