The present study examined possible parallels between the structure of huma
n visuospatial abilities and the organization of the neural systems. Forty-
eight participants were tested on seven speeded visuospatial tasks. Three o
f these tasks were constructed so as to rely primarily on known ventral str
eam functions and four were constructed so as to rely primarily on known do
rsal stream functions. Both sets of tasks spanned approximately the same ra
nge of difficulty as indexed by both the speed and accuracy of decision mak
ing. Factor analysis of response times on the seven tasks revealed only two
significant factors. The putative ventral stream tasks all loaded heavily
on one factor (mean loading = 0.843) but only weakly on the other factor (m
ean loading = 0.222); the putative dorsal stream tasks showed the opposite
pattern in that they all loaded heavily on the second factor (mean loading
= 0.828) but only weakly on the first factor (mean loading = 0.229). These
findings are consistent with the hypothesis that human visuospatial abiliti
es can be classified using categories based on the specializations of under
lying neural structures and systems. (C) 2000 Elsevier Science Ltd. All rig
hts reserved.