Numerosity judgments in peripheral vision: limitations of the cortical magnification hypothesis.
We studied visual numerosity judgments for linear dot arrays with regular spacing under central and off-axis observation conditions. Results indicate that an appropriate increase in stimulus size, as determined by the human cortical magnification factor, may compensate for the retinal inhomogeneity of numerosity judgments. Such a compensation, however, is no longer possible if in the numerosity judgments observers are deprived of the cue of overall dot-array length. Thus, there are aspects of the relative insensitivity of peripheral visual function that are not captured by purely geometrical considerations of the retino-cortical projection.
D000328:Adult; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D013028:Space Perception / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields