Trail Making Test [TMT-50]

Description

The Trail Making Test (TMT-50) is a neuropsychological assessment consisting of two parts, TM-A and TM-B. In Part A, the examinee connects numbered circles from 1 to 25 in ascending order. In Part B, the examinee alternates between numbers and letters, such as 1–A–2–B–3–C. The test is administered individually and timed.

Purpose

The TMT is used to assess:

• visual-perceptual and visuomotor scanning,
• attention,
• psychomotor speed,
• continuity in task execution,
• cognitive flexibility.

It is commonly applied in neuropsychological assessment and may support the evaluation of neurodegenerative conditions and brain injury.

Structure

Part A – TM-A

The examinee connects numbered circles from 1 to 25 in the correct ascending numerical sequence.

Part B – TM-B

The examinee alternates between numbers and letters, for example 1–A–2–B–3–C. Part B is more demanding because it requires greater cognitive flexibility and set-shifting ability.

Scoring

Performance is primarily scored according to the completion time in seconds for each part.

Errors are also recorded, corrected during administration, and taken into account in the overall evaluation.

Generally, shorter completion times indicate better performance, provided that results are interpreted using appropriate normative data.

Validity

According to the provided material, the TMT demonstrates good validity and is associated with other cognitive measures and indicators of frontal-lobe functioning.

It has also been shown to help distinguish between individuals with and without cognitive impairment and to identify organic brain dysfunction.

Reliability and Diagnostic Performance

The provided material reports findings from a study involving individuals with Mild Cognitive Impairment and Alzheimer-type dementia. For TM-B, the following values were reported:

• Correct reclassification: 79.6%
• Sensitivity: 84%
• Specificity: 70%

The material also reports the following threshold values:

• TM-A: 75 seconds
• TM-B: 223 seconds

These values relate to the specific study described in the source and should not be treated as universal diagnostic cut-offs.

Data Analysis and Use

The source describes an application of the TMT in a sample of 49 participants, including older adults without dementia, individuals with Alzheimer-type dementia, and individuals with Mild Cognitive Impairment.

Statistically significant differences were reported between the groups, particularly in TM-B, supporting the usefulness of the test in the assessment of cognitive decline.

Applications

The TMT may be used in:

• neuropsychological assessment,
• evaluation of cognitive decline,
• assessment of Mild Cognitive Impairment,
• Alzheimer-type dementia,
• assessment of brain injury,
• clinical and research studies,
• early detection of executive-function changes.

References

Gaudino, A., Mark, W. G., & Squires, N. K. (1995). Construct validity in the Trail Making Test: What makes Part B harder? Journal of Clinical and Experimental Neuropsychology, 17, 529–535.

Reitan, R. M. (1958). Validity of the Trail Making Test as an indication of organic brain damage. Perceptual and Motor Skills, 8, 271–276.

Reitan, R. M., & Wolfson, D. (1995). Category Test and Trail Making Test as measures of frontal lobe functions. The Clinical Neuropsychologist, 9, 50–56.

Varasolis, S., Tsantali, E., & Tsolaki, M. (2005). The ability of the Trail Making Test to differentiate between elderly individuals without dementia, elderly individuals with Mild Cognitive Impairment, and patients with Alzheimer-type dementia. 2nd Panhellenic Interdisciplinary Conference on Alzheimer’s Disease and Related Disorders, Thessaloniki.