1. General Psychology
CHAPTER 4
MECHANISM OF HUMAN
BEHAVIOR

2. Mechanism of Human Behavior
There are three mechanisms of human behavior that help the
individual to respond and interact to the environment. These are the
receiving mechanisms or receptors, the connecting mechanisms or the
connectors and the reacting mechanisms or reactors.
The Receiving Mechanism
Mechanism of receptors:
this is the different sense ( eyes, ears, nose, mouth and skin)
of the body receive the stimuli from the environment.

3. 3 Kinds of receptors of the human body
that receive the outside stimuli:
•Exteroceptors: a person becomes aware of the color, shape, smell, taste,
sound, heat, softness or roughness and cold of his envi’nt.
through the receptors w/c are located in the eyes, nose,
mouth and skin.
•Proprioceptors: are situated in the lining of the tendons, muscles and joints.
The nerve linings w/c are connected with the nerve
pathways to the brain make the muscles feel the sensations.
•Interoceptors: are found in the linings of the respiratory, digestive and
genital -urinary tracts. These nerves when stimulated produce
orgasmic sensation associated hunger, thirst, sex and excretion.

4. The Eyes and Visual Sensation
• The Eyes:
- The human eye is an organ which reacts to light from several purpose.
- The eyes give sense of vision which allows one to see the world
- One has to consider the
stimulus that produces
vision which is light.
- The eyes react to light which
causes Visual Sensation.

5. - The eyes are ball-shaped so that they moved
in different directions.
- It is found within a bony cavity called Eye Socket.
- The bony cavity which contains the eyeball and its
associated muscles, vessels, and nerves.
Sclerotic coat is the tough white sheath that
forms the outer-layer of the ball. The white
sclerotic continues around the eye; most of
which is not visible while the eyeball is
located in its socket within the face/skull.
The main area of the eye that is not covered
by the area is the front part of the eye that is
protected by the transparent cornea instead.

6. - Cornea is the transparent front part of the
eye that covers the iris, pupil, and anterior
chamber.
- The cornea, with the anterior chamber and
lens, refracts light, with the cornea accounting
for approximately two-thirds of the eye's total
optical power.
- Choroid coat , also known as the
choroidea or choroid coat, is the
vascular layer of the eye, containing
connective tissue, and lying between
the retina and the sclera .
- The front part of Choroid is Iris.

7. - Iris is a thin, circular structure in the eye,
responsible for controlling the diameter and
size of the pupils and thus the amount of light
reaching the retina. "Eye color" is the color of
the iris, which in humans can be green, blue,
brown, and in rarer cases, hazel , grey or
even violet.
- Pupil is a hole located in the center of
the iris of the eye that allows light to enter
the retina. It appears black because light
rays entering the pupil are either absorbed
by the tissues inside the eye directly, or
absorbed after diffuse reflections within
the eye that mostly miss exiting the
narrow pupil.

8. - Once light passes through the pupil, it enters the Lens
which is located behind the pupil.
- The lens act to bend rays of light to focus them on the
retina.

9. •Retina:
- Is the most innermost coat which
contains the true receptor cells.
•Rods:
-Are long and cylindrical.
-Are responsible for twilight vision or light
of low intensity.
•Cones:
-Are short, thick and tapered.
- Are responsible for daylight vision and
colors.

10. •Fovea centralis:
-Is the center of the retina which is the point
of the clearest vision in the daylight.
- Is a very sensitive region of the retina.
•Optic nerve:
-Is a bundle of ganglion axons at the back
of the eyeball.
- It carries visual information to the brain.
•Blind spot:
-As the optic nerve leaves the retina,
there are neither rods nor cones.

11. •Optic nerve:
- The optic nerves coming from each eye splits at
the optic chasm.
- Optic chasm is a point between and behind the
eye wherein the more impulses from the optic
nerve are reversed in the brain.
•Color Vision and Night blindness:
- There are people who have limited
perception of light and colors. People who
find difficulty in seeing light or object at night
are called night-blind because they have
defective rods. Night blindness can be
corrected by taking large doses of vitamin A.
Vitamin A is richly found in green, leafy and
yellow fruits and vegetables.

12. •Color blindness:
There are people who cannot distinguish certain colors either
totally or partially. This condition is called color blindness. There are
certain kinds of color- blindness, like the following:
- Dichromats- can match the entire colors or spectrum into
two colors. There are two of this type deuteranopes
that see red as poor yellow and green as gray and
protanopes that cannot see red but black and green as
whitish gray.
- Trichomats- can see three colors from the spectrum.

13. •Common Eye Deviations from Normal Vision:
-Myopia or Nearsightedness:
This is cause by abnormal long eyeball so that the
image is focused in front of retina. A myopic or nearsighted
person cannot see objects at a far distance. They have to
use eyeglasses with concave lenses.
-Hyperopia or farsightedness:
This happens when the eyeball is so short that the
image is so short that the image is focused in the front of
the retina. A person with this defect cannot see effectively
near objects. A hyperopic person has to use eyeglass with
convex lenses to correct the condition.

14. -Presbyopia:
This is farsightedness of old age which is caused by the
slow hardening of the lens. Since the eyes cannot see near
object one has to put the object little away from him in order
to visualize it. A presbyopic person has to use corrective eye
glasses.
-Astigmatism:
This is caused by the uneven curvature of the cornea.
This generally is congenital (from birth) but it may be caused
by injury of inflammation. Too much eyestrain may contribute
to astigmatism
-Cross-eye:
Generally cross-eye is congenital farsightedness. Crossedeyed person have unequal two visions in two eyes. Crossedeyed persons have one eyed either turned outward or
inward. The treatment could be done through operation.