Attentional bias to brief threat-related stimuli revealed by saccadic eye movements

摘要

According to theories of emotion and attention we are predisposed to orient rapidly towards threat. However, previous examination of attentional cueing by threat signals showed no enhanced capture at brief durations. We propose that the manual response measure employed in previous examinations is not sensitive enough to reveal threat biases at brief stimulus durations. Here, we investigated the time course of orienting attention towards threat-related stimuli in the exogenous cueing task. The type of threat-related stimulus (fearful face or body posture), cue duration (20ms or 100ms) and response mode (saccadic or manual) were systematically varied. In the saccade mode, both enhanced attentional capture and difficulty in disengaging attention from fearful faces and body postures were evident and limited to 20ms cue duration, suggesting that saccadic cueing effects emerge rapidly and appear to be a short lived phenomenon. Conversely, in the manual response mode, fearful faces and bodies impacted only upon the disengagement component of attention at 100ms cue duration, suggesting that manual responses reveal cueing effects which emerge over more extended periods of time. Taken together, the results show that saccades are able to reveal threat biases at brief cue durations consistent with current theories of emotion and attention.