The neural bases of resilient cognitive systems: Evidence of variable neuro-displacement in the semantic system

Abstract

The purpose of this study was to initiate exploration of an equally-important research goal: what are the neurocomputational mechanisms that make these cognitive systems "well engineered" and thus resilient across a range of performance demands and to mild levels of perturbation or even damage? We achieved this aim by investigating the neural dynamics of the semantic network with two task difficulty manipulations. We found that intrinsic resilience-related mechanisms were observed in both the domain-specific semantic representational system and the parallel executive control networks. Functional connectivity between these regions was also increased and these increases were related to better semantic task performance. Our results suggest that higher cognitive functions are made resilient by flexible, dynamic changes (variable neuro-displacement) across both domain-specific and multi-demand networks. Our findings provide strong evidence that the compensatory functional alterations in the impaired brain might reflect intrinsic mechanisms of a well-engineered neural system.

Enhancing vs. inhibiting semantic performance with transcranial magnetic stimulation over the anterior temporal lobe: Frequency- and task-specific effects

“…Similarly, the enhanced semantic performance after 20 Hz rTMS over the left ATL might be attributed to not only the increased cortical excitability at the target site but also the enhanced connectivity within the semantic network. Our recent investigation examining the semantic network showed that there were up-regulated regional activation in the bilateral ATL, left IFG and posterior middle temporal gyrus (pMTG) and the increased functional connectivity between the semantic regions (e.g., the ATL-connectivity, ATL-IFG connectivity, and IFG-pMTG connectivity) in the challenging semantic decision making ( Jung and Lambon Ralph, 2019 ). The enhanced connectivity within the semantic network contributed to better semantic performance with increased task demands.…”

Neural correlates of confusability in recognition of morphologically complex Korean words

“…The ATL is a trans-modal hub in semantic memory [ 83 ]. Recent work has demonstrated significant coupling between the ATL and mPFC when the semantic demand was increased in a given task [ 84 ]. These findings suggest the involvement of semantic processing when the morpheme boundary is positioned between syllables.…”