Context matters: Novel metaphors in supportive and non-supportive contexts

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.

The Psychological Reality of Chinese Deliberate Metaphors from the Reception Side: An Experimental Approach

While the psychological reality of deliberate metaphors remains in ongoing doubt, this study attests to their psychological reality in the Chinese language. Based upon the definition and main tenets of deliberate metaphor, we propose three hypotheses: Compared with non-deliberate metaphors, addressees pay more attention to deliberate metaphors' source domains, display a greater tendency to adopt the source domain's perspective, and spend more time on processing deliberate metaphors. Using Chinese deliberate metaphors as testing materials, we conducted an experiment with 70 Chinese university students whose native language was Chinese. The results confirmed our hypotheses. Compared with non-deliberate metaphors, Chinese deliberate metaphors drew more attention and brought about more perspective changes. Additionally, processing deliberate novel metaphors consumed more time than processing non-deliberate metaphors, thus providing supportive evidence for the psychological reality of Chinese deliberate metaphors. However, less time taken on deliberate conventional metaphors than non-deliberate metaphors might have been caused by our experiment's task design. In a nutshell, our study statistically proves the psychological reality of Chinese deliberate metaphors from the reception side. Future studies may check our findings with a similar experimental paradigm in other languages.

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.

Elucidating the structural-functional connectome of language in glioma-induced aphasia using nTMS and DTI

Glioma‐induced aphasia (GIA) is frequently observed in patients with newly diagnosed gliomas. Previous studies showed an impact of gliomas not only on local brain regions but also on the functionality and structure of brain networks. The current study used navigated transcranial magnetic stimulation (nTMS) to localize language‐related regions and to explore language function at the network level in combination with connectome analysis. Thirty glioma patients without aphasia (NA) and 30 patients with GIA were prospectively enrolled. Tumors were located in the vicinity of arcuate fasciculus‐related cortical and subcortical regions. The visualized ratio (VR) of each tract was calculated based on their respective fractional anisotropy (FA) and maximal FA. Using a thresholding method of each tract at 25% VR and 50% VR, DTI‐based tractography was performed to construct structural brain networks for graph‐based connectome analysis, containing functional data acquired by nTMS. The average degree of left hemispheric networks (M_left) was higher in the NA group than in the GIA group for both VR thresholds. Differences of global and local efficiency between 25% and 50% VR thresholds were significantly lower in the NA group than in the GIA group. Aphasia levels correlated with connectome properties in M_left and networks based on positive nTMS mapping regions (M_pos). A more substantial relation to language performance was found in M_pos and M_left compared to the network of negative mapping regions (M_neg). Gliomas causing deterioration of language are related to various cerebral networks. In NA patients, mainly M_neg was impacted, while M_pos was impacted in GIA patients.

Hemisphere stroke: impact on the semantic lexical aspects of language

OBJECTIVE

To investigate if right hemisphere stroke is associated with decreased lexical-semantic ability.

METHODS

We compared subjects with right hemisphere brain damage after stroke with healthy controls using the validated version of the Montreal Evaluation of Communication to assess lexical-semantic domains of language.

RESULTS

Sixteen patients and thirty-two controls were included. The post-stroke group with right hemispheric brain lesions showed considerable limitations in metaphor interpretation, fluency, and semantic judgment.

CONCLUSION

Individuals with right hemisphere damage after stroke may present with language changes in the lexical-semantic aspects.