Chapter 4 Flashcards
Absolute threshold
The minimum amount of stimulation that an organism can detect for a specific type of sensory input.
Additive colour mixing
Formation of colours by superimposing lights, putting more light in the mixture than exists in any one light by itself.
Afterimage
A visual image that persists after a stimulus is removed. McCollough effect - circles of lines
Auditory localization
Locating the source of a sound in space.
Bottom-up processing
In form perception, progression from individual elements to the whole.
Comparitors
People, objects, events, and other standards that are used as a baseline for comparisons in making judgments.
vComplementary colours
Pairs of colours that produce grey tones when added together.
Convergence
A cue to depth that involves sensing the eyes converging toward each other as they focus on closer objects.
Dark adaptation
The process in which the eyes become more sensitive to light in low illumination.
Distal stimuli
Stimuli that lie in the distance (that is, in the world outside the body).
Farsightedness
A vision deficiency in which distant objects are seen clearly but close objects appear blurry. Focus of light is behind the retina (FAR from lens), can see FAR.
Feature analysis
The process of detecting specific elements in visual input and assembling them into a more complex form.
Feature detectors
Neurons that respond selectively to very specific features of more complex stimuli.
Fechner’s law
A psychophysical law stating that larger and larger increases in stimulus intensity are required to produce perceptible increments in the magnitude of sensation.
Frequency theory
The theory that perception of pitch corresponds to the rate, or frequency, at which the entire basilar membrane vibrates. Basilar is like a drum.
Gate-control theory
The idea that incoming pain sensations must pass through a “gate” in the spinal cord that can be closed, thus blocking pain signals.
Impossible figures
Objects that can be represented in two-dimensional pictures but cannot exist in three-dimensional space.
Just noticeable difference (JND)
The smallest difference in the amount of stimulation that a specific sense can detect.
Kinesthetic system
The sensory system that monitors the positions of the various parts of one’s body (vestibular apparatus, etc).
Lateral antagonism
A process in the retina that occurs when neural activity in a cell opposes activity in surrounding cells. GRID of black and white, you can see grey spots at intersections of white lines due to LA.
Light adaptation
The process whereby the eyes become less sensitive to light in high illumination.
Motion parallax
Cue to depth that involves images of objects at different distances moving across the retina at different rates.
Nearsightedness A
A vision deficiency in which close objects are seen clearly but distant objects appear blurry. Focus of light falls in front of the retina (NEAR lens), can see NEAR.
Opponent process theory
The theory that colour perception depends on receptors that make antagonistic responses to three pairs of colours. Explains afterimages and the need for four names to describe colours. Used high up in processing.
Parallel processing
Simultaneously extracting different kinds of information from the same input. Parvocellular channel does colour while magnocellular does brightness.
Perception
The selection, organization, and interpretation of sensory input.
Perceptual constancy
A tendency to experience a stable perception in the face of continually changing sensory input.
Perceptual hypothesis
An inference about which distal stimuli could be responsible for the proximal stimuli sensed.
Perceptual set
A readiness to perceive a stimulus in a particular way.
Phi phenomenon
The illusion of movement created by presenting visual stimuli in rapid succession.
Pictorial depth cues
Clues about distance that can be given in a at picture.
Linear Perspective (road lines come together)
Texture Gradient
Interposition (things overlapping)
Relative Size (closer = larger)
Height in Plane (near are lower in visual field)
Light and Shadow (3-D)
Place theory
The idea that perception of pitch corresponds to the vibration of different portions, or places, along the basilar membrane. Basilar is like a harp.
Proximal stimuli
The stimulus energies that impinge directly on sensory receptors.
Psychophysics
The study of how physical stimuli are translated into psychological experience.
Receptive field of a visual cell
The retinal area that, when stimulated, affects the ring of that cell.
Retinal disparity
A cue to the depth based on the fact that objects within 25 feet project images to slightly different locations on the left and right retinas, so the right and left eyes see slightly different views of the object.
Reversible figure
A drawing that is compatible with two different interpretations that can shift back and forth.
Signal-detection theory
A psychophysiological theory proposing that the detection of stimuli involves decision processes as well as sensory processes, which are inuenced by a variety of factors besides the physical intensity of a stimulus. q
Subjective contours
The perception of contrours where none actually exist.
Subtractive color mixing
Formation of colors by removing some wavelengths of light, leaving less light than was originally there.
Top-down processing
In form perception, a progression from the whole to the elements.
Trichromatic theory
The theory of color vision holding that the human eye has three types of receptors with differing sensitivities to different wavelengths. Used in low level of processing (cones).
Volley Principle
the groups of auditory nerve fibres fire neural impulses in rapid succession, creating volleys of impulses. accounts for high-frequency sounds in the frequency theory.
Weber’s Law
the size of a JND is a constant proportion of the size of the initial stimulus - weber fraction.
sensory adaptation
an automatic built-in process that keeps people tuned into the changes rather than the constants in their sensory input.
visual pathways
from retina, 90% go directly to LGN and then to the primary visual cortex in the occipital lobe. 10% go to superior colliculus in midbrain, then thalamus then PVC - coordination of visual input with other sensory input.
Gestalt
Phi Phenomenon - illusion of movement
Figure and Ground - reversible figures (Necker cube)
Proximity - things that are near one another seem to belong together
Closure - complete figures that actually have gaps in them
Similarity - group stimuli that are similar
simplicity - ‘Pragnanz’ = good form. organize elements int he simplest way possible
Continuity - see elements in ways that produce smooth continuation
