ABSTRACT
Periods of stressful events, such as those experienced during combat training in the military, may lead to psychological distress and reduced quality of life (QoL). Mental resilience, the capacity to overcome negative effects of setbacks on performance, may help protect one from the adversities associated with basic combat training. Among the factors contributing to mental resilience is cognitive control, the mechanism which helps maintain our goal directed behavior. Here we examined the feasibility of a mobile cognitive control training (CCT) app to engage young adults during their basic military training with the intention of improving resilience, mental health and QoL. 153 participants were randomly assigned to complete 2-3 weeks of either mobile CCT (n = 74) or active control training (ACT, mobile games; n = 79). Resilience, QoL, mood and self-efficacy were assessed at baseline and post-intervention. Participants completed, on average, 7.28 ± 3.03 training sessions (out of the planned 14), indicating relatively low feasibility of CCT during basic combat training period and inconsistent engagement with training. In addition, there was lack of improvement in the training tasks ('target engagement'). Accordingly, no significant time by group interactions were found on any of the outcome measures, potentially due to the limited feasibility. We conclude that short-term mobile CCT has low feasibility during basic combat training and discuss the results of this study considering factors that might have contributed to the lack of feasibility of the training protocol.
ABSTRACT
BACKGROUND: One out of 4 patients who sustains a mild traumatic brain injury (mTBI) experiences persistent complaints, despite the absence of structural brain damage on conventional neuroimaging. Susceptibility to develop post concussive symptoms (PCS) is thought to originate from occult brain dysfunction. However, the influence of such neural changes on the development of persistent PCS is poorly characterized. METHODS: In this article, we aim to integrate findings from longitudinal studies that investigated across the spectrum of neuroimaging modalities the changes within the first twelve months following a mTBI, with the goal of identifying possible predictors or biomarkers of persistent PCS. RESULTS: Nine studies met inclusion criteria: 5 that used resting state functional MRI, 2 that used Diffusion Weighted Imaging, and 2 that used 1H-MR Spectroscopy. All studies indicate significant structural, functional and/or metabolic aberrations that occur in the acute and early subacute phases following a mTBI. However, in patients with persistent PCS, these mTBI-induced damages linger and relate to the severity of PCS. These biomarkers include: decreased diffusion along white matter fiber tracts, alteration of perfusion, disrupted metabolism, and reduced connectivity within several resting state networks. Additionally, in PCS patients, disruptions of brain function can manifest exclusively in the chronic phase. CONCLUSION: This review support the ongoing use of neuroimaging modalities to understand the brain changes that occur throughout the time course of mTBI. Based on the complexity of mTBI, however, more work is required to characterize injury and recovery mechanisms that could impact the emergence and persistence of PCS.
