Total recall: Detecting autobiographical memory retrieval in the absence of behaviour.
Matthew Kolisnyk, Geoffrey Laforge, Marie-Ève Gagnon, Jonathan Erez, Adrian M. Owen
Neuropsychologia May 3, 2025 DOI: 10.1016/j.neuropsychologia.2025.109129 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Case study Case report Peer reviewed |
|---|---|
| Sample size | 1 |
| Population | Patient with a disorder of consciousness |
| Keywords | Autobiographical memory Disorders of consciousness Machine learning Neuro-assessment |
| Key findings | A machine-learning classifier distinguished fMRI activity corresponding to the patient's own autobiographical memories from visually similar scenes of another person's experience, suggesting that autobiographical memory processes remain intact in some DoC patients. |
Abstract
Functional neuroimaging has fundamentally changed our understanding of disorders of consciousness (DoC). While many DoC patients exhibit minimal to no behavioural responsiveness, a significant minority show neural evidence of awareness and preserved cognitive functioning. Although several cognitive functions have been explored in DoC patients, autobiographical memory -- the ability to form and retrieve personal memories -- has yet to be investigated. To address this gap, we used functional magnetic resonance imaging (fMRI) to investigate autobiographical memory in one DoC patient. The patient viewed video clips across three conditions: (1) Own - clips recorded from their perspective during a recent mall visit; (2) Other - clips from a healthy control's visit to the same mall; and (3) Bookstore - novel clips from an entirely different store that had not been visited. We trained a linear support vector classifier to associate fMRI activity in canonical autobiographical memory regions with each condition using data from twelve healthy participants. We then applied the trained model to the patient's data to 'decode' which condition their fMRI activity predicted. The model accurately distinguished between Own, Other, and Bookstore conditions in the patient (Balanced Accuracy = 0.448, p = .032), with performance within the control group range (p = .068). Similarly, the model distinguished between the Own and Other conditions above chance (Balanced Accuracy = 0.609, p = .032) and within the control group's distribution (p = .620), suggesting that the patient was still able to differentiate personal experiences from visually similar scenes, despite being behaviourally unable to report that this was the case. These findings provide preliminary evidence that autobiographical memory processes, critical to conscious awareness and identity, remain intact in some DoC patients, shedding further light on their covert capabilities and inner experiences.