Data associated with the PlosONE publication “Implicit measures of receptive vocabulary knowledge in individuals with severe autism”

Implicit measures of cognition are essential for assessing knowledge in individuals with severe autism because such individuals are often unable to make reliable overt behavioral responses. Here we test whether three implicit measures – eye movement monitoring (EM), pupillary dilation (PD), and event-related potentials (ERPs) – can reliably estimate vocabulary knowledge in individuals with severe autism. Five adults with severe autism were tested in a repeated-measures design with two tasks. High-frequency ‘known’ words (e.g. bus, airplane) and low-frequency ‘unknown’ words (e.g. ackee, cherimoya) were presented in a visual-world task (during which EM and PD data were collected) and a picture-word congruity task (during which ERP data were collected). Using a case study approach with single-subject analyses, we demonstrate that these implicit measures can provide estimates of receptive vocabulary knowledge in the majority of these participants. However, participants differed with respect to which measures were the most sensitive and which variables best predicted vocabulary knowledge. These implicit measures may be useful to assess language abilities in individuals with severe autism, but their use should be tailored to each individual.