Biased emotional attention in post-traumatic stress disorder: a help as well as a hindrance?

Background. From a cognitive neuroscience perspective, the emotional attentional bias in posttraumatic stress disorder (PTSD) could be conceptualized either as emotional hyper-responsiveness or as reduced priming of task-relevant representations due to dysfunction in 'top-down' regulatory systems. We investigated these possibilities both with respect to threatening and positive stimuli among traumatized individuals with and without PTSD. Method. Twenty-two patients with PTSD, 21 trauma controls and 20 non-traumatized healthy participants were evaluated on two tasks. For one of these tasks, the affective Stroop task (aST), the emotional stimuli act as distracters and interfere with task performance. For the other, the emotional lexical decision task (eLDT), emotional information facilitates task performance. Results. Compared to trauma controls and healthy participants, patients with PTSD showed increased interference for negative but not positive distracters on the aST and increased emotional facilitation for negative words on the eLDT. Conclusions. These findings document that hyper-responsiveness to threat but not to positive stimuli is specific for patients with PTSD.