Intro to Psychology - Chapter 5: Sensation and Perception

sensations

the elementary components, or building blocks, of an experience (such as a pattern of light and dark, a bitter taste, or a change in temperature)

perception

the collection of processes used to arrive at a meaningful interpretation of sensations

light

the small part of the electromagnetic spectrum that is processed by the visual system

hue

the dimension of light that produces color; hue is typically determined by the wavelength of light reflecting from an object

brightness

the aspect of the visual experience that changes with light intensity; in general, as the intensity of light increase, so does its perceived brightness

transduction

the process by which external messages are translated into the internal language of the brain

cornea

the transparent and protective outer covering of the eye

lens

the flexible piece of tissue that helps focus light toward the back of the eye

pupil

the hold in the center of the eye that allows light to enter

iris

the ring of colored tissue surrounding the pupil

accommodation

in vision, the process through which the lens changes its shape temporarily to help focus light on the retina

retina

the thing layer of tissue that covers the back of the eye and contains the light-sensitive receptor cells for vision

rods

receptor cells in the retina, located mainly around the sides, that transduce light energy into neutral messages; these visual receptors are highly sensitive and are active in dim light (more rods)

cones

receptor cells in the central portion of the retina that transduce light energy into neural messages; they operate best when light levels are high and they are primarily responsible for the ability to sense color (less cones)

fovea

the "central pit" area in the retina where the cone receptors are located

visual acuity

the ability to process fine detail in vision

receptive field

in vision, the portion of the retina that, when stimulated, causes the activity of higher order neurons to change

blind spot

the point where the optic nerve leaves the back of the eye

dark adaptation

the process through which the eyes adjust to dim light

feature detectors

cells in the visual cortex that respond to very specific visual events, such as bars of light at particular orientations

trichromatic theory

a theory of color vision proposing that color information is extracted by comparing the relative activations of three different types of cone receptors

opponent-process theory

a theory of color vision proposing that cells in the visual pathway inquire their activation levels to one color and decrease their activation levels to another color (example: increasing to red, decreasing to green)

bottom-up processing

processing that is controlled by the physical message delivered to the senses

top-down processing

processing that is controlled by one's beliefs and expectations about how the world is organized

Gestalt principles of organization

the organizing principles of perception proposed by the Gestalt psychologists. These principles include the laws of proximity, similarity, closure, continuation, and common fate

recognition by components

the idea proposed by Biederman that people recognize and can successfully identify fuzzy or incomplete images

monocular depth cues

cues for depth that require input from only one eye

binocular depth cues

cues for depth that depend on comparisons between the two eyes

retinal disparity

a binocular cue for depth that is based on location differences between the images in each eye

convergence

a binocular cue for depth that is based on the extent to which the tow eyes move inward, or converge, when looking at an object

phi phenomenon

a illusion of movement that occurs when stationary lights are flashed in succession

perceptual constancy

perceiving the properties of an object to remain the same even though the physical properties of the snotty message are changing

perceptual illusions

inappropriate interpretations of physical reality; perceptual illusions often occur as a result of the brains using otherwise adaptive organizing principles

sound

the physical message delivered to the auditory system; a mechanical energy that require a medium such as air or water in order to move

pitch

the psychological experience that results from the auditory processing of a particular frequency of sound

pinna

the external flap of tissue normally referred to as the "ear"; it helps capture sound

tympanic membrane

the eardrum, which responds to incoming sound waves by vibrating

middle ear

the portion between the eardrum and the cochlea containing three small bones (the malleus, incus and stapes) that help to intensify and prepare the sound vibrations for passage into the inner ear

cochlea

the bony, snail-shaped sound processor in the inner ear where sound is translated into nerve impulses

basilar membrane

a flexible membrane running thorough the cochlea that, through its movement, displaces the auditory receptor cells or hair cells

place theory

the idea that the location of auditory receptor cells activated by movement of the basilar membrane underlies the perception of pitch

frequency theory

the idea that pitch perception is determined partly by the frequency of neural impulses traveling up the auditory pathway

cold fibers

neurons that respond to a cooling of the skin by increasing the production of neural impulses

warm fibers

neurons that respond vigorously when the temperature of the skin increases

pain

an adaptive response by the body to any stimulus that is intense enough to cause tissue damage

gate-control theory

the idea that neural impulses generated by pain receptors can be blocked, or gated, in the spinal cord by signals produced in the brain

kinesthesia

in perception, the ability to sense the position and movement of one's body parts

semicircular canals

a receptor system attached to the inner ear that respond to movement and acceleration and to changes in upright posture

vestibular sacs

organs of the inner ear that contain receptors through to be primarily responsible for balance

chemoreceptors

receptor cells that react to invisible molecules scattered about in the air or dissolved in liquids, leading to the sense of smell and taste

olfaction

the sense of smell

gustation

the sense of taste

flavor

a psychological term used to describe the gustatory experience; is influenced by taste, smell, and the visual appearance of food, as well as by exceptions about the food's quality

taste buds

the receptor cells on the tongue

psychophysics

a field of psychology in which researchers search for ways to describe the transition from the physical stimulus to the psychological experience of the that stimulus

absolute threshold

the level of intensity that lifts a stimulus over the threshold of conscious awareness; it's usually defined as the intensity level at which people can detect the presence of the stimulus 50% of the time

signal detection

a technique used to determine the ability of someone to detect the presence of a stimulus

difference threshold

the smallest detectable difference in the magnitude of the two stimuli

Weber's law

the principle stating that the ability to notice a difference in the magnitude of two stimuli is a constant proportion of the size of the standard stimulus. Psychologically, the more intense a stimulus is to begin with, ht more intense it will ned to become for one to notice a change