Chapter 3 Flashcards
Visual Perception
Akinetopsia
a disruption of movement perception, with other aspects of perception still intact.
Cornea
Transparent tissue at the front of each eye that plays an important role in focusing the incoming light.
Lens
Transparent tissue located near the front of each eye that plays a role in focusing the incoming light. Muscles control degree of curvature of the lens, allowing the eye to form a sharp image on the retina.
Retina
The light-sensitive tissue that lines the back of the eyeball.
Parallel Processing
System in which many different steps are going on simultaneously.
Rods (Photoreceptor)
Photoreceptor that is sensitive to very low light levels but that is unable to discriminate hues and that has relatively poor acuity.
Cones (Photoreceptor)
Photoreceptor that is able to discriminate hues and that has high acuity. Concentrated in retina’s fovea and become less frequent in the visual periphery.
Acuity
Ability to discern fine detail.
Fovea
Center of retina and the region on the eye in which acuity is best; when a person looks at an object, he or she is lining up that object with the fovea.
Bipolar Cells
Type of neuron in eye. Receive input from photoreceptors and transmit their output to the retinal ganglion cells.
Ganglion Cells
Neuron in eye. Receive input from the bipolar cells, then the axons of the ganglion cells gather together to form the optic nerve, carrying information back to the LGN.
Optic Nerve
Bundle of nerve fibers, formed from the retina’s ganglion cells, that carries information from the eyeball to the brain.
Lateral Geniculate Nucleus (LGN)
Way station in the thalamus that is the first destination for visual information sent from the eyeball to the brain.
Lateral Inhibition
Pattern in which cells, when stimulated, inhibit the activity of neighboring cells.
Edge Enhancement
Process created by lateral inhibition in which the neurons in the visual system five exaggerated responses to edges of surfaces.
Center-Surround Cells
Neuron in visual system that has a donut-shaped receptive field. Stimulation in center of receptive field has one effect on the cell; stimulation in surrounding ring has the opposite effect.
Area V1
Site on Occipital Lobe where axons from the LGN first reach the cerebral cortex. It is the location at which information about the visual world first reaches the brain.
Binding Problem
Task of reuniting the various elements of a scene, elements that are initially addressed by different systems in different parts of the brain.
Spatial Position
Part of the brain registering shape is separate from the parts registering color or motion (just an example).
Conjunction Errors
correctly detecting the features present in a visual display, but making mistakes about how the features are bound together.
Figure/Ground Organization
Determination of what is the figure and what is the ground.
Parvocellular Cells
Cells in the LGN that are specialized for the perception of patterns.
Magnocellular Cells
Cells in the LGN specialized for the perception of motion and depth.
What System
System of visual circuits and pathways leading from visual cortex to temporal lobe and especially involved in object recognition.
Where System
System of visual circuits and pathways leading from visual cortex to the parietal lobe and especially involved in the spatial localization of objects and in the coordination of movements.
Binocular Disparity
Distance cue based on differences between the two eyes’ views of the world. Less pronounced the further away an object is.
Interposition
Blocking of my view of one object by another object.
Neural Synchrony
Pattern of firing by neurons in which neurons in one brain area fire at the same time as neurons in another area; the brain seems to use this pattern as an indication that the neurons in different areas are firing in response to the same stimulus.
Motion Parallax
Depth cue based on the fact that as an observer moves, the retinal images of nearby objects move more rapidly than do the retinal images of objects farther away.
Necker Cube
Two-dimensional figure drawn that can be perceived as a cube viewed from above or as a cube viewed from below.
Unconscious Inference
Steps that perceivers follow in order to take one aspect of the visual scene into account in judging another aspect.
Monocular Distance Cues
Features of the visual stimulus that indicate distance even if the stimulus is viewed with only one eye.
Pictorial Cues
Patterns that can be represented on a flat surface to create the sense of a three-dimensional object.
Single-Cell Recording
Specific cells for specific functions of the body.
Parallel Processing
Ability of the brain to process incoming stimuli of differing quality.
Serial Processing
Ability of the brain to process one stimuli at a time with incoming information.
Form Perception
Shape and size of objects.
Object Recognition
Identification of objects.
