Emotional context modulates embodied metaphor comprehension

Viewing our interlocutor facilitates speech perception, unlike for instance when we telephone. Several neural routes and mechanisms could account for this phenomenon. Using magnetoencephalography, we show that when seeing the interlocutor, latencies of auditory responses (M100) are the shorter the more predictable speech is from visual input, whether the auditory signal was congruent or not. Incongruence of auditory and visual input affected auditory responses approximately 20 ms after latency shortening was detected, indicating that initial content-dependent auditory facilitation by vision is followed by a feedback signal that reflects the error between expected and received auditory input (prediction error). We then used functional magnetic resonance imaging and confirmed that distinct routes of visual information to auditory processing underlie these two functional mechanisms. Functional connectivity between visual motion and auditory areas depended on the degree of visual predictability, whereas connectivity between the superior temporal sulcus and both auditory and visual motion areas was driven by audiovisual (AV) incongruence. These results establish two distinct mechanisms by which the brain uses potentially predictive visual information to improve auditory perception. A fast direct corticocortical pathway conveys visual motion parameters to auditory cortex, and a slower and indirect feedback pathway signals the error between visual prediction and auditory input.

Hemispheric differences in processing the literal interpretation of idioms: Converging evidence from behavioral and fMRI studies

Since Aristotle, many writers have treated metaphors and similes as equals: any metaphor can be paraphrased as a simile, and vice-versa. This property of metaphors is the foundation of standard comparison theories of metaphor comprehension. On this view, metaphors such as “my job is a jail” are literally false, and so cannot be directly interpreted. Instead, such “irrational” assertions are converted to similes (i.e., my job is like a jail) and understood as any literal comparison would be. Comparison theories rely on three assumptions: (1). Literal interpretations have unconditional priority; (2). Metaphor interpretation is optional, triggered whenever a literal interpretation fails to make sense in context; (3). Following assumptions (1) and (2), metaphor processing is not only more difficult than literal, but involves different processing mechanisms. I argue that none of the above assumptions hold. In addition, I show that metaphors cannot always be paraphrased as similes. The different forms of a metaphor – the comparison and categorical forms – have different referents. In comparison form, the metaphor vehicle refers to the literal concept, e.g., in my lawyer is like a shark, the term “shark” refers to the literal fish. In categorical form, my lawyer is a shark, “shark” refers to an abstract (metaphorical) category of predatory creatures. This difference in reference makes it possible for a metaphor and its corresponding simile to differ (a) in interpretability and (b) in meaning. Because a metaphor cannot always be understood in terms of its corresponding simile, I conclude that comparison theories of metaphor are fundamentally flawed. Metaphors can be processed directly as categorization assertions. Furthermore, when such metaphors are novel, they create new categories that are available for public discourse.KeywordsFigurative languageMetaphorSimilarityCatergorization

Empowering Reentrant Projections from V5 to V1 Boosts Sensitivity to Motion

An outstanding chess player needs to accumulate massive visual and spatial information for chess configurations. Visual motion area (MT) is considered as a brain region specialized for visual motion perception and visuospatial attention processing. However, how long-term chess training shapes the functional connectivity patterns of MT, especially its functional subregions, has rarely been investigated. In our study, using resting-state functional connectivity (RSFC) and Granger causality analysis (GCA), we studied the changed functional couplings of MT subregions between 28 chess master players and 27 gender- and age-matched healthy novices to reveal the neural basis of long-term professional chess training. RSFC analysis identified decreased functional connections between right dorsal-anterior subregion (CI1.R) and left angular gyrus, and increased functional connections between right ventral-anterior MT subregion (CI2.R) and right superior temporal gyrus in chess experts. Moreover, GCA analyses further found increased mutual interactions of left angular gyrus and CI1.R in chess experts compared to novice players. These findings demonstrate that long-term professional chess training could enhance spatial perception and reconfiguration and semantic processing efficiency for superior performance.

Problems with pragmatic aspects of language are well attested in individuals on the autism spectrum. It remains unclear, however, whether figurative language skills improve with language status and whether problems in figurative language are no longer present in highly verbal individuals with autism. To investigate whether highly verbal individuals with autism perform similarly as age-, intelligence- and verbal comprehension-matched controls on the processing of one of the most common types of figurative language, metaphors. The goal was to establish whether the participants with autism are primed similarly to controls by figurative expressions (metaphors) presented in different conditions. The experiment was designed as a cross-modal lexical-decision task where metaphors served as primes for target words related to their figurative or literal meaning. Our findings show that both ASD and control participants made very few errors in the experimental task. However, the participants with ASD presented with problems in performance on the task, reflected in significantly slower reaction times compared with the typically developing peer groups. The similar response speed observed between the younger typical control children and the adult ASD participants suggests that the mechanisms underlying metaphor processing (e.g., selection of metaphorical versus literal interpretation) are still developing in high-functioning autism, very much like in typical children. These results may suggest that metaphor processing requires more than adequate language competences. The findings are also suggestive of a delay in developing sensitivity to figurative language, rather than sheer inability. This suggests that a timely training programme can be implemented to improve figurative language abilities in ASD.

A quick look on the history of criticism and literary theory of the current period shows curious reversals and strange returns. Indeed one can see the slow and unrelenting disappearance of rhetoric, justly qualified as restricted, since it has been all too often limited to identifying and classifying of the various figures. It has been replaced by a new criticism, a fundamentally formalist one, the assumptions of which are akin to those of the “text sciences”; if the structure, the “poetical function” of the texts were underlined, it was to the detriment of their functional reference and their meaning to put it simply. There is no doubt that today this approach is running out of steam and is meeting some decline. For that reason, the history of literature is coming back in force and finds a new youth with the developments of the theories of perception. But there reappears also a new interest in a semantic approach of the texts, which is concerned with their references. This approach, which comes from logistics (G. Frege), undoubtedly opens a philosophical horizon, particularly on some kind of ontology. Thus it is not surprising to find that a great many studies question the metaphorical process again from that perspective given the paradoxical nature of its reference and thus of its ontology which could be summed up through the usual exordium of the Majorcan storytellers: “Aixo era y no era” (it was and was not). Paul Ricœur insists on the paradoxical nature of the metaphorical reference since “the metaphor is a way of working on the language which consists in giving the logical subjects predicates that are incompatible with the first ones” (From Text to Action). In his book The Living Metaphor, the French philosopher analyses the concept of the “ontological metaphor” from the idea of the “divided reference”. Ricœur moves away from a purely stylistic or linguistic approach, centred on the word (a deviant denomination) to describe the metaphorical process on the level of the phrase and of the discourse (a non-pertinent predication): “Then there is a metaphor, since we can discern <…> the resistance of words <…> their incompatibility on the level of a literal interpretation of a sentence” (From Text to Action). But that non-pertinence and the abolition of the reference in the everyday reality are not a purely gratuitous verbal game, for they liberate “another kind of reference to other dimensions of reality” (The Living Metaphor). It is that way of tension of the metaphor which we intend to present in our study for it expresses some kind of „ontological vehemence” as Ricœur puts it so well? Let us add that the metaphor seen as a new description of reality, can be conceived, so to speak, as a “model”, in the sense of a prototype which accounts of the way a literary text functions when it is a “opening on the world”, when it places itself “in the service of things that want to be expressed” and when it responds “to the need of a discourse that comes from all forms of experience” (Mimesis, Reference and new figuration in “Time and Narrative”).

Cross-modal plasticity refers to the recruitment of cortical regions involved in the processing of one modality (e.g. vision) for processing other modalities (e.g. audition). The principles determining how and where cross-modal plasticity occurs remain poorly understood. Here, we investigate these principles by testing responses to auditory motion in visual motion area MT+ of congenitally blind and sighted individuals. Replicating previous reports, we find that MT+ as a whole shows a strong and selective responses to auditory motion in congenitally blind but not sighted individuals, suggesting that the emergence of this univariate response depends on experience. Importantly, however, multivoxel pattern analyses showed that MT+ contained information about different auditory motion conditions in both blind and sighted individuals. These results were specific to MT+ and not found in early visual cortex. Basic sensitivity to auditory motion in MT+ is thus experience-independent, which may be a basis for the region's strong cross-modal recruitment in congenital blindness.

Purpose: To investigate the spatiotemporal evolution of cortical activation during the initiation of optokinetic nystagmus using magnetoencephalography. Background: Previous imaging studies of optokinetic nystagmus in humans using positron emission tomography and functional magnetic resonance imaging discovered activation of a large set of cortical and subcortical structures during steady-state optokinetic stimulation, but did not provide information on the temporal dynamics of the initial response. Imaging studies have shown that cortical areas responsible for vision in occipital and temporo-occipital areas are involved, i.e. cortical areas control optokinetic stimulation in humans. Magnetoencephalography provides measures that reflect neural ensemble activity in the millisecond time scale, allowing the identification of early cortical components of visuomotor integration. Design/Methods: We studied neuromagnetic cortical responses during the initiation of optokinetic nystagmus in 6 right-handed healthy subjects. Neuromagnetic activity was recorded with a whole-head magnetoencephalograph, consisting of 143 planar gradiometers. Results: The mean (±SD) latency between stimulus onset and initiation of optokinetic nystagmus was 177.7 ± 59 ms. Initiation of optokinetic nystagmus evoked an early component in the primary visual cortex starting at 40-90 ms prior to the onset of the slow phase of nystagmus. Almost simultaneously an overlapping second component occurred bilaterally in the temporo-occipital area (visual motion areas), pronounced in the right hemisphere, starting at 10-60 ms prior to the slow-phase onset. Both components showed long-duration activity lasting for up to 100 ms after slow-phase onset. Conclusions: Our findings suggest that the initiation of optokinetic nystagmus induces early cortical activation in the occipital cortex and almost simultaneously bilaterally in the temporo-occipital cortex. These cortical regions might represent essential areas for the monitoring of retinal slip.

V5/MT+ modulates spatio-temporal integration differently across and within hemifields: Causal evidence from TMS

Visual information about lip and facial movements plays a role in audiovisual (AV) speech perception. Although this has been widely confirmed, previous behavioural studies have shown interlanguage differences, that is, native Japanese speakers do not integrate auditory and visual speech as closely as native English speakers. To elucidate the neural basis of such interlanguage differences, 22 native English speakers and 24 native Japanese speakers were examined in behavioural or functional Magnetic Resonance Imaging (fMRI) experiments while mono-syllabic speech was presented under AV, auditory-only, or visual-only conditions for speech identification. Behavioural results indicated that the English speakers identified visual speech more quickly than the Japanese speakers, and that the temporal facilitation effect of congruent visual speech was significant in the English speakers but not in the Japanese speakers. Using fMRI data, we examined the functional connectivity among brain regions important for auditory-visual interplay. The results indicated that the English speakers had significantly stronger connectivity between the visual motion area MT and the Heschl’s gyrus compared with the Japanese speakers, which may subserve lower-level visual influences on speech perception in English speakers in a multisensory environment. These results suggested that linguistic experience strongly affects neural connectivity involved in AV speech integration.

Processing of metaphor has long been studied due to implications on human cognition. But less has been explored as to its relationship with lexical access. This is important, because comprehension of conventional metaphors fundamentally hinges on activation of lexicalized metaphorical meanings, but early lexical access models rarely consider a distinction between literal and metaphorical meanings. This study attempts to bring these two lines of research together by investigating processing of lexical metaphors, i.e., metaphorical polysemy (e.g., “pressure”) based on Giora’s (2003) graded salience hypothesis. The graded salience hypothesis states that salient meanings, i.e., “more frequent, more familiar, or more conventional” meanings, are always initially accessed in context. Giora’s model differs from previous models because it comprehensively interprets lexical access as well as figurative language processing, thus receiving much attention in literature (Gibbs, 2001). But it has two major problems: (1) Vague definition of salience, particularly its relationship with frequency, and (2) Unclear criteria for semantic analysis and meaning distinction. To address these issues, this thesis combined a corpus linguistic approach and recent cognitive semantic theories with psycholinguistic experiments. I distinguished sense-level meanings from facet-level meanings based on Chinese Wordnet and calculate their sense frequencies in corpus. In one offline word association task and two online cross-modal lexical priming tasks, I found: Salient, sense-level literal meanings cannot be sufficiently activated in metaphorically-biased contexts. This contradicted the graded salience hypothesis’s prediction but corresponded to Ahrens et al.’s (1998) and Croft and Cruse’s (2004) lexical semantic theories that sense-level meanings cannot coexist in the same context. The study thus has significant implications on the graded salience hypothesis and for metaphor and lexical access research in general; particularly, a refined lexical semantic analysis based on cognitive linguistic theories is necessary. Besides, the results shed light on the relationship between frequency and salience, i.e., how corpus reflects human cognition, as well as how cognitive semantic theories can refine interpretations in psycholinguistic studies. Therefore, the study is expected to have a cross-domain contribution to the general field of cognitive science.

Metaphor is a conventional and ordinary part of language. A theory attempting to explain metaphor must account for the ease with which conventional metaphors are understood, and with the ability to understand novel metaphors as they are encountered. An approach to metaphor, based on the explicit representation of knowledge about metaphors, has been developed to address these issues. This approach asserts that the interpretation of conventional metaphoric language should proceed through the direct application of specific knowledge about the metaphors in the language. Correspondingly, the interpretation of novel metaphors can be accomplished through the systematic extension, elaboration, and combination of knowledge about already well-understood metaphors. MIDAS (Metaphor Interpretation, Denotation and Acquisition System) is a computer program that embodies this approach. MIDAS can be used to perform the following tasks: represent knowledge about conventional metaphors, interpret metaphoric language by applying this knowledge, and dynamically learn new metaphors as they are encountered during normal processing. Knowledge about conventional metaphors is represented in the form of coherent sets of associations between disparate conceptual domains. the representation captures both the details of individual metaphors, and the systematics exhibited by the set of metaphors in the language as a whole. These systematic sets of associations were implemented using the KODIAK knowledge representation language. MIDAS is capable of using this metaphoric knowledge to interpret conventional metaphoric language. The main thrust of this approach is that normal processing of metaphoric language proceeds through the direct application of specific knowledge about the metaphors in the language. This approach gives equal status to all conventional metaphoric and literal interpretations. Moreover, the mechanisms used to arrive at metaphoric and literal interpretations are fundamentally the same. When a metaphor is encountered for which MIDAS has no applicable knowledge, MIDAS calls upon its learning component - the Metaphor Extension System (MES). The approach embodies in the MES asserts that a novel metaphor can best be understood through the systematic extension of an already well-understood metaphor. MIDAS has been integrated as a part of the UNIX Consultant system. UC is a natural language consultant system that provides naive computer users with advice on how to use the UNIX operating system. By calling MIDAS, UC can successfully interpret and learn conventional UNIX domain metaphors, as they are encountered during the course of UC''s normal processing.

Nausea is associated with significant morbidity, and there is a wide range in the propensity of individuals to experience nausea. The neural basis of the heterogeneity in nausea susceptibility is poorly understood. Our previous functional magnetic resonance imaging (fMRI) study in healthy adults showed that a visual motion stimulus caused activation in the right MT+/V5 area, and that increased sensation of nausea due to this stimulus was associated with increased activation in the right anterior insula. For the current study, we hypothesized that individual differences in visual motion-induced nausea are due to microstructural differences in the inferior fronto-occipital fasciculus (IFOF), the white matter tract connecting the right visual motion processing area (MT+/V5) and right anterior insula. To test this hypothesis, we acquired diffusion tensor imaging data from 30 healthy adults who were subsequently dichotomized into high and low nausea susceptibility groups based on the Motion Sickness Susceptibility Scale. We quantified diffusion along the IFOF for each subject based on axial diffusivity (AD); radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA), and evaluated between-group differences in these diffusion metrics. Subjects with high susceptibility to nausea rated significantly (P < 0.001) higher nausea intensity to visual motion stimuli and had significantly (P < 0.05) lower AD and MD along the right IFOF compared to subjects with low susceptibility to nausea. This result suggests that differences in white matter microstructure within tracts connecting visual motion and nausea-processing brain areas may contribute to nausea susceptibility or may have resulted from an increased history of nausea episodes.

Emotional contexts affect memory processes. However, the impact of contextual priming as a function of the emotional valence on the recall of neutral information is not fully understood. The aim of the present study was to evaluate how a conditioning of emotional context during encoding may influence the subsequent memory of otherwise neutral materials in a well-established phenomenon as the serial position effect. Participants performed a free recall task for neutral words in three conditions: (i) word list alone; (ii) word list coupled with positive or neutral images; and (iii) word list coupled with negative or neutral images. Images were presented before each word stimulus. In three different experiments, the emotional context during the word list presentation was manipulated separately for primacy and recency clusters, and for the middle words (‘middlecy’). Emotional context affects free recall of neutral stimuli, changing the serial position curve effect across conditions. Namely, emotional images presented in the primacy and recency clusters worsen accuracy, whereas their occurrence in the ‘middlecy’ cluster reduces the oblivion. The present findings show that the typical pattern related to the serial position curve for neutral information can be shaped by the conditioning of emotional context. Findings have implications in medical-legal contexts in the case of the recollection of events with high emotional content.