 | | | | Related Healthscout Videos | |
|
Page: << Prev | 1 | 2 The study lasted three days. On the first day, the subjects learned to associate images of spiders with a mild electrical shock. Fear was measured by assessing each individual's startle response -- how much their eyes blinked in response to the stimulus. That fear memory was then consolidated -- written to the hard disk, if you will.
The next day, the memory was recalled, but only after the subjects had been given either placebo or propranolol. The idea, Bouton explained, is that at this point, the memory becomes "open to modification" -- just as a computer file can be changed and then rewritten to the hard disk.
Propranolol had already been shown to impact memory reconsolidation in rodents; the question was, would it have the same effect in people. The answer came on day three, when the subjects were tested again: The physiological response to the fear-inducing cue -- pictures of spiders -- was eliminated in the propranolol group, but not in the placebo group, Kindt found.
Text Continues Below
"In principle," said Bouton, "this is a step toward finding a clinical treatment for people with pathological fears."
Indeed, the authors noted that their findings "are consistent with those of a recent preliminary study of patients with post-traumatic stress disorder in which post-retrieval propranolol seemed to reduce subsequent physiological responding to traumatic memory."
Yet much remains unknown. For instance, the current research involved only a very short period of time. Though the memory appeared erased on day three, would that still be true a month later? And, it's unclear how effective will propranolol be against longer-term memories, such as traumatic childhood memories that persist into adulthood.
Besides, the experimental memories were not exactly erased in this study, Taylor noted: The propranolol-treated subjects no longer flinched in reaction to the stimulus, yet they knew that they should. That, Taylor suggested, could limit propranolol's clinical utility.
"Being afraid of something doesn't just involve a physiological response," Taylor said, "it's how you think about it and how it affects your behavior."
More information
For more about anxiety disorders, visit the U.S. National Institute of Mental Health. Page: << Prev | 1 | 2
|
.gif)
