Proceedings of the Annual Meeting of the Cognitive Science Society

Whereas much is known about how humans categorize andreason based on absolute quantities, research investigating theprocessing of relative quantities, such as proportions, iscomparatively limited. The current study used a Stroop-likeparadigm to examine adults’ automatic processing ofnonsymbolic proportions and how presentation formatsmodulate this processing. Participants were asked to compareindividual components across proportions in six differentpresentation formats. Congruity between component size andoverall proportion affected accuracy of comparison, such thatparticipants were less accurate when proportion (the irrelevantdimension) was incongruent with absolute quantity (therelevant) dimension. Moreover, the congruity effect wasmodulated by the presentation format. These findings serve asevidence that humans automatically access relative quantitywhen presented in nonsymbolic formats and provide evidencethat the strength of this processing is modulated by the formatof presentation.