Memory for forgetting in adults with persistent symptoms following concussion

ABSTRACT

Introduction

Persistent memory complaints following concussion often do not coincide with evidence of objective memory impairment. To the extent this clinical presentation represents Functional Cognitive Disorder (FCD), we would expect preservation or even enhancement of memory for instances of forgetting, based on two lines of prior evidence. First, emotional arousal enhances autobiographical memory. People who experience memory lapses as worrisome may better remember them. Second, individuals with FCD can paradoxically provide detailed accounts of memory lapses compared to patients with neurodegenerative disease, who tend to provide vague examples. The current study aimed to better characterize the recall of forgetting events in people with subjective memory problems following concussion.

Methods

The study sample consisted of adults with chronic post-concussion symptoms (N = 37, M = 42.7 years old; 70.27% women; M = 24.9 months post-injury) and normal-range performance on conventional neuropsychological tests. Participants completed a measure of memory complaint severity and the Autobiographical Interview (AI). The AI was used to quantify the richness of narrative recollections of recent instances when they forgot something and (control) personal events that did not involve forgetting. Linear regression modeling assessed the relationship between memory complaint severity and AI variables, including narrative details, valence, arousal, and rehearsal of memories.

Results

There was no association between memory complaint severity and memory for forgetting vs. control events. We further found no association between memory complaint severity and AI performance overall (collapsing across forgetting and control events). Participants with greater memory complaints experienced past memory lapses as more negative than control memories, but did not consistently differ on other AI phenomenological variables.

Conclusion

Autobiographical recall of memory lapses appears preserved but not selectively heightened in people who report experiencing severe memory problems long after concussion. This inconsistency supports conceptualization of persistent memory complaints after concussion as FCD.

KEYWORDS:

• Mild traumatic brain injury
• concussion
• functional cognitive disorder
• autobiographical memory
• Memory

Geolocation information

Data was collected within the province of British Columbia, Canada.

Disclosure statement

N.D.S. receives honoraria for continuing medical education lectures on concussion and fees for medical-legal and clinical neuropsychological consultation. The other authors have no potential conflicts of interests to disclose.

Notes

1. Due to experimenter error inputting the FMDI into Qualtrics, the scale was displayed to participants with an additional option of “5 – Always”. To remedy this error, we collapsed all responses of 5ʹs into 4ʹs.

Additional information

Funding

This work was supported by the VGH & UBC Hospital Foundation.