Some states of consciousness dont occur naturally and must be induced in some way. These include hypnotic
states, meditative states, and drug-induced states.
Hypnosis is a procedure that opens people to the power of suggestion. A hypnotist puts a
Sensation is the process by which physical energy from objects in the world or in the body stimulates the sense
organs. The brain interprets and organizes this sensory information in a process
called perception.Psychophysics is the study of how the physic
Color constancy: Different wavelengths of light are reflected from objects under different lighting
conditions. Outdoors, objects reflect more light in the blue range of wavelengths, and indoors, objects reflect
more light in the yellow range of waveleng
To figure out the location of an object, people must be able to estimate their distance from that object. Two types of
cues help them to do this: binocular cues and monocular cues.
Binocular cues are cues that require both
The Opponent Process Theory
Ewald Hering proposed the opponent process theory. According to this theory, the visual system has receptors
that react in opposite ways to three pairs of colors. The three pairs of colors are red versus green, blue versus yell
Adaptation to Light
Dark adaptation is the process by which receptor cells sensitize to light, allowing clearer vision in dim light. Light
adaptation is the process by which receptor cells desensitize to light, allowing clearer vision in bright light.
Researchers have studied vision more thoroughly than the other senses. Because people need sight to perform
most daily activities, the sense of sight has evolved to be highly sophisticated. Vision, however, would not exist
without the presence of light. L
Hearing, or audition, depends on the presence of sound waves, which travel much more slowly than light
waves. Sound waves are changes in pressure generated by vibrating molecules. The physical characteristics of
sound waves influence the three psychologic
Taste and smell are chemical senses. As light waves stimulate vision and sound waves stimulate sound, chemicals
stimulate taste and smell.
Taste, or gustation, happens when chemicals stimulate receptors in the tongue and throat, on the inside of the
Psychophysics studies the relationship between the physical properties of stimuli and peoples experience
Psychologists assess the acuity of our senses by measuring theabsolute threshold and the difference
threshold and by applying