cognition ch 6

the effects of a stimulus on the sensory organs

the elaboration and interpretation of a sensory stimulus based on, for example, knowledge of how objects are structured

the internal surface of the eyes containing photo receptors that convert light to neural signals

a type of photoreceptor specialized for low levels of light intensity, such as those found at night.

a type of photoreceptor specialized for high levels of light intensity, such as those found during the day, and specialized for the detection of different wavelenghts

the first stage of visual processing in the cortex; the region retains the spatial relationships found on the retina and combines simple visual features into more complex ones

the region of space that elicits a response from a given neuron

cells that respond to light in a particular orientation

cells that respond to light in a particular orientation but do not respond to single points of light

cells that respond to particular orientations and particular lengths

cortical blindness restricted to one half of the visual field (associated with damage to the primary visual cortex in one hemisphere)

cortical blindness restricted to a quarter of the visual field

small region of cortical blindness

symptom in which the patient reports not being able to consciously see stimuli in a particular region but can nevertheless perform visual discrimination accurately

a region of extrastriate cortex associated with color perception

a region of extrastriate cortex associated with motion perception

a failure to perceive color (the world appears to be grayscale), not to be confused with color blindness

a failure to perceive visual motion

the color of a surface is perceived as constant even when illuminated in different lighting conditions

ability to detect whether a stimulus is animate or not from movement cues alone

a memory representation of the three dimensional structure of objects

a failure to understand the meaning of objects due to a deficit at the level of object perception

a failure to understand the meaning of objects due to a deficit at the level of semantic memory

the process of segmenting a visual display into objects versus background surfaces

-law of proximity
-law of similarity
-law of good continuation
-law of closure
-law of common fate

states that the visual elements are more likely to be grouped if they are closer together.

elements will be grouped together if they share visual attributes

edges are grouped together to avoid changes or interruptions

missing parts are "filled" in

elements that move together tend to be grouped together

a failure to integrate parts into wholes in visual perception

an understanding that objects remain the same, irrespective of differences in viewing condition

inability to extract the orientation of an object despite adequate object recognition

the notion that the brain represents different categories in different ways

stored knowledge of the three dimensional structure of familiar faces

an abstract description of people that links together perceptual knowledge with semantic knowledge

impairments of face processing that do not reflect difficulties in early visual analysis (inability to recognize previously familiar faces)