We understand the world by absorbing information through our
senses. Chapter 8 examines sensation and perception, both of
which are necessary to gather and interpret information through
our surroundings.
Section 1 discusses sensations, which occur any time
a stimulus activates a receptor. Psychophysicists study how
stimuli from the world affect the sensory experiences. They
explore how people sense the external world by studying sensory
thresholds, Weber's law, sensory adaptation, and the signal-detection
theory.
Section 2 describes the sense organs—the eyes,
ears, tongue, nose, and skin —as the receptors of sensations,
and details the nature and functioning of each of these organs.
Although people are thought to have five senses, there are
actually more. In addition to vision, hearing, taste, smell,
and touch, the vestibular sense regulates the body's sense
of balance, and the kinesthetic sense provides the sense of
movement and body position.
The way we interpret sensations and organize them into meaningful
experiences is called perception. Section 3 details
the principles of perceptual organization—Gestalt, figure-ground,
and perceptual inference—and describes how people learn
to perceive. The section includes a discussion about depth
perception, and it concludes with a look at illusions and
extrasensory perception.
