An investigation of prospective memory functions in people with traumatic brain injury using Virtual Week

Abstract

Prospective memory (PM) refers to memory for future intentions and is critically linked to independent living. Previous laboratory research has shown that people who have sustained a traumatic brain injury (TBI) have difficulties with PM, but few of these have used measures of PM that closely represent the types of PM activities that occur in everyday life. One measure that incorporates more ecologically valid tasks, and which also allows systematic investigation of different PM task parameters (regular, irregular, and event and time based), is Virtual Week. Consequently, in the present study, Virtual Week was administered to participants with TBI (n = 18) and demographically matched controls (n = 18). Consistent with considerable prior literature, the results indicated that people with TBI had significant difficulties executing PM tasks, with these deficits more pronounced for time-based than for event-based tasks. These data point to there being a relatively global PM deficit in people with TBI. Of particular interest was the finding that the magnitude of TBI impairment was consistent across regular and irregular tasks. Because the key distinction between these tasks is that they place low and high demands on retrospective memory, respectively, these data suggest that failures of retrospective memory are not the major cause of TBI-related impairment in PM. The implications of these results for the assessment and rehabilitation of PM impairment in people with TBI are discussed.

Keywords:

• Prospective memory
• Traumatic brain injury
• Virtual Week
• Event based
• Time based

Acknowledgments

The information in this manuscript and the manuscript itself has never been published either electronically or in print. There are no financial or other relationships that could be interpreted as a conflict of interest affecting this manuscript. This research received no specific grant from any funding agency, commercial or not-for-profit sectors. Rendell and Henry contributions were supported by Australian Research Council, Discovery Grant. The authors gratefully acknowledge Martina Torresi, the participants and their families and friends who co-operated in the present study. The authors also acknowledge the help of Trevor Daniels with programming Virtual Week.

Notes

¹The severity of the two patients with TBI who had neither GCS scores nor duration of PTA was ascertained by the clinical records, reference to their neuropsychological evaluation, and their Level of Cognitive Functioning (LCF) and Functional Independence Measure and Functional Assessment Measure (FIM/FAM) scores.

²The clinician making the ratings on the FIM/FAM and LCF had no knowledge of the PM task, and the evaluation was completed prior to the date of the PM testing.

³The FIM/FAM scale is assessed regularly during the recovery and during the rehabilitation. The score we report is assessed at the last meeting with the patients and is a representative and stable index of their recovery.

⁴Missed responses means that the participants did not remember the target item at any time and little late, late, little early, and early responses were not included in the proportion of missed responses.