PSY 101: Chapter 3

The minimum amount of energy in a sensory stimulus detected 50 percent of the time.

A theory that assumes the detection of faint sensory stimuli depends not only upon a persons physiological sensitivity to a stimulus but also upon his decision criterion for detection, which is based on non-sensory factors.

The minimum difference between two sensory stimuli detected 50 % of the time. It is also sometimes reffered to as the just noticeable difference. (JND)

For each type of sensory judgement that we can make, the measured difference threshold is a constant fraction of the standard stimulus value used to measure it. This constant fraction is different for each type of sensory judgement.

The percieved magnitude of a stimulus is equal to it's actual physical intensity raised to the sam constant power. The constant power is different for each type of sensory judgement.

Our sensitivity to unchanging and repetitious stimuli disappears over time.

The distance in one cycle of a wave, from one crest to the next.

The amount of energy in a wave, it's intensity, which is the height of the wave at it's crest.

The number of times a wave cycles in one second.

The conversion of physical energy into neural signals that the brain can understand.

The focusing of light waves from objects of different distances directly on the retina.

A visual problem in which the light waves from distant objects come into focus in front of the retina, blurring images of these objects.

A visual problem in which the light waves from nearby objects come into focus behind the retina, blurring the images of these objects.

The light-sensitive layer of the eye which is composed of three layers of cells-ganglion, bipolar, and receptor. (the rods and cones)

Receptor cells in the retina that are principally responsible for dim light and peripheral vision.