Previous Page                        4                                 Next Page

Attention

First step in observation.
 It is focusing consciousness on stimulus.
 It is a process of preferentially responding to a stimulus or a range of stimuli.

Titchner,— Attention is a state of sensory clearness with a margin and a focus. "Attention is the aspect of consciousness that relates to the amount of effort exerted in focusing on certain aspects of an experience, so that they became relatively more vivid."
Attention can be voluntary or involuntary
Concentration is sustained attention with continuity in focusing.

Factors influencing attention

1- Objective factors" (Characteristics of stimuli)
a. Intensity of stimulus
b. Frequency of repetition
c. Size
d. Movement
e. Change of stimuli
f. Systemic form or order
g. Contrast

2. Subjective (Qualities of the observer)

a. Habit or familiarity
b .Immediate need ,
c. Profession - Interest or motivation.
d. Innate tendencies

Division of Attention
Ability to focus on more than one stimulus at a time. Usually subjects are unable to attend to more than one thing at a time. It depends upon the amount of mental energy needed for each task.

1.lf two or more tasks do not demand full resources, then they may be performed simultaneously.
2.Performance of one task will disrupt a second, if it makes demands on the resource pool.
3.Subjects themselves are in control of allocation policy and they match these to meet the demands of the task being performed.

Selective attention
The ability to focus on a single stimulus filtering the rest. It is the mental process of restricting to one event at a time. Selective attention provides a means by which we reduce the workload on our mental systems.

Assessment of attention
Span Of attention :It is the number of stimuli one can attend to in one act of attention. Average 6, up to 8 or 9.

Tests for attention
1. Digit span
a. Digit Forward; 836, 6315, 37194 etc up to 9 digits.
b. Digit Backward:
    Expected range
    DF 5-7
    DB3-5
Average difference between DF and DB is 2.

More than 2 are pathological. It has a diagnostic value is mental patients.
Low score of DF and DB in cases of depression, anxiety, and schizophrenia.
High score in cases of paranoid conditions.

2. Cancellation test for illiterate
Digit cancellation
Colour cancellation

3- Tests for concentration
Immediate memory test ( Eysenk- British psychologist)
Letters or digits are used.
37516849
WNXADOR
Ask to repeat only the last few digits.

Perception

Perception is meaningful understanding of stimulus (object)
Perception is that organizing process by which we come to know objects in their appropriate Identity,
Perception involves interpretation and understanding. But sensation refers to the process of receiving information.

Attributes of perception
1. Perception is independent of conscious will.
   e.g. two view points of an ambiguous picture
Cross
Candlestick
Staircase
Necker cube

2. Perception is often creative- e.g : When "viewing a two dimensional building, the creative nature of our mind can fill the missing information based on our past experience i.e., visualizes the interior of the room, doors and roof etc...
3. Perception is influenced by context.
4. Perception is rule bound. It follows the law of reduced cues.
5. Perceptual set or expectancy effect.

Human beings are predisposed to see a number of natural shapes and configuration, e.g. circles, squares, and rectangles etc.., which are fundamental to universe.

6. Perception occurs as a complete whole, and not as unconnected facts. (Gestaltpsychology)
7. Perception is a highly selective process, both subjective and objective factors influence.

Factors influencing perception

1. Proximity ab cd ef
   ab, cd and ef are perceived as single units than be and de
2.Similarity
   Similar things perceive as a single unit

0000000
xxxxxxx
+ + + + +

3.Continuitv- continuous objects are perceived as a single unit.

4. Closure
Tendency to fill incomplete pattern into a coherent whole.

Determinants of Perception
1.Proper function of sense organs
2.Proper function of brain
3. Past experiences
4. Set or attitude

Errors of perception
( Illusion - misperception

Process of perceiving an object in a wrong way.

In illusion, there is a definite discrepancy between what we perceive and the actual facts, Our senses may be deceived in many ways, and these extend to any of the senses. But, in psychological experimentation, visual illusions have received greatest importance.

a. Illusion of length - Mueller-Lyer Illusion.
b. Illusion of area
c. llusion of distortion
d. Illusion of direction
e. Zolliner illusion
f. Poggendorf illusion

Inferences from the study of illusion
1. Illusions are due to misleading stimuli.
2. Due to force of habit, and blindness from new impression
3. Influenced by preoccupation, bias. expectancy
4. Influenced by setting, background, familiarity, emotion, enthusiasm. strong drives.
5. From being satisfied with total general impression. Hallucinations

Hallucinations are sensory experiences for which no adequate sensory stimulus can be discovered. Hallucinations are perceptions without real object or stimulus.

Normal Hallucinations - Not pathological - e.g., dreams, fantasies, visual memories anticipations under stress or anxiety.

Psychotic hallucinations - Pathological. Usually do not realize that their hallucinations are not real.
 
Materials of hallucinations are formed from individual's memories, both conscious and unconscious (repressed), recent or remote. They reflect the motives, interests, preoccupations and experiences of the individual.

Psychotic hallucinations are mostly unpleasant
E.g.: Sees enemies threatening him.
Hears voices cursing him.
Smells foul odors.
Taste putrid flavors.
Disguising touch sensation- crawled upon by vermin.

Normal people can have hallucinations in sensory deprivation- when away from day to day activity in a voyage. (Callentur)

 Previous Page                         4                            Next Page