Oct 4, 2016 - of OKN in the stimulus direction allows us to estimate contrast .... calibrated using a photometer (LS100, Konica Minolta, Japan). ..... may have been pooling evidence before responding, driving the average latency up. 0. 0.5. 1.
www.nature.com/scientificreports
OPEN
received: 07 June 2016 accepted: 15 September 2016 Published: 04 October 2016
Similar contrast sensitivity functions measured using psychophysics and optokinetic nystagmus Steven C. Dakin & Philip R. K. Turnbull Although the contrast sensitivity function (CSF) is a particularly useful way of characterising functional vision, its measurement relies on observers making reliable perceptual reports. Such procedures can be challenging when testing children. Here we describe a system for measuring the CSF using an automated analysis of optokinetic nystagmus (OKN); an involuntary oscillatory eye movement made in response to drifting stimuli, here spatial-frequency (SF) band-pass noise. Quantifying the strength of OKN in the stimulus direction allows us to estimate contrast sensitivity across a range of SFs. We compared the CSFs of 30 observers with normal vision measured using both OKN and perceptual report. The approaches yield near-identical CSFs (mean R = 0.95) that capture subtle intra-observer variations in visual acuity and contrast sensitivity (both R = 0.84, p
