Korean Journal of Biological Psychiatry

Objectives：Trauma patients have attentional bias which enforces traumatic memories and causes cognitive errors. Understanding of such selective attention may explain many aspects of the posttraumatic stress disorder(PTSD) symptoms.

Methods：We used the rapid serial visual presentation(RSVP) method to verify attentional blink in burn patients with PTSD. International affective picture system(IAPS) was used as stimuli and distracters. In the 'neutral test', patients have been presented series of pictures with human face picture as target stimuli. Each picture had 100ms interval. However the distance between target facial pictures was randomized and recognition of second facial picture accuracy was measured. In the 'stress test', the first target was stress picture which arouses patient emotions instead of the facial picture. Neutral and Stress tests were done with seven PTSD patients and 20 controls. In '85ms test' the interval was reduced to 85ms. The accuracy of recognition of second target facial picture was rated in all three tests. Eighty-five ms study was done with eighteen PTSD patients.

Results：Attentional blinks were observed in 100-400ms of RSVP. PTSD patients showed increased recognition rate in the 'stress test' compared with the 'neutral test'. When presentation interval was decreased to 85 ms, PTSD patient showed decrease of attentional blink effect when target facial picture interval was 170ms.

Conclusion：We found attentional blink effect could be affected by stress stimulus in burn patients. And attentional blink may be affected by stimulus interval and the character of stimulus. There may be some other specific mechanism related with selective attention in attentional blink especially with facial picture processing.

Keywords PTSD;RSVP;IAPS.