Miller LJ, McIntosh DN, McGrath J, Shyu V, Lampe M, Taylor AK, Tassone F, Neitzel K, Stackhouse T, Hagerman RJ. (1999). Electrodermal responses to sensory stimuli in individuals with fragile X syndrome: a preliminary report. Am J Med Genet. Apr 2;83(4):268-79.

In this study, the researchers investigated hyperarousal, hyperactivity, aggression, and anxiety in children with Fragile X syndrome. They found the pattern of electrodermal responses (EDRs) to stimulation in one sensory modality predicted the pattern of EDRs in four other sensory systems. In addition, the EDR pattern of individuals with the fragile X mutation was related to their FMR-protein expression. Finally, EDRs in individuals with fragile X syndrome were significantly different from those of normal controls, demonstrating greater magnitude, more responses per stimulation, responses on a greater proportion of trials, and lower rates of habituation. The findings support the theory that individuals with fragile X syndrome have a physiologically based enhancement of reactions to sensations. Because electrodermal activity indexes sympathetic nervous system activity, the data suggest that the over-arousal to sensation may involve the sympathetic system.