The Trail Making task consists of three versions: Numeric, Alphabet, and Alphanumeric. In each version, participants are instructed to connect numbers and/or letters in the correct sequence by tapping on them. Correct selections are highlighted in green, and are accompanied by a positive sound alert. If an incorrect selection is made, a negative sound alert will play, and the sequence will not progress until the correct item is chosen. The task concludes once all items are tapped in the correct order.
The Numeric Version is designed to assess visual scanning and processing speed:
- Participants are instructed to tap the numbers in ascending order (i.e., 1 → 2 → 3...).
- Numbers are randomly placed on the screen, with a different placement on the screen each administration.
The Alphabet Version is designed to assess visual scanning and processing speed:- Participants are instructed to tap the letters in alphabetical order (i.e., A → B → C...).
- Letters are randomly placed on the screen, with a different placement on the screen each administration.
The Alphanumeric Version is designed to assess executive function, particularly cognitive flexibility:
- Participants are instructed to tap the numbers and letters in alternating order (e.g., 1 → A → 2 → B → 3 → C...).
- A mix of numbers and letters are randomly placed on the screen, with a different placement on the screen each administration.
The numeric and alphabetical trails paradigm has been extensively studied and has consistently related to visual scanning and processing speed. The alphanumeric switching trails paradigm has been extensively studied and has been consistently associated with frontal functioning. Other groups have previously published validity data for mobile tests using the trails paradigm, showing that it is feasible and associated with the traditional paper and pencil test.