How mental fatigue affects brain function and cognitive performance in healthy adults: an fMRI study
| ISRCTN | ISRCTN18332448 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN18332448 |
| Sponsor | Vrije Universiteit Brussel |
| Funder | Universitair Ziekenhuis Brussel |
- Submission date
- 11/08/2026
- Registration date
- 14/08/2026
- Last edited
- 12/08/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
Mental fatigue is the feeling of being mentally tired after doing demanding thinking tasks for a long time. It can affect attention, decision-making and performance, but researchers do not yet fully understand what changes occur in the brain when people become mentally fatigued.
This study aimed to find out how mental fatigue affects brain activity and thinking performance in healthy adults. The researchers used functional magnetic resonance imaging (fMRI), a type of brain scan, to measure brain function and blood flow in the brain while participants completed mental tasks.
Who can participate?
Healthy adults aged 18 to 35 years could take part. Participants had to be right-handed, non-smokers and not taking medication. People with medical, mental health or psychiatric conditions, colour blindness, claustrophobia, or any implants that were not safe for MRI scanning could not take part.
What does the study involve?
Participants attended two study sessions. In one session, they completed a challenging computer task called a Stroop task for about 45 minutes while having an fMRI brain scan. This task was designed to make people mentally fatigued.
In the other session, participants watched an emotionally neutral nature documentary for about 45 minutes while having the same type of brain scan. This acted as a comparison condition.
Before and after each session, participants completed a short computer task called a Go/NoGo task, which measures attention, self-control and response inhibition. Participants also completed questionnaires about mental fatigue, mood, sleepiness, attention, boredom, motivation and workload.
What are the possible benefits and risks of participating?
Participants were unlikely to receive a direct health benefit from taking part. However, the study could improve understanding of how mental fatigue affects the brain and cognitive performance, which may help inform future research.
Possible risks included temporary mental tiredness from completing demanding cognitive tasks. Some people may also find MRI scans uncomfortable because they involve lying still in a confined space for a period of time. People with claustrophobia or MRI-incompatible implants were excluded from participation.
Where is the study run from?
The study was run from Vrije Universiteit Brussel and Universitair Ziekenhuis Brussel in Belgium.
When is the study starting and how long is it expected to run for?
August 2024 to August 2025.
Who is funding the study?
The study is funded by Universitair Ziekenhuis Brussel (UZ Brussel), Belgium.
Who is the main contact?
Manon Roose
manon.marie.roose@vub.be
Contact information
Public, Scientific
Pleinlaan 2
Elsene
1050
Belgium
 ORCID ID |
0009-0001-1778-9082 |
|---|---|
| Phone | +32 485 16 37 91 |
| manon.marie.roose@vub.be |
Principal investigator
Pleinlaan 2
Elsene
1050
Belgium
| ORCID ID |
0000-0002-2808-044X |
|---|---|
| Phone | +32 486 02 69 77 |
| bart.roelands@vub.be |
Principal investigator
Laarbeeklaan 101
Jette
1090
Belgium
| ORCID ID |
0000-0003-3647-4446 |
|---|---|
| Phone | +32 472 35 91 75 |
| peter.vanschuerbeek@uzbrussel.be |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Active |
| Assignment | Crossover |
| Purpose | Basic science |
| Participant information sheet | 50074 PIS v1 (Dutch).pdf |
| Scientific title | Brain function and cognitive performance during and after a mentally fatiguing Stroop task compared with an emotionally neutral documentary in healthy adults with different levels of mental fatigue susceptibility: a randomized crossover fMRI study |
| Study objectives | The aim of this study is to investigate the effects of experimentally induced mental fatigue on brain function and cognitive performance in healthy adults using fMRI. |
| Ethics approval(s) |
Approved 28/02/2024, Commissie Medische Ethiek (CME) (Laarbeeklaan 101, Jette, 1090, Belgium; +32 2 477 55 85; ethiek@uzbrussel.be), ref: EC-2023-373 |
| Health condition(s) or problem(s) studied | Mental fatigue and its effects on brain activity and cognitive performance in healthy adults |
| Intervention | Participants completed both an experimental mental fatigue condition and a control condition in a randomized crossover order, with the two experimental sessions separated by at least several days. The order of the two experimental conditions was randomised using the web-based randomisation tool Randomization.com. All participants completed both the mental fatigue and control conditions in a crossover design, with the order of the two conditions determined by the generated randomisation sequence. Mental fatigue condition: Participants performed a prolonged modified Stroop task while undergoing functional magnetic resonance imaging. The task was designed to induce mental fatigue through sustained cognitive effort and lasted approximately 45 minutes. Participants responded to colour-word stimuli using MRI-compatible response buttons. BOLD signal, cerebral blood flow (CBF), and cognitive performance were recorded during the task. Control condition: Participants watched an emotionally neutral nature documentary for approximately 45 minutes while undergoing the same magnetic resonance imaging procedures. The documentary served as a low-cognitive-demand control condition. In both conditions, participants performed a 5-min Go/NoGo task before and immediately after the mental fatigue/control period to assess cognitive control and response inhibition. BOLD signal and CBF were assessed during the task. Subjective mental fatigue and other psychological measures were also assessed during both experimental sessions. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) | |
| Completion date | 02/08/2025 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 35 Years |
| Sex | All |
| Target sample size at registration | 30 |
| Total final enrolment | 31 |
| Key inclusion criteria | 1. Male or female 2. Aged 18–35 years 3. Healthy, with no neurological, cardiovascular or musculoskeletal disorders 4. Right-handed 5. Not using medication 6. Non-smoker |
| Key exclusion criteria | 1. Presence of a chronic health condition, including neurological, cardiovascular, or musculoskeletal disorders 2. Colour blindness 3. Participation in concurrent care or other research trials 4. History of mental or psychiatric disorders: - Increased risk of burnout, defined as a Burnout Assessment Tool score ≥ 2.59 - High general fatigue, defined as a Multidimensional Fatigue Inventory score > 57 - Symptoms of depression, defined as a Beck Depression Inventory-II score > 16 5. Use of medication 6. Non-compliance with pre-trial requirements concerning caffeine intake, strenuous exercise and standardized dietary intake 7. Claustrophobia 8. Metal dental implants, or braces 9. Any non-MRI-compatible implant |
| Date of first enrolment | 30/08/2024 |
| Date of final enrolment | 02/08/2025 |
Locations
Countries of recruitment
- Belgium
Study participating centres
Jette
1090
Belgium
Elsene
1050
Belgium
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | Anonymized individual participant data may be made available upon reasonable request, subject to a data use agreement and applicable ethical and data protection requirements. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | in Dutch version 1 |
12/08/2026 | No | Yes | |
| Protocol file | version 3 | 22/01/2024 | 12/08/2026 | No | No |
Additional files
- 50074 Protocol v3 22Jan2024.pdf
- Protocol file
- 50074 PIS v1 (Dutch).pdf
- in Dutch
Editorial Notes
11/08/2026: Trial's existence confirmed by Commissie Medische Ethiek (CME).
