Assessing adult receptive vocabulary with event-related potentials: An investigation of cross-modal and cross-form priming

This experiment investigated whether a relationship existed between event-related potentials (ERPs) and performance on a standardized measure of receptive vocabulary; a computer adapted version of the Peabody Picture Vocabulary Test-Revised (PPVT-R); using Preschooler, Child, and Adult levels of difficulty. Pictures (N = 90) were presented twice, once paired with a congruent spoken word and again paired with an incongruent word. Two ERP components (PMN and N400) were clearly and reliably larger in response to incongruent than congruent picture/spoken-word pairs. Importantly, ERP differentiation of congruent and incongruent pairs occurred only at vocabulary levels at or below the subjects' psychometrically determined vocabulary range. ERP differentiation did not occur at the highest level of vocabulary where subjects experienced more uncertainty and made more behavioral errors. These results are discussed in relation to the use of ERP measures in the assessment of receptive vocabulary levels.