Executive Function
Trail Making Test B
Measure set shifting and cognitive flexibility with a browser-native Trail Making Test Part B.
Useful for executive-function research, frontal-lobe studies, and batteries that compare TMT-B against TMT-A.
What this task measures
Measures executive function and cognitive flexibility by asking participants to alternate between numbers and letters (1-A-2-B-3-C...).
Core constructs
- Set shifting
- Cognitive flexibility
- Divided attention
- Executive function
- Sequencing ability
Research fit
- Frontal lobe dysfunction detection
- Dementia differential diagnosis
- ADHD executive function assessment
- Traumatic brain injury severity
- Neuropsychological battery standard
Why researchers use ConductCognition
- Hosted browser delivery with no local install burden for participants.
- Study setup, scoring, exports, and participant links in one workflow.
- Transparent pricing instead of opaque enterprise quoting for solo labs.
- Free entry tier plus Academic Pro when you need the full battery and raw exports.
Paradigm overview
Trail Making Test Part B measures executive function and cognitive flexibility. Participants must connect circles by alternating between numbers and letters in ascending order (1-A-2-B-3-C-...8-H), requiring constant switching between two cognitive sets. The 16 circles are randomly positioned on a canvas.
The critical cognitive demand is set-shifting: participants must maintain two parallel sequences (numeric and alphabetic), track their current position in each, and switch between them on every step. This engages the dorsolateral prefrontal cortex and is one of the most widely used clinical measures of executive function.
The TMT B-A difference (Part B time minus Part A time) is a commonly used derived measure that isolates the executive function component by subtracting out the motor speed contribution measured by Part A. This difference score is particularly sensitive to frontal lobe pathology.
Key scoring outputs
Completion Time
msTotal time from first click to connecting the final circle. Primary measure of executive-mediated processing speed.
Lower is better
Completion Time (sec)
secondsSame as completion time, converted to seconds.
Lower is better
Errors
countIncorrect clicks (wrong circle). In TMT-B, errors often reflect sequencing or set-switching failures.
Lower is better
Total Circles
countNumber of circles in the trail (16 for TMT-B: 8 numbers + 8 letters).
Informational
Normative and citation context
Tombaugh TN (2004). Trail Making Test A and B: Normative data stratified by age and education. Archives of Clinical Neuropsychology, 19(2):203-214.
Paper-based norms. Same caveats as TMT-A regarding computerized adaptation.
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