The neural basis of flashback formation: the impact of viewing trauma

Abstract

BackgroundPsychological traumatic events, such as war or road traffic accidents, are widespread. A small but significant proportion of survivors develop post-traumatic stress disorder (PTSD). Distressing, sensory-based involuntary memories of trauma (henceforth ‘flashbacks’) are the hallmark symptom of PTSD. Understanding the development of flashbacks may aid their prevention. This work is the first to combine the trauma film paradigm (as an experimental analogue for flashback development) with neuroimaging to investigate the neural basis of flashback aetiology. We investigated the hypothesis that involuntary recall of trauma (flashback) is determined during the original event encoding.MethodA total of 22 healthy volunteers viewed a traumatic film whilst undergoing functional magnetic resonance imaging (fMRI). They kept a 1-week diary to record flashbacks to specific film scenes. Using a novel prospective fMRI design, we compared brain activation for those film scenes that subsequently induced flashbacks with both non-traumatic control scenes and scenes with traumatic content that did not elicit flashbacks (‘potentials’).ResultsEncoding of scenes that later caused flashbacks was associated with widespread increases in activation, including in the amygdala, striatum, rostral anterior cingulate cortex, thalamus and ventral occipital cortex. The left inferior frontal gyrus and bilateral middle temporal gyrus also exhibited increased activation but only relative to ‘potentials’. Thus, these latter regions appeared to distinguish between traumatic content that subsequently flashed back and comparable content that did not.ConclusionsResults provide the first prospective evidence that the brain behaves differently whilst experiencing emotional events that will subsequently become involuntary memories – flashbacks. Understanding the neural basis of analogue flashback memory formation may aid the development of treatment interventions for this PTSD feature.

Media’s role in broadcasting acute stress following the Boston Marathon bombings

“…This belief persists despite mounting evidence that both live and video observation of threatening content can lead to fear conditioning (10), a central component of traumatic stress responses. More recent work further challenges this key assumption by demonstrating that experimental exposure to a traumatic film can activate fear circuitry in the brain and produce flashbackstwo key processes associated with the development of posttraumatic stress disorder (PTSD) (11). In light of these findings, we suggest that repeatedly engaging with trauma-related stories via the media may prolong the acute experience by constantly reminding people of trauma-related information and encouraging ruminative thinking.…”

Selective Association Between Tetris Game Play and Visuospatial Working Memory: A Preliminary Investigation

“…These memories are sensory‐based and affect‐laden comprising strong visual imagery (Bourne, Mackay, & Holmes, 2013; Holmes, Grey, & Young, 2005; Michael, Ehlers, Halligan, & Clark, 2005). Importantly, the Tetris procedure has been shown to reduce the number of subsequent intrusive memories of a traumatic film, even when it is played after a delay of half an hour (Deeprose et al, 2012; Holmes et al, 2009; Holmes, James, Kilford, & Deeprose, 2010) or up to 6 h later (Holmes et al, 2010), with recent successful translation to real‐life trauma (Iyadurai et al, 2017).…”

MVPA to enhance the study of rare cognitive events: An investigation of experimental PTSD

“…Experimental designs have been developed that mimic PTSD symptoms by inducing mild flashbacks within healthy volunteers through traumatic film footage [4], [5]. However, there is large variance in participant response to the traumatic films, meaning that one cannot a priori determine which specific events a participant will flashback to.…”