Suppression and narrative time shifts in adults with right-hemisphere brain damage

This study examined the functioning of a central comprehension mechanism, suppression, in adults with right-hemisphere damage (RHD) while they processed narratives that cued a shift in time frame. In normal language comprehension, mental activation of concepts from a prior time frame is suppressed. The (re)activation of information following a time frame shift was also assessed.

Twenty adults (12 RHD; 8 non brain-damaged) completed a speeded word recognition task while listening to narratives in 2 conditions: shift ("an hour later") and no shift ("a moment later").

There was no group difference in suppression for response time proportion data (shift/no shift), but cluster analyses identified a suppression deficit in 8 of the adults with RHD. There was overlap in suppression function at the narrative and lexical levels. The group with RHD was significantly delayed in mentally (re)activating new information after a time shift cue.

Results underscore the generality of suppression functioning in adults with RHD. As such, treatment for a suppression deficit at one level may generalize to another level. An apparent independence of suppression and activation deficits suggests that each may need separate treatment. A better understanding of the nature and boundary conditions of suppression and activation deficits should better inform clinical decisions.