Figurative language processing after traumatic brain injury in adults: A preliminary study

Association of cognitive-linguistic deficits to diffusion tensor imaging parameters in moderate to severe traumatic diffuse axonal injury

Cognitive-linguistic functions are an essential part of adequate communication competence. Cognitive-linguistic deficits are common after traumatic diffuse axonal injury (DAI). We aimed to examine the integrity of perisylvian white matter tracts known to be associated with linguistic functions in individuals with DAI and their eventual association with poor cognitive-linguistic outcomes. Diffusion tensor imaging (DTI) results of 44 adults with moderate-to-severe DAI were compared with those of 67 controls. Fractional anisotropy (FA) values of the superior longitudinal fasciculus (SLF), arcuate fasciculus (AF), SLF with frontal connections to the lower parietal cortex, and AF with temporal connections to the lower parietal cortex were measured using tractography. The associations between white matter integrity FA values and cognitive-linguistic deficits were studied in the DAI group. Cognitive-linguistic deficits were determined based on our earlier study using the novel KAT test. No previous studies have examined the associations between white matter integrity and cognitive-linguistic deficits determined using the KAT test. Patients with DAI showed lower FA values in all left-side tracts than the controls. Unexpectedly, the poor cognitive-linguistic outcome in the language comprehension and production domains was associated with high FA values of several tracts. After excluding five cases with the poorest cognitive-linguistic performance, but with the highest values in the DTI variables, no significant associations with DTI metrics were found. The association between white matter integrity and cognitive-linguistic functioning is complex in patients with DAI of traumatic origin, probably reflecting the heterogeneity of TBI.

The Effects of Working Memory Capacity in Metaphor and Metonymy Comprehension in Mandarin-English Bilinguals’ Minds: An fMRI Study

This study investigated the role of working memory capacity (WMC) in metaphoric and metonymic processing in Mandarin–English bilinguals’ minds. It also explored the neural correlations between metaphor and metonymy computations. We adopted an event-related functional magnetic resonance imaging (fMRI) design, which consisted of 21 English dialogic sets of stimuli and 5 conditions: systematic literal, circumstantial literal, metaphor, systematic metonymy, and circumstantial metonymy, all contextualized in daily conversations. Similar fronto-temporal networks were found for the figurative language processing patterns: the superior temporal gyrus (STG) for metaphorical comprehension, and the inferior parietal junction (IPJ) for metonymic processing. Consistent brain regions have been identified in previous studies in the homologue right hemisphere of better WMC bilinguals. The degree to which bilateral strategies that bilinguals with better WMC or larger vocabulary size resort to is differently modulated by subtypes of metonymies. In particular, when processing circumstantial metonymy, the cuneus (where putamen is contained) is activated as higher-span bilinguals filter out irrelevant information, resorting to inhibitory control use. Cingulate gyrus activation has also been revealed in better WMC bilinguals, reflecting their mental flexibility to adopt the subjective perspective of critical figurative items with self-control. It is hoped that this research provides a better understanding of Mandarin–English bilinguals’ English metaphoric and metonymic processing in Taiwan.

The Elephant in the Room: A Systematic Review of Stimulus Control in Neuro-Measurement Studies on Figurative Language Processing

The processing of metaphors and idioms has been the subject of neuroscientific research for several decades. However, results are often contradictory, which can be traced back to inconsistent terminology and stimulus control. In this systematic review of research methods, we analyse linguistic aspects of 116 research papers which used EEG, fMRI, PET, MEG, or NIRS to investigate the neural processing of the two figurative subtypes metaphor and idiom. We critically examine the theoretical foundations as well as stimulus control by performing a systematic literature synthesis according to the PRISMA guidelines. We explicitly do not analyse the findings of the studies but instead focus on four primary aspects: definitions of figurative language and its subtypes, linguistic theory behind the studies, control for factors influencing figurative language processing, and the relationship between theoretical and operational definitions. We found both a lack and a broad variety in existing definitions and operationalisation, especially in regard to familiarity and conventionality. We identify severe obstacles in the comparability and validation potential of the results of the papers in our review corpus. We propose the development of a consensus in fundamental terminology and more transparency in the reporting of stimulus design in the research on figurative language processing.

Cognitive-Linguistic outcome in moderate to severe diffuse axonal injury and association with fatigue

PURPOSE

Individuals with traumatic brain injury (TBI) often have persistent cognitive-linguistic deficits that negatively influence their life. Our objective was to examine the cognitive-linguistic outcome in individuals with moderate to severe diffuse axonal injury (DAI) with a novel test battery. As fatigue is a common symptom affecting the lives of individuals with DAI, we also wanted to assess whether the self-reported fatigue was associated with cognitive-linguistic abilities.

METHODS

Selected cognitive-linguistic subtests of the Finnish KAT test and The Mental Fatigue Scale (MFS) were applied to 48 adults with moderate to severe DAI and 27 healthy controls. The majority of the participants with DAI were in the chronic stage. The groups were compared using ANCOVA. Linear regressions were used to analyze the association between MFS and cognitive-linguistic outcomes.

RESULTS

The participants with DAI had significantly poorer scores than the controls in most cognitive-linguistic variables and reported significantly more fatigue. Two of the four cognitive-linguistic composite variables were associated with the degree of self-reported fatigue.

CONCLUSIONS

Cognitive-linguistic deficits are common in individuals with moderate to severe DAI, and The Finnish KAT test is a valuable tool to detect those. Fatigue was associated with linguistic working memory and language production.

Interpretation of familiar metaphors and proverbs by Polish people in middle and late adulthood

BACKGROUND

The ability to understand figurative language, including metaphors and proverbs, decreases with age, although the phenomenon is not universal. Cognitive capacities and education play an important role in the competence connected with figurative language use and comprehension in people during the second half of life.

AIMS

To identify possible similarities and differences in task performance by subjects representing middle adulthood (40-49 and 50-59 years old) and late adulthood (60-69 and 70-92 years old). Additionally, the analyses took into account factors significantly affecting the results, that is, tasks type (metaphors versus proverbs), the way the answer is given (open-ended versus multiple choice) and types of answers (abstract and concrete). This study also aimed to identify some cognitive correlates of task completion.

METHODS & PROCEDURES

A total of 86 Caucasian subjects, aged 40-92 years, participated in this study (M_{whole group} = 62.37, SD = 15.53); the group included 20 subjects aged 40-49 years (M_age = 45.4; SD = 3.05), 20 aged 50-59 years (M_age = 55.50; SD = 2.64), 20 aged 60-69 years (M_age = 64.40; SD = 2.78), and 26 aged 70-92 years (M_age = 79.15; SD = 6.27). A total of 20 well-known Polish metaphors and 20 popular Polish proverbs were used to assess the level of proverb and metaphor comprehension. The Montreal Cognitive Assessment Scale and Vocabulary subtest of the Polish version of WAIS-R were applied to assess the cognitive functions.

OUTCOMES & RESULTS

The results of the analyses suggest that there are differences as well as certain similarities between the groups. At 70+ years of age, the ability to explain and comprehend metaphors and proverbs decreases when compared with younger adults. In the 70+ group, the ability to grasp the meaning of both metaphors and proverbs is similar, unlike in the younger groups which present a better ability to explain and comprehend metaphors than proverbs. The conditions related to the types of tasks, that is, spontaneous interpretation and choice of responses, do not affect scores of the oldest subjects.

CONCLUSIONS

The analysis of response types, that is, abstract versus concrete, shows that, compared with younger groups, people aged 70+ years tend to less frequently provide abstract explanations and more often give concrete (but correct) responses, referring to situational data or examples from everyday life. Moreover, attention, short-term/delayed memory and lexical reserve influence the ability to use and comprehend figurative language to a varied degree.

WHAT THIS PAPER ADDS

What is already known on the subject Studies focusing on metaphor and proverb interpretation by people in middle and late adulthood are rather scarce, and what is more, they provide inconclusive results. Research has shown that the capacities related to attention and memory, as well as language resources and executive functions, all deteriorate in older people, which negatively affects their ability to understand metaphors and proverbs. However, varied methods are applied to assess these skills, which may explain why the related findings are inconsistent. What this paper adds to existing knowledge The novelty of this study lies in the fact that the analyses took into account the type of task (metaphors versus proverbs), the method of responding (open-ended versus multiple-choice) and the nature of the answer (abstract versus concrete). This allowed us to highlight intergroup differences and to show specific characteristics of proverb and metaphor spontaneous interpretation and choice of correct answers. The results were compared among the participants representing relatively narrow age ranges classified as middle and late adulthood. What are the potential or actual clinical implications of this work? Analysis of how people in middle and late adulthood interpret metaphors and proverbs might constitute an element of preliminary screening assessment showing whether a decrease in this capacity is in the normal range or if it reflects a serious cognitive decline. It would be worthwhile if the diagnostic process included varied task designs, that is, both metaphors and proverbs, as well as spontaneous interpretation and multiple-choice, as well as varied types of responses.

Moving Toward Accurate Assessment of Working Memory in Adults With Neurogenically Based Communication Disorders

Purpose This article presents a viewpoint highlighting concerns regarding currently available assessments of working memory in adults with neurogenic communication disorders. Additionally, we provide recommendations for improving working memory assessment in this population. Method This viewpoint includes a critique of clinical and experimental working memory tests relevant to speech-language pathologists. We consider the terminology used to describe memory, as well as discuss language demands and test construction. Results Clinical and experimental testing of working memory in adults with neurogenic communication disorders is challenged due to theoretical, methodological, and practical limitations. The major limitations are characterized as linguistic and task demands, presentation and response modality effects, test administration, and scoring parameters. Taking these limitations into consideration, several modifications to working memory testing and their relevance to neurogenic populations are discussed. Conclusions The recommendations provided in this article can better guide clinicians and researchers to advocate for improved tests of working memory in adults with neurogenic communication disorders. Future research should continue to address these concerns and consider our recommendations.

Pragmatic abilities in early Parkinson's disease

Language impairment in Parkinson's disease (PD) has been investigated at different levels of linguistic skills. Only a few studies dealt with pragmatic abilities in PD, and these suggest an impairment of pragmatic skills, which might affect quality of life. However, previous studies enrolled patients with heterogeneous symptom severity. The goal of this study is twofold: first, to investigate whether pragmatic skills are compromised at the early stage of PD; second, to explore whether an early pragmatic impairment is explained by a decay of a specific cognitive function. We assessed pragmatic abilities (discourse production, comprehension of narratives, humour, and figurative language), and a cluster of cognitive functions (memory, verbal fluency, inhibition, shifting, and ToM) in a sample of early PD patients and a group of age-matched healthy controls. Early PD patients showed impaired general pragmatic skills (the ability to perform different pragmatic tasks in language production and comprehension), as well as a deficit in the production and comprehension individual scores. Our results suggest that good general cognitive skills (a good overall cognitive level) and high education support patients' pragmatic competence. Inhibitory processes have been found to predict patients' ability to understand figurative language, such as metaphors, and this might be related to frontal lobe dysfunctions.

The Neural Basis of Metaphor Comprehension: Evidence from Left Hemisphere Degeneration

Despite the ubiquity of metaphor in cognition and communication, it is absent from standard clinical assessments of language, and the neural systems that support metaphor processing are debated. Previous research shows that patients with focal brain lesions can display selective impairments in processing metaphor, suggesting that figurative language abilities may be disproportionately vulnerable to brain injury. We hypothesized that metaphor processing is especially vulnerable to neurodegenerative disease, and that the left hemisphere is critical for normal metaphor processing. To evaluate these hypotheses, we tested metaphor comprehension in patients with left-hemisphere neurodegeneration, and in demographically matched healthy comparison participants. Stimuli consisted of moderately familiar metaphors and closely matched literal sentences sharing the same source term (e.g., The interview was a painful crawl / The infant's motion was a crawl). Written sentences were presented, followed by four modifier-noun answer choices (one target and three foils). Healthy controls, though reliably better at literal than metaphor trials, comprehended both sentence conditions well. By contrast, participants with left-hemisphere neurodegeneration performed disproportionately poorly on metaphor comprehension. Anatomical analyses show relationships between metaphor accuracy and patient atrophy in the left middle and superior temporal gyri, and the left inferior frontal gyrus, areas that have been implicated in supporting metaphor comprehension in previous imaging research. The behavioral results also suggest deficits of metaphor comprehension may be a sensitive measure of cognitive dysfunction in some forms of neurodegenerative disease.

Reaction time and cognitive-linguistic performance in adults with mild traumatic brain injury

Objective: The purpose of this study was to characterize cognitive-linguistic performance in adults with mild traumatic brain injury (mTBI) to advance assessment and treatment practices. We hypothesized that individuals with mTBI would demonstrate longer reaction times (RTs) and greater error rates when compared to an orthopedic injury (OI) group on a category-naming task. Method: Participants were age and education-matched adults with mTBI (n = 20; 12 females) and adults with OI (n = 21; 5 females) who were discharged to home after an Emergency Department visit. Our primary task was a category-naming task shown to be sensitive to language deficits after mTBI. The task was adapted and administered under speeded and unspeeded conditions. Results: There was a significant main effect of condition on RT (speeded faster than unspeeded) and accuracy (more errors in the speeded condition). There was a marginally significant effect of group on errors, with more errors in the mTBI group than the OI group. Naming RT and accuracy in both conditions were moderately correlated with injury variables and symptom burden. Conclusions: Our data showed a marginal effect of group on accuracy of performance. Correlations found between naming and neurobehavioural symptoms, including sleep quality, suggest that the latter should be considered in future research.

Impaired comprehension of metaphorical expressions in very mild Alzheimer's disease

BACKGROUND

Brain-damaged patients often have difficulty understanding non-literal language. However, whether patients with Alzheimer's disease (AD) have comprehension deficits of metaphorical expressions, in contrast with non-metaphorical (literal) expressions, remains unclear.

PATIENTS AND METHODS

The subjects were 40 AD patients; 20 had mild AD (17-23 points on the Mini-Mental State Examination [MMSE]), and 20 had very mild AD (≥24 points). Twenty normal elderly controls were also enrolled as a control group. Thirty sentences that contained novel similes (Items) were prepared. For each Item, four explanatory choices, consisting of one correct response and three foils, were provided. The participants were asked to choose the written statement that best represented the Item's meaning. In addition, all the subjects completed the Token Test.

RESULTS

The patients with mild AD had significantly lower scores than the normal controls on both the simile comprehension test and the Token Test. However, the patients with very mild AD exhibited significantly lower scores on the simile comprehension test, but not on the Token Test. The distributions of error types for the simile test differed between the mild AD group and the other groups. The mild AD patients made more errors that were "far" from the correct responses.

CONCLUSION

Patients with AD are more likely to have comprehension deficits of metaphorical expressions than comprehension deficits of non-metaphorical expressions. Pragmatic language dysfunction may precede formal language dysfunction during the progression of AD.

Early adolescent language development following intrathecal chemotherapy for acute lymphoblastic leukaemia

PURPOSE

Central nervous system (CNS) prophylaxis in the treatment of childhood acute lymphoblastic leukaemia (ALL) is routinely achieved through intrathecal chemotherapy (ITC). The presence of high level language deficits in older children who received CNS-directed ITC for ALL in early childhood is yet to be elucidated, with previous research suggesting that high level language deficits may appear later in ALL survivors' development at an age when these skills typically emerge.

METHOD

A test battery covering foundational language skills and higher-order language skills was administered to five participants (aged 10-15 years) with a history of ITC for ALL. Conversion of each child's language performance scores to z scores allowed for clinical interpretation of data across the language areas tested.

RESULT

Foundational language skills were, in general, of no clinical concern. Three of the five children presented with clinically impaired language skills in areas including resolving ambiguity, making inferences and composing novel sentences. Performance variation between the participants and within the individual participants was noted.

CONCLUSION

Given the importance of early adolescent language abilities to academic and social development in late primary and secondary schooling, these preliminary findings suggest further research into emerging adolescent language abilities following ITC for ALL is warranted.

Do executive function and theory of mind predict pragmatic abilities following traumatic brain injury? An analysis of sincere, deceitful and ironic communicative acts

Quality of life and social integration are strongly influenced by the ability to communicate and previous research has shown that pragmatic ability can be specifically impaired in individuals with traumatic brain injury (TBI). In addition, TBI usually results in damage to the frontotemporal lobes with a consequent impairment of cognitive functions, i.e., attention, memory, executive function (EF) and theory of mind (ToM). The role of the underlying cognitive deficits in determining the communicative-pragmatic difficulties of an individual with TBI is not yet completely clear. This study examined the relationship between the ability to understand and produce various kinds of communicative acts, (i.e., sincere, deceitful and ironic) and the above-mentioned cognitive and ToM abilities following TBI. Thirty-five individuals with TBI and thirty-five healthy controls were given tasks assessing their ability to comprehend and produce sincere, deceitful and ironic communicative acts belonging to the linguistic and extralinguistic scales of the Assessment Battery for Communication (ABaCo), together with a series of EF and ToM tasks. The results showed that, when compared to healthy individuals, participants with TBI performed poorly overall in the comprehension and production of all the pragmatic phenomena investigated, (i.e., sincere, deceitful and ironic communicative acts), and they also exhibited impaired performance at the level of all the cognitive functions examined. Individuals with TBI also showed a decreasing trend in performance in dealing with sincere, deceitful and ironic communicative acts, on both the comprehension and production subscales of the linguistic and extralinguistic scales. Furthermore, a hierarchical regression analysis revealed that - in patients with TBI but not in the controls - EF had a significant effect on the comprehension of linguistic and extralinguistic irony only, while the percentage of explained variance increased with the inclusion of theory of mind. Indeed, ToM had a significant role in determining patients' performance in the extralinguistic production of sincere and deceitful communicative acts, linguistic and extralinguistic comprehension of deceit and the linguistic production of irony. However, with regard to the performance of patients with TBI in the various pragmatic tasks investigated, (i.e., sincere, deceitful and ironic communicative acts), EF was able to explain the pattern of patients' scores in the linguistic and extralinguistic comprehension but not in production ability. Furthermore, ToM seemed not to be able to explain the decreasing trend in the performance of patients in managing the various kinds of communicative acts investigated.

Frequência de déficits neuropsicológicos após traumatismo cranioencefálico

O traumatismo cranioencefálico (TCE) pode acarretar mudanças no cotidiano e prejuízos social laboral comunicativo e cognitivo (dificuldades atencionais mnemônicas e executivas). Este estudo buscou caracterizar a ocorrência de déficits neuropsicológicos após o TCE em uma amostra de adultos e verificar se há impacto do nível de severidade do trauma no desempenho cognitivo dos pacientes. Participaram 96 adultos divididos em dois grupos: TCE leve (n=39) e grave (n=57). A gravidade do trauma foi classificada pela Escala de Coma de Glasgow pela duração da perda de consciência. ou pela amnésia pós-traumática. Não houve diferença nas variáveis sociodemográficas idade e escolaridade entre os grupos. Para a comparação entre grupos quanto a ocorrência de déficits neuropsicológicos. utilizou-se o Qui-quadrado. Tarefas verbais e visuoespaciais de funções executivas habilidades linguísticas. mnemônicas verbais compuseram uma bateria neuropsicológica flexível.Os pacientes com TCE leve tiveram menos déficits comparados aos com TCE grave (erros e categorias completadas do Wisconsin Teste de Classificação de Cartas; erros da parte B do Teste Hayling; e na interferência pró e retroativa do teste de aprendizagem verbal de Rey). A severidade do trauma parece diferenciar indivíduos no desempenho de memória episódica no contexto de maior sobrecarga de informações novas e no controle da interferência entre memórias; o mesmo se aplica às funções de flexibilidade e inibição. Fazse necessário um maior investimento em ações de políticas públicas de saúde priorizando intervenção neurognitiva remediativa e métodos de prevenção para acidentes relacionados a lesões traumáticas com alta ocorrência de sequelas.

Proverb comprehension in individuals with agenesis of the corpus callosum

Comprehension of non-literal language involves multiple neural systems likely involving callosal connections. We describe proverb comprehension impairments in individuals with isolated agenesis of the corpus callosum (AgCC) and normal-range general intelligence. Experiment 1 compared Gorham Proverb Test (Gorham, 1956) performance in 19 adults with AgCC and 33 neurotypical control participants of similar age, sex, and intelligence. Experiment 2 used the Proverbs subtest of the Delis-Kaplan Executive Function System (D-KEFS, 2001) to compare 19 adults with AgCC and 17 control participants with similar age, sex, and intelligence. Gorham Proverbs performance was impaired in the AgCC group for both the free-response and multiple-choice tasks. On the D-KEFS proverbs test, the AgCC group performed significantly worse on the free-response task (and all derivative scores) despite normal levels of performance on the multiple-choice task. Covarying verbal intelligence did not alter these outcomes. However, covarying a measure of non-literal language comprehension considerably reduced group differences in proverb comprehension on the Gorham test, but had little effect on the D-KEFS group differences. The difference between groups seemed to be greatest when participants had to generate their own interpretation (free response), or in the multiple choice format when the test included many proverbs that were likely to be less familiar. Taken together, the results of this study clearly show that proverb comprehension is diminished in individuals with AgCC compared to their peers.

Isolated, relative aproverbia without focal lesion

We have seen a patient with a profound, isolated, and quite selective deficit in proverb interpretation-aproverbia. The patient presented to us after an anoxic brain injury with aproverbia. Interestingly, the aproverbia appeared to be premorbid to the presenting event. Furthermore, the patient had no brain lesion that has been associated or even proposed as a cause of deficit in proverb or metaphor interpretation. The patient did have acute bilateral hippocampi lesions and associated severe anterograde amnesia, but he retained good retrograde memory with which he is able to give good, logical but concrete explanations for proverbs. This case highlights the need, importance, and interest in further neuropsychologic, imaging and functional studies of proverb and interpretation in patients and normal subjects populations.

Development and application of cognitive-pragmatic language ability assessment protocol for traumatic brain injury

The study aim was to introduce a newly-developed multifaceted cognitive-pragmatic language assessment protocol. This study was also designed to assess the reliability and validity of the assessment protocol in the discrimination between mild traumatic brain injury (mTBI) and normal control. Individuals in this study were 25 to 64 years old. Ten mTBIs and twenty-two control group were recruited for the preliminary study. Their mean ages were 45.20 and 41.23, respectively. For the main study, we recruited 39 mTBIs and 100 healthy individuals whose mean ages were 44.67 and 40.84, respectively. The newly-developed protocol was completed through a systematic review based on an item analysis. We administered the CAPTBI based on nine domains, 22 subcategories, and 57 items. All nine domains of the CAPTBI were found to be significant variables by which mTBI individuals can be distinguished from normal individuals (p < .001). We also presented the cut-off points by education level to maximize the validity of differentiating the two groups. This study is the first attempt to evaluate mTBI by means of the cognitive-linguistic protocol with multiple domains. The CAPTBI is an appropriate tool for differentiating the cognitive-pragmatic language abilities between mTBI and control group.

Metonymy as Referential Dependency: Psycholinguistic and Neurolinguistic Arguments for a Unified Linguistic Treatment

We examine metonymy at psycho- and neurolinguistic levels, seeking to adjudicate between two possible processing implementations (one- vs. two-mechanism). We compare highly conventionalized systematic metonymy (producer-for-product: "All freshmen read O'Connell") to lesser-conventionalized circumstantial metonymy ("[a waitress says to another:] 'Table 2 asked for more coffee."'). Whereas these two metonymy types differ in terms of contextual demands, they each reveal a similar dependency between the named and intended conceptual entities (e.g., Jackendoff, 1997; Nunberg, 1979, 1995). We reason that if each metonymy yields a distinct processing time course and substantially non-overlapping preferential localization pattern, it would not only support a two-mechanism view (one lexical, one pragmatic) but would suggest that conventionalization acts as a linguistic categorizer. By contrast, a similar behavior in time course and localization would support a one-mechanism view and the inference that conventionalization acts instead as a modulator of contextual felicitousness, and that differences in interpretation introduced by conventionalization are of degree, not of kind. Results from three paradigms: self-paced reading (SPR), event-related potentials (ERP), and functional magnetic resonance imaging (fMRI), reveal the following: no main effect by condition (metonymy vs. matched literal control) for either metonymy type immediately after the metonymy trigger, and a main effect for only the Circumstantial metonymy one word post-trigger (SPR); a N400 effect across metonymy types and a late positivity for Circumstantial metonymy (ERP); and a highly overlapping activation connecting the left ventrolateral prefrontal cortex and the left dorsolateral prefrontal cortex (fMRI). Altogether, the pattern observed does not reach the threshold required to justify a two-mechanism system. Instead, the pattern is more naturally (and conservatively) understood as resulting from the implementation of a generalized referential dependency mechanism, modulated by degree of context dependence/conventionalization, thus supporting architectures of language whereby "lexical" and "pragmatic" meaning relations are encoded along a cline of contextual underspecification.

A possible contributory mechanism for impaired idiom perception in schizophrenia

In this review, we focus on the ability of people with schizophrenia to correctly perceive the meaning of idioms; figurative language expressions in which intended meaning is not derived from the meaning of constituent words. We collate evidence on how idiom perception is impaired, ascertain the clinical relevance of this impairment, and consider possible psychological and neural mechanisms behind the impairment. In reviewing extant literature, we searched the PubMed database, from 1975-2014, focussing on articles that directly concerned schizophrenia and idioms, with follow up searches to explore the viability of possible underlying mechanisms. We learn that there is clear evidence of impairment, with a tendency to err towards literal interpretations unless the figurative meaning is salient, and despite contextual cues to figurative interpretations. Given the importance of idioms in everyday language, the potential impact is significant. Clinically, impaired idiom perception primarily relates to positive symptoms of schizophrenia, but also to negative symptoms. The origins of the impairment remain speculation, with impaired executive function, impaired semantic functions, and impaired context processing all proposed to explain the phenomenon. We conclude that a possible contributory mechanism at the neural level is an impaired dorsolateral prefrontal cortex system for cognitive control over semantic processing.

Impairments in proverb interpretation following focal frontal lobe lesions

The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal "executive" dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven's Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT.

The influence of semantic property and grammatical class on semantic selection

Research to-date has not successfully demonstrated consistent neural distinctions for different types of ambiguity or explored the effect of grammatical class on semantic selection. We conducted a relatedness judgment task using event-related functional magnetic resonance imaging (fMRI) to further explore these topics. Participants judged relatedness within word pairs. Consistent and inconsistent conditions were included along with filler items. Imaging results revealed a main effect of ambiguity in the dorsolateral prefrontal cortex (DLPFC) and parietal cortices. A main effect of grammatical class was observed in the parahippocampal and lingual gyri, and a main effect of consistency was found in the DLPFC, ventrolateral prefrontal cortex (VLPFC) and occipital cortices. Interactions among these factors were observed in the cingulate gyrus and motor cortices in addition to the DLPFC. These results suggest that both ambiguity type and grammatical class modulate semantic selection through different neural regions.

The role of the right hemisphere in metaphor comprehension: a meta-analysis of functional magnetic resonance imaging studies

The role of the right hemisphere (RH) in metaphor comprehension is still controversial. Numerous neuroimaging studies have found that conventionality, sentential context, and task demand can influence the involvement of the RH in metaphor processing. The current meta-analysis used foci from 17 original functional magnetic resonance imaging studies to identify what factors modulate the involvement of the RH in metaphor processing. Activation likelihood estimation was used for quantification. We focused on the contrast of metaphorical meaning processing versus literal meaning processing and calculated the meta-analysis effects when (1) metaphorical meaning is conventional, (2) metaphorical meaning is novel, (3) metaphorical and literal meaning are presented in words, (4) metaphorical and literal meaning are presented in sentential context, (5) task is valence judgment, and (6) task is semantic relatedness judgment. The results indicated that the RH only showed significant effects in metaphor processing when the metaphorical meaning is novel, when metaphorical meaning is presented in sentential context, and when the task is semantic relatedness judgment. The effects were located in right fronto-temporal regions, including inferior frontal gyrus, middle frontal gyrus, insula, superior temporal gyrus, and middle temporal gyrus. These results suggest that conventionality, contextual complexity, and task demand can modulate the effect of figurativeness and influence the involvement of RH in metaphor comprehension. The main role of the RH in metaphor processing is related with activating broad semantic fields and integrating concepts that may have distant semantic relations, and hence provide support for the view that the RH is responsible for processing coarse semantic information in language comprehension.

Old proverbs in new skins - an FMRI study on defamiliarization

We investigated how processing fluency and defamiliarization (the art of rendering familiar notions unfamiliar) contribute to the affective and esthetic processing of reading in an event-related functional magnetic-resonance-imaging experiment. We compared the neural correlates of processing (a) familiar German proverbs, (b) unfamiliar proverbs, (c) defamiliarized variations with altered content relative to the original proverb (proverb-variants), (d) defamiliarized versions with unexpected wording but the same content as the original proverb (proverb-substitutions), and (e) non-rhetorical sentences. Here, we demonstrate that defamiliarization is an effective way of guiding attention, but that the degree of affective involvement depends on the type of defamiliarization: enhanced activation in affect-related regions (orbito-frontal cortex, medPFC) was found only if defamiliarization altered the content of the original proverb. Defamiliarization on the level of wording was associated with attention processes and error monitoring. Although proverb-variants evoked activation in affect-related regions, familiar proverbs received the highest beauty ratings.

Pragmatic and executive functions in traumatic brain injury and right brain damage: An exploratory comparative study

OBJECTIVE

To describe the frequency of pragmatic and executive deficits in right brain damaged (RBD) and in traumatic brain injury (TBI) patients, and to verify possible dissociations between pragmatic and executive functions in these two groups.

METHODS

The sample comprised 7 cases of TBI and 7 cases of RBD. All participants were assessed by means of tasks from the Montreal Communication Evaluation Battery and executive functions tests including the Trail Making Test, Hayling Test, Wisconsin Card Sorting Test, semantic and phonemic verbal fluency tasks, and working memory tasks from the Brazilian Brief Neuropsychological Assessment Battery NEUPSILIN. Z-score was calculated and a descriptive analysis of frequency of deficits (Z< -1.5) was carried out.

RESULTS

RBD patients presented with deficits predominantly on conversational and narrative discursive tasks, while TBI patients showed a wider spread pattern of pragmatic deficits. Regarding EF, RBD deficits included predominantly working memory and verbal initiation impairment. On the other hand, TBI individuals again exhibited a general profile of executive dysfunction, affecting mainly working memory, initiation, inhibition, planning and switching. Pragmatic and executive deficits were generally associated upon comparisons of RBD patients and TBI cases, except for two simple dissociations: two post-TBI cases showed executive deficits in the absence of pragmatic deficits.

DISCUSSION

Pragmatic and executive deficits can be very frequent following TBI or vascular RBD. There seems to be an association between these abilities, indicating that although they can co-occur, a cause-consequence relationship cannot be the only hypothesis.

Severe traumatic brain injury, frontal lesions, and social aspects of language use: a study of French-speaking adults

The purpose of this study was to gain insight into the social (pragmatic) aspects of language use by French-speaking individuals with frontal lesions following a severe traumatic brain injury. Eleven participants with traumatic brain injury performed tasks in three areas of communication: production (interview situation), comprehension (direct requests, conventional indirect requests, and hints), and metapragmatic knowledge. The results of the patients pointed out some strengths (turn-taking in production, and request comprehension, including hints and the speaker's intention) and some weaknesses (topic maintenance in production and metapragmatic knowledge). The patients' good comprehension of requests and their difficulty expressing metapragmatic knowledge suggest that they differ from controls in how they "explain the world": their knowledge of the event sequence was not based on verbally expressible knowledge about the relationship between the structural characteristics of a request utterance and those of its social production context. The pragmatic skills of persons with traumatic brain injury seem to vary across tasks: these individuals have specific strengths and weaknesses in different domains. In addition, marked interindividual differences were noted among the patients: three of them had only one weak point, topic maintenance. These interindividual differences were not systematically linked to performance on executive function tests, but lesion unilaterality (right or left) seems to help preserve patients' pragmatic and metapragmatic skills. The discussion stresses the need to take each patient's strengths and weaknesses into account in designing remediation programs.

LEARNING OUTCOMES

As a result of this activity, the reader will be able to explain the social/pragmatic aspects of language in typical and atypical participants with TBI. As a result of this activity, the reader will be able to identify social/pragmatic weaknesses and strengths.

Nonliteral language in Alzheimer dementia: a review

The use of nonliteral language in clinical assessment, especially testing the patients' ability to interpret proverbs, has a long tradition in psychiatry. However, its diagnostic sensitivity and specificity in dementias is not yet clear. The aim of this review article is to examine the current evidence on nonliteral/figurative language (proverb, metaphor, metonymy, idiom, irony, sarcasm) comprehension in Alzheimer's disease and related disorders. A comprehensive literature search identified 25 studies (16 proverb, 3 metaphor, 0 metonymy, 5 idiom, 3 sarcasm) on nonliteral language comprehension in dementia. Studies predominantly indicate a deficit. Most studies investigated Alzheimer's dementia. Applied correctly, nonliteral language is a worthwhile diagnostic tool to evaluate language and abstract thinking in dementias. During assessment, familiarity testing (e.g., by asking "are you familiar with the proverb XY") is obligatory. Still, future research is needed in several areas: evidence on decline of nonliteral language over the course of the illness is limited. So far, almost no studies delineated proverb comprehension in high risk populations such as patients with mild cognitive impairment. Currently, there is a lack of studies addressing performance in direct comparison to relevant differential diagnosis like older-age depression, delirium, brain lesion, or other psychiatric conditions.