Cognitive control of attention is differentially affected in trauma-exposed individuals with and without post-traumatic stress disorder

Abstract

Background: This study aimed to determine whether patients with post-traumatic stress disorder (PTSD) show difficulty in recruitment of the regions of the frontal and parietal cortex implicated in top-down attentional control in the presence and absence of emotional distracters.

Method: Unmedicated individuals with PTSD (n = 14), and age-, IQ- and gender-matched individuals exposed to trauma (n = 15) and healthy controls (n = 19) were tested on the affective number Stroop task. In addition, blood oxygen level-dependent responses, as measured via functional magnetic resonance imaging, were recorded.

Results: Patients with PTSD showed disrupted recruitment of lateral regions of the superior and inferior frontal cortex as well as the parietal cortex in the presence of negative distracters. Trauma-comparison individuals showed indications of a heightened ability to recruit fronto-parietal regions implicated in top-down attentional control across distracter conditions.

Conclusions: These results are consistent with suggestions that emotional responsiveness can interfere with the recruitment of regions implicated in top-down attentional control; the heightened emotional responding of patients with PTSD may lead to the heightened interference in the recruitment of these regions.

Fig. 1

Example trial sequences : (a) negative view trial ; (b) negative congruent trial ; (c) negative incongruent trial.

Fig. 2

Regions related to task performance showing reduced activity in the presence of negative distracters in the patients with post-traumatic stress disorder (PTSD). Mean (standard deviation) blood oxygen level-dependent (BOLD) responses in healthy control (HC), trauma control (TC) and PTSD participants and relationship between degree of disruption by negative distracters and Clinician Administered PTSD Scale (CAPS) scores for the PTSD and HC individuals within : (a) right inferior parietal lobule, Brodmann area 40 (x, y, z=33, −48, 45) ; (b) right superior frontal cortex, Brodmann area 9 (x, y, z=42, 36, 27).

Fig. 3

Regions related to task performance showing heightened activity in the trauma controls relative to both the patients with post-traumatic stress disorder and the healthy controls. Mean (standard deviation) blood oxygen level-dependent (BOLD) responses within : (a) left dorsolateral frontal cortex, Brodmann area 46 (x, y, z=−57, 33, 18) ; (b) left superior frontal cortex, Brodmann area 9/6 (x, y, z=−54, 6, 45).