The study by Shanahan et al. utilized a variety of measures to assess processing speed. These included linguistic measures such as rapid automatized naming (RAN) and the Stroop test as well as non-linguistic measures such as the WISC Coding subtest, the Trailmaking test and the Stop Signal task. Findings indicated that, despite their differences, these various measures of processing speed were highly correlated with one another, all apparently reflecting a common factor that contributes to both ADHD and Reading Disorder.