False Memories in Mice and Men

 

 experimental mice

 

The New York Times has reported on a study by scientists at the Massachusetts Institute of Technology in which false memories were implanted in mice.  It appears mice can have fake memories just like humans.

The implantation of false memories is a further development of prior discoveries by scientists that specific memories can be trailed to groups of brain cells as the memories form.  Those memories can be invoked later by stimulation of the brain cell collections.   (New York Times.)

In the most recent experiment, the brain cells encoding memory in a mouse were identified and labeled. Then the mouse was put in a blue box.  The researchers made the cluster of memory cells responsive to light.  The mouse was then placed in a red box, and light was used to activate the cells.  The mouse was exposed to mild electric shocks.  When the mouse was put back into the first environment, it showed signs of fear, indicating that it had formed a false memory of being shocked in the red box, where it had not been shocked.  (BBC News Science and Environment).

Memories form in the hippocampus.  Within the brain’s hippocampus is the dentate gyrus.  It is part of a group of neural tissues involved in the creation of certain kinds of memory, as well as habit formation, and the development of learning skills.  (wiseGEEK.) The hippocampus is one of the units of the brain’s limbic system, which influences emotions, visceral responses to emotions, motivation, mood, and sensations of pain and pleasure. (San Diego State University)

False memories can be instilled in mice as well as humans.

False memory syndrome (FMS) describes a condition in which a person’s identity and relationships are affected by memories that are factually incorrect but upon which the person determinedly relies.  The term was coined by Peter J. Freyd, an American mathematician who founded the False Memory Syndrome Foundation.   (See P. R. McHugh, Try to remember: Psychiatry’s clash over meaning, memory and mind.)

Individuals, such as those suffering from dementia or survivors of traumatic brain injury, may exhibit a behavior known as confabulation.  This consists of the replacement of a gap in a person’s memory by a falsification that he or she sincerely believes to be true. [(See Dorland’s Medical Dictionary for Health Consumers (2007).]

In recent years, false memory syndrome has come to public attention with regard to the emergent remembrances of sexual abuse.  Many child abuse victims experience traumatic or dissociative amnesia, preventing them from recognizing the incidence of abuse until they are in adulthood.  Studies of traumatized populations do not support the notion that delayed memories are “false.” [(See S. Dallam, “Crisis or Creation: A systematic examination of false memory claims,” Journal of Child Sexual Abuse (2002)].  However, there are instances in which caseworkers have created false recollections in children regarding sexual abuse.

A study by John DeLuca, Ph.D., director of neuroscience research at the Kessler Medical Rehabilitation Research and Education Corporation, has explained that the rupture of a small  blood vessel in the brain called the anterior communicating artery (ACoA) temporarily cuts off the normal flow of oxygenated blood to areas of the brain necessary for recall. The damage caused by an ACoA rupture can vary from memory impairment alone, or memory impairment accompanied by confabulation.  Confabulation in ACoA patients involves distortions regarding when a genuine event occurred, or what actually occurred (an unreliable remembrance).  [(See D. Pendick, “The Truth about Confabulation,” Memory Loss in the Brain web site (2000)].

False memories can also result from aberrations in the ways in which the brain records and stores information.  The popular notion of memory is that the brain simply stores and retrieves information. DeLuca believes that the brain gathers pieces of events and creates a “rough draft,” relying upon prior experiences and perceptions. The fact-checker in the brain is its executive function.  If that function is impaired, the patient may confabulate by conglomerating fact and fiction. (Pendick, ibid.)

The brain does not exactly record events like a camera, but divides perceptions into parts.  Our experience of our environment is more like the brain’s opinion of what it perceives.  In visual perceptions, for example, light strikes the retina, which interprets the pattern of photons received and creates small “movies” out of the pattern, which are called “tracks.” The tracks are abstractions of specific features of the perceptions.  The tracks are sent to various parts of the brain.  [See John Medina, “Brain Rules:  12 Principles for Surviving and Thriving at Work, Home and School” (2008).] Damage to the brain’s processing mechanisms in this aspect can result in false memories.

False memories can also be implanted by “misinformation effect.” When people who witness an event are later exposed to misleading information about the event, their recollections become distorted.  More than 200 experiments involving over 20,000 individuals and conducted by students under the supervision of Elizabeth F. Loftus, a professor of psychology and adjunct professor of law at the University of Washington, document how exposure to misinformation induces memory distortion. (E. Loftus, “Creating False Memories,” Scientific American, September 1997).

Therapists can also implant false memories in their patients by means of dream analysis, for example.  (PSYBLOG) Therapists using “recovered memory therapy” can also inadvertently

install artificial recall in their subjects.  (See P. G. Turbin, Ph. D., “Beware Of False Memories in Regression Hypnotherapy,” Alchemy Institute of Hypnosis.)

False memories, it seems, are a problem for mice and men.

By:  Tom Ukinski

 

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