Alpha oscillations for processing saliency are generated by common cortical networks in visual attention tasks spanning wide spatial and spatio-temporal scales [article]

Priyanka Ghosh, Dipanjan Roy, Arpan Banerjee
2019 bioRxiv   pre-print
Reorientation of attention towards unexpected salient changes around us is critical for survival. Current understanding from fMRI studies point towards a network comprising of pre-frontal cortical areas (PFC), temporo-parietal junction (TPJ) and insula being responsible for processing and reorienting attention in a myriad of tasks. However, little is known about the temporal structure of the dynamical changes that govern neural systems while reorienting attentional focus to visual stimuli
more » ... ing at very fast and very slow time scales. Using a custom-designed behavioral experiment and simultaneous EEG recordings, we investigated the effect of saliency across different task conditions to see if the underlying neural signatures involved in such rapid attentional shifts change with the task conditions. Interestingly, the EEG signal power at alpha band showed near identical rise in amplitude during salient conditions for a visual search and a dynamic motion tracking task. Source reconstruction underlying the enhanced alpha activity across task conditions revealed the involvement of lateral PFC, right insula and right TPJ which are regions of the Ventral Attention Network responsible for the deployment of bottom-up attention in response to salient stimuli. The results suggested a more general role of alpha oscillations which is dependent on the task context (saliency) but not on the task complexity or goals. Employing source-level effective connectivity analysis, we observed that the posterior right TPJ receives causal influences from the anterior right TPJ. Thus, we characterized the specific roles of both these regions in salient distractor processing for the first time through an EEG study.
doi:10.1101/2019.12.25.888446 fatcat:amx3unxytbhhlapussqlluyqsq