SPATIAL SELECTIVITY IN VISION - FIELD SIZE DEPENDS UPON NOISE SIZE

The size of the visual attentional field was estimated by a modified Stroop task that required the naming of centrally fixated color patches. Noise material consisted of incompatible color words located above and below the color patches, and the target-noise separation was either .5 or 2.5 deg of visual angle. In addition, the size of the noise material subtended either .24 (small) or .57 deg (large) of vertical visual angle. Relative to comparable neutral noise conditions, the large noise material slowed color-naming reaction times (RTs) at both target-noise separations, but the small noise material only affected RT when the tareget-noise separation was .5 deg of visual angle. Assuming that the effects of noise indicate the extent of the attentional field, these results suggest that any estimate of attentional field size is critically dependent upon the size of the noise material. © 1979, The Psychonomic Society, Inc.. All rights reserved.