Narrative Discourse Performance in Traumatic Brain Injury: Does Story Comprehension Predict Story Retelling?

PURPOSE: Little is known about the relationship between discourse comprehension and production in traumatic brain injury (TBI), especially for spoken language. This study examined to what extent narrative discourse comprehension accounts for narrative discourse production outcomes (story grammar, story completeness). A secondary aim was to provisionally test an assumption of a discourse model, the structure building framework (SBF), that discourse comprehension and production share cognitive processes by investigating the strength of the relationship between them. METHOD: Twenty-one individuals with TBI completed story comprehension and story retelling tasks. Discourse measures included the Discourse Comprehension Test, a picture story comprehension task, story grammar, and story completeness. Correlational and multiple regression analyses were performed using comprehension measures as predictors for production measures. RESULTS: There were significant moderate-to-large correlations between all comprehension and production measures. Comprehension measures approached but did not reach significance for predicting story grammar performance but strongly predicted story completeness outcomes. CONCLUSIONS: The story comprehension measures likely tapped content aspects of discourse more so than organization. Results provided support for a link between content-focused discourse comprehension measures and discourse production outcomes, which may have clinical implications for approaches to discourse intervention. Findings were interpreted as providing preliminary support for the SBF's claim that discourse production deploys the same processes involved in discourse comprehension. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.26338045.

Contribution of Working Memory and Inferencing to Narrative Discourse Comprehension and Production in Traumatic Brain Injury.

PURPOSE: The goal of this study was to identify some potential key cognitive and communicative processes underlying narrative discourse ability following traumatic brain injury (TBI). Specifically, this study (a) investigated the contribution of working memory (WM) and inferencing to narrative discourse comprehension and production; (b) tested key assumptions posited by the Structure Building Framework (SBF), a discourse model; and (c) evaluated the potential for inferencing to contribute to discourse ability beyond a shared variance with WM. METHOD: Twenty-one individuals with TBI completed six tasks yielding seven measures: verbal and nonverbal WM updating (WMU-V and WMU-NV, respectively), predictive inferencing, the Discourse Comprehension Test (DCT), a picture story comprehension (PSC) task, and story retelling (story grammar and story completeness). Regression analyses were performed using WM and inferencing as predictors for narrative performance. RESULTS: WM measures were significant predictors of DCT performance and approached significance as predictors of PSC. Inferencing approached significance as a unique predictor for the DCT and story completeness. WMU-V and WMU-NV were highly collinear, and neither WM measure predicted discourse outcomes over and above the other's contribution. CONCLUSIONS: WM was more strongly associated with comprehension processes, whereas inferencing may be associated with both comprehension and production outcomes. Findings were interpreted as supporting SBF assumptions of domain generality of cognitive processes and mechanisms involved in discourse while also challenging assumptions that the same cognitive substrates are marshaled for comprehension and production processes. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23148647.

Telehealth administration of narrative and procedural discourse: A UK and US comparison of traumatic brain injury and matched controls.

BACKGROUND: Impaired discourse production is commonly reported for individuals with traumatic brain injury (TBI). Discourse deficits can negatively impact community integration, return to employment and quality of life. COVID-19 restrictions have reduced in-person assessment services for people with communication impairments. Advances in telehealth may help speech and language therapists (SLTs) to assess monologic discourse more systematically and improve access to services for patients who may find it difficult to attend in-person. AIMS: To examine the feasibility of telehealth administration of narrative and procedural discourse tasks with individuals with TBI and matched controls. METHODS & PROCEDURES: A total of 20 individuals with TBI and 20 healthy controls, aged 18-55 years, were directly recruited from the UK and indirectly recruited from the US. For participants with TBI, time post-injury was at least 3 months with no diagnosis of aphasia. Control participants were matched for sex and as closely as possible for age. Feasibility of measures was based upon the time to administer both narrative tasks, the report of any technological problems, and participant feed. Discourse samples were transcribed verbatim and analysed using story grammar analysis (for narrative discourse) and identification of propositions (for procedural discourse). Interrater reliability was calculated using percentage agreement for 50% of the data. Non-parametric analyses were used to analyse the performance of the two groups. OUTCOMES & RESULTS: Narrative and procedural discourse samples were collected via telehealth in approximately 10 min with no reported technical difficulties or complaints from any participants. For narrative discourse performance, there were significant differences for the TBI and control groups for measures of complete episodes (p < 0.001) and missing episodes (p = 0.005). No significant group differences were noted for any of the procedural discourse measures. CONCLUSIONS & IMPLICATIONS: Results support the feasibility of collecting discourse samples via telehealth. Although the participants' discourse performance distinguished the TBI and control groups on the narrative task, no differences between the groups were noted for the procedural task. The narrative discourse task may have been more difficult than the procedural task, or video cue support reduced the cognitive load of the procedural task. This finding suggests the use of more complex procedural tasks without video cue support may be needed. WHAT THIS PAPER ADDS: What is already known on this subject Although little research has explored the feasibility of administering discourse assessments for individuals with TBI via telehealth, some studies have found that discourse interventions can be feasibly administered via telehealth. It is also well established that individuals with TBI struggle with the supra-structural and macro-linguistic elements of discourse production. Both procedural and narrative discourse tasks have been found to differentiate individuals with TBI from healthy controls. What this paper adds to existing knowledge Few studies have investigated the feasibility of, and procedures for, administering discourse tasks via telehealth. Additionally, the inclusion of multiple types of discourse tasks to parse cognitive-communication abilities is lacking in the current literature. Findings from this study support that narrative and procedural discourse can be feasibly sampled via telehealth and that international collaboration for research on this topic can facilitate such studies. Individuals with TBI performed more poorly on three measures of narrative discourse. No differences between groups were identified for the procedural task. What are the potential or actual clinical implications of this work? Telehealth assessment for discourse provides flexibility for both the individual with TBI and the speech-language therapist and does not compromise the quality of data collected. The administration of discourse tasks and collection of data was not time-consuming and was well accepted by the study participants. Additionally, international research collaboration not only expands potential participation in research but increases the opportunity to recruit and study more diverse groups.

Systematic Review of Discourse and Social Communication Interventions in Traumatic Brain Injury.

PURPOSE: This study reviewed the current state of discourse and social communication interventions in traumatic brain injury (TBI) to provide clinically focused guidance about treatment efficacy, treatment approaches by TBI severity, treatment components, and treatment outcome measures. METHOD: Searches were conducted in five electronic databases and reference lists of topical articles for discourse or social communication interventions in TBI published between 2012 and 2021. Search terms reflected three concepts: TBI, treatment, and cognitive-communication. Studies were evaluated for methodological quality using rating scales specific to study design. RESULTS: Seven hundred sixty-seven records were identified, culminating in 21 studies for qualitative synthesis. All approaches resulted in improvement posttreatment, but durability and strength of evidence varied. Five treatment components were identified as "essential" for fostering change. Discourse approaches were generally more effective in mild-to-moderate TBI, whereas social communication approaches were more effective in moderate-to-severe TBI. Communication outcome measures were generally more sensitive to change than measures of other domains of functioning. CONCLUSIONS: The evidence suggests that discourse and social communication treatments are promising for improving communication in TBI. Selection of treatment components and tailoring treatment to the individual are important clinical considerations. Use of at least two proximal outcome measures that evaluate the target behavior and extent of functional generalization may be advantageous. The field would benefit from additional, more rigorous treatment studies to provide a greater understanding of how best to treat cognitive-communicative impairments in people with TBI. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.19233516.

Analysis of Discourse Production to Assess Cognitive Communication Deficits Following Mild Traumatic Brain Injury With and Without Posttraumatic Stress.

PURPOSE: Cognitive communication deficits can be difficult to assess in individuals with mild traumatic brain injury (mTBI). However, the use of discourse analysis as a direct and sensitive metric of cognitive communication skills has shown promising clinical utility for other TBI severity levels. This exploratory study investigated discourse production in service members and veterans (SMVs) with uncomplicated mTBI with and without posttraumatic stress disorder (PTSD) and SMVs with neither mTBI or PTSD. METHOD: Fifteen SMVs with mTBI and PTSD, 26 with mTBI, and 25 controls with no brain injury (NBI) and without PTSD were given a wordless picture story to elicit spontaneous discourse. Discourse samples were analyzed for global coherence, word count, the use of negative emotion words, cognitive process words, nonfluencies, and story completeness. RESULTS: Results revealed a significant difference between the mTBI (Mdn = 3.33) and NBI (Mdn = 3.50) groups, χ2(3) = 6.044, p = .017, ε2 = .03, for global coherence. Word count differed significantly between the mTBI + PTSD (Mdn = 135) and NBI (Mdn = 195) groups, χ2(3) = 7.968, p = .006, ε2 = .06. No other group differences were observed. DISCUSSION: Structural features of discourse production may serve as potential markers of cognitive communication deficits in mTBI. Furthermore, PTSD may contribute to verbal fluency deficits in individuals with mTBI. Additional research is needed to develop discourse-related measures that are more sensitive to the effects of mTBI and PTSD.

Passive Elaborative Cueing of Retrieval ProcessesFollowing Traumatic Brain Injury.

Purpose: Semantic elaboration is a process in which target information is analyzed in relation to content associated in meaning. The goal of the present study was to examine the use of phrasal cues intended to engage elaborative processes theorized to bolster cognitive performance.Methods: Twenty-two individuals with a history of traumatic brain injury (TBI) and twenty-six neurotypical (NT) individuals were studied. Short phrases intended to elicit elaborative encoding were presented prior to the introduction of a prospective memory task and word-stem completions. Phrases embodied one of three conditions: repeated, semantic, or unrelated information. The stem-completion task was presented between each prospective memory task with fixations serving as cues signaling task completion or functioning as distractors. Event-related potentials (ERPs) were captured during the presentation of word-stems. Following the completion of all word-stems, participants were presented with an old/new recognition task.Results: Linear mixed-effects model analyses revealed a significant effect of condition with respect to word retrieval and recognition memory. Captured ERPs revealed neural signatures resembling a P200.Conclusion: Semantic content increased stimulus saliency, facilitated lexical retrieval, and enhanced retention with the latter process revealing use of semantic cues as a more adept rehearsal strategy than repetition.

Conversational Coordination of Articulation Responds to Context: A Clinical Test Case With Traumatic Brain Injury.

Purpose Coordination of communicative behavior supports shared understanding in conversation. The current study brings together analysis of two speech coordination strategies, entrainment and compensation of articulation, in a preliminary investigation into whether strategy organization is shaped by a challenging communicative context-conversing with a person who has a communication disorder. Method As an initial clinical test case, an automated measure of articulatory precision was analyzed in a corpus of spoken dialogue, where a confederate conversed with participants with traumatic brain injury (n = 28) and participants with no brain injury (n = 48). Results Overall, the confederate engaged in significant entrainment and high compensation (hyperarticulation) in conversations with participants with traumatic brain injury relative to significant entrainment and low compensation (hypoarticulation) in conversations with participants with no brain injury. Furthermore, the confederate's articulatory precision changed over the course of the conversations. Conclusions Findings suggest that the organization of conversational coordination is sensitive to context, supporting synergistic models of spoken dialogue. While corpus limitations are acknowledged, these initial results point to differences in the way in which speech strategies are realized in challenging communicative contexts, highlighting a viable and important target for investigation with clinical populations. A framework for investigating speech coordination strategies in tandem and ideas for advancing this line of inquiry serve as key contributions of this work.

Primed to cue.

The behavioral effects of lexical priming are well studied in the cognitive sciences. Clinical use of the term and widespread implementation of priming based behavioral interventions has remained limited. This is despite the fact that response-contingent cueing, a behavioral intervention technique used during many cognitive-linguistic interventions, is grounded in theories of priming research. The aim of this manuscript is to connect behavioral performance changes observed following priming with those noted following cueing, providing a theoretical rationale for the therapeutic use of both priming and cueing in language and cognitive interventions. In this review, we establish a conceptual basis for how both primes and cues serve to pre-engage the neural system by triggering the retrieval of linked conceptual knowledge, resulting in faster and more accurate responses. Differences between the two (primes and cues) have been linked to timing and conscious intentional engagement, though these distinctions are often task dependent. Additionally, this paper will provide evidence of the clinical utility of priming. Studies of priming in adults with acquired brain injuries are discussed and clinical interventions based on theories of priming are examined. Furthermore, the present work will briefly detail the inhibitory effects of priming to aid clinicians and researchers in deciding how to pair primes and cues with intended retrieval targets. In summation, the present work is intended to bridge two related fields providing both theoretical and clinical insight with respect to the use of primes and cues.

Follow-Up on the Story Goodness Index for Characterizing Discourse Deficits Following Traumatic Brain Injury.

Purpose The Story Goodness Index (SGI) is a hybrid analysis of narrative discourse combining 2 macrostructural measures: story grammar and story completeness. Initially proposed by Lê and colleagues ( Lê, Coelho, Mozeiko, & Grafman, 2011 ), the SGI is intended to characterize the discourse performance of individuals with cognitive-communication disorders. In this study, the SGI was utilized to examine the discourse of 2 groups, one with closed head injuries and another with non-brain injured (NBI) peers. The intent of this study was to ascertain whether the SGI could differentiate the discourse performance of the 2 groups, as was previously reported for individuals with penetrating traumatic brain injury and an NBI comparison group ( Lê, Coelho, Mozeiko, Krueger, & Grafman, 2012 ). Because of the retrospective nature of this study, the wordless visual narrative used to elicit discourse was different from the narrative used by Lê and colleagues (2012) . Method A retrospective analysis of discourse was performed on 55 individuals with a history of closed head injury and 47 NBI socioeconomically matched peers. During the initial assessment, participants were engaged in a narrative retell task. Each participant was shown a wordless picture story and then asked to retell the story to the examiner. Story narratives were reanalyzed for story grammar (organization) and completeness (critical content). Results A significant group difference was noted for the story grammar measure, but not for story completeness. Although the SGI plots depicted the heterogeneity in discourse performance of the 2 groups, a chi-square test of independence revealed no significant association between group membership and SGI quadrant. Conclusions Findings from this study were inconsistent with those of Lê and colleagues. The studies did not use identical SGI protocols; specifically, different picture stimuli were used to elicit the story retells. Therefore, this study cannot be considered a replication. The story used by Lê and colleagues was judged to be more complex, requiring more inference for story interpretation. Future studies should interpret findings within the context of the story stimuli presented.

Changes in discourse structure over time following traumatic brain injury.

The objective of the present study was to investigate structural changes in the narrative discourse of individuals with penetrating traumatic brain injury (pTBI) following immediate and delayed story retellings. Additionally, the potential influence of immediate memory, working memory, and executive functions on narrative discourse performance were examined. The narrative discourse of two groups, 123 with pTBI and 44 non-brain injured (NBI), was sampled. Participants were asked to retell a wordless picture story immediately after viewing it and again 30-min later. Story narratives were analyzed using a variety of microlinguistic and macrostructural measures. Results revealed significant group differences of both microlinguistic and macrostructural measures following the immediate retell, but not following the delayed retell. Regression analyses revealed that immediate memory accounted for a modest degree of the explained variance for the production of critical content during narrative discourse. The observed deficits were relatively stable over a short delay (30 min) and appeared attributable, in part, to difficulty with the encoding and consolidation of story content.

Treatment Response to a Double Administration of Constraint-Induced Language Therapy in Chronic Aphasia.

Purpose: This study investigated changes in oral-verbal expressive language associated with improvements following 2 treatment periods of constraint-induced language therapy in 4 participants with stroke-induced chronic aphasia. Generalization of treatment to untrained materials and to discourse production was also analyzed, as was the durability of the treatment effect. Method: Participants with aphasia were assessed using standardized measures and discourse tasks at 3 to 4 time points to document behavioral changes throughout each of two 30-hr treatment periods of constraint-induced language therapy. Daily probes of trained and untrained materials were also administered. Results: Despite participant heterogeneity, behavioral results for each person with aphasia indicated a positive response to treatment following each treatment period indicated by performance on standardized tests, trained materials, or both. Treatment effects generalized to some degree to untrained stimuli and to discourse measures and were generally maintained at follow-up testing. Conclusions: Data support the utility of a 2nd treatment period. Results are relevant to rehabilitation in chronic aphasia, confirming that significant language gains continue well past the point of spontaneous recovery and can occur in a relatively short time period. Importantly, changes are not confined to a single treatment period, suggesting that people with aphasia may benefit from multiple doses of high-intensity treatment.

Linking inter- and intra-sentential processes for narrative production following traumatic brain injury: Implications for a model of discourse processing.

Some suggest that traumatic brain injury (TBI) produces dissociation between the macrolinguistic and microlinguistic levels of discourse production. This assumption is based primarily on studies that have found preserved intersentential cohesion and/or intra-sentential processing in narratives produced by these individuals. However, few studies exist, if any, that have investigated the relationship between these processes in TBI speakers who do demonstrate such microlinguistic impairments. This study investigated the relationship between impairments of intersentential cohesion and intra-sentential processing in the discourse of 15 speakers with severe TBI. The results demonstrated a significant relationship between the production of cohesive ties and instances of intra-sentential impairment that suggests that utilization of resources for adequate cohesion appears to negatively affect intra-sentential processing following TBI. We propose that macrolinguistic and microlinguistic processes are not independent of one another, as has been proposed, but share cognitive resources that support the planning and production of both local (microlinguistic) and long-distance (macrolinguistic) relationships expressed through discourse.

Does brain volume loss predict cognitive and narrative discourse performance following traumatic brain injury?

PURPOSE: In this study, the authors investigated the relationship between brain volume loss and performance on cognitive measures, including working memory, immediate memory, executive functions, and intelligence, and a narrative discourse production task. An underlying goal was to examine the prognostic potential of a brain lesion metric for discourse outcomes. It was hypothesized that brain volume loss would correlate with and predict cognitive and narrative discourse measures and have prognostic value for discourse outcomes. METHOD: One hundred sixty-seven individuals with penetrating head injury participated. Correlational and regression analyses were performed for the percentages of total brain and hemispheric volume loss and scores on 4 cognitive measures (WMS-III Working Memory and Immediate Memory primary indexes, D-KEFS Sorting Test, and WAIS-III Full Scale IQ) and 7 narrative discourse measures (T-units, grammatical complexity, cohesion, local and global coherence, story completeness, and story grammar). RESULTS: The volumetric measures had significant small-to-moderate correlations with all cognitive measures but only one significant correlation with the discourse measures. Findings from regression analyses were analogous but revealed several models that approached significance. CONCLUSION: Findings suggest that an overall measure of brain damage may be more predictive of general cognitive status than of narrative discourse ability. Atrophy measures in specific brain regions may be more informative.

Characterizing discourse deficits following penetrating head injury: a preliminary model.

PURPOSE: Discourse analyses have demonstrated utility for delineating subtle communication deficits following closed head injuries (CHIs). The present investigation examined the discourse performance of a large group of individuals with penetrating head injury (PHI). Performance was also compared across 6 subgroups of PHI based on lesion locale. A preliminary model of discourse production following PHI was proposed and tested. METHOD: Story narratives were elicited from 2 groups of participants, 167 with PHI and 46 non brain-injured (NBI). Micro- and macrostructural components of each story were analyzed. Measures of memory, executive functions, and intelligence were also administered. All measures were compared across groups and PHI subgroups. The proposed model of discourse production was tested with a structural equation modeling procedure. RESULTS: No differences for the discourse measures were noted across the six PHI subgroups. Three measures distinguished the PHI and NBI groups: narrative length, story grammar, and completeness. The proposed model of discourse production had an adequate-to-good fit with the cognitive and discourse data. CONCLUSION: In spite of differing mechanisms of injury, the PHI group's discourse performance was consistent with what has been reported for individuals with CHI. The model tested represents a preliminary step toward understanding discourse production following traumatic brain injury.

Analysis of narrative discourse structure as an ecologically relevant measure of executive function in adults.

This study examined the narrative discourse production and executive function (EF) abilities of 46 neuro-typical adults (18-98 years old). Two questions were addressed: Is the analysis of narrative structure sensitive to changes associated with aging? & What is the relationship between measures of narrative structure and EF? Narratives were elicited under two conditions and narrative structure was analyzed for the presence of organizing story grammar elements. Narrative structure was significantly correlated with age as well as linguistic and non-linguistic measures of EF. Factor analysis of story structure and EF variables yielded two factors reflecting constructs of output-fluidity and organizational-efficiency. These data suggest that narrative structure and EF represent aspects of goal-directed knowledge that are not bound by a traditional linguistic and non-linguistic division. Thus, narrative structure may represent a global and ecologically valid measure of goal-directed executive function knowledge that is also sensitive to changes associated with typical aging.

Discourse production following injury to the dorsolateral prefrontal cortex.

Individuals with damage to the prefrontal cortex, and the dorsolateral prefrontal cortex (DLPFC) in particular, often demonstrate difficulties with the formulation of complex language not attributable to aphasia. The present study employed a discourse analysis procedure to characterize the language of individuals with left (L) or right (R) DLPFC lesions. All participants were 30-35 years post-onset of injury and presented with persistent discourse impairments. The discourse performance of the R DLPFC group was not significantly different from either the L DLPFC group or the non-injured comparison group. Individuals from the L DLPFC group demonstrated specific difficulties with narrative coherence and inclusion of critical story components. Both measures were significantly different from the comparison group. The discourse ability of the DLPFC groups was significantly correlated with measures of working memory. Findings support the use of discourse analysis for examining language impairments in individuals with PFC lesions.

Predicting story goodness performance from cognitive measures following traumatic brain injury.

PURPOSE: This study examined the prediction of performance on measures of the Story Goodness Index (SGI; Lê, Coelho, Mozeiko, & Grafman, 2011) from executive function (EF) and memory measures following traumatic brain injury (TBI). It was hypothesized that EF and memory measures would significantly predict SGI outcomes. METHOD: One hundred sixty-seven individuals with TBI participated in the study. Story retellings were analyzed using the SGI protocol. Three cognitive measures--Delis-Kaplan Executive Function System (D-KEFS; Delis, Kaplan, & Kramer, 2001) Sorting Test, Wechsler Memory Scale--Third Edition (WMS-III; Wechsler, 1997) Working Memory Primary Index (WMI), and WMS-III Immediate Memory Primary Index (IMI)--were entered into a multiple linear regression model for each discourse measure. Two sets of regression analyses were performed, the first with the Sorting Test as the first predictor and the second with it as the last. RESULTS: The first set of regression analyses identified the Sorting Test and IMI as the only significant predictors of performance on measures of the SGI. The second set identified all measures as significant predictors when evaluating each step of the regression function. CONCLUSION: The cognitive variables predicted performance on the SGI measures, although there were differences in the amount of explained variance. The results (a) suggest that storytelling ability draws on a number of underlying skills and (b) underscore the importance of using discrete cognitive tasks rather than broad cognitive indices to investigate the cognitive substrates of discourse.

Measuring goodness of story narratives.

PURPOSE: The purpose of this article was to evaluate a new measure of story narrative performance: story completeness. It was hypothesized that by combining organizational (story grammar) and completeness measures, story "goodness" could be quantified. METHOD: Discourse samples from 46 typically developing adults were compared with those from 24 adults with acquired brain injuries. Story retellings were elicited and analyzed for episode structure (story grammar). Each story was also evaluated for the presence of 5 key components, yielding the story completeness score. Story goodness was quantified by combining the story grammar and completeness measures using a 2-coordinate grid system. A multivariate analysis of variance was performed as well as correlational analyses between the story grammar and story completeness scores. RESULTS: There were significant group differences on both story grammar and story completeness. Moderate correlations were noted between the 2 measures, suggesting that the indices were not entirely measuring the same abilities. Plotting the 2 sets of scores into quadrants discriminated the comparison group and the group with brain injury into 4 distinct categories of story "goodness." CONCLUSION: The combination of measures provided a more accurate depiction of discourse performance than either measure alone. Results suggest the measure is sensitive, is reliable, and has potential utility for investigating discourse deficits in clinical populations.

Treating underlying attention deficits as a means for improving conversational discourse in individuals with closed head injury: a preliminary study.

BACKGROUND: It is documented that individuals with closed head injury (CHI) demonstrate difficulty with narrative and conversational discourse. Effective conversational discourse requires a complex interaction of linguistic, cognitive, and social abilities [6]. Reduced attention and concentration are among the most common cognitive sequela following CHI [39]. AIMS: The present study investigated whether treatment of attention would facilitate conversational discourse for individuals with CHI. Two treatment protocols were investigated, the first social skills-based, and the second attention-based. It was hypothesized that attention training would improve not only attentional skills but also conversation, however social skills training, would only facilitate conversational skills. METHODS AND PROCEDURES: A single subject multiple treatments comparison design was employed with two individuals who were post-onset of CHI. Treatment effects on conversational performance were calculated using the f statistic [18] for measures of response appropriateness during conversations. OUTCOMES AND RESULTS: Effect sizes suggested that both treatments were active; however, the participants' performances were variable reducing the magnitude of change observed. Results indicated minimal change from baselines, only partially supporting the research hypotheses. CONCLUSIONS: Although the two treatment regimens had some effect on the participants' conversational performances it was not to the extent anticipated. The issues of candidacy for such treatments as well as the importance of incorporating natural contingencies into interventions for conversation training are discussed.

Intervention for executive functions after traumatic brain injury: a systematic review, meta-analysis and clinical recommendations.

A systematic review of studies that focused on the executive functions of problem solving, planning, organising and multitasking by adults with traumatic brain injury (TBI) was performed through 2004. Qualitative and quantitative methods were used to evaluate the 15 studies that met inclusion criteria. Demographic variables, design and intervention features, and impairment and activity/participation outcomes (ICF) (World Health Organization, 2001) were documented. Five randomised control treatment (RCT) studies used step-by-step, metacognitive strategy instruction (MSI) and outcomes were evaluated in a meta-analysis. Effect sizes (ESs) from immediate impairment outcomes after MSI and "control" intervention were similar to each other, and both were significantly larger than chance. ESs from immediate activity/participation outcomes after MSI were significantly larger than the ESs from control intervention, and both were significantly larger than chance. These results, along with positive outcomes from the other group, single-subject design and single case studies, provided sufficient evidence to make the clinical recommendation that MSI should be used with young to middle-aged adults with TBI, when improvement in everyday, functional problems is the goal (Level A) (American Academy of Neurology, 2004). Although maintenance effects were generally positive, there was insufficient data quantitatively to evaluate this. Furthermore, there was insufficient evidence to make clinical recommendations for children or older adults. Intervention that trained verbal reasoning and multi-tasking was promising, although the evidence is insufficient to make clinical recommendations at this time. Additional research needs were highlighted.