Visual discrimination of number without counting.
Observers in this study judged which of two fields contained the greater number of spots. Spots had difference-of-Gaussian luminance profiles and could differ in contrast polarity or were of uniform luminance and could differ in size. Weber fractions for all observers except one varied little except when spots varied in size. It is suggested that the results of this and previous studies might be explained by the existence of neurons tuned for number.
Ross
John
J
School of Psychology, The University of Western Australia, 35 Stirling Highway, Crawley, WA, Australia. jr@psy.uwa.edu.au
D004192:Discrimination, Psychological; D006801:Humans; D008029:Lighting; D008297:Male; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation / Q000379:methods; D012684:Sensory Thresholds; D012858:Size Perception