WASHINGTON - Behavior therapists may have a better way to help anxious patients, thanks to [?] from a UCLA study of different ways to get mice [?] their fears. Rodents have long been used to study learning by [?]. Neuroscientists compared different ways of exposing mice to a stimulus that they had learned to fear, and found that “massing” the feared stimulus - [?] it in concentrated bursts, not pacing it with longer pauses in between -- was surprisingly efficient at helping to [?] its impact.
These findings are significant for clinical behavioral therapy, which has been scientifically proven to work in a range of human anxiety disorders, including specific phobias, panic disorder, social phobia, post-traumatic stress disorder, and obsessive-compulsive disorder.
At the University of California, Los Angeles, the researchers taught mice (in most conditions, eight at a time) to fear harmless white noise by [?]t with a mild shock delivered through the floor of the experimental cage. After a couple of trials, the mice “froze” - just stopped moving, a fear [?] - for about 72 seconds, or 60 percent of the two minutes of white noise. Thus, the white noise became what’s called a “conditioned stimulus.” It may not have been the original source of pain, but it became [?] associated with pain to cause fear all by itself.
Next, Cain and his colleagues separated the mice into three groups and measured how well they overcame their [?] to white noise when they heard it 20 times for two minutes each, without shocks -- with intervals of six, 60 or 600 seconds between each presentation. Repeatedly presenting a conditioned stimulus has long been known to “extinguish” a fear by exposing animals (including humans) to that stimulus without associated pain. In the study, for example, some of the mice learned to trust that white noise would not come with shocks. In a human [?], someone who had developed a fear of dogs after being bitten could be exposed to playful, gentle dogs as a way to re-learn that most are safe.
The only [?] is that anxiety is like an unwanted houseguest: It breezes in quickly, without invitation, and is hard to kick out, as is clear from the fact that the mice feared the white noise after two [?], but needed far more than two exposures to get over it -- and only under certain conditions. Thus, approaches that make treatment more efficient are high on therapists’ wish lists […].