UNIT 1 - Chapter 3 - Sensation and Perception Flashcards
Sensation
The process that occurs when special receptors in the sense organs are activated, allowing various forms of outside stimuli to become neural signals in the brain
Transduction
The process of converting outside stimuli, such as light, into neural activity
Just Noticeable difference (jnd or the the difference threshold)
The smallest difference between two stimuli that is detectable 50% of the time
Absolute threshold
The lowest level of stimulation that a person can consciously detect 50% of the time the stimulation is present
Signal detection theory
Provides a method for assessing the accuracy of judgements or decisions under uncertain conditions; used in perception research and other areas. An individuals correct “hits” and rejections are compared against their “misses” and “false alarms.”
Habituation
Tendency of the brain to stop attending to constant, unchanging information
Sensory adaptation
Tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging
Visual Accomodation
The change in the thickness of the lens as the eye focuses on objects that are far away or close
Rods
Visual sensory receptors found at the back of the retina, responsible for non-color sensitivity to low levels of light
Cones
Visual sensory receptors found at the back of the retina, responsible for color vision and sharpness of vision
Blind spot
Area in the retina where the axons of the three layers of retinal cells exit the eye to form the optic nerve, insensitive to light
Dark adaptation
The recovery of the eye’s sensitivity to visual stimuli in darkness after exposure to bright lights
Light Adaptation
The recovery of the eye’s sensitivity to visual stimuli in light after exposure to darkness
Trichromatic theroy
Theory of color vision that proposes three types of cones: red, blue, and green
Afterimages
Images that occur when a visual sensation persists for a brief time even after the original stimulus is removed
Opponent-Process Theory
Theory of color vision that proposes visual neurons (or groups of neurons) are stimulated by light of one color and inhibited by light of another color
Hertz(Hz)
Cycles or waves per second, a measurement of frequency
Pinna
The visible part of the ear
Auditory canal
Short tunnel that runs from the pinna to the ear drum
Cochlea
Snail-shaped structure of the inner ear that is filled with fluid
Auditory nerve
Bundle of axons from the hair cells in the inner ear
Pitch
Psychological experience of sound that corresponds to the frequency of the sound waves; higher frequencies are perceived as higher pitches
Place theory
Theory of pitch that states that different pitches are experienced by the stimulation of hair cells in different locations on the organ of Corti
Frequency theory
Theory of pitch that states that pitch is related to the speed of vibrations in the basilar membrane
Volley principle
Theory of pitch that states that frequencies from about 400 Hz to 4,000 Hz cause the hair cells (auditory neurons) to fire in a volley pattern, or take turns in firing
Gustation
The sensation of a taste
Olfaction
The sensation of smell
Olfactory bulbs
two bulb-like projections of the brain, located just above the sinus cavity and just below the frontal lobes that receive information from the olfactory receptor cells
somesthetic senses
The body senses consisting of the skin senses, the kinesthetic and proprioceptive senses and the vestibular senses
Kinesthesia
the awareness of body movement
Proprioception
awareness of where the body and body parts are located in relations to each other in space and to the ground
Vestibular Sense
The awareness of the balance, position, and movement of the head and body through space in relation to gravity’s pull
Sensory conflict theory
An explanation of motion sickness in which the information from the eyes conflicts with the information from the vestibular senses, resulting in dizziness, nausea, and other physical discomfort
Perception
The method by which the sensations experienced at any given movement are interpreted and organized in some meaningful fashion
Size Constancy
the tendency to interpret an object as always being the same actual size, regardless of its distance
Shape constantcy
The tendency to to interpret the shape of an object as being constant, even when its shape changes on the retina
Brightness constancy
the tendency to perceive the apparent brightness of an object as the same even when the light conditions change
Binocular cues
cues for perceiving depth based on both eyes
Linear perspective
Monocular depth perception cue; the tendency for parallel lines to appear converging on each other
Relative size
monocular depth perception cue; perception that occurs when objects that a person expects to be of a certain size appear to be small and are, therefore, assumed to be much farther away
Overlap (interposition)
Monocular depth perception cue; the assumption that an object that appears to be blocking part of another object is in front of the second object and closer to the object
Aerial (atmospheric) Perspective
Monocular depth perception cue; the haziness that surrounds objects that are farther away from the viewer, causing the distance to be perceived as greater
Texture gradient
Monocular depth perception cue; the tendency for textured surfaces to appear to become smaller and finer as distance from the viewer increases
Motion Parallax
monocular depth perception cue; the perception of motion of objects in which close objects appear to move more quickly than objects that are farther away
Accomodation
as a monocular cue of depth perception; the brains use of information about changing thickness of the lens of the eye in response to looking at objects that are close or far away
Convergence
binocular depth perception cue; the rotation of the two eyes in their sockets to focus on a single object, resulting in greater convergence for closer objects and lesser convergence if objects are distant
Binocular disparity
binocular depth perception cue; the difference in images between the two eyes, which is greater for objects that are close and smaller for distant objects
Muller-Lyer Illusion
Illusion of line length that is distorted by inward-turning or outward-turning corners on the ends of the lines, causing lines of equal length to appear to be different
Perceptual set (perceptual expectancy)
the tendency to perceive things a certain way because previous experiences or expectations influence those perceptions
Top-down processing
the use of pre-existing knowledge to organize individual features into a unified whole
Bottom-up processing
the analysis of the smaller features to build up to a complete perception
