Biomaterial Database

Testing a computational model of light-adaptation dynamics. 1995

T E von Wiegand, and D C Hood, and N Graham

Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge 02139, USA.

Experiments from the periodic and aperiodic traditions were used to guide the development of a quantitatively valid model of light adaptation dynamics. Temporal contrast sensitivity data were collected over a range of 3 log units of mean luminance for sinusoids of 2 to 50 Hz. Probe thresholds on flashed backgrounds were collected over a range of stimulus-onset asynchronies and background intensities from 0.1 to 1000 td. All experiments were performed foveally in the photopic range and used a consistent stimulus paradigm and psychophysical method. The resulting model represents a merging of elements from both traditions, and consists of a frequency-dependent front-end followed by a subtractive process and static nonlinearity.

UI	MeSH Term	Description	Entries
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D011601	Psychophysics	The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.	Psychophysic
D005425	Flicker Fusion	The point or frequency at which all flicker of an intermittent light stimulus disappears.	Flicker Fusions,Fusion, Flicker,Fusions, Flicker
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000221	Adaptation, Ocular	The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)	Light Adaptation,Adaptation, Light,Adaptations, Light,Adaptations, Ocular,Light Adaptations,Ocular Adaptation,Ocular Adaptations
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012684	Sensory Thresholds	The minimum amount of stimulus energy necessary to elicit a sensory response.	Sensory Threshold,Threshold, Sensory,Thresholds, Sensory
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.