Psychology (MLPS-201)
By the end of the lecture the students will
Recognize the different parts of the brain are linked to carry different
cognitive, sensory and motor functions controlling wellbeing of the
individual
Understand the effect of sensory deprivation on different psychological
functions.
Reticular Activating System:
 It is a network of never fibers extending from the brain stem to the
cerebrum that is involved in one’s level of arousal or activation, so
acting like a valve that either allows sensory messages to pass
from lower centers up to the higher centers of the brain or shuts
them off, partially or totally.
Limbic System:
 It is a collection of small structures, including the amygdale, septal
area, and the hippocampus that are involved in emotional and
motivational reactions, both showing opposite effects to each
other, with respectively produced aggression and rage attributed
to amygdale stimulation. Hippocampus is responsible for transfer
of memories to long-term storage.


It is a small structure near the center of the
brain that is considered to be part of the
limbic system.
It is involved in feeding, drinking,
temperature regulation as well as
regulation of the endocrine system.






It is the final sensory relay station that projects sensory
fibers to their proper location in the cerebrum and that
may be involved in regulating sleep-wake cycles.
Sensory messages from the lower body, eyes, ears and
other senses (except for smell) pass through the thalamus.
The cerebral cortex (cerebrum);
It is a large convoluted outer covering of the brain that is
the seat of cognitive functioning and voluntary action.
It is formed of 2 symmetrical hemispheres (Rt & Lt) that
are separated by a deep fissure running from the front to
the back.
Each cerebral hemisphere is formed of 4 lobes.
The frontal lobes: which are the largest and defined by 2 large
fissures called the central and lateral fissures. It is present in front of
the central fissure and above the lateral fissure.
 The occipital lobes: they are the lobes of the cerebrum at the back
of the brain. the parietal lobes: they are the lobes of the cerebrum
between the frontal lobes and the occipital lobes and above the
lateral fissure.
 The temporal lobes: they are located at the temple below the lateral
fissure and in front of the occipital lobes.
 Functionally these lobes constitute sensory areas. Motor areas and
association areas.

They are those, areas of the cerebral cortex that
receive impulses from our sense receptors.
 Receptor cells in our senses respond to
environmental stimuli to send impulses along
sensory nerve fibers to the spinal cord through
the brain stem to the thalamus then finally to a
variety of sensory areas depending on the
senses
 Visual impulses end in the occipital lobe
concerning the visual area.
 Auditory impulses end in the temporal lobe
concerning the auditory area.

Body senses (touch, pressure, pain) send impulses to
the front of the parietal lobe where specific body
regions are mapped with different ratios of
representation as.
 Areas like the face, lips, fingers which are highly
sensitive are over represented in the body sense area
of the cerebrum.
 It would be important to reintroduce the concept of
cross-laterality which means that, in general, sensory
and motor impulses to and from the brain cross from
the left side of the body to the right side of the brain,
and vice versa.





It is the area that controls voluntary movement,
which is present at the back of the frontal lobe.
The actual decision-making step of whether or
not one should move is probably made toward
the front of the frontal lobe.
Concept of cross-laterality is also applied to the
motor area.
As with the body sense mapping, different parts
of the body and the muscles serving them are
disproportionally represented in the cerebral
cortex motor area
Remaining areas of the cerebrum are called
association areas, they are three: frontal,
parietal and temporal. No occipital association
area.
 Association areas are concerned of processing
higher mental activities and it is where incoming
sensory information is associated.
 Frontal association areas are responsible or
language and speech behaviors as their
destruction causes inability to plan ahead, to
think quickly or to think things thoroughly.


Both cerebral hemispheres are interconnected
with a network of nerve fibers that send
impulses between the two hemispheres.

Lt cerebral hemisphere is connected with speed
and language, it is also responsible for simple
tasks of calculation. It is also concerned with
analytical thinking. It seems also to process
information sequentially handles one thing at a
time.


Rt cerebral hemisphere seems more global in its
approach and seems better able to grasp the big
picture, to see the overall view of an issue, and
to be more creative, more spatially and visually
oriented than the left hemisphere.
It is also useful in solving spatial relations tasks.
Also concerned with more visual imagery than
does the left hemisphere, more musical. Rt
cerebral cortex is more involved in expression
and interpretation of emotions.


Most of what we know about the activities of the
cerebral hemispheres has been learnt from splitbrain subjects.
Split brain is a procedure of separating the
functioning of the two cerebral hemispheres by
destroying the corpus callosum. It is of interest
to mention that split-brain patients appear to
behave quite normally and that only in
laboratory we can see the results of having
made the hemispheres of the cerebrum function
independently.


It is utilization of isolation or reeducation of
exteroceptive stimulation in the psychology
functioning.
Perception; In the psychological laboratories,
the methodological problems for
investigating sensory deprivation are great.
Moreover, the conclusions must be taken
honestly as situation in life differ from those
in the experiments.


Psychoanalytic: One function of the ego is
mastering the external reality. Under S.D.,
psychological processes become dominated by
more primitive “primary thinking”.
Neuropsychological: Normally, the reticular
activating system is a homeostatic system
adjusting inputs and outputs relations. In S.D.,
there is lowered arousal and loss of selective
attention that leads to reactivation of residual
stimuli.
Psychoanalytic

Cognitive: perception operates on a system
of probabilities, creating a cognitive model
useful in programming the reticular
activating system to select stimuli, that is
corrected by feedback information in S.D.,
reduced sensory cues, interferes with the
feedback. The individual cognitive processes
become disorganized.
On psychological functions:
Affective changes:
Negative: In normal, in the form of boredom, restlessness anxiety
and depersonalization, short lived, reversible.
Positive: In psychiatric patients, in the form of improved mood, long
lasting.
Perceptual changes:
 Hallucinations (true, imageries), for 10 to 20 years of subjects.
Cognitive:
 Defective concentration, impaired intellectual and learning
abilities.
Motorceptic performance changes.
Susceptibility to propaganda (brain washing):
 May be increased with liability towards attitude changes.
Brain activities and EEG:
Progressive slowing, continues after S.D. for
hours or weeks.
 Skin conductance, tactile activity and pain
sensitivity:
 Are increased but are short-lived.
 Biochemical measures:
 Others: Inconclusive changes of body
temperature, circulation and respiration.


Military and industrial aspects: Accident
proneness and errors of judgment. Also, in
superhighways and prisons.
 Medical wards (e.s.): Neurology, ophthalmogy,
orthopedics, and postoperative recovery rooms.
 Psychiatric aspects: Developmentally: Results in impaired
intellectual and emotional growth.
 Consultations: Periods of S.D. can add
secondary psychiatric symptomatology.




Isolation of the mental patients: provides
gradual deterioration.
Geriatric subjects: Due to cultural patterns
and physical limitations may deteriorate
furtherly.
Psychiatric treatment: Short periods of S.D.
may be beneficial for some psychotic and
depressed patients.
All correct except one
1.
The hypothalamus is envolved in
2.
Feeding and drinking
3.
Temperature regulation
4. regulation of endocrine system
5.
Motor power
Complete
1-The 4 lobes of the brain are
a) Frontal lobes
b) Occipital lobes
c)
Parietal lobes
 …………….
2-Sensory deprivation affects
a) psychological functions
b) ………………………..