Temporal Summation during Dark Adaptation*

Stewart, Barbara R.

doi:10.1364/josa.62.000449

Cited by 19 publications

(4 citation statements)

References 24 publications

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“…The precipitousness of the rod threshold drop following exposure to intensities near those employed in the VPEL experiments with the illuminated background is indicated by the reduction of the rod threshold by 1.5 log units within 1 sec following extinction of a 2.4-mL 4°circular background centered 5°from the fovea, as measured with a 200-msec 0.5°test flash centered on the adapted retinal region. Threshold during the subsequent 25 sec decreases by only another 0.3 log units, and proceeds to complete dark adaptation with only an additional 0.6-log-units decrease within the subsequent 40 min (Stewart, 1972).13 The difference threshold immediately before the onset of darkness is 1.22 log units above the value that would best fall on the best-fitting exponential for the 200-msec test flash and 0.81 log units above that for a 5-msec test flash (Stewart, 1972). Asymptotic recovery to darkadapted levels within 12 min following termination of exposure to light is typical of rod dark adaptation measured with detection sensitivity following exposure to intensity levels employed in the present experiments, similar to the decay ofVPEL to its dark-adapted baseline.…”

Section: Similarity For Time Courses Ofvpel and Rod Adaptationmentioning

confidence: 97%

“…The final difference threshold measurement was made 6 sec before background extinction, and the first absolute threshold measurement in darkness was taken I sec after background extinction in order to avoid the transient changes associated with background luminance steps at background offset. There are very few data sets that contain measurements of difference thresholds prior to termination of light adaptation along with absolute thresholds early in dark adaptation for which the momentary transients surrounding the introduction of a step to the adapting background do not become confounding issues; Stewart's (1972) is one of these few.…”

Section: Adaptation Ofvpel Within Amentioning

confidence: 99%

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Light and dark adaptation of visually perceived eye level controlled by visual pitch

Matin

1995

Perception & Psychophysics

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The pitch of a visual field systematically influences the elevation at which a monocularly viewing subject sets a target so as to appear at visually perceived eye level (VPEL). The deviation of the setting from true eye level averages approximately 0.6 times the angle of pitch while viewing a fully illuminated complexly structured visual field and is only slightly less with one or two pitched-fromvertical lines in a dark field (Matin & Li, 1994a). The deviation of VPEL from baseline following 20 min of dark adaptation reaches its full value less than 1 min after the onset of illumination of the pitched visual field and decays exponentially in darkness following 5 min of exposure to visual pitch, either 30°topbackward or 20°topforward. The magnitude of the VPEL deviation measured with the dark-adapted right eye following left-eye exposure to pitch was 85%ofthe deviation that followed pitch exposure of the right eye itself. Time constants for VPEL decay to the dark baseline were the same for same-eye and cross-adaptation conditions and averaged about 4 min. The time constants for decay during dark adaptation were somewhat smaller, and the change during dark adaptation extended over a 16% smaller range following the viewing of the dim two-line pitched-from-vertical stimulus than following the viewing of the complex field. The temporal course of light and dark adaptation ofVPEL is virtually identical to the course oflight and dark adaptation of the scotopic luminance threshold following exposure to the same luminance. We suggest that, following rod stimulation along particular retinal orientations by portions of the pitched visual field, the storage of the adaptation process resides in the retinogeniculate system and is manifested in the focal system as a change in luminance threshold and in the ambient system as a change in VPEL.The linear model previously developed to account for VPEL, which was based on the interaction of influences from the pitched visual field and extraretinal influences from the body-referenced mechanism, was employed to incorporate the effects of adaptation. Connections between VPEL adaptation and other cases of perceptual adaptation of visual direction are described.The physical elevation of visually perceived eye level (VPEL) changes linearly with the pitch! of an illuminated visual field (Matin & Fox, 1986Matin, Fox, & Doktorsky, 1987;Matin & Li, 1989b, 1992b, 1992c, 1994a, 1994bMatin, Li, & Doktorsky, 1988;Stoper & Cohen, 1989). Employing the normally illuminated and complexly structured pitchroom shown in Figure 1a, average VPEL values for different groups of 8 subjects in two separate experiments deviated from true eye level by 0.61 and 0.63 times the angle of visual pitch over pitch ranges of 65°and 50°, respectively; one of the experiments involved monocular viewing, and the second involved binocular viewing. The slope of each subject's VPEL-versus-pitch function was linear, with individual slopes that ranged from +0.44 to +0.84. These individual slopes have demonstrated a great deal ...

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Section: Similarity For Time Courses Ofvpel and Rod Adaptationmentioning

confidence: 97%

Section: Adaptation Ofvpel Within Amentioning

confidence: 99%

Light and dark adaptation of visually perceived eye level controlled by visual pitch

Matin

1995

Perception & Psychophysics

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“…Although previous investigators have tracked changes in critical duration during the first few seconds of dark adaptation [14,17], their methods, involving repetitive adaptation-readaptation procedures, are impractical for measuring the long-term changes that occur over the full course of dark adaptation. In contrast, the PULS is able to estimate such changes directly from conventional dark-adaptation thresholds measured simultaneously for brief and long target durations.…”

Section: Critical Duration In the Fully Dark-adapted Eyementioning

confidence: 99%

A computer-controlled system for measuring dark adaptation and other psychophysical functions

Friedburg

Sharpe

Beuel

et al. 1998

Graefe’s Arch Clin Exp Ophthalmol

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“…The visual system integrates light over longer time periods as dark adaptation proceeds. The critical duration changes from about 30-40 ms early in dark adaptation to about 100-200 ms after complete dark adaptation for moderately intense exposures (Crawford, 1937;Stewart, 1972). Over half the change takes place within 10 s after the offset of the adapting field.…”

Section: Reciprocity In Brightness Perceptionmentioning

confidence: 98%

Reciprocity of Intensity and Duration on the Dark Adaptation Effects of Light Pulses

Kosnik¹

2002

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Public reporting burden for this collection of information is estimated lo average 1 hour per response, including the lime for reviewing instructions, searching existng data sources, gathenng and ™ n a n,ng he data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspeco this collection of ,nforTOt,on_,nclud,ngs^geston^; for reducing this burden to Department oFDefense. Washington Headquarters Services. Directorate for Information . 1215 Jefferson Davis Highway. Su.te 204, Ahington.VA 22202-4302 Respondents should be aware that notwithstanding any other provision of law. no person shall be subject to any penalty for failing to comply with a collect«» of information ,f ,t does not display a currently valid OMB control number PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. . REPORT DATE (DD-MM-YYYY)November 2002 2. REPORT TYPE Final TITLE AND SUBTITLE Reciprocity of Intensity and Duration on the Dark Adaptation Effects of Light Pulses AUTHOR(S)William Kosnik PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)Northrop Grumman Information Technology 4241 Woodcock Drive, Suite B100 San Antonio, TX 78228 SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)Air SPONSOR/MONITOR'S ACRONYM(S)AFRL/HEDO SPONSOR/MONITOR'S REPORT NUMBER(S) AFRL-HE-BR-TR-2 002-0107 DISTRIBUTION / AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThis report addressed two questions. First, over what durations and intensities do light exposure of equal energy appear equally bright? Second, do light exposures of equal energy have equivalent effects on the course of dark adaptation? These questions were addressed to refine the AFRL/HEDO flashblindness model. These studies show that reciprocity between duration and intensity is the exception rather than the rule for dark adaptation. The evidence indicates that reciprocity can be expected from about 100 ms to about 10 ms. A study linking a range of short duration exposures from nanoseconds to milliseconds is lacking. During the initial stage of dark adaptation, different duration exposures have very different initial thresholds and recovery functions. From the standpoint of modeling, for exposure durations less than 10 ms, dark adaptation could be described by a single dark adaptation function. Modern lasers now make it possible to study very short duration exposures. SUBJECT TERMS

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Temporal Summation during Dark Adaptation*

Cited by 19 publications

References 24 publications

Light and dark adaptation of visually perceived eye level controlled by visual pitch

Light and dark adaptation of visually perceived eye level controlled by visual pitch

A computer-controlled system for measuring dark adaptation and other psychophysical functions

Reciprocity of Intensity and Duration on the Dark Adaptation Effects of Light Pulses

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