Showing papers by "Mohamed L. Seghier published in 2022"

Multiple functions of the angular gyrus at high temporal resolution

Abstract: Here, the functions of the angular gyrus (AG) are evaluated in the light of current evidence from transcranial magnetic/electric stimulation (TMS/TES) and EEG/MEG studies. 65 TMS/TES and 52 EEG/MEG studies were examined in this review. TMS/TES literature points to a causal role in semantic processing, word and number processing, attention and visual search, self-guided movement, memory, and self-processing. EEG/MEG studies reported AG effects at latencies varying between 32 and 800 ms in a wide range of domains, with a high probability to detect an effect at 300–350 ms post-stimulus onset. A three-phase unifying model revolving around the process of sensemaking is then suggested: (1) early AG involvement in defining the current context, within the first 200 ms, with a bias toward the right hemisphere; (2) attention re-orientation and retrieval of relevant information within 200–500 ms; and (3) cross-modal integration at late latencies with a bias toward the left hemisphere. This sensemaking process can favour accuracy (e.g. for word and number processing) or plausibility (e.g. for comprehension and social cognition). Such functions of the AG depend on the status of other connected regions. The much-debated semantic role is also discussed as follows: (1) there is a strong TMS/TES evidence for a causal semantic role, (2) current EEG/MEG evidence is however weak, but (3) the existing arguments against a semantic role for the AG are not strong. Some outstanding questions for future research are proposed. This review recognizes that cracking the role(s) of the AG in cognition is possible only when its exact contributions within the default mode network are teased apart.

It is time to make neuroimaging research data beneficial to the participants

Abstract: The code of ethical conduct in brain research with neuroimaging tools entails putting in place safe protocols to prevent harm to participants, whether inadvertent or not. A typical consent form for instance includes a list of possible sources of psychological and physical harm to the participant, whereas potential benefit is limited to general statements about knowledge creation. Indeed, benefits to the participant are not always obvious or obtainable. This could change in the near future by recognizing that brain scans collected when the participant was healthy might prospectively serve as a “proper” (subject-specific) control to better understand brain correlates of post-deficit outcome and recovery when the same participant is affected by a particular neurological or mental condition. This might open new avenues for precision neurology, with the ability to derive individualized brainbehavior relationships for diagnosis and prognosis purposes. The current trend in precision neurology promotes the use of AI-powered tools on big data, but this can be complemented by data collected from the same individuals before and after deficit.