June 25, 2004 -- Recalling a traumatic memory may provoke severe distress in people, even if the memory may be a product of their own imagination, according to a new study.

The study showed that people who claim to have been abducted by aliens show the same signs of distress, such as increased heart rate, sweating, and muscle tension, shown by people recalling more plausible traumatic events, such as wartime experiences.

Researchers say these signs of distress are often viewed as a testament to authenticity of a person's memory of a traumatic event, such as childhood abuse. But the researchers say these results show that physiological responses should not be used to verify traumatic memories in the evaluation of posttraumatic stress disorder (PTSD).

Alien Memories Provoke Distress

In the study, researchers recruited people who said they had been abducted by aliens and had them describe their alien encounter as well as other stressful, happy, or neutral memories.

The researchers converted those recollections into 30-second narratives and played them back to the "abductees" while measuring their heart rate, sweat production, and facial muscle tension. For comparison, researchers also played the tapes to a group of people who had no memories of alien abductions.

The study showed that people who said they had been abducted by aliens had strong distressful reactions to the stressful and alien abduction narratives and weaker reactions to the others. The comparison group had little reaction to any of the stories.

The study also showed that people who said they were abducted by aliens also scored higher on measures of psychological traits that make them more likely to experience alterations in consciousness, to have a rich fantasy life, and to endorse unconventional beliefs.

Researchers say that for people who believe they have been abducted by aliens, recalling their abduction can provoke physiological reactions similar to those evoked by more verifiable stressful memories.

Therefore, they say physiological responses are not a valid indicator of whether a memory is real or not.

"Although improbable traumatic memories (e.g. being sexually probed on a spaceship) provoke physiological reactions comparable to those provoked by more conventional and verifiable traumatic memories (e.g. a firefight in Vietnam), one should not conclude that PTSD patients are reporting false memories of trauma," write researcher Richard McNally of Harvard University and colleagues in the July issue of Psychological Science.

"Conversely, the physiological markers of emotion that accompany recollection of a memory cannot be taken as evidence of the memory's authenticity," they conclude.

http://content.health.msn.com/content/arti...e/89/100279.htm

Thoughts? Just thought it was kind of interesting, defining reality...