Volume 7, Number 12, Article 1, Pages 1-23 doi:10.1167/7.12.1 http://journalofvision.org/7/12/1/ ISSN 1534-7362
The perception of suprathreshold contrast and fast adaptive filtering
Peter J. Bex
Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA
[home] [e-mail]
Keith Langley
Department of Psychology, University College London, London, UK
[home] [e-mail]
Abstract

We examine how the perceived contrast of dynamic noise images depends upon temporal frequency (TF) and mean luminance. A novel stepwise suprathreshold matching paradigm shows that both threshold and suprathreshold contrast sensitivity functions may be described by an inverted-U shape as a function of TF. The shape and the peak TF of the tuning function vary with the conditions under which it is measured. Spatiotemporal vision is weakly band-pass at low luminance levels (0.8 cd/m2) but becomes more strongly band-pass at high luminances (40–400 cd/m2). The peak temporal frequencies of the band-pass functions increase with the mean luminance and contrast of the test signals. As a function of increasing image contrast, our results demonstrate that the visual system broadens the spatiotemporal bandwidth of its signal detection mechanisms, especially at high mean luminances. Our results are shown to be consistent with an adaptable signal transmission system in which early luminance-dependent gain control mechanisms, in combination with on-line estimates of contrast via the autocorrelation function lead to an adaptive enhancement of spatiotemporal vision at high temporal frequencies.

View full-text

History
Received November 2, 2006; published September 10, 2007
Citation
Bex, P. J., & Langley, K. (2007). The perception of suprathreshold contrast and fast adaptive filtering. Journal of Vision, 7(12):1, 1-23, http://journalofvision.org/7/12/1/, doi:10.1167/7.12.1.
Keywords
temporal vision, contrast, constancy, gain control, autocorrelation function, noise
Downloads
297 Total; 0.346 /day (DemandFactor)
 
Search
for related articles by these authors
for papers that cite this paper
Get citation






jov