Non-Verbal Counting in Humans: The Psychophysics of Number Representation John Whalen Psychology Department, University of Delaware C. R. Gallistel, Rochel Gelman UCLA Psychology Department This research was supported by NIMH Training Grant number T32MH15795 (JW), and NSF Grant number DBS-9209741 (RG). We wish to thank Keith Holyoak for his helpful comments on an earlier version of this paper, and Peter Mattar for testing subjects. Address correspondence to: John Whalen, Department of Psychology, University of Delaware, Newark, DE, 19716. Phone: (302) 831-0484, Fax: (302) 831-3645, Email: whalen@udel.edu