Pragmatic abilities in multiple sclerosis: The contribution of the temporo-parietal junction

Does the right temporo-parietal junction play a role in processing indirect speech acts? A transcranial magnetic stimulation study

In communication, much information is conveyed not explicitly but rather covertly, based on shared assumptions and common knowledge. For instance, when asked "Did you bring your cat to the vet?" a person could reply "It got hurt jumping down the table", thereby implicating that, indeed, the cat was brought to the vet. The assumption that getting hurt jumping down a table motivates a vet visit is tacitly attributed to the speaker by the listener, which implies Theory of Mind (ToM) processes. In the present study, we apply repetitive transcranial magnetic stimulation to the right temporo-parietal junction (rTPJ), a key brain region underlying ToM, with the aim to disrupt ToM processes necessary for language understanding. We then assess effects on the comprehension of indirect speech acts and their matched direct controls. In one set of conditions, the direct and indirect stimuli where not matched for speech act type, whereas, in the other, these were matched, therefore providing an unconfounded test case for in/directness. When indirect speech acts and direct controls were matched for speech act type (both statements), the indirect ones took longer to process both following sham and verum TMS. However, when the indirect and direct speech acts were not matched for communicative function (accept/decline offer vs. descriptive statement respectively), then a delay was detected for the indirect ones following sham TMS but, crucially, not following verum TMS. Additionally, TMS affected behavior in a ToM task. We therefore do not find evidence that the rTPJ is causally involved in comprehending of indirectness per se, but conclude that it could be involved instead in the processing of specific social communicative activity of rejecting of accepting offers, or to a combination of differing in/directness and communicative function. Our findings are consistent with the view that ToM processing in rTPJ is more important and/or more pronounced for offer acceptance/rejection than for descriptive answers.

Word finding, prosody and social cognition in multiple sclerosis

BACKGROUND

Impairments in speech and social cognition have been reported in people with multiple sclerosis (pwMS), although their relationships with neuropsychological outcomes and their clinical utility in MS are unclear.

OBJECTIVES

To evaluate word finding, prosody and social cognition in pwMS relative to healthy controls (HC).

METHODS

We recruited people with relapsing MS (RMS, n = 21), progressive MS (PMS, n = 24) and HC (n = 25) from an outpatient MS clinic. Participants completed a battery of word-finding, social cognitive, neuropsychological and clinical assessments and performed a speech task for prosodic analysis.

RESULTS

Of 45 pwMS, mean (SD) age was 49.4 (9.4) years, and median (range) Expanded Disability Severity Scale score was 3.5 (1.0-6.5). Compared with HC, pwMS were older and had slower information processing speed (measured with the Symbol Digit Modalities Test, SDMT) and higher depression scores. Most speech and social cognitive measures were associated with information processing speed but not with depression. Unlike speech, social cognition consistently correlated with intelligence and memory. Visual naming test mean response time (VNT-MRT) demonstrated worse outcomes in MS versus HC (p = .034, Nagelkerke's R²  = 65.0%), and in PMS versus RMS (p = .009, Nagelkerke's R²  = 50.2%). Rapid automatised object naming demonstrated worse outcomes in MS versus HC (p = .014, Nagelkerke's R²  = 49.1%). These word-finding measures showed larger effect sizes than that of the SDMT (MS vs. HC, p = .010, Nagelkerke's R²  = 40.6%; PMS vs. RMS, p = .023, Nagelkerke's R²  = 43.5%). Prosody and social cognition did not differ between MS and HC.

CONCLUSIONS

Word finding, prosody and social cognition in MS are associated with information processing speed and largely independent of mood. Impairment in visual object meaning perception is potentially a unique MS disease-related deficit that could be further explored and cautiously considered as an adjunct disability metric for MS.

Linguistic signs in action: The neuropragmatics of speech acts

What makes human communication exceptional is the ability to grasp speaker's intentions beyond what is said verbally. How the brain processes communicative functions is one of the central concerns of the neurobiology of language and pragmatics. Linguistic-pragmatic theories define these functions as speech acts, and various pragmatic traits characterise them at the levels of propositional content, action sequence structure, related commitments and social aspects. Here I discuss recent neurocognitive studies, which have shown that the use of identical linguistic signs in conveying different communicative functions elicits distinct and ultra-rapid neural responses. Interestingly, cortical areas show differential involvement underlying various pragmatic features related to theory-of-mind, emotion and action for specific speech acts expressed with the same utterances. Drawing on a neurocognitive model, I posit that understanding speech acts involves the expectation of typical partner follow-up actions and that this predictive knowledge is immediately reflected in mind and brain.

Case report: Pragmatic impairment in multiple sclerosis after worsening of clinical symptoms

Pragmatics, defined as the ability to integrate language and context to communicate effectively, may be impaired in Multiple Sclerosis (MS). We present the case of a patient with active secondary progressive MS who, after a first neuropsychological assessment that evidenced only a slight pragmatic impairment, suffered a sudden worsening of her clinical conditions, treated with corticosteroids. After this clinical worsening, her pragmatic abilities declined markedly, both in comprehension and production. This worsening was accompanied by a decline only in one attention task, in the context of an overall stable cognitive functioning. We conclude that pragmatics may be a domain particularly susceptible to cognitive worsening, highlighting the importance of its assessment in clinical practice.

Spelling Errors in Brief Computer-Mediated Texts Implicitly Lead to Linearly Additive Penalties in Trustworthiness

Background

Spelling errors in documents lead to reduced trustworthiness, but the mechanism for weighing the psychological assessment (i.e., integrative versus dichotomous) has not been elucidated. We instructed participants to rate content of texts, revealing that their implicit trustworthiness judgments show marginal differences specifically caused by spelling errors.

Methods

An online experiment with 100 English-speaking participants were asked to rate 27 short text excerpts (∼100 words) about multiple sclerosis in the format of unmoderated health forum posts. In a counterbalanced design, some excerpts had no typographic errors, some had two errors, and some had five errors. Each participant rated nine paragraphs with a counterbalanced mixture of zero, two or five errors. A linear mixed effects model (LME) was assessed with error number as a fixed effect and participants as a random effect.

Results

Using an unnumbered scale with anchors of "completely untrustworthy" (left) and "completely trustworthy" (right) recorded as 0 to 100, two spelling errors resulted in a penalty to trustworthiness of 5.91 ± 1.70 (robust standard error) compared to the reference excerpts with zero errors, while the penalty for five errors was 13.5 ± 2.47; all three conditions were significantly different from each other (P < 0.001).

Conclusion

Participants who rated information about multiple sclerosis in a context mimicking an online health forum implicitly assigned typographic errors nearly linearly additive trustworthiness penalties. This contravenes any dichotomous heuristic or local ceiling effect on trustworthiness penalties for these numbers of typographic errors. It supports an integrative model for psychological judgments of trustworthiness.

Fixel-based evidence of microstructural damage in crossing pathways improves language mapping in Post-stroke aphasia

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FBA shows greater specificity in mapping injured fibers in post-stroke aphasia.

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Intra-axonal volume of axons in dual streams is reduced in post-stroke aphasia.

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FBA could locate more precise segments associated with language defects.

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FBA could attribute language subdomain scores to fiber density of distinct tracts.

Background

The complex crossing-fiber characteristics in the dual-stream system have been ignored by traditional diffusion tensor models regarding disconnections in post-stroke aphasia. It is valuable to identify microstructural damage of crossing-fiber pathways and reveal accurate fiber-specific language mapping in patients with aphasia.

Methods

This cross-sectional study collected magnetic resonance imaging data from 29 participants with post-stroke aphasia in the subacute stage and from 33 age- and sex-matched healthy controls. Fixel-based analysis was performed to examine microstructural fiber density (FD) and bundle cross-section alterations of specific fiber populations in crossing-fiber regions. Group comparisons were performed, and relationships with language scores were assessed.

Results

The aphasic group exhibited significant fixel-wise FD reductions in the dual-stream tracts, including the left inferior fronto-occipital fasciculus (IFOF), arcuate fasciculus, and superior longitudinal fasciculus (SLF) III (family-wise-error-corrected p < 0.05). Voxel- and fixel-wise comparisons revealed mismatched distributions in regions with crossing-fiber nexuses. Fixel-wise correlation analyses revealed significant associations between comprehension impairment and reduced FD in the temporal and frontal segments of the left IFOF, and also mapped naming ability to the IFOF. Average features along the whole course of dominant tracts assessed with tract-wise analyses attributed word-level comprehension to the IFOF (r = 0.723, p < 0.001) and revealed a trend-level correlation between sentence-level comprehension and FD of the SLF III (r = 0.451, p = 0.021). The mean FD of the uncinate fasciculus (UF) and IFOF correlated with total and picture naming scores, and the IFOF also correlated with responsive naming subdomains (Bonferroni corrected p < 0.05).

Conclusions

FD reductions of dual streams suggest that intra-axonal volume reduction constitutes the microstructural damage of white matter integrity in post-stroke aphasia. Fixel-based analysis provides a complementary method of language mapping that identifies fiber-specific tracts in the left hemisphere language network with greater specificity than voxel-based analysis. It precisely locates the precise segments of the IFOF for comprehension, yields fiber-specific evidence for the debated UF-naming association, and reveals dissociative subdomain associations with distinct tracts.

Functional anatomy of idiomatic expressions

Idiomatic expressions (IE) are groups of words whose meaning is different from the sum of its components. Neural mechanisms underlying their processing are still debated, especially regarding lateralization, main structures involved, and whether this neural network is independent from the spoken language. To investigate the neural correlates of IE processing in healthy Spanish speakers.Twenty one native speakers of Spanish were asked to select one of 4 possible meanings for IE or literal sentences. fMRI scans were performed in a 3.0T scanner and processed by SPM 12 comparing IE vs. literal sentences. Laterality indices were calculated at the group level. IE activated a bilateral, slightly right-sided network comprising the pars triangularis and areas 9 and 10. In the left hemisphere (LH): the pars orbitalis, superior frontal, angular and fusiform gyrus. In the right hemisphere (RH): anterior insula, middle frontal, and superior temporal gyrus. This network reveals the importance of the RH, besides traditional LH areas, to comprehend IE. This agrees with the semantic coding model: the LH activates narrow semantic fields choosing one single meaning and ignoring others, and the RH detects distant semantic relationships, activating diffuse semantic fields. It is also in line with the configuration hypothesis: both meanings, literal and figurative, are executed simultaneously, until the literal meaning is definitively rejected and the figurative one is accepted. Processing IE requires the activation of fronto-temporal networks in both hemispheres. The results concur with previous studies in other languages, so these networks are independent from the spoken language. Understanding these mechanisms sheds light on IE processing difficulties in different clinical populations and must be considered when planning resective surgery.

The role of language ability in verbal fluency of individuals with multiple sclerosis

BACKGROUND

While cognitive deficits in memory and processing speed have been well-documented in individuals with multiple sclerosis (MS), language is largely considered to be intact. Verbal fluency deficits observed in MS are often attributed to impaired processing speed and executive functions rather than language ability. The current study evaluates the contribution of various cognitive factors to verbal fluency including language ability, oral-motor speed, processing speed, and executive functions.

METHODS

We analyzed pre-existing data from seventy-four (74) individuals with MS who completed a battery of neuropsychological tests designed to assess individual ability for various cognitive factors. We conducted linear multiple regression analyses with letter and category verbal fluency as outcome variables and performance on other cognitive domains (e.g., processing speed, executive functioning) as predictors.

RESULTS

Both vocabulary and processing speed predicted letter fluency while only vocabulary predicted category fluency. These findings suggest that the observed verbal fluency deficits in MS may reflect both impaired language ability and processing speed.

CONCLUSION

We propose that further research on language ability in MS is needed to determine if comprehensive neuropsychological test batteries for persons with MS should include tests of language ability to fully understand the cognitive profile of any given patient. Given the importance of language ability, it may be necessary to conduct a more thorough assessment of language in individuals with MS who experience a deficit in this domain.

How to improve social communication in aging: Pragmatic and cognitive interventions

Among all aspects of the linguistic and communicative competence, pragmatics seems especially vulnerable in aging, due also to cognitive decline. However, pragmatics has never been considered as an intervention target in healthy aging. Here we tested the effects of a novel training program to improve pragmatics (PragmaCom) in older adults, compared with an active cognitive control group in a randomized-controlled-trial design. Both the PragmaCom group and the control group improved in pragmatic skills such as understanding metaphors and avoiding off-topic speech, indicating that it is possible to improve pragmatics in aging both with a specific training and with a cognitive training. Individual cognitive factors predicted pragmatic improvement in the control group, while in the PragmaCom group benefits were less dependent on individual characteristics. We discuss the results in terms of pragmatic plasticity, highlighting the importance of these findings for promoting older adults' social communication and well-being.

Impairment in oral medical comprehension in multiple sclerosis

In multiple sclerosis (MS), medical comprehension of website information and informed consent is reported to be impaired. The aim of the present study was to investigate oral medical comprehension of literal, figurative and humorous language in MS through videos of physician-patient exchanges. A group of 35 MS patients was compared to a control group (38 healthy participants). Participants were shown twelve filmed sketches consisting of a patient's question followed by the doctor's response and had to choose the meaning of the physician's response among three possibilities. Group analyses (non-parametric tests, Mann-Whitney) revealed significantly lower scores for MS patients compared to controls for figurative and humorous items. The opposite was observed for literal items. At the individual level, 17% of MS patients were impaired in their comprehension of figurative items and 32% for humorous items. Among them, 20% were impaired in both categories, 20% selectively in figurative comprehension and 60% selectively in humorous comprehension. These preliminary results suggest that a high proportion of MS patients (40%) may be impaired in the non-literal comprehension of simple medical responses. The better performances obtained for literal items suggest a more concrete linguistic decoding in MS. On a theoretical level, the double dissociations shown between figurative and humorous items in patients are not compatible with a serial model of linguistic processing.

Prevalence of self-reported language impairment in multiple sclerosis and the association with health-related quality of life: An international survey study

BACKGROUND

Language impairment has only recently begun to be considered a clinical manifestation of MS. A decline in language abilities can lead to restricted participation in everyday activities that require communication, including vocational, social, and educational contexts.

OBJECTIVES

The objectives of this study were to identify the prevalence and nature of self-reported language impairment in MS using a validated MS-specific patient-reported outcome measure and to determine the association with health-related quality of life (HRQoL) and demographic and clinical variables.

METHODS

In this cross-sectional study, 160 persons with MS completed the language items of the Speech pathology-specific questionnaire for persons with MS (SMS) to assess language and the 12-Item Short Form Survey (SF-12) to assess HRQoL. Participants were recruited internationally through professional MS bodies and support groups and completed all questionnaires online.

RESULTS

75% of persons with MS in this sample self-reported a language impairment. Of the total sample, 65.7% reported difficulty with word retrieval, 53.8% reported difficulty with expressive language, 49.4% reported difficulty with confrontational naming, and 40.6% reported difficulty with receptive language in spoken discourse. Statistical analyses revealed that age, sex, educational status, country of residence, disease duration, age at time of diagnosis, MS subtype, and medication management, were not associated with the prevalence of self-reported language impairment. Participants with self-reported language impairment had lower HRQoL than those without language impairment, scoring lower on both the SF-12 mental and physical component summary scores, with medium to large effect sizes (Cohen's d = 0.66 - 0.83). Participants with self-reported language impairment had higher rates of unemployment than those without language impairment (χ² = 18.2; p < 0.001).

CONCLUSION

Language can be compromised in persons with MS regardless of clinical and demographic characteristics and is associated with lower HRQoL. These findings indicate that frontline healthcare providers need to be aware of potential language impairment in MS and should make timely referrals to speech pathologists for further evaluation and support. Further research is needed to investigate the underlying neural mechanisms of language impairment in MS. In future, this will help guide the design of evidence-based intervention for these symptoms.

Pragmatic Language Disorder in Parkinson's Disease and the Potential Effect of Cognitive Reserve

It is known that patients with Parkinson's Disease (PD) may show deficits in several areas of cognition, including speech and language abilities. One domain of particular interest is pragmatics, which refers to the capacity of using language in context for a successful communication. Several studies showed that some specific aspects of pragmatics - both in production and in comprehension - might be impaired in patients with PD. However, a clear picture of pragmatic abilities in PD is still missing, as most of the existing studies focused on specific aspects of the pragmatic competence rather than on sketching a complete pragmatic profile. Moreover, little is known on the potential role of protective factors in compensating the decline of communicative skills as the disease progresses. The present study has two aims: (1) to provide a complete picture of pragmatic abilities in patients with PD, by using a comprehensive battery (Assessment of Pragmatic Abilities and Cognitive Substrates, APACS) and by investigating the relationship with other aspects of cognitive functioning (e.g., working memory and Theory of Mind) and (2) to investigate whether Cognitive Reserve, i.e., the resilience to cognitive impairment provided by life experiences and activities, may compensate for the progressive pragmatic deficits in PD. We found that patients with PD, compared to healthy matched controls, had worse performance in discourse production and in the description of scenes, and that these impairments were tightly correlated with the severity of motor impairment, suggesting reduced intentionality of engaging in a communicative exchange. Patients with PD showed also an impairment in comprehending texts and humor, suggesting a problem in inferring from stories, which was related to general cognitive impairment. Notably, we did not find any significant difference between patients and controls in figurative language comprehension, a domain that is commonly impaired in other neurodegenerative diseases. This might be indicative of a specific profile of pragmatic impairment in patients with PD, worth of further investigation. Finally, Cognitive Reserve measures showed a high degree of association with pragmatic comprehension abilities, suggesting that the modification of life-styles could be a good candidate for compensating the possible problems in understanding the pragmatic aspects of language experienced by patients with PD.