ECVP 2007 Abstract

Cite as:
Baker D H, Meese T S, Patel K, Sarwar W, 2007, "Interocular suppression is scale invariant, but ipsiocular suppression is weighted by flicker speed" Perception 36 ECVP Abstract Supplement

Interocular suppression is scale invariant, but ipsiocular suppression is weighted by flicker speed

D H Baker, T S Meese, K Patel, W Sarwar

In human and cat there are two routes to suppression for orthogonal masks: a broadband, non-adaptable, ipsiocular pathway, and a more narrowband, adaptable interocular pathway. We investigated the strength of both types of suppression in humans across spatio-temporal scale using orthogonal pairs of superimposed Gabor patches (mask and target) flickering at four spatial (0.5, 1, 2, 4 cycles deg-1) and two temporal (4 and 15 Hz) frequencies. Mask and target were presented to the same eye or different eyes in 2IFC cross-orientation masking experiments. Masking functions were normalized to baseline detection thresholds and fit by a two-stage model of contrast gain control (Meese et al, 2006 Journal of Vision 6 1224 - 1243) developed to accommodate cross-orientation masking. The weight of ipsiocular suppression was proportional to the square-root of stimulus speed (TF/SF), as in the binocular case (Meese and Holmes, 2007 Proceedings of the Royal Society of London, Series B 274 127 - 136). However, dichoptic-masking functions superimposed, showing that the interocular, presumably cortical, process is scale-invariant. These findings have implications for studies of amblyopia, binocular rivalry, and single-cell physiology.

[Supported by a grant from the Engineering and Physical Sciences Research Council, UK (GR/S74515/01).]

These web-based abstracts are provided for ease of seaching and access, but certain aspects (such as as mathematics) may not appear in their optimum form. For the final published version of this abstract, please see
ECVP 2007 Abstract Supplement (complete) size: 2091 Kb