General Psychology

1. Value of Senses
• There are 5 basic senses but most of us
take our senses for granted. Hellen
Keller was a renowned author and
lecturer who lost both her vision and
hearing at the age of 1 year and 7
months. But she’s able to recognize her
friend by a touch of their face. A house,
by the smell of the house and the
occupants. The story of Hellen Keller is
often used as an inspiring example of
how people can overcome sensory
deficiencies in one or two areas by fully
developing other senses.

2. • The average adult eyeball weights about one ounce.
• The average time between eye blinks is 2.8 seconds.
• The average human eyelash lives about 150 days.
• The pupil of the eye expands as much as 45% when a person looks at
something pleasing.
• The eyes can process 36,000 bits of information every hour.
• You can’t sneeze with your eyes open, can you?
Eyes: Our doorway to the world

3. Sense of Sight / Vision
• Bodily receptor:
• Stimulus:
• Sensitive cells:
• Eyes
• Light waves
• Rods and cones
(located in retina)

4. Characteristics of color
• Hue – name by which the color is identified.
• Saturation – purity or a mixed color. (ex)
• Brightness / intensity – the background of the color that affects the
brightness

5. Parts

6. • The part of the brain that is responsible for vision is….
• Occipital lobe

7. Retina
• Cones
• 6.5 million in each eye
• Contains chemical iodopsin
– sensitive to color in the
presence of light
• Fovea centralis – area with
high concentrations of
cones. Area of clear
detailed vision
• Rods
• 100 millions in each eye.
• Contains rhodopsin –
function is to see in the
dark

8. Scotopia / dark adaptation
• A gradual increase in visual sensitivity under condition of low
illumination.
• Example

9. Photopia / light adaptation
• A gradual decrease in visual sensitivity under condition of high
illumination.
• Example

10. Visual Acuity
• Size of the object/stimulus
• Proximity or distance
• Illumination

11. Visual After Image
• When perception of the visual stimulus does not disappear
immediately upon removal of the stimulus.
• Positive after image – the color resembles the original color.
• Negative after image - the color is opposite of the original.

15. After Images
• Stare at the eye of the red parrot while you slowly count to 20, then
immediately look at one spot in the empty birdcage. The faint, ghostly
image of a blue-green bird should appear in the cage.

16. Blind spot
• End of optic nerve without rods and cones

17. Visual Problems

18. VISUAL PROBLEMS
• Vision is measured by the Snellen Eye Chart (devised
by a Dutch Opthalmologist, Dr. Hermann Snellen in
1862)
• Perfect visual acuity is 20/20
• The Snellen fractions, 20/20, 20/30, etc., are measures
of sharpness of sight. They relate to the ability to
identify small letters with high contrast at a specified
distance

19. Forms of Colorblindness
• Approximately 10% of men and 1% of
women have some form of
colorblindness
• Dichromats
• People who are blind to either red-green
or blue-yellow
• Monochromats
• People who see no color at all, only
shades of light and dark
• Trichromats – people with normal
color vision

20. VISUAL PROBLEMS
• Colors of the rainbow as
viewed by a normal
person
• Colors of the rainbow as
viewed by a person who
can not see the red color
(protanopia)

21. VISUAL PROBLEMS
• Colors of the rainbow as
viewed by a person who
cannot see the green
color (deuteranopia)
• Colors of the rainbow as
viewed by a person who
can not see the blue color
(tritanopia)

30. VISUAL PROBLEMS
• Glaucoma - is another hereditary visual problem; increase in eye pressure caused
by the fluids in the eye cause nerve damage that may ultimately lead to blindness
in one or both eyes
• From 1978 – 1984, the US National Eye Institute conducted studies that actually
proved Cannabis Sativa or Marijuana to effectively lower intraocular pressure
when administered orally, intravenously or by smoking

31. VISUAL PROBLEMS
• Myopia or near-sightedness is a visual problem when the eye has difficulty
focusing distant objects
• Causes:
• Hyperopia or far-sightedness is a visual problem when the eyes has difficulty
focusing near objects

33. Visual problems
• Astigmatism – caused by uneven curvature of the lens.

34. Visual problems
• Cataract – a clouding of the lens inside the eye which leads to
decrease in vision.

35. Visual problems
• Strabismus – eyes are not aligned properly and point in different
direction.

36. • Night blindness – inability to see under low illumination.
• Presbyopia - oldsightedness

37. EARS: the sound we hear/ Audition
If a tree falls in the forest…
• The question “If a tree falls in the forest and there is
no one around to hear it, does it still make a sound?”
• No, it would make no sound.
• Sound is a purely physiological sensation that requires
an ear (and the rest of the auditory system) to
produce it.
• Why deaf are mute and mute are also deaf?

38. Sense of Hearing / Audition
• Bodily receptor:
• Stimulus:
• Sensitive cells:
• Ears
• Sound waves
• Hair cells
• Located in organ of corti
• Organ of corti is located in
cochlea.
• Cochlea is located in inner ear

39. Sense of hearing
• Last sense to develop
• It is where the smallest bone and cartilage can be found.

40. Parts

41. • The part of the brain that s responsible for hearing is:
• Temporal lobe

42. Deafness
• There are generally two types of deafness.
• Conduction deafness is an inability to hear, resulting from
damage to the structures of the middle or inner ear.
• Nerve deafness (Sensorineural Deafness) is an inability to
hear, linked to a deficit in the body’s ability to transmit
impulses from the cochlea to the brain.

43. Hearing Disorders
• Central deafness / Central processing hearing disorder (CPHD) – the
problem is within the part of the brain that interprets sound.