Sensation and Perception Discussion
Sensation and perception
identify processes that differ
primarily in their complexity.
We have a greater number of
senses than is widely believed.
Psychophysics is the study of
the relationship between
physical events and our
experience of those events. The
absolute threshold is the
smallest stimulus that arouses a sensation. The difference
threshold is the smallest change in any stimulation that can be
detected.
The stimulus for vision is light, which has three physical
characteristics: wavelength, intensity, and pureness. The
psychological attributes are hue, brightness, and saturation.
Complementary colors, as well as other colors, may be mixed in
an additive or subtractive process. The receptor for vision is
the eye, which contains rods for black-white vision and cones
for color vision. Vision is poorest at the blind spot and best
at the fovea. Dark adaptation and the Purkinje Shift both
result from the shift from cone- to rod-vision. Color blindness
affects mainly males, but it is a relatively slight vision
problem compared to blindness.
The physical stimulus for hearing is pressure waves, which
have three physical characteristics: frequency, amplitude, and
complexity. We hear sounds in terms of pitch, loudness, and
timbre. The receptor for sound is the ear, within which hair
cells in the cochlea stimulate the auditory nerve. Two major
types of deafness include conduction deafness and nerve
deafness
