|
 |
||
 |
| This glossary contains: 19186 medical terms |
 |
Adaptation
|
|
Adaptation A change in the sensitivity to light of a photoreceptor or the visual system as a whole to match the average light intensity present.
RELATED TERMS--------------------------------------
Sensitivity
1. The reciprocal of the minimum stimulus strength required for the stimulus to be detected reliably (1/threshold) May be related to noise and other mechanisms. 2. Physiologically measured sensitivity averaged over many stimulus/response cycles. A measure of gain. Noise free.
Photoreceptor
A light sensitive neuron. Photoreceptors interact with light which produces changes in their electrical properties which are communicated to other neurons. They constitute the first stage in the physiological process which underlies vision. The human retina, like the retina of most vertebrates, contains two broad classes of photo-receptors, rods and cones.
SIMILAR TERMS--------------------------------------
Adapter protein
A protein acts as a connecting molecule. An adapter protein is critical to intermolecular interactions and plays a role in the regulation of signal transduction initiated by engagement of surface receptors on all cell types. Some adapter proteins are expressed in all tissues, while the expression of other adapter proteins is restricted to specific tissues.
PREVIOUS AND NEXT TERMS--------------------------------------
Accessory optic system (AOS)
Region of the vertebrate midbrain to which some optic nerve fibers project. Cells respond to large slowly moving textured patterns and are selective for both direction and speed of motion suggesting they are involved in the computation of global motion. Possibly used for the detection of retinal slip and used in image stabilization. Consists of two sets of retina ganglion cell fibers and three target nuclei in the anterior portion of the midbrain, the dorsal, medial and lateral nuclei.
Accidental view
A special view of an object in which small perturbations in lighting or viewing direction drastically change its appearance. For example, imagine looking at a pencil straight on from the tip. (As opposed to Generic View).
Acuity
The highest spatial frequency rsolvable with a grating of unity contrast (i.e. the maximum possibly contrast).
Action potential
A photoreceptor's relative spectral sensitivity.
Action spectra
A photoreceptor's relative spectral sensitivity.
Adaptation
Afferent
Heading towards. A system's afferent signals are those entering the system from elsewhere. (As opposed to Efferent)
Affordance
A possibility for action afforded to a perceiver by an object. The affordances of an object depend upon the perceiver as well as upon the characteristics of the object. For example, a stream affords such actions as jumping and paddling to a person, but to an frog it affords swimming.
Aftereffect
A long lasting change in perceived brightness that occurs after prolonged viewing of a given luminance that remains after the luminance has been changed. Presumably due to adaptation in the exposed region.
Afterimage
A long lasting change in perceived brightness that occurs after prolonged viewing of a given luminance that remains after the luminance has been changed. Presumably due to adaptation in the exposed region.
Aggregate field
The area within which the receptive fields of cells in a single hypercolumn of the visual cortex fall.
RELATED TERMS--------------------------------------
Sensitivity
1. The reciprocal of the minimum stimulus strength required for the stimulus to be detected reliably (1/threshold) May be related to noise and other mechanisms. 2. Physiologically measured sensitivity averaged over many stimulus/response cycles. A measure of gain. Noise free.
Photoreceptor
A light sensitive neuron. Photoreceptors interact with light which produces changes in their electrical properties which are communicated to other neurons. They constitute the first stage in the physiological process which underlies vision. The human retina, like the retina of most vertebrates, contains two broad classes of photo-receptors, rods and cones.
SIMILAR TERMS--------------------------------------
Adapter protein
A protein acts as a connecting molecule. An adapter protein is critical to intermolecular interactions and plays a role in the regulation of signal transduction initiated by engagement of surface receptors on all cell types. Some adapter proteins are expressed in all tissues, while the expression of other adapter proteins is restricted to specific tissues.
PREVIOUS AND NEXT TERMS--------------------------------------
Accessory optic system (AOS)
Region of the vertebrate midbrain to which some optic nerve fibers project. Cells respond to large slowly moving textured patterns and are selective for both direction and speed of motion suggesting they are involved in the computation of global motion. Possibly used for the detection of retinal slip and used in image stabilization. Consists of two sets of retina ganglion cell fibers and three target nuclei in the anterior portion of the midbrain, the dorsal, medial and lateral nuclei.
Accidental view
A special view of an object in which small perturbations in lighting or viewing direction drastically change its appearance. For example, imagine looking at a pencil straight on from the tip. (As opposed to Generic View).
Acuity
The highest spatial frequency rsolvable with a grating of unity contrast (i.e. the maximum possibly contrast).
Action potential
A photoreceptor's relative spectral sensitivity.
Action spectra
A photoreceptor's relative spectral sensitivity.
Adaptation
Afferent
Heading towards. A system's afferent signals are those entering the system from elsewhere. (As opposed to Efferent)
Affordance
A possibility for action afforded to a perceiver by an object. The affordances of an object depend upon the perceiver as well as upon the characteristics of the object. For example, a stream affords such actions as jumping and paddling to a person, but to an frog it affords swimming.
Aftereffect
A long lasting change in perceived brightness that occurs after prolonged viewing of a given luminance that remains after the luminance has been changed. Presumably due to adaptation in the exposed region.
Afterimage
A long lasting change in perceived brightness that occurs after prolonged viewing of a given luminance that remains after the luminance has been changed. Presumably due to adaptation in the exposed region.
Aggregate field
The area within which the receptive fields of cells in a single hypercolumn of the visual cortex fall.
We thank you for using the Medical Glossary to search for Adaptation. If you have a better definition for Adaptation than the one presented here, please let us know by making use of the suggest a term option. This definition of Adaptation may be disputed by other professionals. Our attempt is to provide easy definitions on Adaptation and any other medical topic for the public at large.
This dictionary contains 19186 terms.
|
|