COS-PPA: protocol to develop a core outcome set for primary progressive aphasia.

INTRODUCTION: The term primary progressive aphasia (PPA) describes a group of language-led dementias. Disease-modifying treatments that delay, slow or reverse progression of PPA are currently lacking, though a number of interventions to manage the symptoms of PPA have been developed in recent years. Unfortunately, studies exploring the effectiveness of these interventions have used a variety of different outcome measures, limiting comparability. There are more constructs, apart from word retrieval, that are important for people with PPA that have not received much attention in the research literature. Existing core outcome sets (COS) for dementia and non-progressive aphasia do not meet the needs of people with PPA, highlighting a need to develop a specific COS for PPA. METHODS AND ANALYSIS: This protocol describes a three-stage study to identify a COS for PPA interventions in research and clinical practice. The stage 1 systematic review will identify existing speech, language and communication measures used to examine the effectiveness of interventions for PPA in the research literature. Employing a nominal group technique, stage 2 will identify the most important outcomes for people with PPA and their families. The data collected in stages 1 and 2 will be jointly analysed with the project PPI group and will inform the stage 2 modified Delphi consensus study to identify a core outcome measurement set for PPA among a range of research disciplines undertaking intervention studies for people with PPA. ETHICS AND DISSEMINATION: Ethical approval for stage 2 of the study has been sought individually in each country at collaborating institutions and is stated in detail in the manuscript. Stage 3 has been granted ethical approval by the Chairs of UCL Language and Cognition Department Ethics, Project ID LCD-2023-06. Work undertaken at stages 1, 2 and 3 will be published in open-access peer-reviewed journal articles and presented at international scientific conferences. PROSPERO REGISTRATION NUMBER: CRD42022367565.

The impact of ageing on the health and wellbeing of people with thalidomide embryopathy: a comparison of the health impact with the general population.

PURPOSE: As people living with thalidomide embryopathy (TE) are now entering their seventh decade, we examine the impact of ageing and the prevalence of comorbid health conditions reported in holistic needs assessments (HNAs) by individuals with TE, compare it with an age-matched sample of the general population, and explore the relationship between comorbidities and TE pattern of impairment. MATERIALS AND METHODS: The HNA categories were mapped and compared to those of the Health Survey for England (HSE) and analysed across four impairment groups (A-D). RESULTS: 94% (392/415) of individuals with TE residing in the UK participated in the HNA and consented to a secondary analysis of the data. Less than 2% (5/392) reported no comorbidities; 94% reported nervous system problems; including pain, pins and needles and numbness. Individuals with TE reported a significantly greater number of health comorbidities, including musculoskeletal problems, than the age-matched HSE population. CONCLUSIONS: Individuals with TE report significantly more health and well-being concerns than the general population of a similar age. Long-term monitoring is needed to ensure that support and rehabilitation services can meet their evolving needs.

People living with thalidomide's teratogenic effects are now entering their seventh decade.As they age, these individuals experience the long-term consequences linked to over-use of certain joints, including musculoskeletal and neuropathic pain.An understanding of the lived experience of TE with increasing age has the potential to inform the planning and provision of adequate and appropriate rehabilitation services moving forward.Adoption of a holistic approach to rehabilitation could help people living with TE to maintain functional independence as they enter their seventh decade.

Stakeholder views on cognitive communication assessment and intervention for a person living independently in the community with severe traumatic brain injury.

BACKGROUND: Cognitive communication disorder (CCD) following traumatic brain injury (TBI) is well documented and these communication problems impede successful re-integration into community living. While there is growing evidence for intervention to both detect and treat the impact of these deficits across the rehabilitation continuum, there are barriers to accessing services. Cognitive communication impairments may be missed because the person can talk, and this may mask the subtle but debilitating impact of a CCD. Referral to a speech and language therapist (SLT) may be overlooked or not timely, which prevents the individual accessing evidence-based interventions. Inadequate treatment provision and an under- or overestimation of communication capability can potentially undermine the effectiveness of wider team assessment and intervention. AIMS: To report stakeholder views on specialist SLT input for CCD within a multidisciplinary team intervention for a community-dwelling individual with severe TBI. The investigation explored perspectives on understanding of CCD, on practice and on outcomes, in order to inform professional groups on perceived impacts of the evidence-to-practice gap. METHODS AND PROCEDURES: A semi-structured interview methodology was employed with 11 stakeholder participants involved in a single case. Data were evaluated using a thematic framework method. Themes were inductively derived from the stakeholder narratives. OUTCOMES: Stakeholders reported the following outcomes from specialist SLT input for CCD within a collaborative team approach: improved engagement with rehabilitation and support teams, improved health-related quality of life and well-being, and increased client participation in community activities of personal relevance. Stakeholders also reported inequities in wider service provision where limitations in professional understanding of CCD and knowledge of best practice recommendations preclude access to specialist SLT services. CONCLUSIONS: CCDs are under-recognised and this can have a devastating effect on people with CCD and on those around them. Stakeholder reports provide evidence for the effectiveness of SLT practice recommendations for the treatment of CCD following TBI. They also provide additional evidence of persisting barriers to accessing treatment. Future research to explore ways to close this evidence-to-practice gap is required. WHAT THIS PAPER ADDS: What is already known on this subject Cognitive communication difficulties are a well-documented consequence of TBI. There is evidence for the effectiveness of person-centred interventions for CCD across the recovery continuum. International evidence-based practice recommendations are in place for CCD assessment and management. Barriers to accessing SLT expertise for CCD have previously been reported. What this paper adds to existing knowledge This investigation explores the views of a diverse group of stakeholders involved in a single case of a community-dwelling individual with severe TBI. Stakeholders report positive real-world outcomes from SLT interventions for CCD within a coordinated multidisciplinary rehabilitation team. Stakeholder reports also indicate inequities in wider service provision and CCD knowledge gaps amongst professional groups providing rehabilitation services for people with TBI. What are the potential or actual clinical implications of this work? CCDs are under-recognised, with devastating effect for people with CCD and those around them. These findings underscore the importance of raising professional awareness of CCD and best practice recommendations, in order to improve access to SLT expertise for people with CCD following TBI.

The language network is not engaged in object categorization.

The relationship between language and thought is the subject of long-standing debate. One claim states that language facilitates categorization of objects based on a certain feature (e.g. color) through the use of category labels that reduce interference from other, irrelevant features. Therefore, language impairment is expected to affect categorization of items grouped by a single feature (low-dimensional categories, e.g. "Yellow Things") more than categorization of items that share many features (high-dimensional categories, e.g. "Animals"). To test this account, we conducted two behavioral studies with individuals with aphasia and an fMRI experiment with healthy adults. The aphasia studies showed that selective low-dimensional categorization impairment was present in some, but not all, individuals with severe anomia and was not characteristic of aphasia in general. fMRI results revealed little activity in language-responsive brain regions during both low- and high-dimensional categorization; instead, categorization recruited the domain-general multiple-demand network (involved in wide-ranging cognitive tasks). Combined, results demonstrate that the language system is not implicated in object categorization. Instead, selective low-dimensional categorization impairment might be caused by damage to brain regions responsible for cognitive control. Our work adds to the growing evidence of the dissociation between the language system and many cognitive tasks in adults.

Benefit of visual speech information for word comprehension in post-stroke aphasia.

Aphasia is a language disorder that often involves speech comprehension impairments affecting communication. In face-to-face settings, speech is accompanied by mouth and facial movements, but little is known about the extent to which they benefit aphasic comprehension. This study investigated the benefit of visual information accompanying speech for word comprehension in people with aphasia (PWA) and the neuroanatomic substrates of any benefit. Thirty-six PWA and 13 neurotypical matched control participants performed a picture-word verification task in which they indicated whether a picture of an animate/inanimate object matched a subsequent word produced by an actress in a video. Stimuli were either audiovisual (with visible mouth and facial movements) or auditory-only (still picture of a silhouette) with audio being clear (unedited) or degraded (6-band noise-vocoding). We found that visual speech information was more beneficial for neurotypical participants than PWA, and more beneficial for both groups when speech was degraded. A multivariate lesion-symptom mapping analysis for the degraded speech condition showed that lesions to superior temporal gyrus, underlying insula, primary and secondary somatosensory cortices, and inferior frontal gyrus were associated with reduced benefit of audiovisual compared to auditory-only speech, suggesting that the integrity of these fronto-temporo-parietal regions may facilitate cross-modal mapping. These findings provide initial insights into our understanding of the impact of audiovisual information on comprehension in aphasia and the brain regions mediating any benefit.

Verbal ability in postmenopausal women in relation to age, cognitive and reproductive factors.

Word-finding difficulties have been associated with age and, in women, lowered sex hormone levels following menopause. However, there is limited understanding of the ways that specific aspects of word-finding are shaped by women's age, reproductive histories, and background factors such as education. The current study investigated the effects of age, cognitive and reproductive factors on word-finding abilities in 53 healthy postmenopausal women aged 48-79. A questionnaire was used to gather demographic information and reproductive history. A battery of verbal fluency, continuous series, and naming tasks was designed to assess word-finding across different sensory modalities and cognitive demands. Category and letter fluency were quantified as total number of correct words produced on each task. For continuous series, switch rates and switch costs were computed. For the naming tasks, accuracy and latency measures were used. There were three key findings. Firstly, there was a consistent positive association between education and all word-finding measures, i.e., verbal fluency, continuous series, and naming. Secondly, age-related declines were seen on tasks heavily dependent on working memory such as the continuous series task. Thirdly, reproductive factors across the lifespan such as age at menarche and reproductive years showed subtle effects on naming abilities, but not on verbal fluency or continuous series. The results highlight that word-finding abilities in healthy postmenopausal women are shaped by factors associated with their early years (education, age at menarche) and later adult life (age, reproductive years). The study also distinguished between the more global effects of education, and the more task-specific associations with age and reproductive variables, on verbal task performance after menopause.

The human language system, including its inferior frontal component in "Broca's area," does not support music perception.

Language and music are two human-unique capacities whose relationship remains debated. Some have argued for overlap in processing mechanisms, especially for structure processing. Such claims often concern the inferior frontal component of the language system located within "Broca's area." However, others have failed to find overlap. Using a robust individual-subject fMRI approach, we examined the responses of language brain regions to music stimuli, and probed the musical abilities of individuals with severe aphasia. Across 4 experiments, we obtained a clear answer: music perception does not engage the language system, and judgments about music structure are possible even in the presence of severe damage to the language network. In particular, the language regions' responses to music are generally low, often below the fixation baseline, and never exceed responses elicited by nonmusic auditory conditions, like animal sounds. Furthermore, the language regions are not sensitive to music structure: they show low responses to both intact and structure-scrambled music, and to melodies with vs. without structural violations. Finally, in line with past patient investigations, individuals with aphasia, who cannot judge sentence grammaticality, perform well on melody well-formedness judgments. Thus, the mechanisms that process structure in language do not appear to process music, including music syntax.

The role of iconic gestures and mouth movements in face-to-face communication.

Human face-to-face communication is multimodal: it comprises speech as well as visual cues, such as articulatory and limb gestures. In the current study, we assess how iconic gestures and mouth movements influence audiovisual word recognition. We presented video clips of an actress uttering single words accompanied, or not, by more or less informative iconic gestures. For each word we also measured the informativeness of the mouth movements from a separate lipreading task. We manipulated whether gestures were congruent or incongruent with the speech, and whether the words were audible or noise vocoded. The task was to decide whether the speech from the video matched a previously seen picture. We found that congruent iconic gestures aided word recognition, especially in the noise-vocoded condition, and the effect was larger (in terms of reaction times) for more informative gestures. Moreover, more informative mouth movements facilitated performance in challenging listening conditions when the speech was accompanied by gestures (either congruent or incongruent) suggesting an enhancement when both cues are present relative to just one. We also observed (a trend) that more informative mouth movements speeded up word recognition across clarity conditions, but only when the gestures were absent. We conclude that listeners use and dynamically weight the informativeness of gestures and mouth movements available during face-to-face communication.

Survey of tinnitus patients' acceptance of high-definition transcranial direct current stimulation as a management option.

OBJECTIVES: To investigate acceptance of high-definition transcranial direct current stimulation (HD-tDCS) as a management option for tinnitus. DESIGN: Participants completed an online version of the Tinnitus Functional Index (TFI), after which they recorded their satisfaction ratings with different hypothetical intervention outcomes on a 10-point rating scale using Opinio survey software. STUDY SAMPLE: Data from 272 tinnitus sufferers from English-speaking regions worldwide were collected, of which the majority had moderate to severe tinnitus as per TFI. RESULTS: The survey showed that HD-tDCS was considered an acceptable form of tinnitus management, and that the satisfaction rating depended significantly on a number of factors: (1) the strength of the tinnitus reduction following the intervention (p < 0.001); 2) the duration of the intervention (p < 0.001); and (3) the effects of the intervention on either tinnitus loudness or tinnitus-related distress (p < 0.001). Respondents rated their satisfaction with the intervention 10/10 only if it completely eliminated tinnitus loudness, although reductions of 50-80% were also rated highly acceptable. No association was found between tinnitus severity and acceptability ratings. CONCLUSIONS: These findings are important for future HD-tDCS trials for tinnitus, as they demonstrate the need to optimise stimulation protocols to increase effect sizes and decrease time spent on the treatment.

Training flexibility in fixed expressions in non-fluent aphasia: A case series report.

BACKGROUND: Many speakers with non-fluent aphasia (NFA) are able to produce some well-formed word combinations such as 'I like it' or 'I don't know', although they may not use variations such as 'He likes it' or 'I don't know that person'. This suggests that these utterances represent fixed forms. AIMS: This case series investigation explored the impact of a novel intervention aimed at enhancing the connected speech of individuals with NFA. The intervention, motivated by usage-based principles, involved filling open slots in semi-fixed sentence frames. METHODS & PROCEDURES: Five participants with NFA completed a 6-week intervention programme. The intervention trained participants to insert a range of different lexical items into the open slots of high-frequency phrases such as 'I like it' to enable more productive sentences (e.g., 'they like flowers'). The outcomes and acceptability were examined: The primary outcome measure focused on changes in connected narrative, and the availability of trained constructions (e.g., 'I like it') was explored through a story completion test. Two baseline measures of behaviour were taken prior to intervention, and outcomes assessed immediately after intervention and at a 6-week maintenance assessment. OUTCOME & RESULTS: A pre-/post-treatment comparison of connected speech measures showed evidence of enhanced connected speech for two of the five participants (P2 and P5). An analysis of story completion test scores revealed positive change for two participants (P1 and P2). Findings were mixed with regard to baseline stability of outcome measures and post-intervention stability of language changes. The intervention was acceptable to all participants. CONCLUSION & IMPLICATIONS: While this pilot study yielded promising findings with regard to the intervention's acceptability and increased connected speech for some participants, the findings were mixed across the sample of five participants. This research helps inform hypotheses and selection criteria for future studies. WHAT THIS PAPER ADDS: What is already known on the subject Despite difficulties producing grammatically correct sentences, many speakers with aphasia are able to produce well-formed utterances, often representing familiar expressions such as 'I don't know' and 'I like it'. In usage-based Construction Grammar (CxG) theories, familiar utterances are assumed to be processed as one unit and are therefore more resilient to brain damage. CxG assumes that residual utterances such as 'I like it' map onto more abstract sentence frames (e.g., '[REFERENT] like-TENSE [THING]'). What this paper adds to existing knowledge Sentence therapy, informed by CxG principles, is novel in aphasiology, and usage-based interventions need to be evaluated with regard to their impact on language processing at the connected speech level. This case series report explores the acceptability and outcomes of a usage-based sentence therapy. We also introduce and explore the value of an automated, frequency-based analysis tool for evaluating connected speech outcomes in aphasia therapy. What are the potential or actual clinical implications of this work? The findings inform further development of usage-based aphasia interventions targeting word combinations.

Modulatory effects of cognitive exertion on regional functional connectivity of the salience network in women with ME/CFS: A pilot study.

BACKGROUND: A common symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is post-exertional malaise (PEM). Various brain abnormalities have been observed in patients with ME/CFS, especially in insular and limbic areas, but their link with ME/CFS symptoms is still unclear. This pilot study aimed at investigating the association between PEM in ME/CFS and changes in functional connectivity (FC) of two main networks: the salience network (SN) and the default-mode network (DMN). METHODS: A total of 16 women, 6 with and 10 without ME/CFS, underwent clinical and MRI assessment before and after cognitive exertion. Resting-state FC maps of 7 seeds (3 for the SN and 4 for the DMN) and clinical measures of fatigue, pain and cognition were analysed with repeated-measure models. FC-symptom change associations were also investigated. RESULTS: Exertion induced increases in fatigue and pain in patients with ME/CFS compared to the control group, while no changes were found in cognitive performance. At baseline, patients showed altered FC between some DMN seeds and frontal areas and stronger FC between all SN seeds and left temporal areas and the medulla. Significantly higher FC increases in patients than in controls were found only between the right insular seed and frontal and subcortical areas; these increases correlated with worsening of symptoms. CONCLUSIONS: Cognitive exertion can induce worsening of ME/CFS-related symptoms. These changes were here associated with strengthening of FC of the right insula with areas involved in reward processing and cognitive control.

The Language Network Is Recruited but Not Required for Nonverbal Event Semantics.

The ability to combine individual concepts of objects, properties, and actions into complex representations of the world is often associated with language. Yet combinatorial event-level representations can also be constructed from nonverbal input, such as visual scenes. Here, we test whether the language network in the human brain is involved in and necessary for semantic processing of events presented nonverbally. In Experiment 1, we scanned participants with fMRI while they performed a semantic plausibility judgment task versus a difficult perceptual control task on sentences and line drawings that describe/depict simple agent-patient interactions. We found that the language network responded robustly during the semantic task performed on both sentences and pictures (although its response to sentences was stronger). Thus, language regions in healthy adults are engaged during a semantic task performed on pictorial depictions of events. But is this engagement necessary? In Experiment 2, we tested two individuals with global aphasia, who have sustained massive damage to perisylvian language areas and display severe language difficulties, against a group of age-matched control participants. Individuals with aphasia were severely impaired on the task of matching sentences to pictures. However, they performed close to controls in assessing the plausibility of pictorial depictions of agent-patient interactions. Overall, our results indicate that the left frontotemporal language network is recruited but not necessary for semantic processing of nonverbally presented events.

Assessing emergence from a prolonged disorder of consciousness: Current opinion and practice in the UK.

BACKGROUND: A patient in PDOC must demonstrate functional object use or functional communication to confirm they have emerged from this state. A range of tasks and stimuli are used and patients must achieve 100% accuracy. As consciousness occurs along a continuum, determining emergence is not straightforward. OBJECTIVE: To establish the opinions of expert clinicians on how emergence is determined in practice. METHODS: An online survey was completed by clinicians working in specialist rehabilitation settings across the UK. Questions were asked about diagnosis and confidence, informal assessment, formal assessment, and family involvement. Descriptive statistics were used to analyse responses to closed questions. Responses to open questions were analysed using thematic analysis. RESULTS: Seventy-five surveys were analysed. Approximately a third (30.4 %) used tasks other than those recommended to determine emergence. A lack of confidence in tasks to detect the return of functional communication was reported by 46.4%. The majority (78.6%) reported they worked with patients who they felt had emerged, but could not demonstrate it based on the current criteria. A range of stimuli were employed, but 30.6% of respondents were not confident they could choose stimuli appropriately. Respondents reported a range of benefits and challenges when involving family in assessment.

Measuring outcomes of a peer-led social communication skills intervention for adults with acquired brain injury: A pilot investigation.

Reduced social competence following severe acquired brain injury (ABI) is well-documented. This pilot study investigated a peer-led group intervention based on the claim that peer models may be a more effective mechanism for behaviour change than clinician-led approaches. Twelve participants with severe ABI were recruited from a post-acute neurorehabilitation setting and randomly assigned to either a peer-led intervention or a staff-led activity group (usual care) (Clinicaltrials.gov: NCT02211339). The groups met twice a week for 8 weeks. A peer was trained separately to facilitate interaction in the intervention group. Training comprised 16 individual sessions over 4 weeks. Group behaviour was measured twice at baseline, after intervention and at maintenance (4 weeks), using the Adapted Measure of Participation in Conversation (MPC) and the Interactional Network Tool (INT), a newly devised measure of group conversational interaction. Outcome measures showed differential sensitivity. The groups did not differ in baseline behaviour. Findings showed a significant improvement in the treated group on the MPC transaction scale post-intervention (p = .02). The intervention group showed more balanced interaction post-intervention on the INT and at follow-up. Findings show preliminary evidence of the advantage for peer-led groups. The INT shows promise as a method to detect a change in group communication behaviour.Trial registration: ClinicalTrials.gov identifier: NCT02211339.

Automated profiling of spontaneous speech in primary progressive aphasia and behavioral-variant frontotemporal dementia: An approach based on usage-frequency.

Language production provides important markers of neurological health. One feature of impairments of language and cognition, such as those that occur in stroke aphasia or Alzheimer's disease, is an overuse of high frequency, "familiar" expressions. We used computerized analysis to profile narrative speech samples from speakers with variants of frontotemporal dementia (FTD), including subtypes of primary progressive aphasia (PPA). Analysis was performed on language samples from 29 speakers with semantic variant PPA (svPPA), 25 speakers with logopenic variant PPA (lvPPA), 34 speakers with non-fluent variant PPA (nfvPPA), 14 speakers with behavioral variant FTD (bvFTD) and 20 older normal controls (NCs). We used frequency and collocation strength measures to determine use of familiar words and word combinations. We also computed word counts, content word ratio and a combination ratio, a measure of the degree to which the individual produces connected language. All dementia subtypes differed significantly from NCs. The most discriminating variables were word count, combination ratio, and content word ratio, each of which distinguished at least one dementia group from NCs. All participants with PPA, but not participants with bvFTD, produced significantly more frequent forms at the level of content words, word combinations, or both. Each dementia group differed from the others on at least one variable, and language production variables correlated with established behavioral measures of disease progression. A machine learning classifier, using narrative speech variables, achieved 90% accuracy when classifying samples as NC or dementia, and 59.4% accuracy when matching samples to their diagnostic group. Automated quantification of spontaneous speech in both language-led and non-language led dementias, is feasible. It allows extraction of syndromic profiles that complement those derived from standardized tests, warranting further evaluation as candidate biomarkers. Inclusion of frequency-based language variables benefits profiling and classification.

Language in schizophrenia and aphasia: the relationship with non-verbal cognition and thought disorder.

Objective: To determine the relationship between language abnormalities and broader cognitive impairment and thought disorder by examining language and cognition in schizophrenia and aphasia (a primary language disorder).Methods: Cognitive and linguistic profiles were measured with a battery of standardised tests, and compared in a clinical population of n = 50 (n = 30 with schizophrenia and n = 20 with aphasia) and n = 61 non-clinical comparisons (n = 45 healthy controls and n = 16 non-affected first-degree relatives of patients with schizophrenia).Results: Both clinical groups showed linguistic deficits. Verbal impairment was more severe in participants with aphasia, whereas non-verbal performance was more affected in participants with schizophrenia. In schizophrenia, but not in aphasia, verbal and non-verbal performance were associated. Formal thought disorder was associated with impairment in executive function and in grammatical, but not naming, tasks.Conclusion: While patients with schizophrenia and aphasia showed language impairments, the nature and cognitive basis of these impairments may be different; language performance disassociates from broader cognitive functioning in aphasia but may be an intrinsic expression of a broader cognitive impairment in schizophrenia. Thought disorder may represent a core malfunction of grammatical processing. Results suggests that communicative ability may be a valid target in cognitive remediation strategies in schizophrenia.

Disturbing the rhythm of thought: Speech pausing patterns in schizophrenia, with and without formal thought disorder.

Everyday speech is produced with an intricate timing pattern and rhythm. Speech units follow each other with short interleaving pauses, which can be either bridged by fillers (erm, ah) or empty. Through their syntactic positions, pauses connect to the thoughts expressed. We investigated whether disturbances of thought in schizophrenia are manifest in patterns at this level of linguistic organization, whether these are seen in first degree relatives (FDR) and how specific they are to formal thought disorder (FTD). Spontaneous speech from 15 participants without FTD (SZ-FTD), 15 with FTD (SZ+FTD), 15 FDRs and 15 neurotypical controls (NC) was obtained from a comic strip retelling task and rated for pauses subclassified by syntactic position and duration. SZ-FTD produced significantly more unfilled pauses than NC in utterance-initial positions and before embedded clauses. Unfilled pauses occurring within clausal units did not distinguish any groups. SZ-FTD also differed from SZ+FTD in producing significantly more pauses before embedded clauses. SZ+FTD differed from NC and FDR only in producing longer utterance-initial pauses. FDRs produced significantly fewer fillers than NC. Results reveal that the temporal organization of speech is an important window on disturbances of the thought process and how these relate to language.

Comprehension of Embedded Clauses in Schizophrenia With and Without Formal Thought Disorder.

Formal thought disorder (FTD) in schizophrenia (SZ) is clinically manifested primarily through language production, where linguistic studies have reported numerous anomalies including lesser use of embedded clauses. Here, we explored whether problems of language may extend to comprehension and clause embedding in particular. A sentence-picture matching task was designed with two conditions in which embedded clauses were presupposed as either true (factive) or not. Performance across these two conditions was compared in people with SZ and moderate-to-severe FTD (SZ + FTD), SZ with minimal FTD (SZ-FTD), first-degree relatives of people with SZ, and neurotypical controls. The SZ + FTD group performed significantly worse than all others in both conditions, and worse in the nonfactive than in the factive one. These results demonstrate language dysfunction in comprehension specific to FTD is a critical aspect of grammatical complexity and its associated meaning, which has been independently known to be cognitively significant as well.

The language profile of formal thought disorder.

Formal thought disorder (FTD) is clinically manifested as disorganized speech, but there have been only few investigations of its linguistic properties. We examined how disturbance of thought may relate to the referential function of language as expressed in the use of noun phrases (NPs) and the complexity of sentence structures. We used a comic strip description task to elicit language samples from 30 participants with schizophrenia (SZ), 15 with moderate or severe FTD (SZ + FTD), and 15 minimal or no FTD (SZ-FTD), as well as 15 first-degree relatives of people with SZ (FDRs) and 15 neurotypical controls (NC). We predicted that anomalies in the normal referential use of NPs, sub-divided into definite and indefinite NPs, would identify FTD; and also that FTD would also be linked to reduced linguistic complexity as specifically measured by the number of embedded clauses and of grammatical dependents. Participants with SZ + FTD produced more referential anomalies than NC and produced the fewest definite NPs, while FDRs produced the most and thus also differed from NC. When referential anomalies were classed according to the NP type in which they occurred, the SZ + FTD group produced more anomalies in definite NPs than NC. Syntactic errors did not distinguish groups, but the SZ + FTD group exhibited significantly less syntactic complexity than non-SZ groups. Exploratory regression analyses suggested that production of definite NPs distinguished the two SZ groups. These results demonstrate that FTD can be identified in specific grammatical patterns which provide new targets for detection, intervention, and neurobiological studies.