Reorientation of attention in Huntington disease.

Objectives and background: This experiment sought to quantify the extent to which patients with Huntington disease (HD) have difficulties in orienting attention, via a vibrotactile version of a Posner-type cost-benefit paradigm.

Method: Participants were required to push a button in response to a vibration delivered to the index finger of either hand. Prior to each stimulus vibration, a precue (valid, neutral, or invalid) was delivered to the finger. Benefits and costs were calculated from valid and invalid precues.

Results: Although patients with HD were overall slower than the controls, their performance was no different; both patients and controls demonstrated increased benefits from valid compared with invalid and neutral cues. Of interest was the finding that patients, unlike controls, performed significantly slower with the cue presented to the left compared with the right side. The crossed arm configuration proved to be too difficult for the patients with HD, and thus an analysis on these data was not permitted.

Conclusions: Patients may experience difficulties in allocating attentional resources toward their left nonpreferred hand. Overall, findings demonstrate that patients with HD, with minimal caudate damage at early stages of disease onset, may not experience problems in their ability to orient attention.