Suppression and narrative time shifts in right hemisphere brain damage

Narrative comprehension is vital to socializing and everyday communication. Understanding references to time is fundamental to comprehending the context and order of events within a narrative. This study examined the functioning of a central comprehension mechanism, suppression1,2, in narratives that cue a shift in timeframe in individuals with right hemisphere brain damage (RHD). The timeframe in normal narrative processing is assumed to be continuous3-4. Shifts in the timeframe of events trigger the suppression mechanism, which reduces a comprehender’s mental activation of information that was processed before the time shift. When the timeframe of a narrative is disrupted (e.g., something happens “an hour later”), information that was mentally active before the time shift becomes less relevant and is suppressed. Suppression is a general comprehension mechanism that acts across language levels and domains (e,g, words, sentences, narratives, etc.)1,5. Based on evidence of RHD suppression deficit in lexical ambiguity processing6-7, it was predicted that adults with RHD would also have difficulty suppressing information from a prior timeframe following a shift in narrative timeline. In addition, we predicted a correlation between suppression and narrative comprehension, as reported previously for young normal comprehenders1-2,5 and adults with RHD6

Frequency and co-occurrence of suppression and coarse coding deficits in adults with RHD

This study examines two language processing functions that have the potential to create socially handicapping language comprehension difficulties in adults with right hemisphere brain damage (RHD). The first, coarse semantic coding, allows normal comprehenders to bring to mind distant meanings or features of words that are appropriate in highly specific contexts (e.g., the "rotten" feature of the word "apple" in the context of spoiled produce). The second, suppression, is a process that inhibits contextually-irrelevant meanings (e.g., the "card-playing" meaning of the word "spade" in "He dug with the spade."). In prior work, some adults with RHD were found to have impaired suppression1-4 or coarse coding processes5-6. These language processing impairments can make it difficult for individuals with RHD to participate in everyday social communication. For example, they can have trouble thinking beyond the most typical instance of an entity (e.g., an apple that's red, round, and crunchy) when another instance is being referred to (e.g., an apple that's rotten). Another possibility is they can be misled by ambiguities which are commonplace in conversation, and have difficulty getting back on track (e.g., keeping in mind the "card-playing" meaning of the word "spade" in a sentence like "He dug with the spade"). These problems predict comprehension performance on measures of narrative comprehension, as well7,8. To date, there is no information about how prevalent these deficits are, or how often they may co-occur in the same individual. This project identifies the proportions of a sizeable group of adults with RHD that have either a coarse coding deficit, a suppression deficit, co-occurring deficits, or neither deficit in reference to criteria developed from prior studies of healthy control subjects1-3,5,6

Right Hemisphere Damage and Theory of Mind Deficit: A Deficit in the Theory?

This study assessed whether right-hemisphere-damaged (RHD) adults’ deficits in processing alternative meanings of lexical ambiguities would extend to semantic feature representations of unambiguous lexical items. If so, RHD deficit was expected to affect only activation/deactivation for subordinate features that are incompatible with the most common representations of unambiguous words (e.g., ‘rotten’ for ‘apple’). Contrary to predictions, neither RHD nor control participants evidenced a change in activation over time for this type of subordinate features. Continued research on RHD adults’ communicative strengths and weaknesses will have future implications for clinical assessment and management

Implicit Treatment of Underlying Comprehension Processes Improves Narrative Comprehension in Right Hemisphere Brain Damage

Language comprehension deficits in adults with focal right hemisphere brain damage (RHD) can cause considerable social handicap. To date, however, treatment for these deficits remains almost entirely untested. This abstract reports an investigation of whether Contextual Constraint Treatment (CCT) -- a novel, implicit, stimulation-facilitation treatment for language comprehension processes1,2 -- can yield generalized gains to measures of discourse comprehension in adults with RHD. The focus of CCT is motivated by two major accounts of typical RHD language comprehension problems: that they are due to coarse coding or suppression deficits. Coarse coding (CC) activates wide-ranging aspects of word meaning independent of surrounding context. In RHD, CC deficits impair processing of distant meanings/features of words (e.g., “rotten” as a feature of “apple”)3. A normal suppression (SUPP) process reduces mental activation of concepts that become less relevant to a current context. RHD SUPP impairment is indexed by prolonged processing interference from contextually-inappropriate interpretations (e.g., the “ink” meaning of the word “pen,” in the sentence “He built a pen”)4,5. CC and SUPP are partially domain-general language comprehension processes. For example, both predict aspects of discourse comprehension and are hypothesized to underpin figurative language comprehension; SUPP is important for resolving lexical and inferential ambiguities; and CC is involved in processing both literal lexical items and phrasal metaphors1,2,6. Thus, treatment that improves CC and SUPP processes may hold promise for improving a broad range of communicative outcomes. CCT is novel in aiming to facilitate comprehension processes implicitly, through contextual prestimulation. Adults with RHD who perform well on implicit assessments of language processing often have difficulty on metalinguistic assessments of the same operations2. Thus we implemented this approach to avoid confounding treatment of impaired processes with irrelevant, and potentially difficult, task demands

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

A different story on "Theory of Mind" deficit in adults with right hemisphere brain damage

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Supplemental Material - Community Engagement in Research: An Updated Systematic Review of Quantitative Engagement Measurement Scales for Health Studies

Supplemental Material for Community Engagement in Research: An Updated Systematic Review of Quantitative Engagement Measurement Scales for Health Studies by Barbara Gordon, Kristin M. Van De Griend, Victoria L. Scharp, Hannah Ellis, and Mary A. Nies in Evaluation & the Health Professions</p