“Monday Musings” for Monday April 20, 2015
The Science Series: Memory
by Assad Meymandi, MD, PhD, DLFAPA*
Part I: The nature of Memory
Faithful readers of this space recall our review of the book “Searching for Memory” by Daniel Schacter, a UNC alumnus and now professor of psychology at Harvard. In that book with an outline of different types of memory, Schacter devoted a broad section to persistent memory which is the hallmark of Post-traumatic Stress Disorder, recurring unpleasant memories. In this piece, after describing and discussing the phenomenology and architectonics of memory and its types, I will focus on Post-traumatic Stress Disorder.
Schacter’s research explores the relation between conscious and unconscious forms of memory, the nature of memory distortions, how individuals use memory to imagine possible future events, enhancement of online learning, as well as the effects of aging on memory. In general, there are four large categories of memory which are always included in psychiatric evaluation and standard mental status examination. They are:
1) Episodic memory: dealing with the patient’s ability to recount biographic data such as dates, places of significant events of life, marriage, birth of children, service in the Armed Forces, travels and jobs.
2) Somatic memory: has to do with the functions of various parts of the brain, and the reaction of those brain structures to the cascade of neuronal hormones sweeping over them. Somatic memory is often affected by anxiety and depression.
3) Procedural memory: how well the patient can repeat a series of numbers or objects forward and backward, immediately, or after a given time lapse, and how well the patient may recall a seven part story.
4) Verbal fluency memory: testing a patient’s ability to generate words starting with a given letter, such as “O”. The number of such words generated in a given time, say one minute, and the quality of the words generated, reveal much about the patient’s memory and general fund of knowledge and vocabulary. For example, if a patient is asked to generate in one minute words starting with the letter ”O”, and he goes on like a machine giving words in alphabetic order such as “octave, octennial, octet, octillion, octillionth, October, octodecimo, octogenarian, octomerous, octoary, octoploid, octopod, octopus, octoroon, …” etc., you know that he excels in verbal fluency memory and is of superior intellect.
Schacter characterizes memory in a different way. He calls these seven sins of memory “The Seven Sins of Memory: How the Mind Forgets”.
- 1) Transience–the decreasing accessibility of memory. Schacter cited as a somewhat facetious example former President Bill Clinton’s “convenient lapses of memory” during the Monica Lewinsky investigation. Clinton claimed in the hearings that he sometimes couldn’t remember what had happened the previous week.
- 2) Absent-mindedness–lapses of attention and forgetting to do things. Examples, said Schacter, are forgetting where you put your keys or glasses. He noted a particularly famous instance in which cellist Yo-Yo Ma forgot to retrieve his $2.5 million cello from the trunk of a New York City cab.
- 3) Blocking–temporary inaccessibility of stored information, such as tip-of-the-tongue syndrome. Schacter recounted the embarrassment of John Prescott, British deputy prime minister, when a reporter asked him how the government was paying for the expensive Millennium Dome. Prescott struggled to find the word “lottery,” trying “raffles” instead.
- 4) Suggestibility–incorporation of misinformation into memory due to leading questions, deception and other causes.
- 5) Bias— For example, research indicates that people currently displeased with a romantic relationship tend to have a disproportionately negative take on past states of the relationship.
- 6) Persistence–unwanted recollections that people can’t forget, such as the unrelenting, intrusive memories of Post-traumatic Stress Disorder. They become a “tragic prisoner of memory,” and some eventually commit suicide.
- 7) Misattribution–attribution of memories to incorrect sources or believing that you have seen or heard something you haven’t.
Next week, Part II, we will discuss Post-traumatic Stress Disorder which has to do with sustained unwanted, obsessive intrusive memory.
*The writer is Adjunct Professor of Psychiatry, University of North Carolina School of Medicine at Chapel Hill, Distinguished Life fellow American Psychiatric Association, and Founding Editor and Editor-in-Chief, Wake County Physician Magazine (1995-2012). He serves as a Visiting Scholar and lecturer on Medicine, the Arts and Humanities at his alma mater the George Washington University School of Medicine and Health.