Abstract
In previous studies exploring adults' ability to aggregate area information across large sets of elements, participants saw rapidly presented pairs of large dot arrays and were asked to choose the one with the greater aggregate continuous amount (summed area), regardless of discrete number, under a range of experimental conditions. They were unable to assess total continuous amount across large sets accurately; discrete number drove their choices instead, even when choosing the larger number yielded a much smaller total amount, suggesting that systems of discrete number representation are critical to tasks requiring both continuous and discrete quantity estimation in large sets. The current study attempts to answer two follow-up questions. Does this pattern of performance hold for assessments of quantity with physical substances rather than objects? Do children also use discrete number as a cue to continuous quantity in large sets? For each trial, two side-by-side boards were presented, each covered with an array of colored paint blobs. Participants (college students or preschool children) were asked to identify the board containing more paint or (in a separate trial block) more blobs. As in previous studies using computer-generated stimuli, adults' judgments of the total continuous amount present in blobs of a physical substance was heavily influenced by the number of blobs present. Though easy familiarization trials showed that young children understood the task, they showed the same pattern of performance: numerical quantity dominated judgments of continuous amount. Potential implications for theories of quantity representation will be discussed.
This work was supported by a NSF-ROLE grant to E. Spelke.