Feature-specific attention allocation overrules the orienting response to emotional stimuli.

Emotional stimuli are generally thought to be processed in an unconditional fashion. Recent behavioral studies suggest, however, that emotional stimulus processing is critically dependent on attention toward emotional stimulus features. We set out to test this hypothesis using EEG measurements and a modified oddball paradigm. Unexpected emotional stimuli evoked amplitude variations of the P3a (an ERP marker of attention orienting) when attention was directed to emotional stimulus properties but not when non-emotional stimulus properties were attended to. We conclude that emotional stimulus processing is not unconditional, but dependent on top-down attentional control.