Presentation
Search Abstracts | Symposia | Slide Sessions | Poster Sessions | Lightning Talks
The role of the right hemisphere in control and social dimensions of verbal semantics: Insights from an ALE Meta-analysis of 360 Functional Neuroimaging Studies
There is a Poster PDF for this presentation, but you must be a current member or registered to attend SNL 2023 to view it. Please go to your Account Home page to register.
Poster D22 in Poster Session D, Wednesday, October 25, 4:45 - 6:30 pm CEST, Espace Vieux-Port
Eszter Demirkan1, Francesca M. Branzi1; 1University of Liverpool
Language processing has been associated with a bilateral albeit left-lateralised network of brain regions, including the anterior temporal lobe [ATL], inferior frontal gyrus [IFG], posterior middle temporal gyrus [pMTG], and angular gyrus [AG]. However, the involvement of the right frontoparietal and temporal regions (henceforth the ‘right language network’) is not ubiquitous in language tasks and, to date, the role of the right hemisphere for language is not well understood. In this study, we tested two hypotheses regarding the role of the right language network for verbal semantic processing. One possibility is that some of the regions within the right language network support the same semantic function as in the left hemisphere. Nevertheless, they would be particularly engaged when control demands increase. Accordingly, the upregulation of function in these brain areas should be observed only when control demands increase. Another non-mutually exclusive possibility is that the involvement of some parts of the right language network reflects the processing of the social content of the stimuli. If true, then these brain areas should be engaged particularly when stimuli require social cognition processing. To address these hypotheses, we conducted an Activation Likelihood Estimate meta-analysis of 357 functional neuroimaging studies focussing on verbal semantic tasks. To establish which portions of the right language network were particularly sensitive to increased control demands, we compared active regions correlated with hard versus easy task conditions. Task difficulty was established by word or homonym frequency, number of distractors, reduced contextual support, and semantic incongruency, among other criteria. We analysed 1146 activation coordinates. The results revealed that increased semantic control demands modulated activation of the left IFG, left pMTG, and right IFG. Interestingly, right IFG was not included in the verbal semantic network (semantic versus non-semantic stimuli contrast), suggesting that right IFG might be recruited only when semantic demands increase. Then, to establish which portions of the right language network were particularly sensitive to the social nature of the stimuli, we analysed 4150 activation coordinates taken from neuroimaging studies using verbal stimuli with versus without social content. In detail, we analysed separately and contrasted activations derived from verbal semantic tasks using (1) word stimuli without social content (versus non-semantic baseline) and (2) sentences/word stimuli referring to social concepts and likely engaging theory of mind processes (versus non-semantic active baseline). Results revealed that left ATL and left pMTG were activated irrespective of the nature of the stimuli. However, right ATL and right pMTG were activated only by verbal stimuli with social content. Whilst right AG was not modulated by the type of stimuli, left AG showed a functional fractionation depending on the social content of the stimuli. In detail, stimuli with social content activated anterior-ventral portions of the left AG and the temporal parietal junction. Instead, stimuli without social content activated posterior-dorsal portions of the left AG. The current data show that control and social dimensions are critical to understanding the role of the language regions in the right hemisphere.
Topic Areas: Meaning: Lexical Semantics, Control, Selection, and Executive Processes