Page 247 - Understanding Psychology

Summary and Vocabulary
People take in information through their senses. Through their senses they perceive the world around them.
Sensation
Chapter Vocabulary
sensation (p. 208)
perception (p. 208) psychophysics (p. 208) absolute threshold (p. 209) difference threshold (p. 210) Weber’s law (p. 211) signal-detection theory (p. 212) pupil (p. 215)
lens (p. 215)
retina (p. 215)
optic nerve (p. 215) binocular fusion (p. 216) retinal disparity (p. 216) auditory nerve (p. 218) vestibular system (p. 220) olfactory nerve (p. 220) kinesthesis (p. 222)
Gestalt (p. 224)
subliminal messages (p. 226) motion parallax (p. 228) constancy (p. 229)
illusions (p. 229)
extrasensory perception (ESP) (p. 230)
Main Idea: Sensations allow humans to under- stand reality. Sensations occur anytime a stimu- lus activates a receptor.
s The absolute threshold is the weakest amount of a stimulus required to produce a sensation; the dif- ference threshold is the minimum amount of dis- tinction a person can detect between two stimuli.
s Senses are most responsive to increases and decreases, rather than unchanging stimulation.
s Sensory adaptation allows people to notice differ- ences in sensations and react to the challenges of different or changing stimuli.
Main Idea: The sense organs—the eyes, ears, tongue, nose, skin, and others—are the recep- tors of sensations.
s Vision provides people with a great deal of information about the environment and the objects in it.
s Hearing depends on vibrations of the air, called sound waves.
s The body’s sense of balance is regulated by the vestibular system inside the inner ear.
s Smell and taste are known as the chemical senses because their receptors are sensitive to chemical molecules.
s Receptors in the skin are responsible for providing the brain with information about pressure, warmth, cold, and pain.
s Kinesthesis cooperates with the vestibular and visual senses to maintain our sense of movement and body position.
Main Idea: The way we interpret sensations and organize them into meaningful experiences is called perception.
s The Gestalt principles of organization help explain how we group our sensations and fill in gaps to make sense of our world.
s Figure-ground perception is the ability to discrimi- nate properly between figure and ground.
s Perceptual inference is the phenomenon of filling in the gaps in what our senses tell us.
s Learning to perceive is influenced by our needs, beliefs, and expectations.
s People use monocular depth cues and binocular depth cues to perceive distance and depth.
s Incorrect perceptions, created when perceptual cues are distorted, are called illusions.
The Senses
Perception
Chapter 8 / Sensation and Perception 233