In healthy adults, deficits in identifying a second target following a previously attended target in Rapid Serial Visual Presentation (RSVP) occur between intertarget intervals of approximately 100-500 ms. This Attentional Blink (AB) is investigated in nondemented medicated Parkinson's patients using a modification of the standard paradigm that required the identification of two red letters embedded in a black letter distractor stream. Parkinson's patients and controls produced an equivalent AB, although with a different pattern of errors. Thus, the processing and clearance of information was largely preserved in nondemented Parkinson's patients, without evidence of bradyphrenia. However, perseveration of earlier RSVP items in short-term memory was thought to explain the different pattern of errors.