PERCEPTION I:Max Wertheimer, Figure and Ground, Law of Closure

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Introduction to Psychology PSY101

Lesson 17

PERCEPTION I

"Perception is not determined simply by stimulus patterns; rather it is a dynamic searching for the best

interpretation of the available data."

Gregory (1966)

The process of selecting, organizing, and interpreting stimuli; it includes identification,

recognition, and images of the stimulus in question; previous experiences have a role to play in it.

Perception is holistic. Perception is the mental organization and interpretation of sensory information. The

Gestalt psychologists studied extensively the ways in which people organize and select from the vast array

of stimuli that are presented to them, concentrating particularly on visual stimuli. Perception is influenced

by a variety of factors, including the intensity and physical dimensions of the stimulus e.g. such activities of

the sense organs as effects of preceding stimulation; the subject's past experience; attention factors such as

readiness to respond to a stimulus; and motivation and emotional state of the subject. Stimulus elements in

visual organization form perceived patterns according to their nearness to each other, their similarity, the

tendency for the subject to perceive complete figures, and the ability of the subject to distinguish important

figures from background.

If you look at the following figures you may see two overlapping triangles, a cat, and a hut. Why don't we

see them as different separate triangles, ovals, and rectangles???

Different Connotations of the Word `Perception

oProcess, act, or faculty of perceiving.

oEffect or product of perceiving.

oRepresents what is being perceived.

oAwareness of something with the help of sense organs/ sensations.

oFeelings, attitudes, opinions, and images people possess about different places, people, and environment

of various kinds.

oImmediate

or intuitive cognition or comprehension__ capacity to "analyze"/ "see" with the help of

experience.

oThe ability to process or use information coming/ received from the senses

oProcess of classifying sensations.

A Comprehensive Definition of Perception would be that of a cognitive process involving:

· Acquisition,

· Interpretation,

· Selection, and

· Organization of sensory information,

that involves past experiences as well as neurological processes that affect recognition and interpretation.

Gestalt Psychology

The Gestaltists made an important and lasting contribution to our understanding of perceptual processes.

They did show that certain, explicit, factors do affect the way in which incoming stimuli are organized into

figures.

· It developed as a reaction to structuralism in the early 1900s.

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In contrast to the structuralist approach of breaking down conscious experience into elements, or

focusing upon the structure of mind, the Gestalt school emphasized the significance of studying

any phenomenon in its overall form.

Gestalt means "Configuration".

Gestalt psychology emphasized that the "WHOLE" is more than the sum of its parts, and it is

different from it too.

Concentrated on how people consider individual elements together as units or wholes.

The concept of Gestalt applies to everything, objects, ideas, thinking processes and human

relationships.

Any phenomenon in its entirety may be much greater than when seen in a disintegrated form.

Max Wertheimer

· The founder of Gestalt psychology; Kurt Koffka and Wolfgang Kohler followed Wertheimer.

· Wertheimer became aware of a form of apparent motion that was called "phi phenomenon".

Phi phenomenon = when two lights are in close proximity to each other, flashing alternately, appear to be

one light moving back and forth; therefore the whole was different from the separate parts.

· Movement is perceived whereas it never occurred.

· Explanation of phi phenomenon led to a separate school of thought that had deep rooted impact

on learning, ethics, and social psychology.

· We perceive experiences in a way that calls for the simplest explanation, even though reality may be

entirely different. We tend to organize our experience so that it is as simple as possible. = Gestalt

Law of Minimum Principle.

· Gestalt Psychology maintained that the main task of psychology is to explain attitudes, events,

behaviors etc as `complete' or `whole'__ not in terms of elements or disintegrated parts; the overall

impact is what makes perception.

Figure and Ground

How do we perceive a figure against a background?

Certain processes are involved in distinguishing a certain figure or

object from a ground.

We do not just passively receive what is reflected on to our retinas;

we try to give a meaning to what we see, and therefore `understand'

our sensations

Gestalt Laws of Perceptual Organization

Organizing raw sensory stimuli into meaningful experiences involve "cognition", a set of mental

activities that includes thinking, knowing, and remembering. Knowledge and experiences are

extremely important for perception, because they help us make sense of the input to our sensory

systems.

· We organize our experiences according to certain rules, in a simple way:

I. The Law of Closure.

II. The Law of Proximity.

III. The Law of Continuity.

IV. The Law of Similarity.

V. The Law of Simplicity.

VI. The Law of Common Fate.

VII. The Law of Enclosure/ Connectivity.

I. Law of Closure

The perceptual tendency to fill in the gaps and complete the contours; perceiving the disconnected parts as

the whole object. We mentally close the gaps and perceive the figure given below as wholes.

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This tendency enables us to perceive whole objects from incomplete and imperfect forms

II. Law of Proximity

We have the perceptual tendency to group together the auditory and visual events that are close or near one

another; they are perceived as a coherent object. In the figures below, we see that on the left, there appears

to be three horizontal rows, versus three columns on the right.

III. Law of Continuity/

Good Continuation

We tend to group the stimuli

into smooth and continuous

patterns or parts. Humans have a capability to continue contours whenever the elements of the pattern

establish an implied direction.

In the drawing below, we see a curved line with a straight line

running through it. In the other, we do not see the drawing as

consisting of the two segments and perceive it as a continuous

pattern.

IV. Law of Similarity

The tendency to perceive objects, patterns or

stimuli which are similar in appearance as a

group; parts of the visual field that are similar in

color, light, texture, shape, or any other quality

are seen as one.

Elements that appear similar will be perceived as part of the same form/

sequence; there seems to be a triangle in the circles and the smaller triangles

are perceived as one group.

V. Law of Simplicity/ Law of

Prägnanz

People intuitively prefer the simplest,

most stable, straightforward, and basic

form of possible organizations. A stimulus

is organized into as good and simple a form as possible; `good' refers to

symmetrical, simple, and regular.

In the following figure you tend to see

four squares rather than ends of logs of

wood or biscuit packs.

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In this one you tend to see two separate shapes rather than different separate parts joined together.

In the figure on the right you see a diamond inside black lines and not as an `M' under a `W', which actually

is the case.

VI. Law of Common Fate

It is the tendency to group together the objects that move together, or seem to move together, and in the

same direction. When they are being seen in actual motion, humans' will mentally group them as moving in

the same direction. Because of this we often see flocks of birds or herds of cattle, or boys or girls playing

together as one group

VII. Law of Enclosure/ Connectivity

It is our perceptual tendency to perceive features/ patterns, such as dots

or objects as a single unit when uniform and linke; lines, dots, areas,

objects etc are perceived as single or same unit when combined or linked.

Feature Analysis

· The process of perceiving a shape, pattern, object, or scene by attending to the individual elements

making it up.

· The Gestaltist emphasis was upon the way we interpret the individual elements as a pattern/

sequence which has some sort of meaning; The organized or well formed sequence gives a different

percept or meaning as compared to when separate parts or elements are observed.

· The approach of feature analysis looks into the individual components in order to understand the

entire nature of what we perceive.

· The feature analysis starts with the activation of the neurons in the brain, as they are sensitive to

particular spatial configurations such as circles, angles, edges, curves etc. Since these neurons are

individually present, it is taken to be the evidence of the idea that any pattern, sequence or

component can be broken down into simpler events or parts e.g. the letter "P" is the combination

of a vertical line, and a semi- circle; or an "X" is a combination of a "v' on an inverted "V".

· 150 million objects can be produced out of just 36 fundamental components.

In summary

· Stimuli are first broken down into their component parts; these parts are then compared to data

stored in our memory in order to find a match; the stimulus is identified and recognized once a

match is found.

· The feature analysis starts with the activation of the neurons in the brain, as they are sensitive to

particular spatial configurations such as circles, angles, edges, curves etc. Since these neurons are

individually present, it is taken to be the evidence of the idea that any pattern, sequence or

component can be broken down into simpler events or parts e.g. the letter "P" is the combination

of a vertical line, and a semi- circle; or an "X" is a combination of a "v' on an inverted "V".

· 150 million objects can be produced out of just 36 fundamental components.

· The figure below shows the process of how we perceive a `B' as a `B'.

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Decision

Steps in Feature Analysis

a. Identify the feature, shape of any object, of which the image falls on the retina.

b. Combine/ gather object in some form/pattern so that some sort of

representation can be formed.

c. In the final stage, we identify/ compare each component/element/ object with

the help of past experiences or memories.

Top- Down and Bottom- Up Processing

`Top- Down' processing refers to the perceptual phenomenon guided/ and influenced by;

oKnowledge,

oExperience,

oMotivation and

oExpectation

A-e- yo- g-o - ng t- sc--l?

Top- down processing is guided by the higher mental/ knowledge faculty such as meaning of the sentence

of which the important letters are missing__ individuals are able to understand the meaning of the sentence

and fill in the gaps by using their prior experiences and memories.

Bottom- Up processing refers to the

Process of recognizing and processing of information about the individual component/ part of the

stimulus.

Humans will be unable to identify the object component unless they are able to recognize and

understand the shape and features of each element that makes it up; in the sentence "A-e- yo- g-o - ng

t- sc--l?" you will not be able to identify the sentence unless you recognize the individual shapes

making up the overall form of the letters.

Top- down and bottom- up processing occur simultaneously and have an interaction with each other,

which makes it possible to understand the complex perceptual phenomena.

The process of perception involves the environmental stimuli, which is interpreted, analyzed and

integrated with the help of past experiences.

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