Experimental design. Each experimental run consisted of two detection-only blocks, one unpleasant block, and one neutral block. During the unpleasant and neutral blocks, pictures were presented for 3 seconds and immediately followed by a sequence of eight target-detection trials. Participants were instructed to attend to each picture for as long as it was displayed and to press a button with the right index finger as quickly as possible after target onset. After eight target-detection trials, a new picture appeared on the screen. In the detection-only blocks, a 3-s black screen preceded the sequence of target-detection trials. Stimuli are not drawn to scale.