Temporal property in attention bias for negative facial emotion revealed in dot-probe task

Attention bias for negative facial expressions over neutral expressions has typically been studied using a dot-probe paradigm and spatial cueing paradigm. In the dot-probe paradigm, a pair of facial stimuli (one with negative emotion and the other with neutral emotion) appears at two different spatial locations on a screen. Immediately after the disappearance of the facial stimulus, a dot emerges randomly at one of the two locations: the location for the previous negative stimulus (“congruent” condition) or the location for the previously neutral stimulus (“incongruent” condition). A shorter reaction time is typically found in the congruent condition than the incongruent condition. In the spatial cueing paradigm, when a cue with neutral (or negative) emotion is followed by a target with neutral emotion, detection for the target at a cued location shortly after the cue is enhanced (shorter reaction time), but detection after a longer interval is impaired (longer reaction time, called inhibition of return, IOR). In the current study, we utilized a dot-probe paradigm, where we presented a pair of faces with the same identity but one with an angry expression and the other with a neutral expression. The time interval between the facial stimuli and the dot varied randomly among 50 ms, 500 ms, and 1000 ms. For the short time interval of 50 ms, we found the typical attention bias indicated by shorter reaction time in the congruent condition than that of the incongruent condition, but the magnitude of the attention bias diminished for the longer time intervals either 500 ms or 1000 ms. Our results suggest that the effect from the two paradigms is similar for a short time interval, however, the reversal of RT for longer time interval typically found in the spatial cueing paradigm is absent in the dot-probe paradigm.