Heightened Attentional Capture by Threat in Veterans With PTSD
This is the final of the three Emotional Attentional Blink papers that cover the EAB in subjects with different disorders. This paper by Bunmi O. Olatunji, Thomas Armstrong, Maureen McHugo, and David Zald covers the EAB in subjects with Post-Traumatic Stress Disorder (PTSD).
Summary: This paper is alot like the other two! The paper also used a typical Emotional Attentional Blink paradigm: an RSVP stream with a single target and an emotional distractor between 2 and 8 landscape distractors before the target. However, the experimenters add combat-related distractors into the mix this time. The experiment had three experimental groups: veterans with PTSD, veterans without PTSD, and a comparable control group. Each performed the described task, and the experimenters compared the groups' performances. The veteran+PTSD group responds similarly to the veteran-PTSD and control groups in all conditions but the combat distractors; only the veterans with PTSD demonstrated an EAB to these images. Dr. Olatunji theorizes that this increased EAB is the result of a general inability to disengage attention from emotional distractors due to their status as threat-relevant in veterans with PTSD.
The Take-Away: The Emotional Attentional Blink is different in subjects with PTSD, most likely as a result of an increased inability to disengage attentional resources from images that subjects have implicitly (unconsciously) learned are salient due to emotional connections.
My Thoughts: This paper once again points to the inability to disengage attention from emotional targets as the cause of a larger EAB, which makes sense. However, there is a twist here: the combat targets only elicit an EAB in veterans with PTSD, not in the control or other veterans without PTSD. This means that the veterans with PTSD must have been conditioned to find combat images threat-relevant, most likely as a result of their traumatic experiences that led to PTSD.
This isn't unheard of at all, and connects well with previous research by Stephen D. Smith, Steven B. Most, Leslie A. Newsome, and David H. Zald (2012). In their paper, "An emotion-induced attentional blink elicited by aversively conditioned stimuli," the authors find that neutral stimuli can elicit an EAB after being consistently paired with a loud burst of disturbing noise. This clearly demonstrates that subjects can be conditioned to give images emotional significance, or salience, that leads to further disruptive processing. It's important to remember that this is all done subconsciously, and that the EAB is not the result of subjects willingly giving too many attentional resources to the emotional distractor; the distractor captures attention, and this has nothing to do with volitional attention.