PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 869003

Peripheral area-intensity interaction in scotopic visual reaction time.

J D Edmonds·W O Dwyer
View original source ↗Export metadata ↓

Abstract

Two observers performed simple reaction-time responses to peripheral stimuli of varying intensity (-2.5 to +1.0 log td) and angular subtense (10 to 210 min). The area-intensity combinations that produced each of three scotopic reaction-time criteria were calculated. Analysis of these combinations showed that the area-intensity reciprocity could not be predicted by traditional theories of spatial summation. Like earlier findings for peripheral photopic reaction-time criteria, the results indicated that for small stimulus sizes, area has a greater effect than intensity in determining the scotopic reaction-time responses.

Explore related subjects

Dark AdaptationFemaleHumansMalePhotic StimulationReaction TimeVision, OcularJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J D Edmonds, W O Dwyer. 1977. Peripheral area-intensity interaction in scotopic visual reaction time.. https://doi.org/10.1097/00006324-197702000-00006

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

LED-generated multifocal ERG on- and off-responses in complete congenital stationary night blindness -- a case report.

We report on the application of a light emitting diode (LED) screen to elicit multifocal ERG on- and off-responses in a patient presenting with the complete type of congenital stationary night blindness (cCSNB): A 63-years old woman was diagnosed with cCSNB by means of standard ERG procedures and dark adaptometry. To confirm this diagnosis and to investigate topographical differences of on- and off-responses a multifocal approach employing long-duration stimuli was added. Results of mfERG-testing were averaged in three groups (a central area of 7.5 degrees , a ring area of 7.5-21.9 degrees and a peripheral ring of 21.9-31.1 degrees ). When compared to normal controls (n = 4) on-responses (P1-amplitudes) were severely reduced symmetrically at all eccentricities, while off-responses showed no reduction resulting in an increased off/on-ratio. Furthermore on-latencies of P1 were delayed symmetrically at all eccentricities, whereas off-latencies were normal. To our knowledge this is the first report of multifocal on- and off-responses in a CSNB-patient. Stimulus-generation with a LED-screen provides the advantage of a stable luminance during the long-duration on-phase.

Dark Adaptation↗
PubMed2006

Is the spectacle lens jack-in-the-box phenomenon really due to the lenses?

The calculation of the extent of the ring scotoma around positive lenses, as conventionally taught to students of clinical optics, indicates that the scotoma is of a significant size. Using knife-edge lenses this study shows that the calculations are invalid due to the finite size of the eye's entrance pupil and in many instances the scotoma is shown not to exist. The effect noticed in clinical practice is probably largely due to the frame and the edging techniques used which add to the refractive scotoma which is present with high powered lenses, large apertures and/or small pupil sizes.

Dark Adaptation↗