Highly superior autobiographical memory

How it works

Give a person with HSAM a date, such as 14 March 2003, and they tell you the day of the week, what they did, and what was in the news. They answer in seconds and describe it as effortless. Many say the memories come on their own, as vivid scenes they cannot switch off¹.

The ability is narrow. In standard laboratory memory tests, such as remembering word lists or strings of digits, people with HSAM do not score higher than other people⁴. It is memory for their own lives, not memory in general. They also form false memories when tested with standard suggestion tasks¹.

A brain scan of Jill Price shows a larger temporal lobe and caudate nucleus, a region also linked to habit and obsessive behaviour¹. Many people with HSAM describe obsessive traits, such as collecting and organising. Nobody knows whether constant reviewing of the past creates the memory or the memory creates the habit. In the people studied at UC Irvine, the memories go back to about age 10⁴.

How common it is

This is a count of confirmed people, not a share of the population. Fewer than 100 people worldwide had been identified with HSAM by 2021¹. Most were found by one group, at the University of California, Irvine. By 2012 that team had assessed more than 500 people who thought they had the ability and had confirmed 33 of them⁴. Those 500 people put themselves forward, so they are not a random sample⁴. Confirmation needs a hard test on public events by date. Nobody has screened the general population, so the true rate is unknown.

Is it a problem?

Sometimes. HSAM can disrupt daily life, as it did for Jill Price¹. Some people with it describe the constant flow of memory as tiring or hard to switch off, though it does not affect memory for facts or lists¹. There is nothing to diagnose here. Memory changes that involve confusion, forgetting recent events, or getting lost are unrelated and worth mentioning to a doctor.

History and culture

The first published case was Jill Price, known in the 2006 paper as “AJ”². She contacted memory researchers at the University of California, Irvine, in 2000. A team led by James McGaugh studied her for six years⁵. After the 2006 paper, more than 200 people contacted McGaugh¹. The actress Marilu Henner has it and has described it on television³. The word hyperthymesia was coined for the first case. HSAM is another name for it¹.