Abstract
Although intrusive memories are characteristic of many psychological disorders, the neurobiological underpinning of these involuntary recollections are largely unknown. In this study we used functional magentic resonance imaging (fMRI) to identify the neural networks associated with encoding of negative stimuli that are subsequently experienced as intrusive memories. Healthy partipants (N = 42) viewed negative and neutral images during a visual/verbal processing task in an fMRI context. Two days later they were assessed on the Impact of Event Scale for occurrence of intrusive memories of the encoded images. A sub-group of participants who reported significant intrusions (n = 13) demonstrated stronger activation in the amygdala, bilateral ACC and parahippocampal gyrus during verbal encoding relative to a group who reported no intrusions (n = 13). Within-group analyses also revealed that the high intrusion group showed greater activity in the dorsomedial (dmPFC) and dorsolateral prefrontal cortex (dlPFC), inferior frontal gyrus and occipital regions during negative verbal processing compared to neutral verbal processing. These results do not accord with models of intrusions that emphasise visual processing of information at encoding but are consistent with models that highlight the role of inhibitory and suppression processes in the formation of subsequent intrusive memories.
Highlights
Involuntary intrusive memories, thoughts or images are often distressing symptoms that occur in a wide variety of clinical disorders, including posttraumatic stress disorder (PTSD) [1], depression [2], health anxiety [3], agoraphobia [4], and social anxiety [5]
This study found that, compared to a control condition, both voluntary and involuntary recall were associated with regional cerebral blood flow increases in the posterior cingulate gyrus, left precuneus, and right parahippocampal gyrus
Thirteen participants were categorized into the low intrusion group (5 female, 8 male) with a mean intrusion score of 0.46 (SD = 0.52), and 13 participants were classified in the high intrusion group (9 female, 4 male) with a mean intrusion score of 10.08 (SD = 2.38)
Summary
Involuntary intrusive memories, thoughts or images are often distressing symptoms that occur in a wide variety of clinical disorders, including posttraumatic stress disorder (PTSD) [1], depression [2], health anxiety [3], agoraphobia [4], and social anxiety [5]. Despite their prevalence and clinical impact, the neural mechanisms underlying intrusions are not well understood. Kim Felmingham is a PLOS One Editorial Board member. We stipulate that "this does not alter our adherence to PLOS ONE Editorial policies and criteria."
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
