Deficits in selective attention in symptomatic Huntington disease: assessment using an attentional blink paradigm

BACKGROUND: Impaired selective attention in Huntington disease (HD) may manifest as difficulty in identifying a single target embedded among a series of distractors in rapid serial visual presentation tasks.

METHOD: We used an attentional blink (AB) paradigm to examine whether attentional control is impaired in symptomatic HD. Fourteen HD patients and 13 age-matched healthy controls performed a rapid serial visual presentation task in which 2 targets (T1 and T2) and numerous distractors were presented in rapid succession. We assessed the accuracy of T1 identification and the AB (impaired T2 detection after the correct identification of T1).

RESULTS: Among the HD patients, identification of T1 was significantly impaired and AB was significantly larger but not longer. The HD patients also made significantly more random errors.

CONCLUSIONS: Frontostriatal or frontoparietal dysfunction is likely to compromise attentional control in HD, such that well-masked and rapidly presented target stimuli are difficult to detect and identify, especially as the difficulty level increases. Although we previously reported no AB deficits in presymptomatic HD, with manifest disease we found that the progressive frontoparietal cortical changes compromise attentional control mechanisms.