La Sapienza - Università di Roma

logo de La Sapienza per la stampa

A New Study on Hyperthymesia

11-07-2018

Imagine remembering every day of your life, every detail … Many of us can accurately remember about events that caused great emotions (such as a wedding day, the birth of a child, our first kiss, someone’s death, but we usually pretty much forget everything about “normal” days. However, there is an exceedingly small percentage of individuals who can even remember “normal” days with an incredible accuracy. They have an autobiographical hyper-memory, also known as Hyperthymesia. For the first time, these individuals are at the centre of a study employing functional magnetic resonance (fMRI) to understand the neurobiological mechanisms that allow this extraordinary capacity.

The study, which is experimentally held at the Rome Fondazione Santa Lucia IRCCS, was coordinated by Valerio Santangelo, Simone Macrì and Patrizia Campolongo. The results, which were published on the authoritative Proceedings of the National Academy of Sciences of the United States of America(PNAS)co, involved various research centres, including the Italian Istituto Superiore di Sanità, University of Perugia, University of California – Irvine and Sapienza University.

“We monitored eight people with Hyperthymesia identified amidst the Italian population, starting in 2015, and 21 individuals with normal memory as controls,” explains the first author of the study, 

Valerio Santangelo (University of Perugia and Fondazione Santa Lucia IRCCS. “The extraordinary thing is that, besides remembering the day of the week of years before (i.e., they remembered that August 3, 2011 was a Wednesday!), they were also capable of remembering how they were dressed on that day, what they ate, what films they saw, etc. Moreover, even more surprisingly, they exhibited absolutely no hesitation or effort to remember events from decades ago.”

During the fMRI scans, the individuals were asked to remember relatively recent autobiographical events (i.e., “when was last time you took a train?”) and ones in the more distant past (i.e., “when was the first time you kissed someone?”). They had 30 seconds to press a button to indicate that they had remembered what they had just been asked (access phase to the memory) and then continue to relive the event in as much detail as possible (elaboration phase of the memory).

“As was to be expected,” explains the last author of the study, Patrizia Campolongo, Sapienza University and Fondazione Santa Lucia, “subjects with autobiographical hyper-memory remembered a greater number of details and more vividly than the control subjects. Surprisingly, however, the functional differences between the two groups were only evident in the access phase, but not in the elaboration phase. During the access phase, individuals with Hyperthymesia revealed a greater activation of the median prefrontal cortex and its functional connectivity with the hippocampus, especially when summoning remote memories. These results seem to demonstrate that hyper-memory mainly consists in the ability to access, via a pre-frontal/hippocampus circuit, the mnemic traces that were not accessible to the control subjects. Thus, this could explain their greater ability to shed light on minute details of their past.”

These results will allow us to push the frontiers of research on memory, which has been traditionally studies in terms of hyper-operation in pathological conditions. “Understanding the neurobiological systems that underlie Hyperthymesia,” concludes Simone Macrì, Istituto Superiore di Sanità, “will provide us with precious indications on how to intervene (in terms of cerebral stimulation) to restore an adequate memory for patients in pathological conditions.”

The study group will continue to study individuals with Hyperthymesia in the Italian population through custom-tailored tests conducted telephonically.

 

References

Enhanced Brain Activity Associated with Memory Access in Highly Superior Autobiographical Memory - Valerio Santangelo, Clarissa Cavallina, Paola Colucci, Alessia Santori, Simone Macrì, James L. McGaugh and Patrizia Campolongo - PNAS July 9, 2018. 201802730; published ahead of print: July 9, 2018. https://doi.org/10.1073/pnas.1802730115

For further information:

Patrizia Campolongo

"Vittorio Erspamer" Department of Physiology and Pharmacology, Sapienza University

 patrizia.campolongo@uniroma1.it