Proceedings of the Annual Meeting of the Cognitive Science Society

Both English-speakers whose access to number language is artificially compromised by verbal interference and thePirah ̃a (an Amazonian tribe without exact number words) appear to rely on analog magnitude estimation for representing non-symbolic exact quantities greater than 3. Here, 10 participants with aphasia from stroke performed the same 5 counting tasksfrom these previous studies. Performance was poorest when targets were not visible during response (70% correct) and bestwhen targets were presented as subitizable groups of 2 and 3 (98% correct). Western Aphasia Battery-Revised subtest scoreswere reliably correlated with performance across counting tasks suggesting ways that both speech and naming may contributeto errors. Coefficients of variation for particular tasks, and significant correlations between target magnitude with both errorrate and size across tasks suggests use of analog magnitude estimation for verbally impaired participants. Diverse forms oflanguage impairment may contribute to errors on nonverbal counting tasks.