Five digit test (FDT) is appropriate both for English and non-English speakers, and competent readers and illiterate subjects. The cognitive requirements of doing the tasks are very low. The subject need to name digits 1 to 5 and recognized perceptual pattern of 1 to 5 elements (Hsieh & Tori, 2007).
It is divided into four parts. Each part contains 50 items. The items are groups of digits or stars printed inside the frames. The digits can either be named as the number printed in the frame (two 5s are read as “five”), or counted how many digits are in the frame (two 5s are counted as “two”). Part 1 and part 2 measure processing speed. Part 3 and part 4 measure response inhibition. In part 1, a subject reads groups of digits. In part2, the subject counts groups of stars. In part 3, the subject counts conflictive items and items and avoids naming them (if two 5s are presented, the correct response is “two” and not “five”). In part 4, the subject needs to switch between counting (80% of the items) and naming (20% of the items) the number, whenever the item has a darker frame. For each part, test scores are the amount of performance time in seconds plus the total of errors made (Hsieh & Tori, 2007; Verdejo, Toribio, Orozco, Puente, & Perez-Garcia, 2005).
Hsieh, S. L., & Tori, C. D. (2007). Normative data on cross-cultural neuropsychological tests obtained from Mandarin-speaking adults across the life span. Arch Clin Neuropsychol, 22(3), 283-296.
Verdejo, A., Toribio, I., Orozco, C., Puente, K. L., & Perez-Garcia, M. (2005). Neuropsychological functioning in methadone maintenance patients versus abstinent heroin abusers. Drug Alcohol Depend, 78(3), 283-288.