Generalization of a Novel, Implicit Treatment for Coarse Coding Deficit

The language comprehension deficits in adults with focal right hemisphere brain damage (RHD) can cause considerable social handicap. To date, however, treatment for language deficits in this population remains almost entirely untested. This abstract reports a single-subject experimental design study, performed to investigate whether Contextual Constraint Treatment -- a novel, implicit, stimulation-facilitation treatment for language comprehension processes -- can yield generalized gains to broader measures of language comprehension in adults with RHD. The focus of Contextual Constraint Treatment (CCT) is motivated by two major accounts of common language comprehension problems in adults with RHD: coarse coding and suppression deficits. The patient in this study had a coarse coding (CC) deficit, so we describe here only the CC version of the treatment. CC processes activate wide-ranging aspects of word meaning independent of the surrounding context, and CC deficits in adults with RHD impair the processing of distant meanings or features of words (e.g., “rotten” as a feature of “apple”)1. CC is a partially domain-general language comprehension process. That is, CC ability predicts aspects of discourse comprehension, is hypothesized to underpin figurative language comprehension, and is involved in processing phrasal metaphors2. Thus, treatment that improves CC processes has the potential to generalize to a range of communicative outcomes. CCT is novel in aiming to facilitate comprehension processes implicitly, through contextual prestimulation. This approach contrasts with the majority of treatments for neurologically-based cognitive-linguistic disorders, which are direct, explicit, and/or metalinguistic. We implemented this approach to avoid confounding treatment of impaired processes with irrelevant, and potentially difficult, task demands, as adults with RHD who can perform well on implicit assessments of language processing often have difficulty with metalinguistic assessments of the same processing operations2