Researchers Find that 
Timing Is Most Important in Wiping Out Memory of Fear

       Banishing a fear-inducing memory might be a matter of the right timing, according to new research conducted at NYU.
       Marie Monfils, an assistant professor of psychology at the University of Texas at Austin, has taken advantage of a key time when memories are ripe for change to substantially modify memories of fear into benign memories and to keep them that way. A former post-doctoral researcher at NYU, Monfils conducted the study with colleagues in the laboratory of NYU professor Joseph LeDoux, one of the study’s co-authors.
       The finding, published in Science Express, an online publication of Science, is a significant advance in learning how memory can be manipulated in rodents. It also could indicate a potential treatment for humans suffering from anxiety-related disorders.
       Current treatments are not dependably long lasting and some of the treatments include drugs, many of which would be hard to administer locally in humans and have harmful side effects.
       The experiment began by inducing fear in rats by sounding a tone and then shocking them under the feet. Eventually, the rat would exhibit fear from just hearing the tone. The standard treatment for getting rid of the fear response is to sound the tone repeatedly, without a shock. Eventually, the rat does not exhibit fear at the sound, and this method is called extinction.
       There is something else going on when a stimulus evokes the fear response. The memory of fear is being reconsolidated, or recommitted, to long-term memory. Each time memory is retrieved (by giving a single presentation of the sound), it is susceptible to change, and the reconsolidation process can be interrupted (usually pharmacologically).
       Monfils’ idea was to alter the timing of the extinction process. In her experiment, the tone to stimulate a fear response was sounded. Then, after an interval, which made this initial tone presentation stand out, extinction training was applied. The rats treated with this technique showed lower levels of fear induced by the sound itself, but also smaller chances that the original fear memory would spontaneously resurface.
       Monfils says the findings may lead to treating humans with anxiety disorders.