Visuospatial tasks during trauma may reduce intrusive memories of that event

03/01/04

Viewers who tapped out a pattern while watching a disturbing Viewers who tapped out a pattern while watching a disturbing Viewers who tapped out a pattern while watching a disturbing video suffered fewer intrusions during the following week

Washington -- During the French Revolution, tricoteurs knitted away while watching hundreds lose their heads to the guillotine. Did their knitting make it less traumatic? In three experiments, University College London researchers found that viewers who performed a visuospatial task while they watched a distressing video suffered fewer intrusive memories in the following week than viewers who performed a verbal task. Spontaneously occurring intrusive memories of a traumatic event – flashbacks -- are a hallmark of posttraumatic stress disorder (PTSD).

The research appears in the March issue of the Journal of Experimental Psychology: General, which is published by the American Psychological Association (APA).

Participants (212 in all) viewed a 12.5-minute trauma video with five scenes of horrific content – footage of the aftermath of actual car accidents, including injured victims screaming, workers moving dead bodies, and body parts amid the wreckage. Viewers were assigned to either an experimental group (which varied by task type during viewing) or a control (no task) group. For the next seven days, they recorded any intrusive memories of the video in a diary, noting the content of each intrusion.

During the following week, viewers who, during the video, had tapped out a specified pattern on a hidden keyboard -- a visuospatial task – had significantly fewer intrusive memories the video than control-group viewers, who had watched without doing anything else. The authors conclude, "Our data clearly establish that processes at encoding are critical in influencing the likelihood of later reported intrusions, presumably because they affect the representations that individuals form of the event."

Researcher Emily Holmes, D.Clin.Psy., explains that the same types of memory resources may be involved in processing both particular visuospatial tasks and the sensory aspects of traumatic stimuli, especially traumatic visuospatial stimuli such as images of the scene. Thus, when performed during a traumatic event, visuospatial tasks may reduce encoding of that type of memory and therefore lead to fewer intrusions. Interestingly, other viewers who repeatedly practiced the same task before the video and then performed it during the film also had significantly fewer reported intrusions than viewers who had no task during the video. However, not all types of "distraction" during trauma may be good for flashbacks. Yet another experiment revealed that verbal distraction – counting down by threes -- was associated with a greater number of subsequent intrusions than those of a control group. This finding suggests that verbal interference may limit the kind of verbal and conceptual processing that could help viewers "make sense" of the disturbing images. Fully encoded traumatic images would thus be left available in undigested form, easily summoned by everyday reminders.

The research supports a "dual-representation" theory of PTSD that proposes that traumas are encoded both in the form of higher-level verbal memories and as lower-level sensory memories. As a result, sensory and verbal interference may have changed the intrusion rate in opposite ways. Holmes likens visuospatial/sensory memory to raw film footage, filled with incoherent images that surface as flashbacks, and verbal/conceptual memory to a news broadcast, with narration to explain events and put them in perspective.

The research does not shed any direct light on the brain systems underlying these processes, but Holmes notes that clinical neuroscientists have found that during traumatic flashbacks, brain areas involved in verbal processing may be less active. She says, "That finding is consistent with our findings but further research is clearly needed."

The implications for real-world trauma treatment are clear. Although, says Holmes, "this research is at an early stage and not conclusive, it does suggest there may be a psychological way to reduce post-trauma intrusions, rather than a medical way such as taking medication. It would be very helpful to examine these tasks immediately post-trauma, such as in the emergency room."

Plus, Holmes points out that a psychological remedy could be within a traumatized individual's control, cost-effective and non-invasive. She says, "Future research is clearly needed before we apply this method to real trauma situations, and we must also consider the long-term consequences – positive or negative -- of any intervention".

Finally, the possible buffering effect of visuospatial tasks may also extend to the treatment of psychological disorders other than PTSD that are now also thought to involve intrusive imagery, such as worry (generalized anxiety disorder), insomnia, social phobia, agoraphobia, psychosis and others.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
    Published on PsychCentral.com. All rights reserved.

 

 

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