Figure 1. Correlation between baseline measures of cognitive performance and Parkinson disease–related cognitive pattern (PDCP) activity.

(A) Relationship between baseline verbal learning performance and PDCP expression in the levodopa (left) and placebo (right) treatment groups. At baseline, higher PDCP expression was associated with more impaired verbal learning performance in both treatment groups. Squares and triangles refer respectively to cognitive responders (R) and nonresponders (NR) to treatment; see Methods. (B) Relationship between baseline PDCP expression and levodopa-mediated changes in verbal learning performance. Higher baseline PDCP scores correlated with greater improvement in cognitive functioning during levodopa treatment. The horizontal dashed line represents the cutoff (+0.44) for meaningful treatment-mediated change in verbal learning based on the reliable change index (see text). The vertical dashed line represents the baseline PDCP value (+1.01) that corresponded to this behavioral response cutoff. Baseline measures of network activity above this value were found to be associated with improved cognitive functioning during levodopa treatment.