EEG cortical sources of face and word as distractors during emotional interference

Objectives: Faces and words bearing emotional valence are commonly encountered affective stimuli by humans. It is known that emotional distractors interfere with the task goal and disrupt the cognitive performance. However, the differential cortical sources involved as neural substrates, to process emotional distractors, while affecting performance during the presence of another emotional stimuli, (emotional interference) is still unexplored. Materials and Methods: Emotional interference was studied in 20 healthy adults (25.15 ± 2.978) while performing face-word interference (FwI) and Word-face interference (WfI) tasks, wherein words with emotions and faces were distractors and 128 channel electroencephalogram was acquired simultaneously. Further, standardised low-resolution electromagnetic tomography-based source analysis was done to study the differences in the cortical activity between the tasks across 66 gyri. Results: Higher reaction time (RT) and lower accuracy percentage were seen for categorising face in presence of word (FwI) versus word in presence of face (WfI) ( P < 0.001). We observed no difference in RT and lower accuracy percentage between incongruent FWI trials as compared to congruent FWI trials. In addition, we observed higher RT and lower accuracy percentage between incongruent WFI trials as compared to congruent WFI trials. Source analysis revealed higher cortical activity across 60 gyri and significantly lower cortical activity across three gyri during performance of FwI compared to WfI task ( P < 0.05/66). Activation of areas associated with saliency, conflict and goal directed behaviour exhibited consistently higher activity in FwI trials compared to WfI trials indicating the robustness of face processing and the hierarchical interplay of neural substrates in conditions of cognitive control. Conclusion: Cortical processing of face emerged as more potent distractor compared to an emotional word during emotional interference task.