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.
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References
1.
AtkinsonJ.CampbellF WFrancisM R, 1976“The magic number 4 $ 0: A new look at visual numerosity judgements”Perception5327–334.
2.
BurgessA.BarlowH B, 1983“The precision of numerosity discrimination in arrays of random dots”Vision Research23811–820.
3.
JevonsW S, 1871“The power of numerical discrimination”Nature3363–372.
4.
KaufmanE LLordM WReeseT.VolkmannJ., 1949“The discrimination of visual number”American Journal of Psychology62498–525.
5.
MandlerG.SheboB J, 1982“Subitizing: An analysis of its component processes”Journal of Experimental Psychology: General1111–22.
6.
NiederA.MillerE K, 2003“Coding of cognitive magnitude: Compressed scaling of numerical information in the primate prefrontal cortex”Neuron37149–157.
7.
PiazzaM.MechelliA.ButterworthB.PriceC J, 2002“Are subitizing and counting implemented as separate or functionally overlapping processes?”Neuroimage15435–446.
8.
SimonT JVaishnaviS., 1996“Subitizing and counting depend on different attentional mechanisms: Evidence from visual enumeration in afterimages”Perception & Psychophysics58915–926.
9.
TrickL MPylyshynZ., 1993“What enumeration studies can show us about spatial attention: Evidence for preattentive processing”Journal of Experimental Psychology: Human Perception and Performance19331–351.
