​​                                             THE PHENOMENON CALLED HSAM 

Highly Superior Autobiographical Memory (HSAM) is a recently discovered phenomenon.  It is a condition in which the individual can recall the vast majority of personal experiences and events in their lives.  It was previously known as Hyperthymesia.  Whereas most people might recall 1-2 days of each year of their life, and what they were doing on a specific date, HSAM individuals can recall mostly every day of their lives!  Recollection occurs without hesitation or conscious effort. 

Bob Petrella is one of only 50 known individuals in the world identified with HSAM. 

In medical studies done by researchers, it's been revealed that the caudate nuclei in Petrella and others is SEVEN times larger than the average person.  In relative terms, it's a person measuring 10-feet tall. 

                                                              WHAT IT'S NOT:

It's not photographic.   It's not an autistic or savant.   It's not absolute.   
In other words, like everyone else, people with HSAM can occasionally forget where they left their keys, or parked their car.   

It is important to draw a distinction between those with HSAM and those with other forms of exceptional memory, who generally use mnemonic or similar rehearsal strategies to memorize long strings of subjective information.  Memories recalled by HSAMS individuals tend to be personal, autobiographical accounts of both significant and mundane events in their lives. 

This extensive and highly unusual memory does not derive from the use of mnemonic strategies; it is encoded involuntarily and retrieved automatically. 

Despite being able to remember the day of the week on which a particular date fell, people with HSAM are not using calendrical calculators like some people with autism or savant syndrome. 

Rather, their recall tends to be constrained to a person's lifetime and is believed to be an unconscious process. 

While it is a rather exclusive fraternity, Petrella has extended his ability to others with certain memory techniques that he has taught to non-HSAM individuals that have been helpful in improving memory.   

                                              HSAM RESEARCH STUDIES 

TESTING: The testing of Bob Petrella and others entailed a variety of standardized and neuropsychological tests in their diagnosis.  These included tests of language, calculations, IQ, visual-spacial and visual-motor functions.  They also devised novel tests to examine the extent of memory abilities.  These mostly consisted of questions pertaining to specific dates and events in history. 

MRI scans done by researchers at the University of California Irvine reveal two abnormally large areas in the brain.  " That discovery could lead to breakthroughs on how memories are formed and kept," says Dr. Larry Cahill, one of the lead neuroscientists in charge of the studies.  The two magnified areas in the brain are the caudate nuclei- typically used for memory when forming automatic habits- and a port of the temporal lobe that stores facts, dates and events. "

These two areas of the brain may be working together, in a way unknown before, to make detailed recall of every day as automatic as remembering to brush your teeth in the morning or to put on a seat belt, the research team speculates . 

This may be a key piece of the puzzle as to how memory works, and may be used in future research to help people with memory disorders. 


Memory expert Howard Eichenbaum of Boston University says, " Looking at memory from a superior perspective gives us a new tool.  It may just broaden our knowledge and ability to know what's going on.""

The result certainly pushes us beyond the boundaries of what we might normally think,"  stated Eichenbaum.;  " It violates a standard principle that most of us have, which is that normal memory is pretty damn optimized"


Superior autobiographical memory could, in theory, give neuroscientists insights form the opposite pole.   " We have a new tool in which we can look at memory when it is functioning at a higher level," states lead Researcher Aurora LePort.  These studies might also furnish a new appreciation of critical balancing act between remembering and forgetting to keep from getting overpowered by thought and emotion. 


The new research released today provides insight into one of the neuroscience's most intriguing mysteries: how the human brain learns and remembers. These studies illustrate the profound influence that specific changes in either the brain's structure, function or both, can have on human behavior. 

The study used magnetic resonance imaging (MRI) to obtain a deeper understanding of how the brains of these individuals are functioning to form and retrieve autobiographical memories. The study compared the brains of 11 people with HSAM (Including Bob Petrella) with those of a group of control participants with average memory, revealing significant differences in the shape and size of brain regions that may contribute to participant's memory abilities. 

In other words, like everyone else, people with HSAM can occasionally forget where they left their keys, or parked their car.   

" Those results suggest that the brain structures shown to be structurally different are probably contributing to our HSAM participant's phenomenal autobiographical memory abilities, " said UCI lead researcher Aurora Leport. 

Boston researcher Howard Eichenbaum says, " Such research will also help us develop more effective interventions and treatments for brain diseases and conditions that interfere with- and sometimes even destroy- our ability to learn and remember. "


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