Sensation And Perception Chapter 8 Flashcards
akinetopsia
A condition in which damage to an area of the cortex involved in motion perception causes blindness to motion.
aperture problem
Occurs when only a portion of a moving stimulus can be seen, as when the stimulus is viewed through a narrow aperture or through the "field of view" of a neurons' receptive field. This can result in misleading information about the direction in which the stimulus is moving.
apparent motion
An illusion of movement that occurs whentwo objects separated in space are presented rapidly, one after another, separated by a brief time interval.
biological motion
Motion produced by biological organisms. Most of the experiments on __________________ have used walking humans with lights attached to their joints and limbs as stimuli.
coherence
In research on movement perception in which arrays of moving dots are used as stimuli, the degree of correlation between the direction of the moving dots. Zero percent ___________ means all of the dots are moving independently; 100 percent ________ means all of the dots are moving in the same direction.
comparator
A structure hypothesized by the corollary discharge theory of movement perception. The corollary discharge signal and the sensory movement signal meet at the ______________ to determine whether movement will be perceived.
corollary discharge signal
A copy of the motor signal thatis sent to the eye muscles to cause movement of the eye. The copy is sent to the hypothetical comparator of corollary discharge theory.
corollary discharge theory
The theory that explains motion perception as being determined both by movement of the image on the retina and by signals that indicate movement of the eyes.
delay unit
A component of the Reichardt detector proposed to explain how neural firing occurs to different directions of movement. The ____________ delays the transmission of nerve impulses as they travel from the receptors toward the brain.
event boundary
The point in time when one event ends and another begins.
event
A segment of time at a particular location that is perceived by observers to have a beginning and an ending.
global optic flow
Information for movement that occurs when all elements in a scene move. The perception of _______________ indicates that it is the observer that is moving and not the scene.
illusory motion
Perception of motion when there actually is none.
image displacement signal
In corollary discharge theory, the signal that occurs when an image moves across the visual receptors.
implied motion
When a still picture depicts an action that involves motion, so that an observer could potentially extend the action depicted in the picture in his or her mind based on what will most likely happen next.
induced motion
The illusory movement of one object that is caused by the movement of another object that is nearby.
local disturbance in the optic array
Occurs when one object moves relative to the environment, so that the stationary background is covered and uncovered by the moving object. This __________________ indicates that the object is moving relative to the environment.
motion aftereffects
An illusion that occurs after a person views a moving stimulus and then sees movement in the opposite direction when viewing a stationary stimulus immediately afterward.
motor signal
In corollary discharge theory, the signal that is sent to the eye muscles when the observer moves or tries to move his or her eyes.
optic array
The structured pattern of light created by the presence of objects, surfaces, and textures in the environment.
output unit
A component of the Reichardt detector that compares signals received from two or more neurons. According to Reichardt's model, activity in the _________ is necessary formotion perception.
point light walkers
A biological motion stimulus created by placing lights at a number of places on a person's body and having an observer view the moving-light stimulus that results as the person moves in the dark.
real motion
The physical movement of a stimulus. Contrasts with apparent motion.
real motion neuron
Neuron in the monkey's cortex that responds when movement of an image across the retina is caused by movement of a stimulus, but does not respond when movement across the retina is caused by movement of the eyes.
Reichart detector
A neural circuit proposed by Werner Reichardt,in which signals caused by movement of a stimulus across the receptors are processed by a delay unit and an output unit so that signals are generated by movement in one direction but not in the opposite direction.
representational momentum
Occurs when motion depicted in a still picture continues in an observer's mind.
shortest path constraint
In the perception of apparent motion, the principle that apparent movement tends to occur along the shortest path between two stimuli.
transcranial magnetic stimulation
Presenting a strong magnetic field to the head that temporarily disrupts the functioning of a specific area of the brain.