Hyperthymesia is an extremely rare neuropsychological condition marked by an extreme memory for personal history, often referred to as autobiographical memory. This syndrome, which is also known as piking, was first defined in an article from the neuropsychological journal Neurocase. The article states that the primary characteristics of a person with hyperthymesia syndrome are spending abundant time thinking about personal memories and having exceptional personal memory recall.
When a person with piking is given a date, she will often recall what day of the week the date fell on and any personal information surrounding her on that date. She may remember her school teacher’s name and how he was dressed or what television show and episode played on that date. If a historical event on that day was of personal interest to the person with hyperthymesia, that historical event may be recalled as well.
People with this syndrome tend to have poor eidetic or photographic memory and often complain of having trouble with rote memory tasks often required in school. They also do not have superior abilities or even sometimes normal abilities to remember sequences of numbers. People with this syndrome also have trouble with memory building skills and do not seem to easily improve their rote memory when memory skills and tools are taught to them. The key to the superior memory of a person with hyperthymesia is based solely on the recall of information that is personally linked to him.
Many people feel that this form of superior autobiographical memory recall would be a gift, but in reality it can be a curse. A person suffering from this syndrome has great difficulty stopping the flow of memories. Dates or conversation about a past event will often trigger a memory which will in turn trigger another memory and another in a cascade effect that locks the person with hyperthymesia into the past. This form of remembering, where one memory leads to another memory, is called episodic retrieval mode, and it is often virtually impossible to stop or extremely hard to control.
Preliminary positron emission tomography and magnetic resonance imaging (MRI) scans suggest that this problem may be rooted in the parts of the brain known as the left and right prefrontal cortex, the anterior cingulate gyrus, the caudate nuclei, and the temporal lobe. The left and right prefrontal cortex and the anterior cingulate gyrus are parts of the brain thought to control the episodic retrieval mode. In people with hyperthymesia, this area may be underdeveloped and contribute to the inability to stop memory flow. An MRI of one person with hyperthymesia has shown that their caudate nuclei and part of the temporal lobe are disproportionately larger than normal. This finding may suggest that these two brain areas may function together to perform personal memory recall and are accentuated in people with hyperthymesia.