Research into time series of Tourette tics explores the patterns in observed tics for patients with Tourette's syndrome. In a series of experiments, the start time of tics was measured during a number of activities. The waiting times between tics were studied, and it was found that the mean wait increased during physical activity, as well as subsequent waiting times appearing independently. The waiting times were modelled using statistical distributions, including Pareto, Exponential and Gamma fits. The tics reviewed included physical tics, such as eye blinking, mouth movement and shoulder shrugging, as well as vocal tics such as grunting. Both Pareto and Exponential distributions were rejected, and it was found that the Gamma distribution best models the tic waiting time, however some limitations were found in such a fit.
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