A teenager from Poland diagnosed with a rare memory condition has been shown to experience an unusually high rate of involuntary memories, even when engaged in a simple, repetitive task. In a study published in Cortex, researchers report that a 16-year-old boy, identified in the study as KCL, demonstrated a marked propensity for spontaneous autobiographical memories to intrude on his thoughts far more often than a control group.
Highly Superior Autobiographical Memory (HSAM) is a rare condition in which individuals can recall past personal events with extraordinary detail. While much of the prior work has focused on deliberate recollection in adults, scientists have begun exploring the spontaneous side of remembering—memories that surface without any conscious effort. The current work builds on earlier evidence that HSAM can be observed in early adolescence and seeks to measure involuntary memories under controlled laboratory conditions.
The researchers, led by Krystian Barzykowski of the Institute of Psychology at Jagiellonian University in Poland, recruited a 16-year-old Polish participant who reported a constant influx of memories and the ability to recall events from at least half his life. The participant’s abilities were first assessed with a set of standard memory quizzes and then cross-checked against a control group comprising eight typical adults and one other 16-year-old boy.
On a test asking for the dates of recent public events, KCL scored 51 percent, compared with an average around 20 percent for the comparison group. In a separate task requiring the recall of verifiable news and personal memories from randomly selected calendar dates, KCL achieved 83 percent, well above the control mean of about 29 percent. Barzykowski said the results surpassed established HSAM thresholds on both measures, confirming the participant’s exceptional memory by formal criteria.
To probe involuntary memories, the team used a computer-based vigilance task: participants watched a steady stream of horizontal lines and pressed a button at rare vertical-line appearances. During the task, random everyday phrases appeared as potential memory triggers, and on each interruption participants were asked to describe what they were thinking about and rate their level of focus and whether their thoughts were intentional or spontaneous. The design was intended to capture thoughts as they happened, minimising reliance on diary entries or retrospective reporting.
Though the participant’s mind wandered at a similar rate to the comparison group, the content of his off-task thoughts diverged markedly. The control group reported that around 39 percent of wandering thoughts were memories; by contrast, 87 percent of KCL’s off-task thoughts were involuntary personal memories. Barzykowski described the result as striking for a single case, noting that the frequency of involuntary memories was almost three standard deviations above the comparison-group mean and fell within the extreme upper range.
Additional questionnaires revealed that KCL held substantially higher confidence in his memory abilities than typical individuals and scored particularly high on episodic memory, which concerns recalling specific personal experiences. He, however, described his subjective feeling of remembering—its vividness and emotional intensity—as broadly aligned with the general population.
Barzykowski stressed that HSAM does not equate to a photographic or infallible memory. “One important misconception is that HSAM means having a photographic or infallible memory. It does not,” he said, emphasising that the study focused on accessibility—how readily autobiographical information can be retrieved or enter awareness—rather than universal accuracy. He noted that even with HSAM, people remain susceptible to memory distortions.
Researchers also caution that the study centres on a single participant and remote testing may offer less environmental control than in-person sessions. They stress that whether these findings extend to other individuals with HSAM remains to be seen and call for studies involving more participants to determine generalisability. They also acknowledge that the participant’s own descriptions of thoughts formed the basis for judging what qualified as a personal memory during the task, suggesting future work could incorporate physiological measures to deepen understanding.
Looking ahead, Barzykowski said the next step is to determine whether the pattern generalises to a larger group of people with HSAM and to explore why autobiographical memories become so accessible. “Whether incidental cues activate memories more strongly, whether the threshold for a memory entering consciousness is lower, and whether heightened sensitivity to cues contributes to this process” are questions the team aims to pursue. He argued that studying an extreme case of autobiographical accessibility can illuminate why some memories surface spontaneously while others do not.
The study’s authors, Krystian Barzykowski, Valerio Santangelo, Lia Kvavilashvili and Chris J. A. Moulin, describe the work as a valuable step in decoding the mechanics of memory and highlight the potential for engaging more people with HSAM in scientific assessment. The project was supported by the European Union’s Horizon research and innovation programme.
