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Intrusive memories to traumatic footage: the neural basis of their encoding and involuntary recall.

Clark IA, Holmes EA, Woolrich MW, Mackay CE - Psychol Med (2015)

Bottom Line: Signal change associated with intrusive memory involuntary recall was modelled using finite impulse response basis functions.We found a widespread pattern of increased activation for Intrusive v. both Potential and Control scenes at encoding.The left inferior frontal gyrus and middle temporal gyrus showed increased activity in Intrusive scenes compared with Potential scenes, but not in Intrusive scenes compared with Control scenes.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry,University of Oxford,Warneford Hospital,Oxford OX3 7NG,UK.

ABSTRACT

Background: A hallmark symptom after psychological trauma is the presence of intrusive memories. It is unclear why only some moments of trauma become intrusive, and how these memories involuntarily return to mind. Understanding the neural mechanisms involved in the encoding and involuntary recall of intrusive memories may elucidate these questions.

Method: Participants (n = 35) underwent functional magnetic resonance imaging (fMRI) while being exposed to traumatic film footage. After film viewing, participants indicated within the scanner, while undergoing fMRI, if they experienced an intrusive memory of the film. Further intrusive memories in daily life were recorded for 7 days. After 7 days, participants completed a recognition memory test. Intrusive memory encoding was captured by comparing activity at the time of viewing 'Intrusive scenes' (scenes recalled involuntarily), 'Control scenes' (scenes never recalled involuntarily) and 'Potential scenes' (scenes recalled involuntarily by others but not that individual). Signal change associated with intrusive memory involuntary recall was modelled using finite impulse response basis functions.

Results: We found a widespread pattern of increased activation for Intrusive v. both Potential and Control scenes at encoding. The left inferior frontal gyrus and middle temporal gyrus showed increased activity in Intrusive scenes compared with Potential scenes, but not in Intrusive scenes compared with Control scenes. This pattern of activation persisted when taking recognition memory performance into account. Intrusive memory involuntary recall was characterized by activity in frontal regions, notably the left inferior frontal gyrus.

Conclusions: The left inferior frontal gyrus may be implicated in both the encoding and involuntary recall of intrusive memories.

No MeSH data available.


Related in: MedlinePlus

Neural basis of intrusive memory encoding. (a) Whole-brainanalysis of the encoding of Intrusive v. Potentialv. Control scenes, increased blood oxygen level-dependent (BOLD)responses in colour for each contrast. (b) Region-of-interest(ROI) analysis for the left inferior frontal gyrus (IFG) and middle temporal gyrus(MTG) showing the BOLD percentage signal change for Intrusive and Potential scenesrelative to Control scenes. (c) Whole-brain analysis of theencoding of Intrusive recognized v. Potential recognized,increased BOLD response shown in colour. (d) ROI analysis for theleft IFG and MTG showing the BOLD percentage signal change for Intrusiverecognized and Potential recognized picture stills. Values are means, withstandard deviations represented by vertical bars. R, Right; L, left.
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fig02: Neural basis of intrusive memory encoding. (a) Whole-brainanalysis of the encoding of Intrusive v. Potentialv. Control scenes, increased blood oxygen level-dependent (BOLD)responses in colour for each contrast. (b) Region-of-interest(ROI) analysis for the left inferior frontal gyrus (IFG) and middle temporal gyrus(MTG) showing the BOLD percentage signal change for Intrusive and Potential scenesrelative to Control scenes. (c) Whole-brain analysis of theencoding of Intrusive recognized v. Potential recognized,increased BOLD response shown in colour. (d) ROI analysis for theleft IFG and MTG showing the BOLD percentage signal change for Intrusiverecognized and Potential recognized picture stills. Values are means, withstandard deviations represented by vertical bars. R, Right; L, left.

Mentions: Whole-brain analysis comparing Intrusive with Potential (Fig. 2a, top row) and Control scenes (Fig. 2a, middle row) revealedwidespread increases in activation, including the putamen, rostral anterior cingulatecortex, insula, thalamus and ventral occipital cortex. Signal change extracted frompredefined ROIs showed, as predicted, differences in activation in the MTG and left IFGbetween Intrusive and Potential scenes but not between Intrusive and Control scenes(Fig. 2b). Comparison ofPotential scenes with Control scenes at the whole-brain level (Fig. 2a bottom row) revealed increased activationin the thalamus and ventral occipital cortex. Table1 shows peak voxel coordinates. Fig. 2.


Intrusive memories to traumatic footage: the neural basis of their encoding and involuntary recall.

Clark IA, Holmes EA, Woolrich MW, Mackay CE - Psychol Med (2015)

Neural basis of intrusive memory encoding. (a) Whole-brainanalysis of the encoding of Intrusive v. Potentialv. Control scenes, increased blood oxygen level-dependent (BOLD)responses in colour for each contrast. (b) Region-of-interest(ROI) analysis for the left inferior frontal gyrus (IFG) and middle temporal gyrus(MTG) showing the BOLD percentage signal change for Intrusive and Potential scenesrelative to Control scenes. (c) Whole-brain analysis of theencoding of Intrusive recognized v. Potential recognized,increased BOLD response shown in colour. (d) ROI analysis for theleft IFG and MTG showing the BOLD percentage signal change for Intrusiverecognized and Potential recognized picture stills. Values are means, withstandard deviations represented by vertical bars. R, Right; L, left.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4697303&req=5

fig02: Neural basis of intrusive memory encoding. (a) Whole-brainanalysis of the encoding of Intrusive v. Potentialv. Control scenes, increased blood oxygen level-dependent (BOLD)responses in colour for each contrast. (b) Region-of-interest(ROI) analysis for the left inferior frontal gyrus (IFG) and middle temporal gyrus(MTG) showing the BOLD percentage signal change for Intrusive and Potential scenesrelative to Control scenes. (c) Whole-brain analysis of theencoding of Intrusive recognized v. Potential recognized,increased BOLD response shown in colour. (d) ROI analysis for theleft IFG and MTG showing the BOLD percentage signal change for Intrusiverecognized and Potential recognized picture stills. Values are means, withstandard deviations represented by vertical bars. R, Right; L, left.
Mentions: Whole-brain analysis comparing Intrusive with Potential (Fig. 2a, top row) and Control scenes (Fig. 2a, middle row) revealedwidespread increases in activation, including the putamen, rostral anterior cingulatecortex, insula, thalamus and ventral occipital cortex. Signal change extracted frompredefined ROIs showed, as predicted, differences in activation in the MTG and left IFGbetween Intrusive and Potential scenes but not between Intrusive and Control scenes(Fig. 2b). Comparison ofPotential scenes with Control scenes at the whole-brain level (Fig. 2a bottom row) revealed increased activationin the thalamus and ventral occipital cortex. Table1 shows peak voxel coordinates. Fig. 2.

Bottom Line: Signal change associated with intrusive memory involuntary recall was modelled using finite impulse response basis functions.We found a widespread pattern of increased activation for Intrusive v. both Potential and Control scenes at encoding.The left inferior frontal gyrus and middle temporal gyrus showed increased activity in Intrusive scenes compared with Potential scenes, but not in Intrusive scenes compared with Control scenes.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry,University of Oxford,Warneford Hospital,Oxford OX3 7NG,UK.

ABSTRACT

Background: A hallmark symptom after psychological trauma is the presence of intrusive memories. It is unclear why only some moments of trauma become intrusive, and how these memories involuntarily return to mind. Understanding the neural mechanisms involved in the encoding and involuntary recall of intrusive memories may elucidate these questions.

Method: Participants (n = 35) underwent functional magnetic resonance imaging (fMRI) while being exposed to traumatic film footage. After film viewing, participants indicated within the scanner, while undergoing fMRI, if they experienced an intrusive memory of the film. Further intrusive memories in daily life were recorded for 7 days. After 7 days, participants completed a recognition memory test. Intrusive memory encoding was captured by comparing activity at the time of viewing 'Intrusive scenes' (scenes recalled involuntarily), 'Control scenes' (scenes never recalled involuntarily) and 'Potential scenes' (scenes recalled involuntarily by others but not that individual). Signal change associated with intrusive memory involuntary recall was modelled using finite impulse response basis functions.

Results: We found a widespread pattern of increased activation for Intrusive v. both Potential and Control scenes at encoding. The left inferior frontal gyrus and middle temporal gyrus showed increased activity in Intrusive scenes compared with Potential scenes, but not in Intrusive scenes compared with Control scenes. This pattern of activation persisted when taking recognition memory performance into account. Intrusive memory involuntary recall was characterized by activity in frontal regions, notably the left inferior frontal gyrus.

Conclusions: The left inferior frontal gyrus may be implicated in both the encoding and involuntary recall of intrusive memories.

No MeSH data available.


Related in: MedlinePlus