PERCEPTION MEANING Perception is a process of interpreting

PERCEPTION

MEANING Perception is a process of interpreting senses i. e. making them meaningful. Its actually a process of nervous system which cannot be observed directly but can only be experienced. It is the immediate activation of sensation resulting from the stimulus and is structured and organized in nature.

PERCEPTION OF FORM Almost always we perceive parts of varying sensuous mass as different forms, shapes and patterns. Perception is converting sensation into awareness of objects. One of basic dynamisms of visual perception consists of our organizing tendency to see well defined parts of our environment as objects distinct from their surround. A contour separates the object from ground.

PHENOMENAL PROPERTIES OF FIGURE AND BACKGROUND 1. 2. 3. Characteristics of figure and background. Figures are seen as bounded and organized. Figures are also more striking and seem to stand out from their background rather than unorganized background. A figure stands in front of the background which extends behind it, in an unbroken manner.

4. Figure is more lively, actually it is the carrier of movement. Even in the case of apparent movement, what is figural is also the conveyer of motion. 5. Figure shares the character of while background is like a substance or informed material. 6. Figure is always better attended to and is more likely to suggest meaning and excites deep feelings. 7. Relatively to background figure is also better remembered.

1. 2. 3. 4. Rubin (1915, 21) also mentioned similar type of characteristics of figure and background. These are Figure has shape while background is always formless. Figure has always some characteristics of frm while background cannot be described in terms of some characteristics. Figure is perceived in front while background is perceived the figure extending continuously. Figure is more impressive and so better remembered.

DETERMINANTS OF FIGURE AND BACKGROUND Gestalt psychologists like Werthiemer and Koffka conducted various studies to explain that perception is organized. He propounded some laws of perceptual organization.

LAWS OF PERCEPTUAL ORGANIZATION Law of Proximity-Things that are near each other readily form units tending to be grouped together. Nearness may be in space or time e. g.

Similarity – A number of separate items of several different types. such items which resemble one other in some respect constitutes a group or unit by itself. Things may resemble each other in many different quantitative and qualitative ways e. g. colour, form intensity etc. Common Fate – Things which move simultaneously in same direction are readily seen as a group. They possess a sort of similarity in their motion.

Continuity – The group of thing forms a uniform direction in some respect. Area – As a closed region is made smaller it tends more strongly to be seen as a figure. A factor that is obviously closely related to proximity. Orientation – In some kind of pattern alignment with the main areas of space seems to be determining factor. Thus, Rubin (1921) found that cross made up of vertical and horizontal lines is more likely to be seen as figure than one with oblique limbs.

Symmetry – the more symmetrical is the shape the more strongly it itends to be seen as a figure. Closure – The regions that are marked off by close contours tend to be seen as figure more than do those with open or incomplete contours e. g.

1. Homogeneity or Simplicity – The areas which are homogenous in nature are seen as figure. Conformity with the observer’s set – Einstellung is a German word that means directed readiness for a particular perceptual event. Werthiemer distinguished two kinds of einstellung Subjective to see a certain grouping and to do so even though the law of organization do not favour that grouping or even if they oppose it objectively. Einstellung means physical perseveration i. e. the tendency to continue seeing the given figural organization even after the conditions no longer favour it.

Experience – Subjective or organismic conditions like past experiences influences the process of formation of perceptual grouping or perception units.

CHARACTERISTICS OF OBJECTS WHICH DETERMINE FORM AND SHAPE Contours – Imagined boundaries that are used by subjects to separate shape from rest of the field. Edges – They are an angular boundaries that are used to organize different perceptual properties of objects for perception of form. Figure – It is an organised part of environment first studied by Rubin. Boundaries – Lines which separate one object from the other object.

PERCEPTION OF SPACE Space refers to a domain or a field in which the individual is situated and within it he/she moves about. In space we study depth, distance and location. Depth – relative difference between two objects. Retina gets the image of the object through focusing in lens. Image on retina is received in terms of all the characteristics of space. This image on retina is not the true copy of objects but it is the careful combination of different characteristics of objects.

There are three dimensions in the space. Third dimension is percieved by the brain automatically by using some cues. Brain uses two types of cues. 1. Cues of distance 2. Cues of depth.

CUES Cues are nothing but characteristics of the stimulus variables which make it possible to perceive the distance between distance and depth. The perceiver is not aware regarding the cues. Importance of cues was first studied by Leonardo da Vinci

CUES OF DEPTH 1. These cues may be related with stimulus characteristics of eye and with both or single eye. NON – VISUAL CUES Convergence – It is the bending of the eyes towards the nose while perceiving the object. It is determined by cillary muscles which control the movement of lens. More the convergence more the stress. It is utilized just to get the image of object on fovea of retina. Convergence is possible up to a limit and it is tmeasured in terms of angular degrees.

2. ACCOMODATION – It refers to the frequency or focusing of the lens to get the image on fovea. As the camera focuses the lens as per distance of the object to get clearest images. Similarly the eye focus the lens as per distance of object the size of lens are controlled by cilliary muscles where convergence stops. Accommodation starts and it operates up to 180 feets.

BINOCULAR CUES When the images are formed in both the eyes on their respective foveas, then these areas are known as corresponding areas. When the images are not on fovea then it is known as non- corresponding areas. When there is some disparity in corresponding and non- corresponding areas then these messages go straight to brain and brain uses some cues.

DOUBLE IMAGES Except fixated object the images of other objects are not in fovea. When all the objects are in same direction the information of double image of other objects goes to the brain where it is analysed and used as a cue of depth perception.

BINOCULAR DISPARITY As our eyes are separated by a few inches, they were objects from slightly different angles. This difference in angle causes a slight difference in the retinal images called retinal disparity. Although small, it is a powerful cue for depth. The value of this cue or a device for viewing two slightly different pictures. One with one eye and the other with other eye.

MONOCULAR CUES 1. A number of spatial cues require only a single eye for their reception and are labeled as monocular cues. INTERPOSITION- It refers to the appearance of one object partially concealing or overlapping other. If one object is partially covered by another the fully exposed is perceived as nearer.

2. SIZE – If a person knows the real size of a visible object and know the size of the retinal image it subtends at the eye. We have a good potential indication of its distance. 3. RELATIVE SIZE- This cue applies when two similar or identical shapes of different sizes are viewed simultaneously or in close succession, in such cases larger stimulus generally will appear closer to the viewerthan the smaller one.

4. FAMILIAR OR ASSUMED SIZE- If a person know the object’s real or distal size and we can register its proximal or retinal size then a person can till what his absolute distance is. This cue is particularly important to the space perception because it is the only one which by its very definitions requires past experiences in the sense of learning some rule.

5. SHADING AND LIGHTING- Surface of the object nearest the light source is the brightest. As the surface recedes from the light it appears less bright and more darkly shadowed. 6. ELEVATION- Elevation may play a role in the perception of both relative and absolute distance. The objects appearing higher in the visual field are generally perceived as being located at a greater distance from the viewer than are objects that appear lower to various field.

7. TEXTURE GRADIENTS – When we look at any textured surface, the elements composing the texture become denser as distance increases. 8. ARIEL PERSPECTIVE- When viewing the terrain outdoors objects in the far distance are generally seen less clearly than objects located close.