Making It Right? Some Thoughts about the Future of Treatment for Right Hemisphere Cognitive-Communication Disorders.

This article reflects on the future of intervention for language and communication disorders that follow unilateral damage to the right cerebral hemisphere. The author first introduces some of the challenges inherent in this task: a very small and preliminary evidence base and a limited number of investigators conducting treatment research for most of the consequences of these disorders, more general difficulties of translating evidence to practice, and limited graduate training in the area. The article then addresses some predictions and hopes for the future. The author foresees progress in defining the disorders and in clinicians' knowledge of the heterogeneity of the population, the multifaceted nature of complex impairments, and the expanding range of well-justified treatment options. The article next discusses the potential of noninvasive brain stimulation techniques, virtual reality-based approaches to intervention, and the promise of telerehabilitation. Finally, the author voices a concern that undeniably important new trends in health care, such as emphases on patient-reported outcomes and patient satisfaction measures, could penalize the subset of the client population that lacks awareness of or minimizes their deficits, and calls for vigilant clinician advocates in such cases.

Contextual Constraint Treatment for coarse coding deficit in adults with right hemisphere brain damage: generalisation to narrative discourse comprehension.

Coarse coding is the activation of broad semantic fields that can include multiple word meanings and a variety of features, including those peripheral to a word's core meaning. It is a partially domain-general process related to general discourse comprehension and contributes to both literal and non-literal language processing. Adults with damage to the right cerebral hemisphere (RHD) and a coarse coding deficit are particularly slow to activate features of words that are relatively distant or peripheral. This manuscript reports a pre-efficacy study of Contextual Constraint Treatment (CCT), a novel, implicit treatment designed to increase the efficiency of coarse coding with the goal of improving narrative comprehension and other language performance that relies on coarse coding. Participants were four adults with RHD. The study used a single-subject controlled experimental design across subjects and behaviours. The treatment involved pre-stimulation, using a hierarchy of strong and moderately biased contexts, to prime the intended distantly related features of critical stimulus words. Three of the four participants exhibited gains in auditory narrative discourse comprehension, the primary outcome measure. All participants exhibited generalisation to untreated items. No strong generalisation to processing non-literal language was evident. The results indicate that CCT yields both improved efficiency of the coarse coding process and generalisation to narrative comprehension.

Rehabilitation for cognitive-communication disorders in right hemisphere brain damage.

Although the left hemisphere of the brain has long been linked with language, the right cerebral hemisphere also contributes importantly to cognitive operations that underlie language processing and communicative performance. Adults with right hemisphere damage (RHD) typically do not have aphasia, but they often have communication disorders that may have a substantial impact on their social functioning. After a brief summary of communicative and cognitive characteristics of RHD in adults and of extant theoretical accounts of common communicative difficulties, this article discusses rehabilitation issues, approaches, evidence, and needs.

Manipulating articulatory demands in non-word repetition: a 'late-8' non-word repetition task.

The purpose of this paper was to examine the psychometric properties of a non-word repetition task (NRT), the Late-8 Non-word Repetition Task (L8NRT). This task was designed similarly to the NRT, but contains only Late-8 consonants to increase articulatory demands and avoid ceiling effects in studies with adolescents and adults. Thirty college students were administered the Woodcock Reading Mastery Tests-Revised/Normative Update WRMT-RNU, L8NRT and NRT. Results showed that inter- and intra-rater reliability of the L8NRT were high; split-half reliability was significant and comparable to that of the NRT. Average L8NRT scores were significantly lower than NRT scores overall and at all non-word lengths but the shortest (1 syllable). Both measures correlated significantly, at similar levels, with Total WRMT-RNU score. We conclude that the psychometric properties of the L8NRT were acceptable, but an error analysis suggested ways in which the task might be improved to better control perceptual demands and articulatory feature overlap.

Spousal suffering and partner's depression and cardiovascular disease: the Cardiovascular Health Study.

OBJECTIVES: To assess the effects of suffering in a spouse on prevalent and incident psychiatric (depression) and physical morbidity (cardiovascular disease [CVD]) in their partner, controlling for known risk factors for depression and CVD. DESIGN: Descriptive longitudinal study. PARTICIPANTS: A total of 1,330 older married couples enrolled in the Cardiovascular Health Study, a large epidemiologic study of the elderly. MEASUREMENTS: Predictor variables were physical, psychological, and existential/spiritual indicators of suffering. Primary outcomes were prevalent and incident depression and CVD. RESULTS: Controlling for known risk factors for depression, the authors found a dose-response relationship between suffering in a spouse and concurrent depression in their partner as well as a relationship between suffering and the partner's future risk for depression. With respect to CVD, and controlling for subclinical CVD at baseline, husbands whose wives reported high levels of suffering also had higher rates of prevalent CVD, but there were no significant associations between wives suffering and husbands incident CVD. There were no associations between husbands' suffering and wives' prevalent or incident CVD. CONCLUSION: Exposure to spousal suffering is an independent and unique source of distress in married couples that contributes to psychiatric and physical morbidity. More attention should be paid to the interpersonal effects of suffering in married couples and to its role in contributing to morbidity.

Consonant Age-of-Acquisition Effects in Nonword Repetition Are Not Articulatory in Nature.

Purpose: Most research examining long-term-memory effects on nonword repetition (NWR) has focused on lexical-level variables. Phoneme-level variables have received little attention, although there are reasons to expect significant sublexical effects in NWR. To further understand the underlying processes of NWR, this study examined effects of sublexical long-term phonological knowledge by testing whether performance differs when the stimuli comprise consonants acquired later versus earlier in speech development. Method: Thirty (Experiment 1) and 20 (Experiment 2) college students completed tasks that investigated whether an experimental phoneme-level variable (consonant age of acquisition) similarly affects NWR and lexical-access tasks designed to vary in articulatory, auditory-perceptual, and phonological short-term-memory demands. The lexical-access tasks were performed in silence or with concurrent articulation to explore whether consonant age-of-acquisition effects arise before or after articulatory planning. Results: NWR accuracy decreased on items comprising later- versus earlier-acquired phonemes. Similar consonant age-of-acquisition effects were observed in accuracy measures of nonword reading and lexical decision performed in silence or with concurrent articulation. Conclusion: Results indicate that NWR performance is sensitive to phoneme-level phonological knowledge in long-term memory. NWR, accordingly, should not be regarded as a diagnostic tool for pure impairment of phonological short-term memory. Supplemental Materials: https://doi.org/10.23641/asha.5435137.

The effect of speaking rate on serial-order sound-level errors in normal healthy controls and persons with aphasia.

BACKGROUND: Although many speech errors can be generated at either a linguistic or motoric level of production, phonetically well-formed sound-level serial-order errors are generally assumed to result from disruption of phonologic encoding (PE) processes. An influential model of PE (Dell, 1986; Dell, Burger & Svec, 1997) predicts that speaking rate should affect the relative proportion of these serial-order sound errors (anticipations, perseverations, exchanges). These predictions have been extended to, and have special relevance for persons with aphasia (PWA) because of the increased frequency with which speech errors occur and because their localization within the functional linguistic architecture may help in diagnosis and treatment. Supporting evidence regarding the effect of speaking rate on phonological encoding has been provided by studies using young normal language (NL) speakers and computer simulations. Limited data exist for older NL users and no group data exist for PWA. AIMS: This study tested the phonologic encoding properties of Dell's model of speech production (Dell, 1986; Dell,et al., 1997), which predicts that increasing speaking rate affects the relative proportion of serial-order sound errors (i.e., anticipations, perseverations, and exchanges). METHODS & PROCEDURES: The effects of speech rate on the error ratios of anticipation/exchange (AE), anticipation/perseveration (AP) and vocal reaction time (VRT) were examined in 16 normal healthy controls (NHC) and 16 PWA without concomitant motor speech disorders. The participants were recorded performing a phonologically challenging (tongue twister) speech production task at their typical and two faster speaking rates. OUTCOMES & RESULTS: A significant effect of increased rate was obtained for the AP but not the AE ratio. Significant effects of group and rate were obtained for VRT. CONCLUSION: Although the significant effect of rate for the AP ratio provided evidence that changes in speaking rate did affect PE, the results failed to support the model derived predictions regarding the direction of change for error type proportions. The current findings argued for an alternative concept of the role of activation and decay in influencing types of serial-order sound errors. Rather than a slow activation decay rate (Dell, 1986), the results of the current study were more compatible with an alternative explanation of rapid activation decay or slow build-up of residual activation.

Negative Word Production in Adults With Right Hemisphere Brain Damage: Effects of Implicit Assessment and Contextual Bias.

PURPOSE: Both theory and evidence suggest that unilateral right hemisphere brain damage (RHD) should impair the processing of negative emotions. Typical metalinguistic assessments, however, may obscure processing strengths. This study investigated whether adults with RHD would produce proportionately fewer negative emotion words than control participants in an implicit assessment task and whether a negatively toned contextual bias would enhance performance. METHODS: Eleven participants with RHD and 10 control participants without brain damage watched a video in 2 parts and described each segment. Between segments, participants evaluated the emotion conveyed by sentences designed to induce the negative bias. RESULTS: The primary outcome measure, percentage of negative emotion words in video descriptions, did not differ between groups. After the contextual bias, this measure significantly increased for both groups, whereas production of motion words, a control variable, remained constant. CONCLUSIONS: Findings are consistent with a view that attributes some deficient RHD performances to the nature and/or demands of explicit metalinguistic assessment tasks. These results call for modulation of prevailing hypotheses that attribute negative emotion processing as an undifferentiated whole solely to the right cerebral hemisphere. The results also further substantiate the rationale of an experimental treatment that exploits contextual bias and priming for individuals with RHD.

Voxel-Based Lesion Symptom Mapping of Coarse Coding and Suppression Deficits in Patients With Right Hemisphere Damage.

PURPOSE: This study examined right hemisphere (RH) neuroanatomical correlates of lexical-semantic deficits that predict narrative comprehension in adults with RH brain damage. Coarse semantic coding and suppression deficits were related to lesions by voxel-based lesion symptom mapping. METHOD: Participants were 20 adults with RH cerebrovascular accidents. Measures of coarse coding and suppression deficits were computed from lexical decision reaction times at short (175 ms) and long (1000 ms) prime-target intervals. Lesions were drawn on magnetic resonance imaging images and through normalization were registered on an age-matched brain template. Voxel-based lesion symptom mapping analysis was applied to build a general linear model at each voxel. Z score maps were generated for each deficit, and results were interpreted using automated anatomical labeling procedures. RESULTS: A deficit in coarse semantic activation was associated with lesions to the RH posterior middle temporal gyrus, dorsolateral prefrontal cortex, and lenticular nuclei. A maintenance deficit for coarsely coded representations involved the RH temporal pole and dorsolateral prefrontal cortex more medially. Ineffective suppression implicated lesions to the RH inferior frontal gyrus and subcortical regions, as hypothesized, along with the rostral temporal pole. CONCLUSION: Beyond their scientific implications, these lesion-deficit correspondences may help inform the clinical diagnosis and enhance decisions about candidacy for deficit-focused treatment to improve narrative comprehension in individuals with RH damage.

Inference generation during text comprehension by adults with right hemisphere brain damage: activation failure versus multiple activation.

Evidence conflicts as to whether adults with right hemisphere brain damage (RHD) generate inferences during text comprehension. M. Beeman (1993) reported that adults with RHD fail to activate the lexical-semantic bases of routine bridging inferences, which are necessary for comprehension. But other evidence indicates that adults with RHD activate multiple interpretations in various comprehension domains. In addition, the activation of contextually inappropriate interpretations is prolonged for many adults with RHD and predicts poor discourse comprehension. This study contrasted Beeman's activation failure hypothesis with the prediction that adults with RHD would generate multiple interpretations in text comprehension. The relation between activation of textually incompatible inferences and discourse comprehension was also investigated for this group. Thirty-seven adults with RHD and 34 without brain damage listened to brief narratives that required a bridging inference (BI) to integrate the text-final sentence. This final sentence, when isolated from its text, was strongly biased toward a contextually incompatible alternate interpretation (AI). Auditory phoneme strings were presented for lexical decision immediately after each text's initial and final sentence. Adults with RHD were both faster and more accurate in making lexical decisions to BI-related target words in final-sentence position than in initial-sentence position. Thus, contrary to the activation failure hypothesis, adults with RHD generated the lexical-semantic foundations of BIs where they were required by the text. AI generation was evident in accuracy data as well, but not in response time data. This result is partially consistent with the multiple activation view. Finally, greater activation for contextually incompatible interpretations was associated with poorer discourse comprehension performance by adults with RHD.

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

PURPOSE: 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. METHOD: 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"). RESULTS: 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. CONCLUSION: 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.

Generalization of a Novel, Implicit Treatment for Coarse Coding Deficit in Right Hemisphere Brain Damage: A Single Subject Experiment.

BACKGROUND: This manuscript reports generalization effects of Contextual Constraint Treatment for an adult with right hemisphere brain damage (RHD). Contextual Constraint Treatment is designed to stimulate inefficient language comprehension processes implicitly, by providing linguistic context to prime, or constrain, the intended interpretations of treatment stimuli. The study participant had a coarse coding deficit, defined as delayed mental activation of particularly distant semantic features of words (e.g., rotten as a feature of "apple"). Treatment effects were expected to generalize to auditory comprehension of narrative discourse, and perhaps to figurative language interpretation, because coarse coding has been hypothesized and/or demonstrated to support these abilities. AIMS: This treatment study aimed to induce generalization of Contextual Constraint Treatment in an adult with RHD with inefficient coarse coding. METHODS #ENTITYSTARTX00026; PROCEDURES: The participant in this study was a 75 year old man with RHD and a coarse coding deficit. A single subject experimental design across behaviors (stimulus lists) was used to document performance in baseline, treatment, and follow-up phases. Treatment consisted of providing brief, spoken context sentences to prestimulate, or constrain, intended interpretations of stimulus items. The participant made no explicit associations or metalinguistic judgments about the constraint sentences or stimulus words; rather, these contexts served only as implicit primes. Probe tasks were adapted from prior work on coarse coding in RHD. The dependent measure was the percentage of responses that met predetermined response time criteria. There were two levels of contextual constraint, Strong and Moderate. Treatment for each item began with the provision of the Strong constraint context, to minimize the production or reinforcement of erroneous or exceedingly slow responses. Generalization was assessed to a well-standardized measure of narrative discourse comprehension and to several metalinguistic tasks of figurative language interpretation. OUTCOMES #ENTITYSTARTX00026; RESULTS: Treatment-contingent gains, associated with respectable effect sizes, were evident after a brief period of treatment on one stimulus list. Generalization occurred to untrained items, suggesting that the treatment was facilitating the underlying coarse coding process. Most importantly, generalization was evident to narrative comprehension performance, for both overall accuracy and accuracy answering questions about implied information, and all of these gains maintained through three follow-up sessions. CONCLUSIONS: Though the results are still preliminary, this single-subject experimental design documents the potential for meaningful gains from a novel treatment that implicitly targets an underlying language comprehension process in an adult with RHD.

A novel, implicit treatment for language comprehension processes in right hemisphere brain damage: Phase I data.

BACKGROUND: This manuscript reports the initial phase of testing for a novel, "Contextual constraint" treatment, designed to stimulate inefficient language comprehension processes in adults with right hemisphere brain damage (RHD). Two versions of treatment were developed to target two normal comprehension processes that have broad relevance for discourse comprehension and that are often disrupted by RHD: coarse semantic coding and suppression. The development of the treatment was informed by two well-documented strengths of the RHD population. The first is consistently better performance on assessments that are implicit, or nearly so, than on explicit, metalinguistic measures of language and cognitive processing. The second is improved performance when given linguistic context that moderately-to-strongly biases an intended meaning. Treatment consisted of providing brief context sentences to prestimulate, or constrain, intended interpretations. Participants made no explicit associations or judgments about the constraint sentences; rather, these contexts served only as implicit primes. AIMS: This Phase I treatment study aimed to determine the effects of a novel, implicit, Contextual Constraint treatment in adults with RHD whose coarse coding or suppression processes were inefficient. Treatment was hypothesized to speed coarse coding or suppression function in these individuals. METHODS #ENTITYSTARTX00026; PROCEDURES: Three adults with RHD participated in this study, one (P1) with a coarse coding deficit and two (P2, P3) with suppression deficits. Probe tasks were adapted from prior studies of coarse coding and suppression in RHD. The dependent measure was the percentage of responses that met predetermined response time criteria. When pre-treatment baseline performance was stable, treatment was initiated. There were two levels of contextual constraint, Strong and Moderate, and treatment for each item began with the provision of the Strong constraint context. OUTCOMES #ENTITYSTARTX00026; RESULTS: Treatment-contingent gains were evident after brief periods of treatment, for P1 on two treatment lists, and for P2. P3 made slower but still substantial gains. Maintenance of gains was evident for P1, the only participant for whom it was measured. CONCLUSIONS: This Phase I treatment study documents the potential for considerable gains from an implicit, Contextual constraint treatment. If replicated, this approach to treatment may hold promise for individuals who do poorly with effortful, metalinguistic treatment tasks, or for whom it is desirable to minimize errors during treatment. The real test of this treatment's benefit will come from later phase studies of study, which will test broad-based generalization to various aspects of discourse comprehension.

Can high-level inferencing be predicted by Discourse Comprehension Test performance in adults with right hemisphere brain damage?

BACKGROUND: Adults with right hemisphere brain damage (RHD) can have considerable difficulty in drawing high-level inferences from discourse. Standardised tests of language comprehension in RHD do not tap high-level inferences with many items or in much depth, but nonstandardised tasks lack reliability and validity data. It would be of great clinical value if a standardised test could predict performance on high-level inferencing measures. AIMS: This study addressed whether performance of adults with RHD on the Discourse Comprehension Test (DCT; Brookshire & Nicholas, 1993) could predict their performance on a nonstandardised measure of high-level inference in narrative comprehension. METHODS #ENTITYSTARTX00026; PROCEDURES: This study used a within-group correlational design. Participants were 32 adults with damage limited to the right cerebral hemisphere, as a result of cerebrovascular accident. Half of the participants were male and half female. Participants averaged 64.5 years of age and 14.2 years of education. Participants listened to narrative stimuli and to yes/no questions about each narrative. Each DCT narrative was followed by the standard 8 questions about stated or implied main ideas or details. The high-level inferencing task contained 6 narrative scenarios from Winner, Brownell, Happé, Blum, and Pincus (1998). Each scenario describes a character who commits a minor transgression and later denies it. Two versions of each story are designed to induce different interpretations of the character's denial. In one version, the character tells a white lie when he is unaware that he was seen committing the transgression. In the other versions, when aware of being seen, the character makes an ironic joke. The narratives were interrupted periodically by comprehension questions. Four Pearson correlation coefficients were computed, between each of two DCT predictor variables (total accuracy for all comprehension questions; accuracy on questions about implied information) and two indicators of high-level inferencing (total accuracy to answer experimental questions in Joke stories; total accuracy to answer experimental questions in Lie stories). OUTCOMES #ENTITYSTARTX00026; RESULTS: Correlation coefficients were low-to-moderate, and nonsignificant. CONCLUSIONS: Performance on the DCT by adults with RHD did not predict their high-level inferencing performance, as measured in this study. The issue that motivated this study should be pursued further in light of the potential advantages to be gained, for both clinical and research purposes. It may be, however, that specific measures of various types of high-level inferencing will need to be developed and validated.

Imageability effects on sentence judgement by right-brain-damaged adults.

BACKGROUND: For decades researchers assumed visual image generation was the province of the right hemisphere. The lack of corresponding evidence was only recently noted, yet conflicting results still leave open the possibility that the right hemisphere plays a role. This study assessed imagery generation in adult participants with and without right hemisphere damage (RHD). Imagery was operationalised as the activation of representations retrieved from long-term memory similar to those that underlie sensory experience, in the absence of the usual sensory stimulation, and in the presence of communicative stimuli. AIMS: The primary aim of the study was to explore the widely held belief that there is an association between the right hemisphere and imagery generation ability. We also investigated whether visual and visuo-motor imagery generation abilities differ in adults with RHD. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants included 34 adults with unilateral RHD due to cerebrovascular accident and 38 adults who served as non-brain-damaged (NBD) controls. To assess the potential effects of RHD on the processing of language stimuli that differ in imageability, participants performed an auditory sentence verification task. Participants listened to high- and low-imageability sentences from Eddy and Glass (1981) and indicated whether each sentence was true or false. The dependent measures for this task were performance accuracy and response times (RT). OUTCOMES #ENTITYSTARTX00026; RESULTS: In general, accuracy was higher, and response time lower, for low-imagery than for high-imagery items. Although NBD participants' RTs for low-imagery items were significantly faster than those for high-imagery items, this difference disappeared in the group with RHD. We confirmed that this result was not due to a speed-accuracy trade-off or to syntactic differences between stimulus sets. A post hoc analysis also suggested that the group with RHD was selectively impaired in motor, rather than visual, imagery generation. CONCLUSIONS: The disproportionately high RT of participants with RHD in response to low-imagery items suggests that these items had other properties that made their verification difficult for this population. The nature and extent of right hemisphere patients' deficits in processing different types of imagery should be considered. In addition, the capacity of adults with RHD to generate visual and motor imagery should be investigated separately in future studies.

Theoretical Considerations for Understanding "Understanding" by Adults With Right Hemisphere Brain Damage.

This article reviews and evaluates leading accounts of narrative comprehension deficits in adults with focal damage to the right cerebral hemisphere (RHD). It begins with a discussion of models of comprehension, which explain how comprehension proceeds through increasingly complex levels of representation. These models include two phases of comprehension processes, broad activation of information as well as pruning and focusing interpretation of meaning based on context. The potential effects of RHD on each processing phase are reviewed, focusing on factors that range from relatively specific (e.g., how the right versus the left hemisphere activate word meanings; how the right hemisphere is involved in inferencing) to more general (the influence of cognitive resource factors; the role of suppression of contextually-irrelevant information). Next, two specific accounts of RHD comprehension difficulties, coarse coding and suppression deficit, are described. These have been construed as opposing processes, but a possible reconciliation is proposed related to the different phases of comprehension and the extent of meaning activation. Finally, the article addresses the influences of contextual constraint on language processing and the continuity of literal and nonliteral language processing, two areas in which future developments may assist our clinical planning.

Activation and maintenance of peripheral semantic features of unambiguous words after right hemisphere brain damage in adults.

BACKGROUND: The right cerebral hemisphere (RH) sustains activation of subordinate, secondary, less common, and/or distantly related meanings of words. Much of the pertinent data come from studies of homonyms, but some evidence also suggests that the RH has a unique maintenance function in relation to unambiguous nouns. In a divided visual field priming study, Atchley, Burgess, and Keeney (1999) reported that only left visual field/RH presentation yielded evidence of continuing activation of peripheral semantic features that were incompatible with the most common image or representation of their corresponding nouns (e.g., rotten for "apple"). Activation for weakly related features that were compatible with the dominant representation (e.g., crunchy) was sustained over time regardless of the visual field/hemisphere of initial stimulus input. Several studies report that unilateral right hemisphere brain damage (RHD) in adults affects the RH's meaning maintenance function, but this work also has centred on homonyms, and/or more recently metonymic and metaphoric polysemous words. AIMS: The current investigation examined whether RHD deficits in processing secondary and/or distantly related meanings of words, typically observed in studies of homonyms, would extend to peripheral, weakly related semantic features of unambiguous nouns. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants were 28 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Participants listened to spoken sentences that ended with an unambiguous noun. Each sentence was followed by a spoken target phoneme string. Targets included peripheral semantic features of the sentence-final noun that were either compatible or incompatible with the dominant mental images of the noun, and were presented at two intervals after that noun. A lexical decision task was used to gauge both the early activation and maintenance of activation for these weakly related semantic features. OUTCOMES #ENTITYSTARTX00026; RESULTS: Accuracy data demonstrated activation (priming) for both types of peripheral features, in both groups, shortly after presentation of the corresponding noun. Neither group evidenced continuing activation for either type of feature at a longer interval. These results are interpreted as reflecting rapid decay/poor maintenance of activation for distantly related features for both groups. The lack of a biasing context, however, did not provide an appropriate test for previously reported suppression deficits after RHD. Fast decay of activation of compatible semantic features was unexpected for the control group. Adults with RHD were less accurate than the control group at both test intervals for the features that are semantically more distant from their associated nouns (Related-incompatible features). Accordingly, it is argued that the RHD group's poor maintenance of activation for these features reflects a deficit, rather than normal performance. The interpretation of results from this study is complicated by the lack of RT priming for either type of semantic feature, and for either participant group. CONCLUSIONS: The right cerebral hemisphere appears to be necessary for activating semantic features that are particularly distantly related to their corresponding lexical items, and for sustaining activation of these features in the absence of a biasing context. Because lexical processing has been linked with discourse comprehension for adults with RHD, more work in this area should enhance clinical management in the future.

Coarse coding and discourse comprehension in adults with right hemisphere brain damage.

BACKGROUND: Various investigators suggest that some discourse-level comprehension difficulties in adults with right hemisphere brain damage (RHD) have a lexical-semantic basis. As words are processed, the intact right hemisphere arouses and sustains activation of a wide-ranging network of secondary or peripheral meanings and features-a phenomenon dubbed "coarse coding". Coarse coding impairment has been postulated to underpin some prototypical RHD comprehension deficits, such as difficulties with nonliteral language interpretation, discourse integration, some kinds of inference generation, and recovery when a reinterpretation is needed. To date, however, no studies have addressed the hypothesised link between coarse coding deficit and discourse comprehension in RHD. AIMS: The current investigation examined whether coarse coding was related to performance on two measures of narrative comprehension in adults with RHD. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants were 32 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Coarse coding was operationalised as poor activation of peripheral/weakly related semantic features of words. For the coarse coding assessment, participants listened to spoken sentences that ended in a concrete noun. Each sentence was followed by a spoken target phoneme string. Targets were subordinate semantic features of the sentence-final nouns that were incompatible with their dominant mental representations (e.g., "rotten" for apple). Targets were presented at two post-noun intervals. A lexical decision task was used to gauge both early activation and maintenance of activation of these weakly related semantic features. One of the narrative tasks assessed comprehension of implied main ideas and details, while the other indexed high-level inferencing and integration. Both comprehension tasks were presented auditorily. For all tasks, accuracy of performance was the dependent measure. Correlations were computed within the RHD group between both the early and late coarse coding measures and the two discourse measures. Additionally, ANCOVA and independent t-tests were used to compare both early and sustained coarse coding in subgroups of good and poor RHD comprehenders. OUTCOMES #ENTITYSTARTX00026; RESULTS: The group with RHD was less accurate than the control group on all measures. The finding of coarse coding impairment (difficulty activating/sustaining activation of a word's peripheral features) may appear to contradict prior evidence of RHD suppression deficit (prolonged activation for context-inappropriate meanings of words). However, the sentence contexts in this study were unbiased and thus did not provide an appropriate test of suppression function. Correlations between coarse coding and the discourse measures were small and nonsignificant. There were no differences in coarse coding between RHD comprehension subgroups on the high-level inferencing task. There was also no distinction in early coarse coding for subgroups based on comprehension of implied main ideas and details. But for these same subgroups, there was a difference in sustained coarse coding. Poorer RHD comprehenders of implied information from discourse were also poorer at maintaining activation for semantically distant features of concrete nouns. CONCLUSIONS: This study provides evidence of a variant of the postulated link between coarse coding and discourse comprehension in RHD. Specifically, adults with RHD who were particularly poor at sustaining activation for peripheral semantic features of nouns were also relatively poor comprehenders of implied information from narratives.

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

BACKGROUND: Difficulties in social cognition and interaction can characterise adults with unilateral right hemisphere brain damage (RHD). Some pertinent evidence involves their apparently poor reasoning from a "Theory of Mind" perspective, which requires a capacity to attribute thoughts, beliefs, and intentions in order to understand other people's behaviour. Theory of Mind is typically assessed with tasks that induce conflicting mental representations. Prior research with a commonly used text task reported that adults with RHD were less accurate in drawing causal inferences about mental states than at making non-mental-state causal inferences from control texts. However, the Theory of Mind and control texts differed in the number and nature of competing discourse entity representations. This stimulus discrepancy, together with the explicit measure of causal inferencing, likely put the adults with RHD at a disadvantage on the Theory of Mind texts. AIMS: This study revisited the question of Theory of Mind deficit in adults with RHD. The aforementioned Theory of Mind texts were used but new control texts were written to address stimulus discrepancies, and causal inferencing was assessed relatively implicitly. Adults with RHD were hypothesised not to display a Theory of Mind deficit under these conditions. METHODS #ENTITYSTARTX00026; PROCEDURES: The participants were 22 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Participants listened to spoken texts that targeted either mental-state or non-mental-state causal inferences. Each text was followed by spoken True/False probe sentences, to gauge target inference comprehension. Both accuracy and RT data were recorded. Data were analysed with mixed, two-way Analyses of Variance (Group by Text Type). OUTCOMES #ENTITYSTARTX00026; RESULTS: There was a main effect of Text Type in both accuracy and RT analyses, with a performance advantage for the Theory of Mind/mental-state inference stimuli. The control group was faster at responding, and primed more for the target inferences, than the RHD group. The overall advantage for Theory of Mind texts was traceable to one highly conventional inference: someone tells a white lie to be polite. Particularly poor performance in mental-state causal inferencing was not related to neglect or lesion site for the group with RHD. CONCLUSIONS: With appropriate stimulus controls and a relatively implicit measure of causal inferencing, this study found no "Theory of Mind" deficit for adults with RHD. The utility of the "Theory of Mind" construct is questioned. A better understanding of the social communication difficulties of adults with RHD will enhance clinical management in the future.

Gesture and aphasia: Helping hands?

BACKGROUND: The study of communicative gestures is one of considerable interest for aphasia, in relation to theory, diagnosis, and treatment. Significant limitations currently permeate the general (psycho)linguistic literature on gesture production, and attention to these limitations is essential for both continued investigation and clinical application of gesture for people with aphasia. AIMS: The aims of this paper are to discuss issues imperative to advancing the gesture production literature and to provide specific suggestions for applying the material herein to studies in gesture production for people with aphasia. MAIN CONTRIBUTION: Two primary perspectives in the gesture production literature are distinct in their proposals about the function of gesture, and about where gesture arises in the communication stream. These two perspectives will be discussed, along with three elements considered to be prerequisites for advancing the research on gesture production. These include: operational definitions, coding systems, and the temporal synchrony characteristics of gesture. CONCLUSIONS: Addressing the specific elements discussed in this paper will provide essential information for both continued investigation and clinical application of gesture for people with aphasia.