Salient affective scenes compete with concurrent visual responses in the absence of task demands

Visual attention systems of the human brain resolve competition between concurrent inputs by prioritizing information that is relevant to an observer's goals, motives, and biological states. Research shows that concurrent distractors-especially emotionally salient stimuli-reduce task performance and visual responses to task cues. In many naturalistic viewing situations however, there are multiple competing cues with no obvious demarcation between task and distractor. The present study examined whether viewing two overlapping task-irrelevant stimulus streams produces emotion-dependent competition in visual cortex. Steady-state visual evoked potential (ssVEP) frequency tagging independently quantified visuocortical activity elicited by a picture (6.7 Hz) stream that overlapped with a central fixation-cross flickering at 15 Hz. We replicated established interference effects within the picture stream, showing that rapidly changing emotionally salient (pleasant and unpleasant) pictures elicited a strong reduction in the 6.7 Hz ssVEP envelope relative to neutral pictures. The 15 Hz ssVEP to the flickering fixation cross paralleled these findings, being more attenuated when competing with emotional, compared to neutral pictures. Change-point analyses indicated that competition latency varied with picture saliency, occurring earlier for pleasant and unpleasant than for neutral streams. Together, the present study suggests that visuocortical mass activity displays emotion-modulated competition effects in the absence of task demands.