Trail Making Test
Background
The Trail Making Test (TMT) is a widely used neuropsychological assessment that measures visual attention, processing speed, and mental flexibility.
The test was originally developed by John Partington in 1938 and published in 1949 under the name "Partington’s Pathways Test" as a measure of general intellectual ability. A revised version of the test was added to the U.S. Army’s "Army Individual Test Battery" under the name "Trail Making Test" in 1944 as a screening tool for general intellectual ability as well as to examine soldiers with brain injuries during World War II. Ralph Reitan is credited with adapting the test for general clinical use in 1950. Ever since, the Trail Making Test has been a popular cognitive-behavioral screening tool for brain injuries and dementia and is frequently used to evaluate treatment/intervention outcomes as well as recovery gains post-injury.
The classic Trail Making Test is a paper&pencil test and consists of 2 different trails, trail A and trail B. Each trail requires the participant to manually connect certain dots as fast as possible without skipping dots and without lifting the pen.
Trail A: Trail A presents the participant with strategically placed numbered dots from 1 to 25 that must be connected in sequence from the smallest to the largest number (1-2-3...). This trail mainly measures processing speed on the backdrop of a visual search task.
Trail B: Trail B presents the participant with strategically placed numbered dots (1-13) and letter dots (A-L) that participants must connect shifting from numbers to letters in numerical (numbers) as well as alphabetical (letters) order (from 1-A-2-B-3-C....). Thus, Trail B adds a set-shifting component to the task requiring a certain degree of cognitive flexibility for a successful finish.
The Millisecond implementation of the Trail Making Task adapts the procedure to the computer. The task runs on touchscreens as well as mouse-controlled devices.
Task Procedure
Participants first work on Trail A (+ short practice trail) and then on Trail B (+ short practice trail) without any time constraints. By default, errors are announced by highlighting the last correct dot and forcing participants to return to it.
What it Measures
The Trail Making Test (TMT) measures visual attention, processing speed, and mental flexibility.
Psychological domains
- Complex Attention: Both parts require visual scanning, searching, and sustained attention.
- Processing Speed: Measured by the total time taken to complete the tasks, reflecting both mental and motor processing speeds.
- Executive Functioning: This is the primary domain measured by Part B, which requires set-shifting, a component of cognitive flexibility
Main Performance Metrics
- Trail Completion Time: This is the primary score. Lower times indicate better cognitive function.
- Difference Score: Difference in Completion Time of TrailB-TrailA as a measure of set shifting costs
Psychiatric Conditions
The following patient groups show impaired performance on the Trail Making Test:
- Dementia
- Mild Cognitive Impairment (MCI)
- Parkinson’s Disease
- Huntington's Disease
- Traumatic Brain Injury (TBI)
- Stroke
- Major Depression (MDD)
- Attention Deficit Hyperactivity Disorder (ADHD)
An implementation of the Trail Making Test introduced by Reitan (1955)
References
Search Google Scholar for peer-reviewed, published research using the Inquisit Trail Making Test.
R. M. Reitan, R. M. (1955). The relation of the trail making test to organic brain damage. Journal of Consulting Psychology
Reitan R. M. (1958). Validity of the Trail Making test as an indicator of organic brain damage. Percept. Mot Skills, 8, 271-276.
Tombaugh, T.N.T.N (2004). "Trail Making test A and B: Normative Data Stratified by Age and Education". Archives of Clinical Neuropsychology : The Official Journal of the National Academy of Neuropsychologists 19 (2): 203–214.