| Abstract | We used eye-tracking to investigate lexical processing in aphasic participants by examining the fixation
time course for rhyme (e.g., carrot–parrot) and cohort (e.g., beaker–beetle) competitors. Broca’s aphasic
participants exhibited larger rhyme competition effects than age-matched controls. A re-analysis of previously
reported data (Yee, Blumstein, & Sedivy, 2008) confirmed that Wernicke’s aphasic participants
exhibited larger cohort competition effects. Individual-level analyses revealed a negative correlation
between rhyme and cohort competition effect size across both groups of aphasic participants. Computational
model simulations were performed to examine which of several accounts of lexical processing deficits
in aphasia might account for the observed effects. Simulation results revealed that slower
deactivation of lexical competitors could account for increased cohort competition in Wernicke’s aphasic
participants; auditory perceptual impairment could account for increased rhyme competition in Broca’s
aphasic participants; and a perturbation of a parameter controlling selection among competing alternatives
could account for both patterns, as well as the correlation between the effects. In light of these simulation
results, we discuss theoretical accounts that have the potential to explain the dynamics of spoken
word recognition in aphasia and the possible roles of anterior and posterior brain regions in lexical processing
and cognitive control. |