AUTHOR=Chan Aldrich , Harvey Philip , Hernandez-Cardenache Rene , Alperin Noam , Lee Sang , Hunt Christopher , Petersen Nick , Northoff Georg , Robertson Nadine , Ouyang Jason , Karasik Ryan , Williams Kate TITLE=Trauma and the default mode network: review and exploratory study JOURNAL=Frontiers in Behavioral Neuroscience VOLUME=Volume 18 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/behavioral-neuroscience/articles/10.3389/fnbeh.2024.1499408 DOI=10.3389/fnbeh.2024.1499408 ISSN=1662-5153 ABSTRACT=While PTSD continues to be researched in great depth, less attention has been given to the continuum of traumatic responses that resides outside this diagnosis. This investigation begins with a literature review examining the spectrum of responses through the lens of the default mode network (DMN). To build upon this literature, a systematic exploratory study was incorporated, examining DMN-related neuropsychological functioning of 27 participants (16 trauma-exposed, and 11 non-trauma-exposed), with a subset (15 participants) completing neuroimaging. This study revealed that in comparison to the control group, the trauma-exposed group had reductions in their capacity for self-referential processing, social cognition, autobiographical recall, prospection, and increased mind-wandering. While correlations were encountered between cognitive findings and brain volume, comparative volumetric findings between trauma-exposed and non-t rauma exposed were insignificant. This suggests that the conservation of DMN structural integrity may play a role in resilience, supporting the existing theory that reduced hippocampal volume may be a pre-existing vulnerability to PTSD rather than a consequence and that reductions in DMN related cognition are functionally mediated.