Summation characteristics of the detection of compound gratings

Many classical experiments have shown that two superimposed gratings are more easily detected than a single grating, in keeping with probability theory. Here we test the rules for the detection of 2-component compound gratings by extending the range of parameters used in previous experiments. Two co...

Full description

Saved in:
Bibliographic Details
Published in:Vision research (Oxford) 2009-08, Vol.49 (16), p.2056-2066
Main Authors: Plainis, S., Parry, N.R.A., Panorgias, A., Sapountzis, P., Murray, I.J.
Format: Article
Language:English
Subjects:
Adult
Biological and medical sciences
Compound gratings
Contrast
Contrast Sensitivity - physiology
Eye and associated structures. Visual pathways and centers. Vision
Fundamental and applied biological sciences. Psychology
Humans
Interactions
Middle Aged
Motion Perception - physiology
Pattern Recognition, Visual - physiology
Perceptual Masking
Photic Stimulation
Probability summation
Psychophysics
Sensory Thresholds
Spatial frequency channels
Vertebrates: nervous system and sense organs
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Many classical experiments have shown that two superimposed gratings are more easily detected than a single grating, in keeping with probability theory. Here we test the rules for the detection of 2-component compound gratings by extending the range of parameters used in previous experiments. Two complementary methods of deriving summation indices are described. Data are presented so that the conditions for the transition from probability to neural summation are easily identified. True probability summation occurs only when grating contrasts are carefully perceptually equalised and spatial frequency differs by more than a factor of 2. A wide range of contrast ratios of the component gratings were explored such that gratings were at different contrasts, relative to respective thresholds. We find clear evidence of suppressive interactions when the compound gratings are composed of a close to threshold low frequency component and a below-threshold higher spatial frequency component.
ISSN:0042-6989
1878-5646
DOI:10.1016/j.visres.2009.05.006