credit: http://commons.wikimedia.org/wiki/File:Mirror_baby.jpg
When we see children moving their bodies uncontrollably, we sometimes tell them to calm their bodies and thereby draw their attention to the unwanted behavior. But for people with Tourette’s syndrome, being more aware of their tics may actually exacerbate the actions. In a new study, researchers found that people with Tourette’s syndrome who watched themselves in the mirror actually had more tics than those who did not.
Motor and verbal tics that are characteristic of Tourette’s syndrome, also known as Gilles de la Tourette syndrome (GTS), range from the simple to complex, explains Valerie Brandt of the University of Lübeck in Germany. “Simple motor tics are essentially ‘normal’ movements. A single eye blinking tic is not different from a normal eye blink,” she says. “However, tics appear exaggerated because they are often repeated – often rapidly – several times consecutively, or they are performed in an extreme manner.” Complex tics can include facial grimacing, touching objects, or jumping, while vocal tics can range from simple throat clearing to involuntary swearing.
Having experienced tics as a child, Brandt has long been interested in Tourette’s syndrome. She and her colleagues were specifically interested in learning how paying attention to tics may alter their frequency. Current therapies for Tourette’s syndrome include drawing attention to tics and then making it difficult to execute the tic by introducing a competing response.
“We assumed that increased awareness of tics may enhance tic control in GTS patients,” says co-author Margaret Lynn, a cognitive neuroscientist at Ghent University in Belgium. “Instead, symptoms got better when patients focused their attention away from tics.”
In their study, just published in Cognitive Neuroscience, Brandt, Lynn and colleagues observed Tourette’s patients under two conditions, in a room either with a mirror or without one. The researchers filmed the participants to record the number and type of tics. In a follow-up experiment, the patients viewed videos of themselves edited to exclude tics.
They found that tic frequency increased when the patients watched themselves in the mirror but not when they watched themselves on video absent the tics. This surprising finding suggests that tics operate off a feedback loop in which observing tics, Lynn says, makes the subsequent tics more likely.
“This isn’t a case of mere mimicry; patients in the mirror condition exhibited a wide variety of non-repetitive tics,” she explains. “This might suggest that all tics in a person’s repertoire share a common coding.”
This work is the first to directly investigate attention and tic frequency in Tourette’s patients. And based on their findings, Brandt says, “we may have to alter the way we think about possible future behavioral therapies for GTS.”
A potential tic management strategy that some researchers have been exploring is biofeedback, in which physical processes such as heart rate, breathing, and muscle activity can be regulated by increasing self-awareness. “Our findings show that this may not be the best long-term strategy to decrease tics,” Brandt says. “Instead, paying attention to an external task appears to be more effective in reducing symptoms and does not even require active suppression. This effect needs to be studied in more detail but may have important implications for future behavioral strategies.”
Indeed, Brandt’s team plans to look at whether distraction, for example through a motor skill task, is an effective way to decrease tics. “Ultimately I would like to aid the development of new behavioral therapies that don’t require effortful tic suppression,” Brandt says. “Also, I would like to raise public awareness that tics are not unusual, and I would like to promote acceptance of tics, especially in children.”
-Lisa M.P. Munoz
