Attentional bias toward fearful facial expressions: EEG correlates in theta oscillations
Robert D. Torrence1, Lucy J. Troup1,2, Donald C. Rojas1; 1Colorado State University, 2University of the West of Scotland
Rapid attention to threatening stimuli in the environment has been a necessary trait throughout evolution. Fearful faces can signal the location of the threat to an observer. Previous research used behavioral (i.e. reaction time) and neuroimaging (e.g. fMRI, EEG, ERP) methods to examine attentional bias toward emotion facial expressions. Diao et al. (2017), found that theta oscillations in the contralateral electrodes to angry facial expressions were elevated. This study examined theta oscillations in response to fearful faces. The participants (N = 11) performed a standard dot-probe task that consisted of three trial types: fear congruent (i.e. dot appears behind the fearful face), fear incongruent (i.e. dot appears behind neutral face), and neutral (i.e. two neutral faces). The face pairs were displayed simultaneously for 50ms on the left and right side of the screen. The trial ended when the participant indicated the location of the dot. Inter-trial interval was 2 seconds. EEG data was analyzed using an average reference and filtered using a .1-30 Hz bandpass filter. ICA was used for artifact correction and rejection. Time-frequency analysis was conducted on electrodes PO7 and PO8. Elevated theta oscillations in the posterior contralateral electrode to the fearful facial expression were present around 200ms after face onset. These results were consistent with previous research that indicated greater theta oscillations in attention toward angry faces. This study then contributes to the existing body of research that there were elevated theta oscillations posterior contralateral to threat-related facial expressions.
Topic Area: ATTENTION: Spatial