Fronto-Parietal EEG asymmetry interactions predict negative attention bias: A secondary data analysis.

Attention bias (AB), the excessive attentional selection of certain stimuli over others, is found in individuals suffering from depression. Similarly, alpha asymmetries, the lateralization of inhibitory cortical activity in the EEG alpha band (8-13 Hz) have been linked to depression and motivational direction. By contrasting novel and more reliable AB metrics against alpha asymmetries in an exploratory data analysis, we aimed to examine whether hemispheric differences are associated with AB scores, which could in turn refine the current model of AB metrics. Fifty nonclinical females, aged 18-30 years with minimal-to-moderate depressive symptoms were included. The participants performed two sessions of the dot-probe task, measuring AB, consisting of 160 trials each. Primary and ratio AB scores were calculated by using the novel response-based calculations. Furthermore, resting-state 32-channel EEG was measured for 2.5 min. Alpha asymmetry scores were calculated for frontal (F3/F4, F7/F8) and parietal electrode pairs (P3/P4, P7/P8). Correlations and interactions were analyzed. The primary AB scores were positively associated with frontal asymmetries, whereas parietal asymmetries showed negative associations. The ratio AB scores also showed regional differences. Parietal asymmetries interacted significantly with frontal asymmetries and AB. There was a moderate positive correlation between the BDI-II scores and the bias ratio. Our results suggest that alpha asymmetries contribute to individual differences in attention bias, with frontoparietal asymmetry interactions playing a notable role. These findings highlight hemispheric asymmetries as important to consider in future models of attention bias. Nonetheless, the associations are preliminary and call for replication.