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Title: A primarily serial, foveal accumulator underlies approximate numerical estimation
The approximate number system (ANS) has attracted broad interest due to its potential importance in early mathematical development and the fact that it is conserved across species. Models of the ANS and behavioral measures of ANS acuity both assume that quantity estimation is computed rapidly and in parallel across an entire view of the visual scene. We present evidence instead that ANS estimates are largely the product of a serial accumulation mechanism operating across visual fixations. We used an eye-tracker to collect data on participants’ visual fixations while they performed quantity-estimation and -discrimination tasks. We were able to predict participants’ numerical estimates using their visual fixation data: As the number of dots fixated increased, mean estimates also increased, and estimation error decreased. A detailed model-based analysis shows that fixated dots contribute twice as much as peripheral dots to estimated quantities; people do not “double count” multiply fixated dots; and they do not adjust for the proportion of area in the scene that they have fixated. The accumulation mechanism we propose explains reported effects of display time on estimation and earlier findings of a bias to underestimate quantities.  more » « less
Award ID(s):
1901262
PAR ID:
10146541
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Proceedings of the National Academy of Sciences
Volume:
116
Issue:
36
ISSN:
0027-8424
Page Range / eLocation ID:
17729 to 17734
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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