The interpreter's brain during rest - Hyperconnectivity in the frontal lobe

Abstract

Language in its highest complexity is a unique human faculty with simultaneous translation being among the most demanding language task involving both linguistic and executive functions. In this context, bilingually grown up individuals as well as simultaneous interpreters (SIs) represent appropriate groups for studying expertise-related neural adaptations in the human brain. The present study was performed to examine if a domain-specific neural network activation pattern, constituted by brain regions involved in speech processing as well as cognitive control mechanisms can be detected during a task-free resting state condition. To investigate this, electroencephalographic (EEG) data were recorded from 16 SIs and 16 age and gender-matched multilingual control subjects. Graph-theoretical network analyses revealed interhemispheric hyperconnectivity between the ventral part of the prefrontal cortex (pars opercularis and pars triangularis) and the dorsolateral prefrontal cortex (DLPFC) in language experts compared to multilingual controls in the alpha frequency range. This finding suggests that the high cognitive demands placed on simultaneous interpreting lead to an increased neural communication between prefrontal brain regions essentially engaged in supporting executive control-a neural fingerprint that is even detectable during rest.

Fig 1. Significant network of the NBS analysis between the SIs and the controls in the lower alpha (8 Hz– 10 Hz) frequency band is shown in the sagittal, horizontal and coronal views (the blue spheres represent the location of the centroid voxels of the 84 BAs that entered the NBS analysis).

SIs show increased functional connectivity (depicted in red) in a network containing BA9, BA44, 45 and 46 (enlarged blue spheres) spanning both hemispheres (p = 0.046, FWE-corrected). A = anterior, L = left hemisphere, R = right hemisphere.