Towards objectively quantifying sensory hypersensitivity: a pilot study of the "Ariana effect"

Background. Normally one habituates rapidly to steady, faint sensations. People with sensory hypersensitivity (SH), by contrast, continue to attend to such stimuli and find them noxious. SH is common in Tourette syndrome (TS) and autism, and methods to quantify SH may lead to better understanding of these disorders. In an attempt to objectively quantify SH severity, the authors tested whether a choice reaction time (CRT) task was a sensitive enough measure to detect significant distraction from a steady tactile stimulus, and to detect significantly greater distraction in subjects with more severe SH. Methods. Nineteen ambulatory adult volunteers with varying scores on the Adult Sensory Questionnaire (ASQ), a clinical measure of SH, completed a CRT task in the alternating presence and absence of tactile stimulation. Results. Tactile stimulation interfered with attention (i.e., produced longer reaction times), and this effect was significantly greater in participants with more SH (higher ASQ scores). Accuracy on the CRT was high in blocks with and without stimulation. Habituation within stimulation blocks was not detected. Conclusion. This approach can detect distraction from a cognitive task by a steady, faint tactile stimulus that does not degrade response accuracy. The method was also sensitive to the hypothesized enhancement of this effect by SH. These results support the potential utility of this approach to quantifying SH, and suggest possible refinements for future studies.