|
 |
||
 |
| This glossary contains: 19186 medical terms |
 |
Simple cells
|
|
Simple cells One of three cell classifications for cells in the primary visual cortex (V1) proposed by Hubel & Wiesel. Simple cells show rectangular antagonistic on/off zones responding to bars of a particular orientations. They are described as a performing a linear filtering operation followed by a threshold nonlinearity. In a linear system the average response to a drifiting cosine grating will be a cosine at the same frequency. Because of the threshold, response to the negative half-cycles are suppressed.
RELATED TERMS--------------------------------------
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
Cortex
The outer layer of the cerebrum, densely packed with nerve cells.
SIMILAR TERMS--------------------------------------
PREVIOUS AND NEXT TERMS--------------------------------------
Sensitivity control
Adjustment of eye sensitivity to compensate for a change in illumination.
Sensory fusion
The combining of drawing together of two images which fall on different points in the two retinas without changing the vergence of the two eyes.
Short-Sightedness
See Myopia.
Short-term visual store
Visual memory not affected by masking, not in anatomical coordinates, limited in capacity. Less is retained from complex images than simple images.
Silent substitution
If the action spectra of all photoreceptors types are known, spatial or temporal stimulus patterns can be designed which are invisible to some cone types while producing suprathreshold contrast for others. Thus one can study the range of psychophysical performance that is available for solely one type of cone signal.
Simple cells
Size constancy
The fact that the perception of the sizes of objects remains remarkably constant at varying distance despite the fact that the image projected on the retina changes.
Stabilized retinal images
Technique for examining perception without eye movement accompanied by loss of color and contour perception. Demonstrates that movement of an image across the retina is vital for perception.
Stereoscope
Device for creating a 3-D image of a drawn objects. Works by projects two different images of the objects to the eyes.
Stiles-Crawford effect
Light entering the eye through the center of the pupil is more effective than light entering at a peripheral point near the edge of the pupil. This is largely to to the directionally sensitive photoreceptors which are oriented towrad the center of the pupil. This helps to minimize the effect of stray light.
Stimulus equivalence
If the stimulus controlling behavior is a pattern of light on the retina than an infinite number of images are equivalent in their effects.
RELATED TERMS--------------------------------------
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
Cortex
The outer layer of the cerebrum, densely packed with nerve cells.
SIMILAR TERMS--------------------------------------
PREVIOUS AND NEXT TERMS--------------------------------------
Sensitivity control
Adjustment of eye sensitivity to compensate for a change in illumination.
Sensory fusion
The combining of drawing together of two images which fall on different points in the two retinas without changing the vergence of the two eyes.
Short-Sightedness
See Myopia.
Short-term visual store
Visual memory not affected by masking, not in anatomical coordinates, limited in capacity. Less is retained from complex images than simple images.
Silent substitution
If the action spectra of all photoreceptors types are known, spatial or temporal stimulus patterns can be designed which are invisible to some cone types while producing suprathreshold contrast for others. Thus one can study the range of psychophysical performance that is available for solely one type of cone signal.
Simple cells
Size constancy
The fact that the perception of the sizes of objects remains remarkably constant at varying distance despite the fact that the image projected on the retina changes.
Stabilized retinal images
Technique for examining perception without eye movement accompanied by loss of color and contour perception. Demonstrates that movement of an image across the retina is vital for perception.
Stereoscope
Device for creating a 3-D image of a drawn objects. Works by projects two different images of the objects to the eyes.
Stiles-Crawford effect
Light entering the eye through the center of the pupil is more effective than light entering at a peripheral point near the edge of the pupil. This is largely to to the directionally sensitive photoreceptors which are oriented towrad the center of the pupil. This helps to minimize the effect of stray light.
Stimulus equivalence
If the stimulus controlling behavior is a pattern of light on the retina than an infinite number of images are equivalent in their effects.
We thank you for using the Medical Glossary to search for Simple cells. If you have a better definition for Simple cells than the one presented here, please let us know by making use of the suggest a term option. This definition of Simple cells may be disputed by other professionals. Our attempt is to provide easy definitions on Simple cells and any other medical topic for the public at large.
This dictionary contains 19186 terms.
|
|