The effects of the contrast, spatial frequency, and

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Bowling, AC 1985, 'The effects of the contrast, spatial frequency, and temporal frequency of a surrounding field upon the detection thresholds of gratings', Perception & Psychophysics, vol. 38, no. 5, pp. 387-391.

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Three experiments, in which the temporal and spatial characteristics of square-wave gratings surrounding a central test field were varied, are reported. The detection thresholds of 1-sec presentations of a 5-Hz counterphase flickering .5-cycle/deg (cpd) sinusoidal grating were measured under the different surround conditions. Threshold was found to increase with increasing surround contrast, and to be confined to surround spatial frequencies of 2 cpd and below. Maximum threshold elevation occurred with surround drift frequencies at about 8 Hz, irrespective of spatial frequency. It was concluded that the surround effect is probably due to an inhibitory interaction between transient-type mechanisms in the central visual field and the pheriphery.