Supervision
Prof. Dr. Ramez N. Bedwani
Outcomes

giving meaning to external stimuli is affected
by external factors ( symbols and signals) and
internal factors (receptors, habit, set, attitude).
Faulty perception occurs both in normal and
diseased persons.
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Giving meaning to sensation i.e. to know
environment by the use of senses.
We receive signs and perceive meanings.
Symbols:
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1.
Stimuli which stand for an object e.g.: a name of any one stands for the
person named.
Signals:
Stimuli received from the object e.g. smoke is a signal for fire.
1.
We perceive object and relations between them
2.
We perceive sounds, distance and time.
3.
We perceive ideas conclusions and concepts which are our tools of
thinking.
4.
We perceive much about our body(body image, e.g. where is my toe
etc)
5.
We perceive much about our psyche and its functions like emotions
and thoughts. (and occasionally our motives)
6.
We perceive some bodily functions. e.g. sense of micturition.
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
Perception is related to a meaningful whole
1. Similarity:
Similar stimuli tend to be grouped together.
2.Proximity:
Proximate objects tend to be grouped together.
3.Closure:
Stimuli tend to be grouped together in order to
perceive a defective whole as a closed one.
4.Symmetry:
For example asymmetric triangles are liable to be
perceived as symmetrical ones. (see figure)
5. Approximation:
There is a tendency to perceive the poor figure as if
they were exact and good.
6. Good continuation:
In the figure we see how we tend to continue lines to
make rectangles instead of perceiving lines
separately.
7. Competition and cooperation of grouping tendencies.
In every stimulus pattern the elements of stimulus
have some degree of proximity , similarity, continuity
etc. At a time all kind of grouping tendencies are at
work. (Sometimes they work in the same direction of
or- .and sometimes they compete with one another
lowest figure)
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Mood (emotion)
Our mood influences markedly our perception e.g when
you are sad you perceive every thing as bad
Need: when we are hungry we selectively perceive(smel)
odours of food.
Interests: every one perceives what he is interested in
more than any other thing.
Mental set: as much as you are prepared to do something
or to find something, it is likely to do it or find it and to
overlook other things
Habit &Familiarity habit is based on past experience. You
read AMATONY as ANATOMY out of habit.
Aesthetic factors = (the same as good form in figural
factors): The pleasant figure will be perceived where aqn
irregular figure will be overlooked.

a.
b.
c.
Illusion:False perception of an external stimulus. may
occur by factors in the individual, in the stimulus
or in both
Illusion due to physical causes e.g. mirrors
illusion: a person looking in the mirror perceives
his figure as if it exists behind the mirror on the
others side.
Habit and familiarity e.g. as said before,
AMATONY is read as ANATOMY due to habit..
Set and expectation (e.g. waiting and important
telephone call may make us perceive the bell
door as a telephone call.

a.
b.
Déjà vu phenomenon: illusion
of familiarity: the
person feels that he has previously
experienced what he is experiencing at the
present time.
Under normal conditions particularly during
adolescence.
In disease, in temporal lobe epilepsy.
Hallucinations:
Hallucinations: are mental impressions of sensory
vividness occurring without external stimulus.
occur normally or under experimental conditions:
1.
Dreaming and hypnagogic states (hypnagogic
states are states just before sleep).
2.
With severe emotions
3.
With stimulation of the sense organs (Wax in the
ears, or pressure on the eye globe).
4.
During sensory deprivation experiments.
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1.
2.
3.
4.
In pathological conditions hallucinations are
met with in the following examples:
Most psychotic disorders.
Organic brain disease (OBS)
Temporal lobe epilepsy
Intoxication (especially with LSD25)
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Set
Definition
Set refers to the fact that the organism is
usually prepared at moment for the stimuli he
is going to receive and for the response he is
going to make.
Preparatory set:
The organism is preparing himself to the act that
the he will soon perform. e.g. an athlete runner is
training daily for physical fitness and developing
skills.
2. The set to start:
You know what is going to happen and you
prepare yourself to start reacting to a specific
stimulus (e.g. runner on the mark waiting to
listen to the pistol shot to start)
3. The set to continue: It means that the activity
continues towards the goal.
1.
1. Mental set:
This refers to the sets when the task is
predominantly mental such as studying or
solving a mathematical problem
2. Situational set:
The set differs according to the situation e.g.
A singer singing to himself in the bath room
performs differently from when singing to
his audience in a theatre

Definition:It is the time that elapses between receiving a
stimulus and responding to it. It differs with
the type of reaction which could be:

Simple reaction time
Here the individual knows the single
stimulus he will receive and the single
response he has to make e.g. to press a button
on hearing a signal. It usually lasts for 0.14
sec for a sound or a touch and 0.18 sec for
light.
That reaction corresponds to our behavior in
everyday life expecting the next green traffic
lights.

Choice reaction time
The individual is required to make certain
different responses to specific different
stimuli e.g. raise right hand whenever a red
light is shown its duration is usually 0.24 sec
for sound and 0.28 for light
This reaction corresponds to our behavior in
everyday life in playing tennis

The associative reaction tennis
The individual knows nothing about the
definite specificity of the coming stimulus,
although he knows its nature and the rule
how to respond.
This reaction corresponds to our behavior in
everyday life in answering questions in
mathematical problems in spotting slides
under the microscope or in MCQ
examinations.
All correct except one
1. Extroceptor are
a.Distant receptors
b.Contact receptors
c.Visceroceptos
2. We perceive
a.Signs
b.Symbols.
c.Attention
3. Faulty perception
a.Camouflage
b.Illusion
c.Hallucinations
d.Proximity
‫‪Perception Function‬‬
‫‪Sensor deprivation‬‬
‫‪Sensor areas of brain‬‬
‫الشيماء مصطفى عبد العاطي حجازي‬
‫امل محمد احمد احمد سويدان‬
‫اميرة اسعد يوسف االسكندراني‬
‫أميرة صالح مرشدي عبد السالم‬
‫انجي عبد الموجود يوسف محمود‬
‫اوركيد اشرف السيد قطب‬
‫ايمان سعيد محمد ابو حطب‬
‫ايمان محمدى يوسف القزاز‬
‫آيه رجب عبد العزيز بركات‬
‫آيه حماده عطية ابو الخير‬
‫أبانوب عوض ناجي مسعد‬
‫باخوم سدراك نظير سدراك‬