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Psychophysical evidence for sustained and transient detectors in human vision
Author(s) -
Kulikowski J. J.,
Tolhurst D. J.
Publication year - 1973
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1973.sp010261
Subject(s) - flicker , spatial frequency , modulation (music) , optics , contrast (vision) , physics , sensitivity (control systems) , transient (computer programming) , computer science , acoustics , electronic engineering , engineering , operating system
1. The sensitivity to temporally modulated sinusoidal gratings was determined. Two thresholds could be distinguished for the modulated gratings: the contrast at which flicker could be perceived and the contrast at which the spatial structure became distinct. 2. The flicker detection thresholds and pattern recognition threshold varied independently as functions of the spatial and temporal frequencies, suggesting that the two thresholds represent the activity of two independent systems of channels. 3. The channels detecting flicker prefer low and medium spatial frequencies. They have a pronounced decline in sensitivity at low temporal frequencies of sinusoidal modulation. They respond twice as well to gratings whose phase is alternated repetitively as to gratings turned on and off at the same rate. 4. The channels responsible for the discrimination of spatial structure are most responsive at high and medium spatial frequencies. There is no decline in sensitivity at low temporal frequencies. These channels respond equally well to alternating and on/off gratings up to about 8 Hz. 5. The temporal properties as revealed with sinusoidal modulation, suggest that the flicker‐detecting channels would give transient responses to prolonged presentation of stimuli: the channels responsible for analysing the spatial structure would give sustained responses. The responses of the two types of channel to alternating and on/off gratings confirm this suggestion.