英语翻译Previous studies with word stimuli have shown a consiste

英语翻译Previous studies with word stimuli have shown a consistent pattern of vigilance for threat words in GAD across diåerent stimulus durations ranging from 14 ms to 1000 ms.The time course of the attentional bias is an important issue.Persistent,maladaptive or clinical anxiety has been seen as resulting from a failure of emotional processing,and it has been suggested that brief exposure to threat,followed by avoidance,might produce the conditions for incomplete emotional processing of threat stimuli or sensitization to such stimuli.Similarly,brief attentional vigilance to threat followed by attentional avoidance might underlie the maintenance of excessive anxiety states.While no evidence has been found of avoidance following initial vigilance to threat faces in high anxious normals using stimulus durations of 500 ms and 1250 ms,such evidence has been found with severe threat stimuli and similar stimulus durations in a non-clinical sample who were fearful of blood-injury.It is therefore important to test this hypothesis of a vigilance-avoidance pattern of bias in a clinically anxious sample with pictorial representations of threat.Individuals with GAD were selected as the clinical sample for the present study,given that GAD reflects the extreme end of the spectrumof trait diåerences in vulnerability to anxiety.The pattern of attentional bias over the first and second halves of the task was also examined.Broadbent& Broadbent (1988) found the bias to be stronger in the second half of the task,suggesting that the effect is `due to increasing post-attentive awareness of the presence of threatening words’.Thus,although there is evidence that automatic processes are involved in the attentional bias for threat in clinical and non-clinical anxiety,the findings of Broadbent & Broadbent (1988) suggest that strategic influences contribute to the bias.Thus,it is informative to examine whether an attentional bias for threat face stimuli similarly develops over the course of the task.Consequently,the present study investigated attentional biases for threatening and happy emotional facial expressions in GAD.A probe discrimination task was used to assess attentional bias,similar to that used by Bradley et al.(1998).In this task,on each trial,a pair of faces was presented side by side,and immediately after thefaces disappeared a probe stimulus appeared in the location of one of the faces.