Decomposing metaphor processing at the cognitive and neural level through functional magnetic resonance imaging

Weighing the role of social cognition and executive functioning in pragmatics in the schizophrenia spectrum: A systematic review and meta-analysis

Pragmatic impairment is diffused in schizophrenia spectrum disorders, but the literature still debates its neurocognitive underpinnings. This systematic review and meta-analysis aimed to investigate the neurocognitive correlates of pragmatic disorders in schizophrenia and determine the weight of social cognition and executive functioning on such disorders. Of the 2,668 records retrieved from the literature, 16 papers were included in the systematic review, mostly focused on non-literal meanings and discourse production in schizophrenia. Ten studies were included in the meta-analysis: pragmatics was moderately associated with both social cognition and executive functions (especially inhibition), but the link with social cognition was stronger. The mediation analysis showed that social cognition mediated the relationship between executive functions and pragmatics. Based on this, we proposed a hierarchical neurocognitive model where pragmatics stems from social cognition, while executive functions are the fertile ground supporting the other two domains, and we discuss its theoretical and clinical implications.

Changed brain entropy and functional connectivity patterns induced by electroconvulsive therapy in majoy depression disorder

OBJECTIVE

Our objective is to innovatively integrate both linear and nonlinear characteristics of brain signals in Electroconvulsive Therapy (ECT) research, with the goal of uncovering deeper insights into the pathogenesis of Major Depressive Disorder (MDD) and identifying novel targets for other physical intervention therapies.

METHODS

We measured brain entropy (BEN) in 42 MDD patients and 42 matched healthy controls (HC) using rs-fMRI data. Brain regions that differed significantly in patients with MDD before and after ECT were extracted. Then, we use these brain regions as seed points to investigate the differences in whole-brain resting-state functional connectivity (RSFC) patterns before and after ECT.

RESULTS

Compared to HCs, patients had higher BEN levels in the right precuneus (PCUN.R) and right angular gyrus (ANG.R). After ECT, patients had lower BEN levels in the PCUN.R and ANG.R. Compared with before ECT, patients showed significantly increased RSFC after ECT between the PCUN.R and right middle temporal gyrus and ANG.R. Significantly increased RSFC was observed between the ANG.R and right middle frontal gyrus and right supramarginal gyrus after ECT.

CONCLUSION

Combining the linear and nonlinear characteristics of brain signals can effectively explore the pathogenesis of depression and provide new targets for ECT.

What does metaphoric language say about aggression? The relationships between metaphoric language, impulsivity, and aggression

Aggressive behavior among adolescents has been identified as a serious worldwide problem, especially when combined with trait impulsivity. This study investigates the impact of an overlooked aspect of language, namely, metaphor comprehension, on impulsivity and aggression in adolescents. A total of 204 adolescents completed self-reported questionnaires assessing impulsivity and aggression and underwent tests assessing familiar and less familiar metaphor comprehension. The findings reveal inverse relationships between metaphor comprehension and both impulsivity and aggression. Regarding aggression, notable distinctions were observed in the correlations between familiar and less familiar metaphors with specific aggression types. Additionally, impulsivity was found to mediate the relationship between the comprehension of familiar metaphors and aggression. These results are elucidated in the context of cognitive and executive functions, emphasizing the significance of considering metaphor comprehension as a cognitive process capable of modulating aggressive behavior.

Neural network of metaphor comprehension: an ALE meta-analysis and MACM analysis

The comprehension of metaphor, a vivid and figurative language, is a complex endeavor requiring cooperation among multiple cognitive systems. There are still many important questions regarding neural mechanisms implicated in specific types of metaphor. To address these questions, we conducted activation likelihood estimation meta-analyses on 30 studies (containing data of 480 participants) and meta-analytic connectivity modeling analyses. First, the results showed that metaphor comprehension engaged the inferior frontal gyrus, middle temporal gyrus, fusiform gyrus, lingual gyrus, and middle occipital gyrus-all in the left hemisphere. In addition to the commonly reported networks of language and attention, metaphor comprehension engaged networks of visual. Second, sub-analysis showed that the contextual complexity can modulate figurativeness, with the convergence on the left fusiform gyrus during metaphor comprehension at discourse-level. Especially, right hemisphere only showed convergence in studies of novel metaphors, suggesting that the right hemisphere is more associated with difficulty than metaphorical. The work here extends knowledge of the neural mechanisms underlying metaphor comprehension in individual brain regions and neural networks.

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

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

Non-literal language processing is jointly supported by the language and theory of mind networks: Evidence from a novel meta-analytic fMRI approach

Going beyond the literal meaning of language is key to communicative success. However, the mechanisms that support non-literal inferences remain debated. Using a novel meta-analytic approach, we evaluate the contribution of linguistic, social-cognitive, and executive mechanisms to non-literal interpretation. We identified 74 fMRI experiments (n = 1,430 participants) from 2001 to 2021 that contrasted non-literal language comprehension with a literal control condition, spanning ten phenomena (e.g., metaphor, irony, indirect speech). Applying the activation likelihood estimation approach to the 825 activation peaks yielded six left-lateralized clusters. We then evaluated the locations of both the individual-study peaks and the clusters against probabilistic functional atlases (cf. anatomical locations, as is typically done) for three candidate brain networks-the language-selective network (Fedorenko, Behr, & Kanwisher, 2011), which supports language processing, the Theory of Mind (ToM) network (Saxe & Kanwisher, 2003), which supports social inferences, and the domain-general Multiple-Demand (MD) network (Duncan, 2010), which supports executive control. These atlases were created by overlaying individual activation maps of participants who performed robust and extensively validated 'localizer' tasks that selectively target each network in question (n = 806 for language; n = 198 for ToM; n = 691 for MD). We found that both the individual-study peaks and the ALE clusters fell primarily within the language network and the ToM network. These results suggest that non-literal processing is supported by both i) mechanisms that process literal linguistic meaning, and ii) mechanisms that support general social inference. They thus undermine a strong divide between literal and non-literal aspects of language and challenge the claim that non-literal processing requires additional executive resources.

Linguistic signs in action: The neuropragmatics of speech acts

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

Bibliometric assessment of world scholars' international publications related to conceptual metaphor

Research on metaphor has gained increasing attention of world's scholars since the publication of Lakoff and Johnson's collaborated book Metaphors We Live By in 1980. The present study comprises a pioneering review of publications on Conceptual Metaphor Theory (CMT). It aimed to use the CiteSpace software to provide a clear overview of international research in relation to CMT. In total, 4,458 bibliometric recordings ranging from 1980 to 2022 were collected from the Web of Science (WOS) Core Collection. The descriptive analysis presents the trend of annual publications, the top 10 most prolific journals and the top 10 most productive authors. A document co-citation analysis was conducted via CiteSpace to navigate the key documents in this field. A visualization of keywords and its cluster analysis were conducted to show the research fields and dominant topics. The top 5 keywords with high frequency were language, comprehension, conceptual metaphor, discourse, and figurative language. The most prominent 5 clusters are labeled as right hemisphere, self, time, teacher education, and corpus linguistics. The present review through CiteSpace flags the need for more investigations of CMT from more aspects or interdisciplinary studies, such as metaphor translation, metaphor in literature, metaphor and corpus linguistics, etc.

N400 differences between physical and mental metaphors: The role of Theories of Mind

Whether Theory of Mind (ToM) contributes to metaphor understanding has been largely investigated in language acquisition and decay. Yet we know very little about the role of ToM in real-time processing of metaphors in neurotypical adults. Here, we tested the relationship between ToM and metaphor through Event Related Potentials (ERPs) by capitalizing on the difference between metaphors inviting inferences on physical (Boxers are pandas) vs. mental aspects (Teachers are books). Physical metaphors involved a larger and sustained negativity compared to mental ones. This pattern resembled concreteness effects and suggests that physical metaphors may benefit from both verbal and perceptual information. Moreover, higher scores in the Reading the Mind in the Eyes Test (RMET), but not in the Animation task, were associated with a reduction of the N400 amplitude for both physical and mental metaphors. When exploring the ERP temporal trajectory with Generalized Additive Mixed Modeling, earlier differences between metaphors characterized individuals with higher RMET scores. Among the various ToM components, thus, emotion recognition seems to be involved in the processing of metaphors in general, with an earlier impact on the mental type. These findings highlight the multifaceted nature of metaphor, at the crossroad of language, social and perceptual experience.

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.

The Overnight Retention of Novel Metaphors Associates With Slow Oscillation-Spindle Coupling but Not With Respiratory Phase at Encoding

Accumulating evidence emphasizes the relevance of oscillatory synchrony in memory consolidation during sleep. Sleep spindles promote memory retention, especially when occurring in the depolarized upstate of slow oscillation (SO). A less studied topic is the inter-spindle synchrony, i.e. the temporal overlap and phasic coherence between spindles perceived in different electroencephalography channels. In this study, we examined how synchrony between SOs and spindles, as well as between simultaneous spindles, is associated with the retention of novel verbal metaphors. Moreover, we combined the encoding of the metaphors with respiratory phase (inhalation/exhalation) with the aim of modulating the strength of memorized items, as previous studies have shown that inhalation entrains neural activity, thereby benefiting memory in a waking condition. In the current study, 27 young adults underwent a two-night mixed-design study with a 12-h delayed memory task during both sleep and waking conditions. As expected, we found better retention over the delay containing sleep, and this outcome was strongly associated with the timing of SO–spindle coupling. However, no associations were observed regarding inter-spindle synchrony or respiratory phase. These findings contribute to a better understanding of the importance of SO–spindle coupling for memory. In contrast, the observed lack of association with inter-spindle synchrony may emphasize the local nature of spindle-related plasticity.

The role of the left and right inferior frontal gyrus in processing metaphoric and unrelated co-speech gestures

Gestures are an integral part of in-person conversations and complement the meaning of the speech they accompany. The neural processing of co-speech gestures is supported by a mostly left-lateralized network of fronto-temporal regions. However, in contrast to iconic gestures, metaphoric as well as unrelated gestures have been found to more strongly engage the left and right inferior frontal gyrus (IFG), respectively. With this study, we conducted the first systematic comparison of all three types of gestures and resulting potential laterality effects. During collection of functional imaging data, 74 subjects were presented with 5 s videos of abstract speech with related metaphoric gestures, concrete speech with related iconic gestures and concrete speech with unrelated gestures. They were asked to judge whether the content of the speech and gesture matched or not. Differential contrasts revealed that both abstract related and concrete unrelated compared to concrete related stimuli elicited stronger activation of the bilateral IFG. Analyses of lateralization indices for IFG activation further showed a left hemispheric dominance for metaphoric gestures and a right hemispheric dominance for unrelated gestures. Our results give support to the hypothesis that the bilateral IFG is activated specifically when processing load for speech-gesture combinations is high. In addition, laterality effects indicate a stronger involvement of the right IFG in mismatch detection and conflict processing, whereas the left IFG performs the actual integration of information from speech and gesture.

Functional anatomy of idiomatic expressions

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

The correlation between white matter integrity and pragmatic language processing in first episode schizophrenia

Objective: Higher-order language disturbances could be the result of white matter tract abnormalities. The study explores the relationship between white matter and pragmatic skills in first-episode schizophrenia. Methods: Thirty-four first-episode patients with schizophrenia and 32 healthy subjects participated in a pragmatic language and Diffusion Tensor Imaging study, where fractional anisotropy of the arcuate fasciculus, corpus callosum and cingulum was correlated with the Polish version of the Right Hemisphere Language Battery. Results: The patients showed reduced fractional anisotropy in the right arcuate fasciculus, left anterior cingulum bundle and left forceps minor. Among the first episode patients, reduced understanding of written metaphors correlated with reduced fractional anisotropy of left forceps minor, and greater explanation of written and picture metaphors correlated with reduced fractional anisotropy of the left anterior cingulum. Conclusions: The white matter dysfunctions may underlie the pragmatic language impairment in schizophrenia. Our results shed further light on the functional neuroanatomical basis of pragmatic language use by patients with schizophrenia.

Case Report: Theory of Mind and Figurative Language in a Child With Agenesis of the Corpus Callosum

In this case report, we studied Theory of Mind (ToM) and figurative language comprehension in a 7.2-year-old child, conventionally named RJ, with isolated and complete agenesis of the corpus callosum (ACC), a rare malformation due to the absence of the corpus callosum, the major tract connecting the two brain hemispheres. To study ToM, which is the capability to infer the other’s mental states, we used the classical false belief tasks, and to study figurative language, i.e., those linguistic usages involving non-literal meanings, we used tasks assessing metaphor and idiom comprehension. RJ’s intellectual level and his phonological, lexical, and grammatical abilities were all adequate. In both the ToM false belief tasks and novel sensory metaphor comprehension, RJ showed a delay of 3 years and a significant gap compared to a typically developing control group, while in idioms, his performance was at the border of average. These outcomes suggest that RJ has a specific pragmatic difficulty in all tasks where he must interpret the other’s communicative intention, as in ToM tasks and novel sensory metaphor comprehension. The outcomes also open up interesting insights into the relationships between ToM and figurative language in children with isolated and complete ACC.

Enhancing creativity by altering the frontoparietal control network functioning using transcranial direct current stimulation

The left angular gyrus (AG), part of the frontotemporal network, is implicated in creative thinking, including verbal creativity tasks such as novel metaphor generation. The current study tested the effects of tDCS over the left AG on two metaphor generation tasks. The study was a randomized, double-blind, sham-controlled, crossover study of anodal vs. cathodal stimulation by tDCS. Compared to sham, cathodal stimulation resulted in significantly increased novel metaphor generation, while anodal stimulation increased conventional metaphor generation. Higher motivation (behavioral approach system's "fun-seeking") was associated with greater metaphor creativity in the sham condition, and lower fun seeking was associated with producing a greater quantity of conventional metaphors. Following active stimulation, motivation traits no longer contributed to creative metaphor generation. Thus, the beneficial effect of cathodal tDCS over the left AG in generation of novel metaphors is through restraining the control network. The current study gives a glimpse into the neural basis for creative thinking.

Verbal and Figural Creativity in Children With Autism Spectrum Disorder and Typical Development

Previous studies have shown that individuals with autism spectrum disorder (ASD) demonstrate lower performance on creativity tasks. Yet, recent findings suggest that individuals with ASD are not necessarily impaired in verbal creativity, as measured by the novel metaphor generation task. The current study investigates verbal and figural creativity in 40 children with ASD (aged 11–14 years) and 39 peers with typical development (TD) (aged 11–15 years). We also tested the contribution of executive functions to the creative performance. A sentence completion questionnaire was used to test creative verbal generation, while a task of drawing non-existent objects was used to assess figural abilities. The results indicate that children with ASD generated a greater quantity of creative metaphors and showed greater use of a specific kind of representational change on the figural creativity task: cross-category insertions (e.g., a house with a tail). However, no correlation was found between the metaphor generation task and the use of cross-category insertions for either group. Results also showed that, whereas phonemic fluency contributed to the explained variance in novel metaphor generation in the ASD group, fluid intelligence, although only marginally, contributed to variance in novel metaphor generation in the TD group. These findings suggest that verbal creativity and figural creativity are two separate abilities relying on different cognitive resources. Our results show that those with ASD and TD differ in the cognitive abilities they use to perform the metaphor generation task. The research points to a unique creative cognition profile among children with ASD.

Effective Connectivity Study Guiding the Neuromodulation Intervention in Figurative Language Comprehension Using Optical Neuroimaging

The current study is aimed at establishing links between brain network examination and neural plasticity studies measured by optical neuroimaging. Sixteen healthy subjects were recruited from the University of Macau to test the Granger Prediction Estimation (GPE) method to investigate brain network connectivity during figurative language comprehension. The method is aimed at mapping significant causal relationships across language brain networks, captured by functional near-infrared spectroscopy measurements (fNIRS): (i) definition of regions of interest (ROIs) based on significant channels extracted from spatial activation maps; (ii) inspection of significant causal relationships in temporal resolution, exploring the experimental task agreement; and (iii) early identification of stronger causal relationships that guide neuromodulation intervention, targeting impaired connectivity pathways. Our results propose top-down mechanisms responsible for perceptive-attention engagement in the left anterior frontal cortex and bottom-up mechanism in the right hemispheres during the semantic integration of figurative language. Moreover, the interhemispheric directional flow suggests a right hemisphere engagement in decoding unfamiliar literal sentences and fine-grained integration guided by the left hemisphere to reduce ambiguity in meaningless words. Finally, bottom-up mechanisms seem activated by logographic-semantic processing in literal meanings and memory storage centres in meaningless comprehension. To sum up, our main findings reveal that the Granger Prediction Estimation (GPE) integrated strategy proposes an effective link between assessment and intervention, capable of enhancing the efficiency of the treatment in language disorders and reducing the neuromodulation side effects.

Understanding Novel Metaphors: A Milestone in the Developmental Trajectory of Children with Agenesis of the Corpus Callosum?

This study explores novel metaphor comprehension in a 7.2-year-old child (conventionally called RJ) with complete and isolated agenesis of the corpus callosum (ACC). RJ's cognitive level was adequate for his age as well as most of his linguistic competencies. The child's performance was compared to typically developing (TD) controls on a test assessing novel metaphor comprehension for preschoolers. RJ's performance showed a delay of about three years in relation to the expected level for his age, and also a significant gap compared to the TDs. The results highlighted the possibility to detect weaknesses in understanding novel metaphors in children with ACC, in spite of their apparently adequate linguistic capabilities. An early detection of a weakness in this area can pave the way to neurolinguistic treatment in order to enhance the understanding of nonliteral meaning, which, in the developmental trajectory, will be increasingly involved in everyday life communication. Future research should explore more in-depth a capability that intrinsically requires high interconnectivity, such as novel metaphor comprehension, in a brain in development where the major tract connecting the two hemispheres is missing.

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.

Improved and residual functional abnormalities in major depressive disorder after electroconvulsive therapy

Electroconvulsive therapy (ECT) can induce fast remission of depression but still retain the residual functional impairments in major depressive disorder (MDD) patients. To delineate the different functional circuits of effective antidepressant treatment and residual functional impairments is able to better guide clinical therapy for depression. Herein, voxel-level whole brain functional connectivity homogeneity (FcHo), functional connectivity, multivariate pattern classification approaches were applied to reveal the specific circuits for treatment response and residual impairments in MDD patients after ECT. Increased FcHo values in right dorsomedial prefrontal cortex (dmPFC) and left angular gyrus (AG) and their corresponding functional connectivities between dmPFC and right AG, dorsolateral prefrontal cortex (dlPFC), superior frontal gyrus, precuneus (Pcu) and between left AG with dlPFC, bilateral AG, and left ventrolateral prefrontal cortex in MDD patients after ECT. Moreover, we found decreased FcHo values in left middle occipital gyrus (MOG) and lingual gyrus (LG) and decreased functional connectivities between MOG and dorsal postcentral gyrus (PCG) and between LG and middle PCG/anterior superior parietal lobule in MDD patients before and after ECT compared to healthy controls (HCs). The increased or normalized FcHo and functional connections may be related to effective antidepressant therapy, and the decreased FcHo and functional connectivities may account for the residual functional impairments in MDD patients after ECT. The different change patterns in MDD after ECT indicated a specific brain circuit supporting fast remission of depression, which was supported by the following multivariate pattern classification analyses. Finally, we found that the changed FcHo in dmPFC was correlated with changed depression scores. These results revealed a specific functional circuit supporting antidepressant effects of ECT and neuroanatomical basis for residual functional impairments. Our findings also highlighted the key role of dmPFC in antidepressant and will provide an important reference for depression treatment.

Humor comprehension and creative cognition: Shared and distinct neurocognitive mechanisms as indicated by EEG alpha activity

Humor comprehension is increasingly recognized as showing parallels to more conventional creative cognition; yet our understanding of brain mechanisms underlying creative cognition in a humorous context is still limited. The present study addressed this issue by investigating functional patterns of EEG alpha activity while 93 participants viewed nonverbal humorous cartoons until they indicated having recognized the punch line, and subsequently vocalized their idea as to what constituted it. In a similar fashion, EEG was also assessed during performance of the Alternate Uses Task (AUT), in order to identify similarities and differences in EEG alpha activity implicated in conventional creative cognition vs. humor comprehension. Analyses revealed a pattern of robust task-related alpha power increases in both tasks, which were markedly more right-lateralized at ventral fronto-temporal sites in the humor task as compared to the AUT. Findings are interpreted in line with recent literature on the functional role of alpha activity in the creativity domain. Altogether, this study adds further evidence to the particular role of EEG alpha oscillations in creative cognition and supports the idea that conventional creative ideation and the comprehension of humor share neural mechanisms affiliated to creative cognition.

Metaphor processing is supramodal semantic processing: The role of the bilateral lateral temporal regions in multimodal communication

This paper presents an fMRI study on healthy adult understanding of metaphors in multimodal communication. We investigated metaphors expressed either only in coverbal gestures ("monomodal metaphors") or in speech with accompanying gestures ("multimodal metaphors"). Monomodal metaphoric gestures convey metaphoric information not expressed in the accompanying speech (e.g. saying the non-metaphoric utterance, "She felt bad" while dropping down the hand with palm facing up; here, the gesture alone indicates metaphoricity), whereas coverbal gestures in multimodal metaphors indicate metaphoricity redundant to the speech (e.g. saying the metaphoric utterance, "Her spirits fell" while dropping the hand with palm facing up). In other words, in monomodal metaphors, gestures add information not spoken, whereas the gestures in multimodal metaphors can be redundant to the spoken content. Understanding and integrating the information in each modality, here spoken and visual, is important in multimodal communication, but most prior studies have only considered multimodal metaphors where the gesture is redundant to what is spoken. Our participants watched audiovisual clips of an actor speaking while gesturing. We found that abstract metaphor comprehension recruited the lateral superior/middle temporal cortices, regardless of the modality in which the conceptual metaphor is expressed. These results suggest that abstract metaphors, regardless of modality, involve resources implicated in general semantic processing and are consistent with the role of these areas in supramodal semantic processing as well as the theory of embodied cognition.

Feature Uncertainty Predicts Behavioral and Neural Responses to Combined Concepts

The cognitive and neural structure of conceptual knowledge affects how concepts combine in language and thought. Examining the principles by which individual concepts (e.g., diamond, baseball) combine into more complex phrases (e.g., "baseball diamond") can illuminate not only how the brain combines concepts but also the key ingredients of conceptual structure. Here we specifically tested the role of feature uncertainty in the modulation of conceptual brightness evoked by adjective-noun combinations (e.g., "dark diamond") in male and female human subjects. We collected explicit ratings of conceptual brightness for 45 noun concepts and their "dark" and "light" combinations, resulting in a measure reflecting the degree of conceptual brightness modulation in each noun concept. Feature uncertainty was captured in an entropy measure, as well as in a predictive Bayesian model of feature modulation. We found that feature uncertainty (i.e., entropy) and the Bayesian model were both strong predictors of these behavioral effects. Using fMRI, we observed the neural responses evoked by the concepts and combinations in a priori ROIs. Feature uncertainty predicted univariate responses in left inferior frontal gyrus, and multivariate responses in left anterior temporal lobe were predicted by degree of conceptual brightness modulation. These findings suggest that feature uncertainty is a key ingredient of conceptual structure, and inform cognitive neuroscience theories of conceptual combination by highlighting the role of left inferior frontal gyrus and left anterior temporal lobe in the process of flexible feature modulation during comprehension of complex language.SIGNIFICANCE STATEMENT The meaning of a word depends on the words surrounding it. The challenge of understanding how flexible meaning emerges in language can be simplified by studying adjective-noun phrases. We tested whether the uncertainty of a feature (i.e., brightness) in a given noun concept (e.g., diamond) influences how the adjective and noun concepts combine. We analyzed feature uncertainty using two probabilistic measures, and found that feature uncertainty predicted people's explicit interpretations of adjective-noun phrases (e.g., "dark diamond"). Using fMRI, we found that combined concepts evoked responses in left inferior frontal gyrus and left anterior temporal lobe that related to our measures of feature modulation and uncertainty. These findings reveal the cognitive and neural processes supporting conceptual combination and complex language use.

Elucidating the role of selective attention, divergent thinking, language abilities, and executive functions in metaphor generation

Metaphoric language is one of the most common expressions of creative cognition in everyday life. However, the cognitive mechanisms underlying metaphor generation remain largely unexplained. In this study, we aimed to investigate the relationship between various cognitive functions and both novel and conventional metaphor generation. Ninety-five undergraduate students were administered a metaphor generation task that assesses novel and conventional metaphor generation, along with a battery of different cognitive measures: vocabulary; divergent thinking (Tel Aviv Creativity Test), working memory (WM) via digit span tests, executive functions (EFs) using the Behavioral Rating Inventory of Executive Function (BRIEF) questionnaire, and selective attention (lateralized global-local digit task). Results of a path analysis indicated that - whereas only selective attention contributed to conventional metaphor generation - selective attention, divergent thinking, and EFs contributed to novel metaphor generation beyond vocabulary and WM. Thus, the results indicate that although both novel and conventional metaphor generation are linked to attentional resources and inhibitory control, the greater creativity inherent in novel metaphor generation appears to reflect a more complex set of cognitive processes than conventional metaphor generation.

A leopard cannot change its spots: A novel pragmatic account of concretism in schizophrenia

Concretism is a well-known feature of schizophrenia, tracing back to the early descriptions of the disease and commonly associated with the literal interpretation of figurative expressions such as proverbs, metaphors, and idioms. However, figurative expressions are not all alike in terms of linguistic and pragmatic processes. Determining if some figurative types are more impaired than others and if the type of task affects the performance constitutes an open issue with implications for the description of the clinical profile and for treatment. We run a fine-grained assessment of figurative language comprehension by comparing 47 patients with schizophrenia and 39 controls in three figurative types (idioms, metaphors, proverbs) presented in two response formats (multiple-choice, verbal-explanation), considering also the role of cognitive and clinical variables and the impact on quality of life. Mixed-effects models analysis revealed that: i) patients performed worse than controls across figurative types and response formats, indicating a diffuse impairment; ii) there is an interplay of figurative type and response format, which makes verbal-explanation of proverbs especially challenging; iii) in patients, problems in figurative language are largely connected with formal thought disorder and global IQ. Moreover, multiple-choice of metaphors was associated with patients' quality of life. This study offers a novel account of concretism, framed in pragmatics and figurative language processing. Adopting this perspective allowed us to describe the nuances of concretism, which areas in the figurative domain are especially challenging for patients and which ones capture differences in functioning, in order to guide intervention programs and integration in society.

Uncovering cortical activations of discourse comprehension and their overlaps with common large-scale neural networks

We conducted a meta-analysis of 78 task-based functional magnetic resonance imaging (fMRI) studies (1976 total participants) to reveal underlying brain activations and their overlap with large-scale neural networks in the brain during general discourse comprehension and its sub-processes. We found that discourse comprehension involved a neural system consisting of widely distributed brain regions that comprised not only the bilateral perisylvian language zones, but also regions in the superior and medial frontal cortex and the medial temporal lobe. Moreover, this neural system can be categorized into several sub-systems representing various sub-processes of discourse comprehension, with the left inferior frontal gyrus and middle temporal gyrus serving as core regions across all sub-processes. At a large-scale network level, we found that discourse comprehension relied most heavily on the default network, particularly on its dorsal medial subsystem. The pattern associated with large-scale network cooperation varied according to the respective sub-processes required. Our results reveal the functional dissociation within the discourse comprehension neural system and highlight the flexible involvements of large-scale networks.

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

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

Structural alterations of the brain preceded functional alterations in major depressive disorder patients: Evidence from multimodal connectivity

BACKGROUND

Recent studies showed that major depressive disorder (MDD) has been involved in abnormal functional and structural connections in specific brain regions. However, comprehensive researches on MDD-related alterations in the topological organization of brain functional and structural networks are still limited.

METHODS

Functional network (FN) was constructed from resting-state functional MRI temporal series correlations and structural network (SN) was established by Diffusion tensor imaging (DTI) data in 58 MDD patients and 71 healthy controls (HC). The measurements of the network properties were calculated for two networks respectively. Correlations were conducted between altered network parameters and Hamilton depression scale (HAMD) score. Additionally, network resilient analysis were conducted on FN and SN.

RESULTS

The losses of small-worldness charateristics and the decline of nodal efficiency across FN and SN were found in MDD patients. Based on network-based statistic (NBS) approach, the decreased connections in MDD patients were mainly found in the superior occipital gyrus, superior temporal gyrus for FN and SN, while the increased connections were distributed in putamen, superior frontal gyrus only for SN. Compared with the FN, the SN showed less resilient to targeted or random node failure. Besides, altered edges in NBS and regions with decreased nodal efficiency were negatively associated with HAMD score in MDD patients.

LIMITATIONS

The samples size is small and most of the MDD patients take different antidepressant medications.

CONCLUSIONS

Alterations of SN in the brain of MDD patients preceded that of FN to some extent, and reorganization of the brain network was a mechanism which compensated for functional and structural alterations during disease progression.

Idiomatic expressions evoke stronger emotional responses in the brain than literal sentences

Recent neuroscientific research shows that metaphors engage readers at the emotional level more strongly than literal expressions. What still remains unclear is what makes metaphors more engaging, and whether this generalises to all figurative expressions, no matter how conventionalised they are. This fMRI study aimed to investigate whether idiomatic expressions - the least creative part of figurative language - indeed trigger a higher affective resonance than literal expressions, and to explore possible interactions between activation in emotion-relevant neural structures and regions associated with figurative language processing. Participants silently read for comprehension a set of emotionally positive, negative and neutral idioms embedded in short sentences, and similarly valenced literal sentences. As in studies on metaphors, we found enhanced activation of the left inferior frontal gyrus and left amygdala in response to idioms, indexing stronger recruitment of executive control functions and enhanced emotional engagement, respectively. This suggests that the comprehension of even highly conventionalised and familiar figurative expressions, namely idioms, recruits regions involved in emotional processing. Furthermore, increased activation of the IFG interacted positively with activation in the amygdala, suggesting that the stronger cognitive engagement driven by idioms may in turn be coupled with stronger involvement at the emotional level.

Interpreting physical and mental metaphors: Is Theory of Mind associated with pragmatics in middle childhood?

We investigated the association between individual differences in metaphor understanding and Theory of Mind (ToM) in typically developing children. We distinguished between two types of metaphors and created a Physical and Mental Metaphors task, echoing a similar distinction for ToM. Nine-year-olds scored lower than older age-groups in ToM as well as in the interpretation of mental, but not physical, metaphors. Moreover, nine-year-olds (but not older children) who are better in ToM are also better in interpreting mental, but not physical, metaphors. This suggests that the link between metaphor and ToM is stronger when metaphorical interpretation involves mental aspects, and it is more evident in early rather than later childhood.

A Quantitative Meta-analysis of Neuroimaging Studies of Pragmatic Language Comprehension: In Search of a Universal Neural Substrate

Pragmatics may be defined as the ability to communicate by expressing and recognizing intentions. The objective of this meta-analysis was to identify neural substrates for comprehension of pragmatic content in general, as well as the differences between pragmatic forms, and to describe if there is differential recruitment of brain areas according to natural language. This meta-analysis included 48 functional magnetic resonance imaging studies that reported pragmatic versus literal language contrasts. The pragmatic forms were speech acts, metaphors, idioms, and irony. Effect Size-Signed Differential Mapping software was used to calculate the mean for all contrasts as well as for each pragmatic form, and make comparisons among all forms. Due to variations in pragmatic content configuration such as natural language, stimulus modality, and writing systems, these variations were also analyzed with subgroups' analyses. The analyses found a highly reproducible bilateral fronto-temporal and medial prefrontal cortex network for pragmatic comprehension. Each pragmatic form showed a specific convergence pattern within this bilateral network. Natural language analyses showed that fronto-temporal regions were recruited by Germanic languages, while only left frontal areas were recruited by Romance languages, and right medial prefrontal cortex by Japanese. In conclusion, pragmatic language comprehension involves classical language areas in bilateral perisylvian regions, along with the medial prefrontal cortex, an area involved in social cognition. Together, these areas could represent the "pragmatic language network". Nonetheless, when proposing a universal neural substrate for all forms of pragmatic language, the diversity among studies in terms of pragmatic form, and configuration, must be taken into consideration.

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

Recent studies showed that multiple sclerosis (MS) patients might experience communicative deficits, specifically in pragmatics (i.e., the ability to integrate the context-dependent aspects of language). A crucial region for pragmatics is the temporo-parietal junction, in particular the so-called Geschwind's area (GA), which is involved in high-level language processes, including the comprehension of narratives, metaphor, and irony. We evaluated the relationship between pragmatic abilities, measured through the Assessment of Pragmatic Abilities and Cognitive Substrates (APACS) test, and the functional connectivity (FC) of the bilateral GAs, assessed through a seed-based analysis of Resting-State fMRI in patients with MS. A positive correlation was observed between APACS scores and the FC for both the right and the left GA and the paracingulate cortex. Our findings suggest that the brain FC for social communication involves connections extending over both hemispheres, including right and left GAs and right and left paracingulate cortex, possibly impaired in patients with MS. This study offers preliminary evidence for future researches enrolling also a control sample to explore the involvement of GA in pragmatics in neurological disorders as well as in healthy conditions.

Regional cerebral metabolism alterations affect resting-state functional connectivity in major depressive disorder

Background

¹⁸F-FDG positron emission tomography (PET) is a reliable technique to quantify regional neural glucose metabolism even with major depressive disorder (MDD) heterogeneous features. Previous study proposed that in the resting-state (RS), pairs of brain regions whose regional glucose metabolic rates were significantly correlated were functionally associated. This synchronicity indicates a neuronal metabolic and functional interaction in high energy efficient brain regions. In this study, a multimode method was used to identify the RS-FC patterns based on regional metabolism changes, and to observe its relationship with the severity of depressive symptoms in MDD patients.

Methods

The study enrolled 11 medication-naive MDD patients and 14 healthy subjects. All participants received a static ¹⁸F-FDG PET brain scan and a resting-state functional magnetic resonance imaging (RS-fMRI) scan. SPM5 software was used to compare brain metabolism in MDD patients with that in healthy controls, and designated regions with a change in metabolism as regions of interest (ROIs). The glucose metabolism-based regional RS-FC Z values were compared between groups. Then group independent component analysis (ICA) was used to identify the abnormal connectivity nodes in the intrinsic function networks. Finally, the correlation between abnormal RS-FC Z values and the severity of depressive symptoms was evaluated.

Results

Patients with MDD had reduced glucose metabolism in the putamen, claustrum, insular, inferior frontal gyrus, and supramarginal gyrus. The metabolic reduction regions impaired functional connectivity (FC) to key hubs, such as the Inferior frontal gyrus (pars triangular), angular gyrus, calcarine sulcus, middle frontal gyrus (MFG), located in dorsolateral prefrontal cortex (DLPFC)/parietal lobe, salience network (SN), primary visual cortex (V1), and language network respectively. There was no correlation between aberrant connectivity and the severity of clinical symptoms.

Conclusions

This research puts forward a possibility that focal neural activity alteration may share RS-FC dysfunction and be susceptible to hubs in the functional network in MDD. In particular, the metabolism and function profiles of the Inferior frontal gyrus (pars triangularis) should be emphasized in future MDD studies.

Pragmatic competence and its relationship with the linguistic and cognitive profile of young adults with dyslexia

The study assessed the pragmatic skills of 19 well-compensated Italian-speaking young adults with dyslexia compared with controls. A comprehensive pragmatic assessment tool was employed, targeting production and comprehension (Assessment of Pragmatic Abilities and Cognitive Substrates [APACS]). Participants were also administered a series of standardized tests to assess verbal and non-verbal cognitive abilities, including executive functions and social cognition tests. Data were analysed with the aim of understanding whether pragmatic abilities are compromised in dyslexia and of exploring associations between pragmatic performance and other cognitive domains. The performance of the dyslexia group was poorer than that of the control group in both expressive and receptive modalities. Data showed diffuse problems across several domains, with the greatest challenge posed by inferring nonliteral meanings, which indicates that pragmatic inefficiency is an important aspect of the linguistic and communicative profile of dyslexia in adulthood. Explorative correlations highlighted a relation between pragmatic performance and reading and vocabulary abilities, as well as between pragmatics and working memory. This suggests that pragmatic difficulties are strongly tied to the most distinctive aspects of dyslexia, namely, phonological awareness, verbal short-term memory, pseudo-word repetition, whereas the link with high-level executive functions and Theory of Mind is negligible.

Factors Influencing Right Hemisphere Engagement During Metaphor Comprehension

Although the left hemisphere is critical for language, clinical, behavioral, and neuroimaging research suggest that the right hemisphere also contributes to language comprehension. In particular, research has suggested that figurative language may be one type of language that preferentially engages right hemisphere regions. However, there is disagreement about whether these regions within the right hemisphere are sensitive to figurative language per se or to other factors that co-vary with figurativeness. In this article, we will review the neuroimaging literature on figurative language processing, focusing on metaphors, within the context of several theoretical perspectives that have been proposed about hemispheric function in language. Then we will examine three factors that may influence right hemisphere engagement: novelty, task difficulty, and context. We propose that factors that increase integration demands drive right hemisphere involvement in language processing, and that such recruitment is not limited to figurative language.

Finding features, figuratively

Object concepts refer to unique clusters of properties that can be selectively activated or inhibited depending on what information is currently relevant. This conceptual "stretching" enables limitless new meanings to be generated, and figurative language provides a useful framework in which to study this conceptual flexibility. Here we probe the cognitive and neural mechanisms underlying the comprehension of novel metaphors as a means of understanding the conceptual flexibility inherent to language processing more generally. We show that novel metaphor comprehension involves the activation or inhibition of conceptual properties that are either relevant or irrelevant to the metaphor, and that left inferior frontal gyrus is recruited in this process, supporting a role for this region in the fine-tuning of conceptual meaning. Our results are consistent with a flexible, compositional account of conceptual structure in which semantic control mechanisms operate over conceptual properties during figurative language comprehension in order to create context-dependent meaning.

Lexical-Semantic Search Under Different Covert Verbal Fluency Tasks: An fMRI Study

Background: Verbal fluency is a measure of cognitive flexibility and word search strategies that is widely used to characterize impaired cognitive function. Despite the wealth of research on identifying and characterizing distinct aspects of verbal fluency, the anatomic and functional substrates of retrieval-related search and post-retrieval control processes still have not been fully elucidated. Methods: Twenty-one native English-speaking, healthy, right-handed, adult volunteers (mean age = 31 years; range = 21-45 years; 9 F) took part in a block-design functional Magnetic Resonance Imaging (fMRI) study of free recall, covert word generation tasks when guided by phonemic (P), semantic-category (C), and context-based fill-in-the-blank sentence completion (S) cues. General linear model (GLM), Independent Component Analysis (ICA), and psychophysiological interaction (PPI) were used to further characterize the neural substrate of verbal fluency as a function of retrieval cue type. Results: Common localized activations across P, C, and S tasks occurred in the bilateral superior and left inferior frontal gyrus, left anterior cingulate cortex, bilateral supplementary motor area (SMA), and left insula. Differential task activations were centered in the occipital, temporal and parietal regions as well as the thalamus and cerebellum. The context-based fluency task, i.e., the S task, elicited higher differential brain activity in a lateralized frontal-temporal network typically engaged in complex language processing. P and C tasks elicited activation in limited pathways mainly within the left frontal regions. ICA and PPI results of the S task suggested that brain regions distributed across both hemispheres, extending beyond classical language areas, are recruited for lexical-semantic access and retrieval during sentence completion. Conclusion: Study results support the hypothesis of overlapping, as well as distinct, neural networks for covert word generation when guided by different linguistic cues. The increased demand on word retrieval is met by the concurrent recruitment of classical as well as non-classical language-related brain regions forming a large cognitive neural network. The retrieval-related search and post-retrieval control processes that subserve verbal fluency, therefore, reverberates across distinct functional networks as determined by respective task demands.

Functional network-based statistics in depression: Theory of mind subnetwork and importance of parietal region

OBJECTIVE

The functional network analysis of whole brain is an emerging field for research in depression. We initiated this study to investigate which subnetwork is significantly altered within the functional connectome in major depressive disorder (MDD).

METHODS

The study enrolled 52 first-episode medication-naïve patients with MDD and 40 controls for functional network analysis. All participants received the resting-state functional imaging using a 3-Tesla magnetic resonance scanner. After preprocessing, we calculated the connectivity matrix of functional connectivity in whole brain for each subject. The network-based statistics of connectome was used to perform group comparisons between patients and controls. The correlations between functional connectivity and clinical parameters were also performed.

RESULTS

MDD patients had significant alterations in the network involving "theory of mind" regions, such as the left precentral gyrus, left angular gyrus, bilateral rolandic operculums and left inferior frontal gyrus. The center node of significant network was the left angular gyrus. No significant correlations of functional connectivity within the subnetwork and clinical parameters were noted.

CONCLUSION

Functional connectivity of "theory of mind" subnetwork may be the core issue for pathophysiology in MDD. In addition, the center role of parietal region should be emphasized in future study.

The Neuronal Correlates of Indeterminate Sentence Comprehension: An fMRI Study

Sentences such as The author started the book are indeterminate because they do not make explicit what the subject (the author) started doing with the object (the book). In principle, indeterminate sentences allow for an infinite number of interpretations. One theory, however, assumes that these sentences are resolved by semanticcoercion, a linguistic process that forces the noun book to be interpreted as an activity (e.g., writing the book) or by a process that interpolates this activity information in the resulting enriched semantic composition. An alternative theory, pragmatic, assumes classical semantic composition, whereby meaning arises from the denotation of words and how they are combined syntactically, with enrichment obtained via pragmatic inferences beyond linguistic-semantic processes. Cognitive neuroscience studies investigating the neuroanatomical and functional correlates of indeterminate sentences have shown activations either at the ventromedial pre-frontal cortex (vmPFC) or at the left inferior frontal gyrus (L-IFG). These studies have supported the semantic coercion theory assuming that one of these regions is where enriched semantic composition takes place. Employing functional magnetic resonance imaging (fMRI), we found that indeterminate sentences activate bilaterally the superior temporal gyrus (STG), the right inferior frontal gyrus (R-IFG), and the anterior cingulate cortex (ACC), more so than control sentences (The author wrote the book). Activation of indeterminate sentences exceeded that of anomalous sentences (…drank the book) and engaged more left- and right-hemisphere areas than other sentence types. We suggest that the widespread activations for indeterminate sentences represent the deployment of pragmatic-inferential processes, which seek to enrich sentence content without necessarily resorting to semantic coercion.

Disentangling Metaphor from Context: An ERP Study

A large body of electrophysiological literature showed that metaphor comprehension elicits two different event-related brain potential responses, namely the so-called N400 and P600 components. Yet most of these studies test metaphor in isolation while in natural conversation metaphors do not come out of the blue but embedded in linguistic and extra-linguistic context. This study aimed at assessing the role of context in the metaphor comprehension process. We recorded EEG activity while participants were presented with metaphors and equivalent literal expressions in a minimal context (Experiment 1) and in a supportive context where the word expressing the ground between the metaphor's topic and vehicle was made explicit (Experiment 2). The N400 effect was visible only in minimal context, whereas the P600 was visible both in the absence and in the presence of contextual cues. These findings suggest that the N400 observed for metaphor is related to contextual aspects, possibly indexing contextual expectations on upcoming words that guide lexical access and retrieval, while the P600 seems to reflect truly pragmatic interpretative processes needed to make sense of a metaphor and derive the speaker's meaning, also in the presence of contextual cues. In sum, previous information in the linguistic context biases toward a metaphorical interpretation but does not suppress interpretative pragmatic mechanisms to establish the intended meaning.

You may now kiss the bride: Interpretation of social situations by individuals with right or left hemisphere injury

While left hemisphere damage (LHD) has been clearly shown to cause a range of language impairments, patients with right hemisphere damage (RHD) also exhibit communication deficits, such as difficulties processing prosody, discourse, and social contexts. In the current study, individuals with RHD and LHD were directly compared on their ability to interpret what a character in a cartoon might be saying or thinking, in order to better understand the relative role of the right and left hemisphere in social communication. The cartoon stimuli were manipulated so as to elicit more or less formulaic responses (e.g., a scene of a couple being married by a priest vs. a scene of two people talking, respectively). Participants' responses were scored by blind raters on how appropriately they captured the gist of the social situation, as well as how formulaic and typical their responses were. Results showed that RHD individuals' responses were rated as significantly less appropriate than controls and were also significantly less typical than controls and individuals with LHD. Individuals with RHD produced a numerically lower proportion of formulaic expressions than controls, but this difference was only a trend. Counter to prediction, the pattern of performance across participant groups was not affected by how constrained/formulaic the social situation was. The current findings expand our understanding of the roles that the right and left hemispheres play in social processing and communication and have implications for the potential treatment of social communication deficits in individuals with RHD.

Figurative language processing in atypical populations: the ASD perspective

This paper is intended to provide a critical overview of experimental and clinical research documenting problems in figurative language processing in atypical populations with a focus on the Autistic Spectrum. Research in the comprehension and processing of figurative language in autism invariably documents problems in this area. The greater paradox is that even at the higher end of the spectrum or in the cases of linguistically talented individuals with Asperger syndrome, where structural language competence is intact, problems with extended language persist. If we assume that figurative and extended uses of language essentially depend on the perception and processing of more concrete core concepts and phenomena, the commonly observed failure in atypical populations to understand figurative language remains a puzzle. Various accounts have been offered to explain this issue, ranging from linking potential failure directly to overall structural language competence (Norbury, 2005; Brock et al., 2008) to right-hemispheric involvement (Gold and Faust, 2010). We argue that the dissociation between structural language and figurative language competence in autism should be sought in more general cognitive mechanisms and traits in the autistic phenotype (e.g., in terms of weak central coherence, Vulchanova et al., 2012b), as well as failure at on-line semantic integration with increased complexity and diversity of the stimuli (Coulson and Van Petten, 2002). This perspective is even more compelling in light of similar problems in a number of conditions, including both acquired (e.g., Aphasia) and developmental disorders (Williams Syndrome). This dissociation argues against a simple continuity view of language interpretation.