A 2003 study published on Springer.com looked at pramipexole in comparison with I-dopa. The study subjects were twenty right-handed patients with early or mild PD. They were evaluated using neuropsychological and clinical assessments during three treatment modalities. 1. When in the off treatment condition; 2. When on pramipexole and 3. When on i-dopa. In comparison to the off treatment condition, the DA-agonist pramipexole produced a significant impairment of short term verbal memory, attentional-executive functions, and verbal fluency, while l-dopa did not. Pramipexole opposite to l-dopa, failed to improve FAS and Stroop tests. Pramipexole may worsen cognitive functions although not exceeding normative values.