Sub-test of the Delis-Kaplan Executive FunctionSystem (D-KEFS; Delis, Kaplan, & Kramer,2001), designed to measure cognitive flexibility or processing speed by means of a visuomotor sequencing task. The D-KEFS Trail making test onsists of a series of five conditions: visual scanning, number sequencing,letter sequencing, number-letter switching, and motor speed. In the visualscanning condition, the particpant crosses all the 3s that appear on theresponse sheet. In the number sequencing condition, the particpant draws a lineconnecting all the number 1 tot 16 in order, while distractor letters appear onthe same page. In the number-letter sequencing condition, the participant isrequired to switch back and forth between connecting numbers and letters (i.e.,1, A, 2, B, etc., to P, 16). In the motor speed condition, the participant traces over a dotted line connecting circle on the page as quickly as possible, toindex their motor drawing speed. The test has been adapted for use with pre-school children aged 2 to 6 years, and labeled TRAILS-P.