SENSATION AND PERCEPTION
VISION SENSORY AND PERCEPTUAL PROCESSING
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
There are an equal number of rods and cones. Cones detect black and white
|
|
|
there are an equal number of rods and cones. Rods detect Black and White
|
|
|
there are more cones than rods and cones detect black and white
|
|
|
There are more rods than cones and rods detect black and white
|
Detailed explanation-1: -The rods are more numerous, some 120 million, and are more sensitive than the cones. However, they are not sensitive to color. The 6 to 7 million cones provide the eye’s color sensitivity and they are much more concentrated in the central yellow spot known as the macula.
Detailed explanation-2: -Rods produce a black and white response, which is actually a reaction to variations in luminance. Moving from a very light environment into a dark environment results in a change in sensitivity of the visual system due to dark adaptation.
Detailed explanation-3: -Unlike cones, rods are able to detect light at a much lower level. This is why we see only black and white in dimly lighted rooms or while out viewing a star-filled night sky.
Detailed explanation-4: -Despite the fact that perception in typical daytime light levels is dominated by cone-mediated vision, the total number of rods in the human retina (91 million) far exceeds the number of cones (roughly 4.5 million). As a result, the density of rods is much greater than cones throughout most of the retina.
Detailed explanation-5: -There are 2 types of photoreceptors: rods, which detect dim light and are used for night vision, and cones, which detect different colors and require brightly lit environments.