CAN CHILDREN WITH GILLES-DE-LA-TOURETTE-SYNDROME EDIT THEIR INTENTIONS

In this paper we describe a cognitive mechanism, the Intention Editor, which is triggered whenever there are several intentions competing in parallel with each other. This mechanism is hypothesized to be a subcomponent of a larger mechanism, the Supervisory Attentional System (SAS: Shallice, 1988) which serves inhibition in general. The Intention Editor interrupts one of several simultaneously activated intentions, preventing it from executing its action, utterance, or thought. This mechanism appears to develop during the first five to six years of life. We propose that an impairment in the development of this mechanism may account for the triad of symptoms in children with Gilles de la Tourette Syndrome (GTS): involuntary movements, involuntary utterances, and obsessive thoughts. This mechanism is tested with normal children aged 3-6 years old, and with children with GTS, in two experiments. In Experiment 1, subjects were required to make one hand movement while inhibiting making a (different) hand movement that the other hand was simultaneously making. In Experiment 2, they were asked to say one thing while inhibiting saying something else. On both tasks, normal 6-year-olds were significantly better than normal 4-year-olds, but children with GTS performed worse than normal 6-year-olds, despite having a mean age of 12 years. These results constitute preliminary evidence for the theory that the Intention Editor is dysfunctional in GTS.