Nonliteral language in Alzheimer dementia: a review

How Does Understanding of Social Situations and Other's Intention Contribute to Idiom and Irony Comprehension in Autism Spectrum Disorder?

Background/Objectives: Figurative language is a central tool for enriching spoken and written languages, and it is important for building social relationships. Difficulties in figurative language understanding may impair social adjustment. Some studies have found more gaps in the understanding of irony and idioms among children with autism spectrum disorder (ASD) compared to those of their peers with typical development (TD). To date, no studies have examined the relationship between the ability to understand social situations (as a separate ability) and the ability to understand irony and idioms. The present study examined the roles of theory of mind (ToM) and social situation understanding in the comprehension of idioms and ironic criticism. Methods: The current study included 58 participants aged 8-11, including 28 children with high-functioning ASD and 30 children with TD matched by age, gender, and nonverbal intelligence. All the participants completed a ToM questionnaire that assesses their understanding of others' intentions, as well as a questionnaire pertaining to their comprehension of social situations, ironic criticism, and idioms. Results: TD children outperformed the autistic children in idiom and irony understanding, as well as in ToM and social situation understanding. Understanding social situations and ToM contributed to idiom and irony understanding, with ToM ability uniquely contributing to irony (but not to idiom) understanding. Path analysis revealed that social cognitive abilities mediated the link between group affiliation and vocabulary, affecting figurative language comprehension. Conclusions: The present study demonstrates that social cognition skills influence the ability to understand ironic criticism and idioms, mediating the association between vocabulary and figurative language comprehension.

Enhancing socio-communicative functions in an MCI patient with intra-nasal insulin: a case report

This report examines extended intra-nasal insulin treatment [INI] for an Insulin Resistant early Mild Cognitive Impairment [MCI] patient. Patient [EJ] also had medial temporal lobe [MTL] damage, poor short-term memory, significant irritability, and social and linguistic withdrawal at treatment start. Compared to baseline, nine months INI treatment increased grey matter volume, lowered beta-amyloid levels, and improved MCI and FAS scores. Patient also increased pragmatic capacities in social conversation and procedural memory. These findings align with results from prior clinical trials on INI and suggest that treatment can slow neurodegenerative disease progression in early MCI patients.

Figurative language processing in autism spectrum disorders: A review

Impairments in the broader domain of pragmatics are considered to be a defining feature of Autism Spectrum Disorders (ASD). A challenging aspect of pragmatic competence is the ability to process nonliteral language. Interestingly, previous studies in figurative language comprehension in ASD have demonstrated conflicting results regarding participants' performance. The main scientific debate focuses on the underlying skills which facilitate processing of nonliteral speech in ASD. Namely, Theory of Mind (ToM), language abilities and Executive functions (EFs) are regarded as factors affecting autistic individuals' performance. This review addresses figurative language comprehension in ASD in light of the above three interpretive accounts. We reviewed data from recent studies in this field concluding that autistic children indeed encounter systematic difficulties in the processing of non-literal language. Moreover, only ToM and verbal skills were found to correlate the most with figurative language comprehension in ASD. Notably, we found that differences related to research methodology and tasks' properties may have led to discrepancies between studies' results. Finally, we argue that future studies should encompass in their experimental design figurative comprehension tasks with minimal linguistic demands and also measures of ToM, verbal ability and EFs in order to shed more light in the independent contribution of those skills to the processing of nonliteral language in ASD.

Proverb comprehension in schizophrenia: A comprehensive review and meta-analysis.2

BACKGROUND

Examination of proverb comprehension has a long tradition in clinical diagnostics of individuals with schizophrenia (iSCZ). Deficits in the comprehension are considered common. Interpretations of proverbs are traditionally measured by their degree of abstraction and concreteness ('literalness'), but iSCZ's responses may also be illogical or 'bizarre'. Experimental research on proverb comprehension starts in the 1940s. Since then, the specificity of proverb tests has often been questioned, but has never been the subject of a meta-analysis. The aim of this meta-analysis is to include all experimental research, including historical studies, that meets quality criteria and compares the responses to proverbs in iSCZ with those in healthy controls (HC) or clinical controls (CC).

METHODS

PubMed, Web of Science, and PsycInfo databases were searched. After coding 121 articles, 27 (median publication year 1982) were included and multi-level meta-analyses performed. Moderator analyses were performed on response format (multiple-choice vs. verbal responses), proverb test, scoring method, language, acute vs. chronic stage of iSCZ, time of publication, clinical vs. healthy control group, age, IQ/education, and gender. Publication bias was assessed using funnel plots, trim and fill method and Egger's test.

RESULTS

The search identified 27 eligible studies for inclusion. Studies were published between 1956 and 2020 and predominantly older than 30 years (median: 1982). The Gorham Proverbs Test was the most established test and predominantly conducted in English. CC mostly consisted of depressive disorders. Pooled estimates yielded statistically significant less abstract (g = -1.00; 95%CI, -1.34 to -1.67), more concrete (g = 0.69; 95%CI, 0.35-1.03), and more bizarre (g = 1.08; 95%CI, 0.74-1.41) responses in iSCZ compared to controls. The type of control group moderated all three effects, with greater differences of iSCZ compared to HC than to CC in abstraction and bizarreness, and no significant group difference between iSCZ and CC in concreteness. Meta-regressions indicated IQ/education and age as possible sources of variability in abstraction and bizarreness.

CONCLUSIONS

While lower abstraction and higher bizarreness seems a characteristic of iSCZ, the diagnostic specificity of a concrete response was astonishingly low. The lack of a unified definition for concretism and limited consideration of cultural diversity contributed to these complex findings. Future research should focus on exploring the qualitative aspects of proverb comprehension and the association between symptomatology types and misinterpretations to improve diagnostic accuracy.

Speech and language markers of neurodegeneration: a call for global equity

In the field of neurodegeneration, speech and language assessments are useful for diagnosing aphasic syndromes and for characterizing other disorders. As a complement to classic tests, scalable and low-cost digital tools can capture relevant anomalies automatically, potentially supporting the quest for globally equitable markers of brain health. However, this promise remains unfulfilled due to limited linguistic diversity in scientific works and clinical instruments. Here we argue for cross-linguistic research as a core strategy to counter this problem. First, we survey the contributions of linguistic assessments in the study of primary progressive aphasia and the three most prevalent neurodegenerative disorders worldwide-Alzheimer's disease, Parkinson's disease, and behavioural variant frontotemporal dementia. Second, we address two forms of linguistic unfairness in the literature: the neglect of most of the world's 7000 languages and the preponderance of English-speaking cohorts. Third, we review studies showing that linguistic dysfunctions in a given disorder may vary depending on the patient's language and that English speakers offer a suboptimal benchmark for other language groups. Finally, we highlight different approaches, tools and initiatives for cross-linguistic research, identifying core challenges for their deployment. Overall, we seek to inspire timely actions to counter a looming source of inequity in behavioural neurology.

The scope of using pragmatic language tests for early detection of dementia: A systematic review of investigations using figurative language

INTRODUCTION

Dementia cases are expected to rise to 81.1 million in 2040. Efforts are underway to develop diagnostic methods to facilitate early detection of the disease. Herein we review research findings focusing on pragmatic dysfunction in patients with dementia and evaluate the usefulness of assessing dementia and its progress with a battery of tests assessing figurative language skills.

METHODS

A total of 74,778 article titles were identified from EMBASE, PubMed, and Google Scholar databases. After systematic screening, 51 journal articles were selected for the final review.

RESULT

The review suggests that impaired figurative language might be a marker for early cognitive decline. Different forms of figurative language may be impaired at different stages of the disease and in different types of dementia involving different neuropathologies.

CONCLUSION

The use of pragmatic tests in combination with the existing diagnostic protocols might increase the probability of early diagnosis. HIGHLIGHTS Pragmatic impairment could be a marker of early cognitive impairment. Figurative language-an important pragmatic aspect-is disrupted in mild cognitive impairment (MCI) and early Alzheimer's disease (AD). Figurative language impairment might precede literal language impairment. Pragmatic tests could be more sensitive than standard neuropsychological tests. Inclusion of pragmatic tests in diagnostic guidelines might bolster early detection.

Beyond Last Words: Patterns of Linguistic and Interactional Behavior in a Historical Sample of Dying Hospital Patients

Patterns of linguistic and interactional behavior by people at the very end of their lives are not well described, partly because data is difficult to obtain. This paper analyzes descriptions of 486 deaths gathered from 1900 to 1904 in the first-ever clinical study of dying by noted Canadian physician, Sir William Osler. Only 16 patients were noted speaking, and only four canonical last words were reported. The most frequent observation by medical staff was that the deaths were quiet (n = 30), though range of other behaviors were noted (e.g., moaning, delirium, seeming intention to speak). Osler's problematic study left behind data whose analysis is a small step toward empirically characterizing the linguistic and interactional details of a previously under-described phenomena as well as the importance of the social context in which they occur.

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.

On the Role of Bilateral Brain Hypofunction and Abnormal Lateralization of Cortical Information Flow as Neural Underpinnings of Conventional Metaphor Processing Impairment in Schizophrenia: An fMRI and EEG Study

Figurative language processing (e.g. metaphors) is commonly impaired in schizophrenia. In the present study, we investigated the neural activity and propagation of information within neural circuits related to the figurative speech, as a neural substrate of impaired conventional metaphor processing in schizophrenia. The study included 30 schizophrenia outpatients and 30 healthy controls, all of whom were assessed with a functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) punchline-based metaphor comprehension task including literal (neutral), figurative (metaphorical) and nonsense (absurd) endings. The blood oxygenation level-dependent signal was recorded with 3T MRI scanner and direction and strength of cortical information flow in the time course of task processing was estimated with a 64-channel EEG input for directed transfer function. The presented results revealed that the behavioral manifestation of impaired figurative language in schizophrenia is related to the hypofunction in the bilateral fronto-temporo-parietal brain regions (fMRI) and various differences in effective connectivity in the fronto-temporo-parietal circuit (EEG). Schizophrenia outpatients showed an abnormal pattern of connectivity during metaphor processing which was related to bilateral (but more pronounced at the left hemisphere) hypoactivation of the brain. Moreover, we found reversed lateralization patterns, i.e. a rightward-shifted pattern during metaphor processing in schizophrenia compared to the control group. In conclusion, the presented findings revealed that the impairment of the conventional metaphor processing in schizophrenia is related to the bilateral brain hypofunction, which supports the evidence on reversed lateralization of the language neural network and the existence of compensatory recruitment of alternative neural circuits in schizophrenia.

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.

Embodiment and personal identity in dementia

Theories of personal identity in the tradition of John Locke and Derek Parfit emphasize the importance of psychological continuity and the abilities to think, to remember and to make rational choices as a basic criterion for personhood. As a consequence, persons with severe dementia are threatened to lose the status of persons. Such concepts, however, are situated within a dualistic framework, in which the body is regarded as a mere vehicle of the person, or a carrier of the brain as the organ of mental faculties. Based on the phenomenology of embodiment, this paper elaborates a different approach to personal identity in dementia. In this perspective, selfhood is primarily constituted by pre-reflective self-awareness and the body memory of an individual, which consists in the embodiment and enactment of familiar habits, practices and preferences. After describing the different types of body memory, the paper develops a phenomenology of dementia as a loss of reflexivity and meta-perspective. This is contrasted with the preservation of individual forms of body memory even in the later stages of the illness. The ethical consequences of an embodied approach to dementia are outlined. A final look is given to narrativistic and constructionist concepts of the self in dementia.

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.

Familiarity, empathy and comprehension of metaphors in patients with borderline personality disorder

Research on figurative language has a long tradition in psychiatry, as it is employed in psychotherapy and its (mis)comprehension plays a substantial role in differential diagnostics of schizophrenic spectrum disorders. Although often associated with empathy and mentalization, it has never been addressed in borderline personality disorder (BPD). Therefore, this study investigated metaphor comprehension and its relationship to cognitive and affective empathy in 20 patients with BPD and 20 matched healthy controls who completed a metaphor task comprising conventional metaphors (CM), novel metaphors (NM), meaningless stimuli (MS), and a rating scale of familiarity, a factor known to influence performance. For cognitive and affective empathy, the interpersonal reactivity index was applied. At first patients with BPD seemed to have significantly more problems in comprehending CM, but not NM or MS, and were less familiar with CM. When familiarity with the stimulus was controlled, this difference disappeared. As for empathy, only fantasy was positively related to familiar CM beyond borderline symptoms. Results indicate that the comprehension of novel metaphorical meaning is preserved in patients with BPD.

Developmental Steps in Metaphorical Language Abilities: The Influence of Age, Gender, Cognitive Flexibility, Information Processing Speed, and Analogical Reasoning

PURPOSE

Metaphor is a specific type of figurative language that is used in various important fields such as in the work with children in clinical or teaching contexts. The aim of the study was to investigate the developmental course, developmental steps, and possible cognitive predictors regarding metaphor processing in childhood and early adolescence.

METHOD

One hundred sixty-four typically developing children (7-year-olds, 9-year-olds) and early adolescents (11-year-olds) were tested for metaphor identification, comprehension, comprehension quality, and preference by the Metaphoric Triads Task as well as for analogical reasoning, information processing speed, cognitive flexibility under time pressure, and cognitive flexibility without time pressure.

RESULTS

Metaphor identification and comprehension consecutively increased with age. Eleven-year-olds showed significantly higher metaphor comprehension quality and preference scores than seven- and nine-year-olds, whilst these younger age groups did not differ. Age, cognitive flexibility under time pressure, information processing speed, analogical reasoning, and cognitive flexibility without time pressure significantly predicted metaphor comprehension.

CONCLUSIONS

Metaphorical language ability shows an ongoing development and seemingly changes qualitatively at the beginning of early adolescence. These results can possibly be explained by a greater synaptic reorganization in early adolescents. Furthermore, cognitive flexibility under time pressure and information processing speed possibly facilitate the ability to adapt metaphor processing strategies in a flexible, quick, and appropriate way.

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.

A New Test for Irony Detection: The Influence of Schizotypal, Borderline, and Autistic Personality Traits

Irony has repeatedly been suggested as a language based social cognition task. It has been argued to show specific variances in psychiatric disorders and healthy adults with certain personality traits. Above that, irony comprehension is based on a complex interplay of the informational context, the relationship of the conversational partners, and the personality of the recipient. The present study developed a video-based German language test for a systematic examination of irony detection accuracy (Tuerony). The test includes (i) a stereotypical conversation partner (doctor, actor) in (ii) different perspectives (direct interaction, neutral observer) and (iii) a bilateral chat history on a conventional messenger service interface with ironic criticism, ironic praise, literal criticism, and literal praise. Based on the continuous approach of psychiatric symptoms, schizotypal, borderline, and autistic personality traits were associated with irony detection accuracy in a healthy sample. Given the often reported role of mentalization in irony detection, these associations were also investigated. First, a broad variance of irony comprehension in our healthy sample could be shown. Second, schizotypal and borderline, but not autistic traits were significantly negatively associated with irony detection accuracy. Finally, in the current healthy sample, neither variation of the conversational context nor mentalization characteristics were significantly associated with performance beyond personality traits. The current results therefore highlight two aspects for future research in irony comprehension: the importance of ecological valid tests and the role of the individual personality of the recipient.

Figurative language comprehension in individuals with autism spectrum disorder: A meta-analytic review

We present a meta-analysis of studies that compare figurative language comprehension in individuals with autism spectrum disorder and in typically developing controls who were matched based on chronological age or/and language ability. A total of 41 studies and 45 independent effect sizes were included based on predetermined inclusion criteria. Group matching strategy, age, types of figurative language, and cross-linguistic differences were examined as predictors that might explain heterogeneity in effect sizes. Overall, individuals with autism spectrum disorder showed poorer comprehension of figurative language than their typically developing peers (Hedges' g = -0.57). A meta-regression analysis showed that group matching strategy and types of figurative language were significantly related to differences in effect sizes, whereas chronological age and cross-linguistic differences were not. Differences between the autism spectrum disorder and typically developing groups were small and nonsignificant when the groups were matched based on the language ability. Metaphors were more difficult to comprehend for individuals with autism spectrum disorder compared with typically developing controls than were irony and sarcasm. Our findings highlight the critical role of core language skills in figurative language comprehension. Interventions and educational programmes designed to improve social communication skills in individuals with autism spectrum disorder may beneficially target core language skills in addition to social skills.

The Comprehension of Familiar and Novel Metaphoric Meanings in Schizophrenia: A Pilot Study

Miscomprehension of nonliteral (“figurative”) language like metaphors, proverbs, idioms, and ironic expressions by patients with schizophrenia is a phenomenon mentioned already in historical psychiatric descriptions. However, it was only recently that studies did differentiate between novel and conventional metaphors, a factor that is known to influence the difficulty of comprehension in healthy subjects. Further, familiarity with stimuli is an important factor for comprehension, which was not recommended in utmost previous studies. In this study, 23 patients with DSM IV schizophrenia and 19 healthy control subjects performed a newly-developed German metaphor comprehension test with three types of stimuli: novel metaphors, conventional German metaphors, and meaningless statements. During the test procedure, participants indicated familiarity with the stimulus and then matched the meaning with one out of four given alternatives. Familiarity rankings did not significantly differ between patients and control subjects. However, on descriptive level, there was a tendency for healthy controls to be more familiar with conventional metaphors than schizophrenic patients. Further, comprehension of conventional and novel metaphors differed significantly between the groups, with higher performance in healthy controls. Considering only those metaphors that had been ranked as familiar, patients only revealed significant lower performance opposed to controls regarding novel metaphors, while they did not differ in conventional metaphors. Taken together, the results indicate that patients with schizophrenia might show an altered way of comprehension in novel metaphors, leading to more misunderstandings. However, their previously reported impairments in conventional metaphors might rather be due to a lack of familiarity with the stimuli—making conventional metaphors to novel metaphors in the individual case.

Linguistic Features Identify Alzheimer's Disease in Narrative Speech

BACKGROUND

Although memory impairment is the main symptom of Alzheimer's disease (AD), language impairment can be an important marker. Relatively few studies of language in AD quantify the impairments in connected speech using computational techniques.

OBJECTIVE

We aim to demonstrate state-of-the-art accuracy in automatically identifying Alzheimer's disease from short narrative samples elicited with a picture description task, and to uncover the salient linguistic factors with a statistical factor analysis.

METHODS

Data are derived from the DementiaBank corpus, from which 167 patients diagnosed with "possible" or "probable" AD provide 240 narrative samples, and 97 controls provide an additional 233. We compute a number of linguistic variables from the transcripts, and acoustic variables from the associated audio files, and use these variables to train a machine learning classifier to distinguish between participants with AD and healthy controls. To examine the degree of heterogeneity of linguistic impairments in AD, we follow an exploratory factor analysis on these measures of speech and language with an oblique promax rotation, and provide interpretation for the resulting factors.

RESULTS

We obtain state-of-the-art classification accuracies of over 81% in distinguishing individuals with AD from those without based on short samples of their language on a picture description task. Four clear factors emerge: semantic impairment, acoustic abnormality, syntactic impairment, and information impairment.

CONCLUSION

Modern machine learning and linguistic analysis will be increasingly useful in assessment and clustering of suspected AD.

Speaking in Alzheimer's Disease, is That an Early Sign? Importance of Changes in Language Abilities in Alzheimer's Disease

It is known that Alzheimer’s disease (AD) influences the temporal characteristics of spontaneous speech. These phonetical changes are present even in mild AD. Based on this, the question arises whether an examination based on language analysis could help the early diagnosis of AD and if so, which language and speech characteristics can identify AD in its early stage. The purpose of this article is to summarize the relation between prodromal and manifest AD and language functions and language domains. Based on our research, we are inclined to claim that AD can be more sensitively detected with the help of a linguistic analysis than with other cognitive examinations. The temporal characteristics of spontaneous speech, such as speech tempo, number of pauses in speech, and their length are sensitive detectors of the early stage of the disease, which enables an early simple linguistic screening for AD. However, knowledge about the unique features of the language problems associated with different dementia variants still has to be improved and refined.

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.

Are There Any Connections between Language Deficits and Cognitive Slowing in Alzheimer's Disease?

Background

Speech disorders already occur in the early phases of Alzheimer's disease (AD). As a possible cause, problems of executive processes are discussed. Cognitive slowing is also repeatedly addressed.

Aims

Are there any connections between cognitive slowing and speech disorders in AD? And is there a relationship between cognitive slowing and executive processes?

Methods

The data of 72 healthy controls and 52 AD patients were examined with regard to their language performance and their response times in a computerized Stroop paradigm.

Results

The AD patients showed significantly worse results in all language tests as well as much longer reaction times in all Stroop conditions, especially in the interference condition (Stroop 3). Speech errors and response times correlated with severity (MMSE), and the speech errors correlated with the reaction times in Stroop 3 (interference condition, which reflects the processing time of executive processes).

Conclusion

The most interesting question now is: How are language processing and executive processing time (Stroop 3) related?

The importance of being apt: metaphor comprehension in Alzheimer's disease

We investigated the effect of aptness in the comprehension of copular metaphors (e.g., Lawyers are sharks) by Alzheimer's Disease (AD) patients. Aptness is the extent to which the vehicle (e.g., shark) captures salient properties of the topic (e.g., lawyers). A group of AD patients provided interpretations for metaphors that varied both in aptness and familiarity. Compared to healthy controls, AD patients produced worse interpretations, but interpretation ability was related to a metaphor's aptness rather than to its familiarity level, and patients with superior abstraction ability produced better interpretations. Therefore, the ability to construct figurative interpretations for metaphors is not always diminished in AD patients nor is it dependent only on the novelty level of the expression. We show that Alzheimer's patients' capacity to build figurative interpretations for metaphors is related to both item variables, such as aptness, and participant variables, such as abstraction ability.

Non-literal language deficits in mild cognitive impairment

BACKGROUND

Verbal language deteriorates in Alzheimer's disease, contributing to dramatic disturbances in the ability to communicate. The presence of language disturbances may be detected at earlier phases of the neurodegenerative process, like mild cognitive impairment (MCI). In daily verbal interactions, people mostly use literal language, but sometimes they employ non-literal language, which requires listeners to interpret messages beyond the plain meaning of the words and can be quite demanding. In the present study, we tested the hypotheses that patients with MCI may have deficits in non-literal language, and these deficits are more pronounced than deficits in literal language.

METHODS

Participants were recruited in a private memory clinic and senior universities. General cognitive evaluation included a comprehensive neuropsychological battery, the Mini-Mental State Examination, and the instrumental activities of daily living scale. Literal language was assessed with the semantic decision test, Token Test, and literal text comprehension test, and non-literal language with the proverbs comprehension, idiomatic expressions and non-literal text comprehension tests.

RESULTS

Fifty-two participants with MCI and 31 controls were recruited. Patients with MCI had lower scores in all complex language tests, both literal (Token Test, semantic decision and literal text) and non-literal (proverbs, idiomatic expressions, and non-literal text), than the controls; the difference in literal text score was marginally significant. As much as 69% of MCI participants had deficits (performance below 1.5 SD of the mean) on at least one of the complex language tasks. Deficits were more frequent on the proverbs comprehension and semantic decision tests, and the deficits on these tests did not significantly differ from that on the Token Test.

CONCLUSION

Patients with MCI are hindered in understanding complex language, both literal and non-literal. In daily living, these complex language deficits could compromise effective verbal interactions with the others. Amelioration of these deficits should be an important intervention target as part of a comprehensive rehabilitation strategy for patients with cognitive decline.

Irony and proverb comprehension in schizophrenia: do female patients "dislike" ironic remarks?

Difficulties in understanding irony and sarcasm are part of the social cognition deficits in patients with schizophrenia. A number of studies have reported higher error rates during comprehension in patients with schizophrenia. However, the relationships of these impairments to schizotypal personality traits and other language deficits, such as the comprehension of proverbs, are unclear. We investigated irony and proverb comprehension in an all-female sample of 20 schizophrenia patients and 27 matched controls. Subjects indicated if a statement was intended to be ironic, literal, or meaningless and furthermore rated the meanness and funniness of the stimuli and certainty of their decision. Patients made significantly more errors than controls did. Globally, there were no overall differences in the ratings. However, patients rated the subgroup of stimuli with answers given incorrectly as having significantly less meanness and in case of an error indicated a significantly higher certainty than controls. Across all of the study participants, performances in irony (r = -0.51) and proverb (r = 0.56) comprehension were significantly correlated with schizotypal personality traits, suggesting a continuum of nonliteral language understanding. Because irony is so frequent in everyday conversations, this makes irony an especially promising candidate for social cognition training in schizophrenia.

Development of metaphors to explain cognitive behavioural principles for patients with medically unexplained symptoms in Sri Lanka

BACKGROUND

Medically unexplained symptoms (MUS) are common in primary care across cultures, accounting for high consultations with multiple providers and unnecessary investigations. Cognitive behavioural therapy (CBT) is efficacious for MUS and reduces physical symptoms, psychological distress and disability. Two intervention trials by the author and his group remain the only reported trials from the developing world.

MATERIAL

A treatment package was designed by modifying a CBT model. The modifications were innovative use of locally relevant appropriate language and strategies that were simple enough while conforming to the CBT principles. The aim was to convey the principles of CBT to people using simple techniques--using metaphor. These are described in the paper as generic metaphors that could be used to explain the CBT principles and specific ones for patients with MUS.

DISCUSSION

Metaphor is an effective clinical tool. The author's clinical experience and patients' feedback suggest that these metaphors are helpful in conveying the CBT principles to patients. To develop metaphors appealing to the client and effective clinically, carrying out qualitative research among patients' explanatory model is an important prerequisite. The generic and MUS-specific metaphors reported here should be tried in other cultural and clinical settings and evaluated. Further systematic work including qualitative work for consensus evaluation among CBT experts as well as opinion on user-friendliness of these techniques tested among CBT practitioners will be needed.

Beyond the N400: complementary access to early neural correlates of novel metaphor comprehension using combined electrophysiological and haemodynamic measurements

The simultaneous application of different neuroimaging methods combining high temporal and spatial resolution can uniquely contribute to current issues and open questions in the field of pragmatic language perception. In the present study, comprehension of novel metaphors was investigated using near-infrared spectroscopy (NIRS) combined with the simultaneous acquisition of electroencephalography (EEG)/event-related potentials (ERPs). For the first time, we investigated the effects of figurative language on early electrophysiological markers (P200, N400) and their functional relationship to cortical haemodynamic responses within the language network (Broca's area, Wernicke's area). To this end, 20 healthy subjects judged 120 sentences with respect to their meaningfulness, whereby phrases were either literal, metaphoric, or meaningless. Our results indicated a metaphor-specific P200 reduction and a linear increase of N400 amplitudes from literal over metaphoric to meaningless sentences. Moreover, there were metaphor related effects on haemodynamic responses accessed with NIRS, especially within the left lateral frontal cortex (Broca's area). Significant correlations between electrophysiological and haemodynamic responses indicated that P200 reductions during metaphor comprehension were associated with an increased recruitment of neural activity within left Wernicke's area, indicating a link between variations in neural activity and haemodynamic changes within Wernicke's area. This link may reflect processes related to interindividual differences regarding the ability to classify novel metaphors. The present study underlines the usefulness of simultaneous NIRS measurements in language paradigms - especially for investigating the functional significance of neurophysiological markers that have so far been rarely examined - as these measurements are easily and efficiently realizable and allow for a complementary examination of neural activity and associated metabolic changes in cortical areas.

Isn't it ironic? Neural correlates of irony comprehension in schizophrenia

Ironic remarks are frequent in everyday language and represent an important form of social cognition. Increasing evidence indicates a deficit in comprehension in schizophrenia. Several models for defective comprehension have been proposed, including possible roles of the medial prefrontal lobe, default mode network, inferior frontal gyri, mirror neurons, right cerebral hemisphere and a possible mediating role of schizotypal personality traits. We investigated the neural correlates of irony comprehension in schizophrenia by using event-related functional magnetic resonance imaging (fMRI). In a prosody-free reading paradigm, 15 female patients with schizophrenia and 15 healthy female controls silently read ironic and literal text vignettes during fMRI. Each text vignette ended in either an ironic (n = 22) or literal (n = 22) statement. Ironic and literal text vignettes were matched for word frequency, length, grammatical complexity, and syntax. After fMRI, the subjects performed an off-line test to detect error rate. In this test, the subjects indicated by button press whether the target sentence has ironic, literal, or meaningless content. Schizotypal personality traits were assessed using the German version of the schizotypal personality questionnaire (SPQ). Patients with schizophrenia made significantly more errors than did the controls (correct answers, 85.3% vs. 96.3%) on a behavioural level. Patients showed attenuated blood oxygen level-dependent (BOLD) response during irony comprehension mainly in right hemisphere temporal regions (ironic>literal contrast) and in posterior medial prefrontal and left anterior insula regions (for ironic>visual baseline, but not for literal>visual baseline). In patients with schizophrenia, the parahippocampal gyrus showed increased activation. Across all subjects, BOLD response in the medial prefrontal area was negatively correlated with the SPQ score. These results highlight the role of the posterior medial prefrontal and right temporal regions in defective irony comprehension in schizophrenia and the mediating role of schizotypal personality traits.

What dementia reveals about proverb interpretation and its neuroanatomical correlates

OBJECTIVE

Neuropsychologists frequently include proverb interpretation as a measure of executive abilities. A concrete interpretation of proverbs, however, may reflect semantic impairments from anterior temporal lobes, rather than executive dysfunction from frontal lobes. The investigation of proverb interpretation among patients with different dementias with varying degrees of temporal and frontal dysfunction may clarify the underlying brain-behavior mechanisms for abstraction from proverbs. We propose that patients with behavioral variant frontotemporal dementia (bvFTD), who are characteristically more impaired on proverb interpretation than those with Alzheimer's disease (AD), are disproportionately impaired because of anterior temporal-mediated semantic deficits.

METHODS

Eleven patients with bvFTD and 10 with AD completed the Delis-Kaplan Executive Function System (D-KEFS) Proverbs Test and a series of neuropsychological measures of executive and semantic functions. The analysis included both raw and age-adjusted normed data for multiple choice responses on the D-KEFS Proverbs Test using independent samples t-tests. Tensor-based morphometry (TBM) applied to 3D T1-weighted MRI scans mapped the association between regional brain volume and proverb performance. Computations of mean Jacobian values within select regions of interest provided a numeric summary of regional volume, and voxel-wise regression yielded 3D statistical maps of the association between tissue volume and proverb scores.

RESULTS

The patients with bvFTD were significantly worse than those with AD in proverb interpretation. The worse performance of the bvFTD patients involved a greater number of concrete responses to common, familiar proverbs, but not to uncommon, unfamiliar ones. These concrete responses to common proverbs correlated with semantic measures, whereas concrete responses to uncommon proverbs correlated with executive functions. After controlling for dementia diagnosis, TBM analyses indicated significant correlations between impaired proverb interpretation and the anterior temporal lobe region (left>right).

CONCLUSIONS

Among two dementia groups, those with bvFTD, demonstrated a greater number of concrete responses to common proverbs compared to those with AD, and this performance correlated with semantic deficits and the volume of the left anterior lobe, the hub of semantic knowledge. The findings of this study suggest that common proverb interpretation is greatly influenced by semantic dysfunction and that the use of proverbs for testing executive functions needs to include the interpretation of unfamiliar proverbs.

Communicative competence in Alzheimer's disease: metaphor and sarcasm comprehension

The purpose of this study was to evaluate the deficits of metaphor and sarcasm comprehension in Alzheimer's disease (AD), as pragmatic interpretation such as metaphor and sarcasm comprehension is required in social communication. A total of 31 young normal controls, 104 aged normal controls (ANC), 42 patients with amnesic mild cognitive impairment (aMCI), and 30 patients with mild AD were evaluated by Metaphoric and Sarcastic Scenario Test, which consists of 5 metaphoric and 5 sarcastic questions with 5 answer choices. Scores were analyzed using the repeated measures analysis of variance (metaphor/sarcasm vs 4 participant groups). Sarcasm comprehension, which requires second-order Theory of Mind (ToM), started to deteriorate in ANC, and metaphor comprehension, which requires first-order ToM, started to deteriorate in aMCI, and both deteriorated as disease progressed. Literal interpretation of pragmatic language is characteristic in patients with mild AD. Such misinterpretation would result in social miscommunication, even if they still retained semantic-lexical competence.

Neuropsychology of Alzheimer's disease

The expression of neurodegenerative diseases can be categorized into three main symptomatic domains: neurological, cognitive and, neuropsychiatric. This review focuses on the cognitive profile and neuropsychological assessment of Alzheimer's disease (AD). The topography and progression of brain neuropathology determines the cognitive expression of the disease. Thus, in accordance with the initial involvement of the medial temporal lobe, cognitive changes in AD start with specific difficulties in encoding and storage of new information. This particular memory deficit can be optimally detected with memory tests that enhance mnemonic retrieval by means of encoding specificity technique such as the Free and Cued Selective Reminding Test (FCSRT). Along the course of the disease, the neuropathology spreads to association cortices, and other neuropsychological deficits can be detected. A comprehensive neuropsychological examination encompassing several cognitive domains can provide a pattern of altered and preserved functions that is helpful to early detection, differential diagnosis and even prognosis of progression in predementia stages. The use of adapted and standardized instruments is necessary to properly estimate cognitive and functional performance in AD.

Neural correlates of metonymy resolution

Metonymies are exemplary models for complex semantic association processes at the sentence level. We investigated processing of metonymies using event-related functional magnetic resonance imaging (fMRI). During an 1.5Tesla fMRI scan, 14 healthy subjects (12 female) read 124 short German sentences with either literal (like "Africa is arid"), metonymic ("Africa is hungry"), or nonsense ("Africa is woollen") content. Sentences were constructed so that they obey certain grammatical, semantic, and plausibility conditions and were matched for word frequency, semantic association, length and syntactic structure. We concentrated on metonymies that were not yet fossilised; we also examined a wide variety of metonymic readings. Reading metonymies relative to literal sentences revealed signal changes in a predominantly left-lateralised fronto-temporal network with maxima in the left and right inferior frontal as well as left middle temporal gyri. Left inferior frontal activation may reflect both inference processes and access to world knowledge during metonymy resolution.