Incidental retrieval of emotional contexts in post-traumatic stress disorder and depression: An fMRI study

Matthew G Whalley,Michael D Rugg,Adam P.R Smith,Raymond J Dolan,Chris R Brewin

doi:10.1016/j.bandc.2008.05.008

Matthew G Whalley, Michael D Rugg + Show 3 more

Open Access

https://doi.org/10.1016/j.bandc.2008.05.008

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Abstract

In the present study, we used fMRI to assess patients suffering from post-traumatic stress disorder (PTSD) or depression, and trauma-exposed controls, during an episodic memory retrieval task that included non-trauma-related emotional information. In the study phase of the task neutral pictures were presented in emotional or neutral contexts. Participants were scanned during the test phase, when they were presented with old and new neutral images in a yes/no recognition memory task. fMRI results for the contrast between old and new items revealed activation in a predominantly left-sided network of cortical regions including the left middle temporal, bilateral posterior cingulate, and left prefrontal cortices. Activity common to all three groups when correctly judging pictures encoded in emotional contexts was much more limited. Relative to the control and depressed groups the PTSD group exhibited greater sensitivity to correctly recognised stimuli in the left amygdala/ventral striatum and right occipital cortex, and more specific sensitivity to items encoded in emotional contexts in the right precuneus, left superior frontal gyrus, and bilateral insula. These results are consistent with a substantially intact neural system supporting episodic retrieval in patients suffering from PTSD. Moreover, there was little indication that PTSD is associated with a marked change in the way negatively valenced information, not of personal significance, is processed.

Highlights

Behavioural studies of memory for emotionally neutral material have indicated that in post-traumatic stress disorder (PTSD) there is a small but consistent deficit that is greater for verbal than nonverbal material (Brewin, Kleiner, Vasterling, & Field, 2007)
Participants in the PTSD group scored significantly higher than control participants on the Impact of Event Scale-Revised (IES-R; Weiss & Marmar, 1997), t(24.8) = 11.53, p
We investigated neural changes associated with PTSD by examining brain activity associated with memory retrieval for neutral items encoded in emotional contexts

Summary

Introduction

Behavioural studies of memory for emotionally neutral material have indicated that in post-traumatic stress disorder (PTSD) there is a small but consistent deficit that is greater for verbal than nonverbal material (Brewin, Kleiner, Vasterling, & Field, 2007). In this study we attempt to compensate for some of the limitations of the script-driven imagery paradigm by investigating the neural correlates of retrieving memories in which the emotional valence is created experimentally rather than through personal experience. Previous script-driven imagery studies have found that PTSD is associated with reduced activity in the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) (Bremner et al, 1999; Lanius et al, 2001; Shin et al, 1999). In other studies attempts have been made to provoke symptoms by playing combat-related or neutral sounds to veterans with PTSD. These have found increased amygdala activity in the combat condition (Liberzon et al, 1999; Pissiota et al, 2002). Other reviews have pointed out that neuroimaging studies have yet to provide evidence relevant to theoretically important manifestations of PTSD, such as intrusive thoughts and memories (Frewen & Lanius, 2006; Liberzon & Martis, 2006)

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