Prospective Memory in Service Members with Mild Traumatic Brain Injury

Prospective memory (PM) is the ability to remember the intention to perform an action in the future. Following mild traumatic brain injury (mTBI), the brain structures supporting such PM may be compromised. PM is essential for remembering activities specific to TBI survivors that promote recovery, such as following doctors' orders, taking necessary medications, completing physical rehabilitation exercises, and maintaining supportive social relationships. Since the year 2000, more than 315,897 US Service Members are reported to have sustained an mTBI1, yet little has been done to address possible PM concerns. Therefore, identifying impaired PM and interventions that may ameliorate such deficits is important. The primary aim of this study was to determine whether task encoding using implementation intentions leads to better PM performance than encoding using rote rehearsal in Service Members with mTBI (n = 35) or with bodily injuries but no TBI (n = 8) at baseline and 6 months later.

Participants were randomized to one of the two encoding conditions. They were asked to remember to complete a series of four tasks over the course of a 2-hour event-related potential session and to contact a staff member during a specified 2-hour window later that day. PM performance was assessed based on completion of each task at the appropriate time. IRB approval was obtained from The Catholic University of America, Walter Reed National Military Medical Center, and Ft. Belvoir Community Hospital.

Service Members with mTBI using implementation intentions outperformed those using rote rehearsal. The effect of injury type and the interaction between encoding condition and injury type did not yield differences that were statistically significant.

The results suggest that implementation intentions may be a useful PM remediation strategy for those who have sustained mTBI. Future research should validate these findings in a larger sample.