Effect of prefrontal cortex damage on resolving lexical ambiguity in text.

The function of suppression of context-inappropriate meanings during lexical ambiguity resolution was examined in 25 adults with prefrontal cortex damage (PFCD) localized to the left (N=8), right (N=6), or bilaterally (N=11); and 21 matched Controls. Results revealed unexpected inverse patterns of suppression between PFCD and Control groups, with measures suggesting decreased interference across time in the PFCD group and increased interference in the Control group. The PFCD group, however, had significantly lower accuracy rates for the context-inappropriate condition. Results suggest a loss of the control aspects of inhibitory processes in lexical ambiguity resolution following PFCD. An aging effect on suppression function is also suggested.