Mental FatigueCOG-PREDNCT07877389
Predicting Declines in Attention and Memory During a Prolonged Mental Task
A study testing Individually Calibrated Time Load Dual-back Task With Seated Rest in people with Mental Fatigue and Cognitive Performance, run by DSW Ideis University at 1 site in Poland.
Trial summary
This study will investigate whether heart activity and changes in the skin's ability to conduct electricity can help predict performance during a demanding computer task. These signals reflect how the body responds to mental effort. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Mental Fatigue, Cognitive Performance
- What is being tested?
- Individually Calibrated Time Load Dual-back Task With Seated Rest
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 250 participants
- Where
- 1 sitePoland
- Study dates
- Dec 2026to Dec 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 18-30 years.
- Good general health according to self-report.
- Normal or corrected-to-normal vision and ability to read the letters and digits presented on the screen.
- Ability to understand instructions in Polish and perform the computer task.
- Provision of voluntary informed consent.
Who cannot join
- Neurological, psychiatric, or cardiovascular conditions that significantly affect participant safety, task performance, or heart rhythm.
- Use of medications or substances that significantly affect heart rhythm, arousal, or cognitive performance.
- Acute infection, fever, feeling unwell, or skin damage that makes sensor placement difficult.
- Failure to understand the task after repetition of the instructions and practice, or unsuccessful calibration.
- Caffeine or nicotine use within four hours, alcohol consumption within 24 hours, or intense physical exercise within 12 hours before the visit.
- Absence or withdrawal of informed consent.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Maciej Lachowicz Vice Dean of the Instute of Health, PhD contact
Poland1 site
DSW Ideis, Institute of health studies
Wroclaw, Lower Silesian Voivodeship, 53-611
About this study
Official title: Prediction of Cognitive Performance Decline Based on Autonomic Activity and Subjective State During Sustained Cognitive Load
This study will investigate whether heart activity and changes in the skin's ability to conduct electricity can help predict performance during a demanding computer task. These signals reflect how the body responds to mental effort. The main question is whether measurements taken at rest and near the beginning of the task help predict later accuracy, beyond information about sleep the previous night, current sleepiness, and initial task performance.
Healthy young adults will attend one visit lasting approximately 50-60 minutes. Participants will complete a questionnaire and wear sensors that record heart activity and skin responses. After a five-minute resting measurement, participants will learn a computer task involving letters and numbers. The task requires remembering the previous letter and deciding whether numbers are odd or even. A short calibration will adjust the presentation speed to each participant.
Read more
Participants will then perform the task for 16 minutes at the selected speed and rate their fatigue and the demands of the task. After these ratings, participants will rest quietly for five minutes and repeat the task for four minutes at the same speed.
The researchers will also examine how performance, fatigue, and body responses change during the task and after rest. The study is intended to improve understanding of sustained mental effort and is not a medical diagnostic assessment.
Read the detailed description
COG-PRED is a prospective, single-group laboratory study of cognitive performance during sustained mental effort. Subjective fatigue, autonomic responses, and task performance may change at different rates. The study will examine whether resting autonomic activity and early physiological responses provide information about subsequent performance beyond that available from sleep duration, sleepiness, and initial task accuracy. All participants will follow the same sequence of procedures, without randomization or a separate control group.
Cognitive load will be induced using a study-specific implementation of the Time Load Dual-back (TloadDback) task. Letters and digits will alternate on the screen. Participants will respond when a letter matches the preceding letter and withhold a response when it does not. For digits, participants will classify each number as odd or even. Responses will be made with the dominant hand, while the hand carrying the skin conductance electrodes remains supported.
Following familiarization, a shortened adaptive calibration will identify an individual presentation interval using a criterion of at least 85% weighted accuracy. Search blocks will contain 30 stimuli, and the selected interval will be checked in a separate 40-stimulus verification block. Calibration will last no longer than five minutes. Participants who do not obtain a verified interval will not proceed to the main task. Once verified, the interval will remain fixed throughout the main task and the post-rest task. Individual calibration adjusts task pace but does not assume identical subjective workload across participants.
Physiological recording will cover the resting measurement, task phases, and recovery period. Cardiac and skin conductance signals will be synchronized with stimulus and response events. Resting features will be derived from the final four minutes of the five-minute baseline. Early task responses will be characterized by changes from this baseline during the first four minutes of the main task.
Prespecified linear regression models will assess later task accuracy while accounting for initial accuracy. A reference model containing previous-night sleep duration, pretask sleepiness, and initial accuracy will be compared with an expanded model that additionally includes resting heart rate, heart rate variability, skin conductance, and their early task changes. Predictive performance will be assessed using 10-fold cross-validation at the participant level. Physiological information recorded after the prediction window will not be used as an early predictor.
Immediately after the main task, participants will rate mental fatigue and complete the six dimensions of the National Aeronautics and Space Administration Task Load Index (NASA-TLX), scored as an unweighted mean. These assessments will precede the full five-minute seated rest. Participants will then rate fatigue and perform a four-minute task with a new stimulus sequence at the same calibrated speed. The total interval between the main task and the post-rest task will be recorded.
Secondary analyses will describe performance and physiological changes over time and compare the final four minutes of the main task with the four-minute post-rest task. Relationships between autonomic recovery and changes in performance will be explored separately. Because there is no no-rest control condition, changes after the break will not be interpreted as effects attributable solely to rest.
- Conditions
- Mental Fatigue, Cognitive Performance
- Being tested
- Individually Calibrated Time Load Dual-back Task With Seated Rest
- Keywords
- Sustained Cognitive Load, Time Load Dual-back (TloadDback), Working Memory, Sustained Attention, Heart Rate Variability, Electrodermal Activity, Skin Conductance, Cognitive Performance Prediction, Sleep Duration, Sleepiness, Perceived Workload, Post-Rest Recovery
- Medical subject headings
- Mental Fatigue, Sleepiness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Individually Calibrated Time Load Dual-back Task With Seated RestBehavioural
Participants perform the Time Load Dual-back task, alternating letter 1-back matching with odd/even digit classification. A study-specific adaptive calibration starts at 1400 ms and tests presentation intervals between 400 and 1600 ms. Search blocks contain 30 stimuli; the selected interval must achieve at least 85% weighted accuracy in a separate 40-stimulus verification block. Calibration is limited to five minutes; participants without a verified interval do not proceed to the main task. The verified interval is used for a 16-minute main task and a four-minute post-rest task. Fatigue and workload ratings follow the main task, before five full minutes of quiet seated rest. A fatigue rating precedes the post-rest task. Task pace remains fixed after calibration.
| Study group | Role | What they receive |
|---|---|---|
| Calibrated Cognitive Load and Post-Rest Assessment | Experimental | Participants undergo a five-minute seated baseline, task familiarization, and individual calibration of the Time Load Dual-back (TloadDback) task. After successful calibration, participants complete a 16-minute task combining letter matching with odd/even digit classification. Task pace remains fixed at the individually verified level. Immediately afterward, participants rate mental fatigue and perceived workload, followed by five full minutes of seated rest. Participants then rate fatigue and complete a four-minute post-rest task at the same pace, followed by final fatigue and well-being ratings. Cardiac activity and skin conductance are recorded throughout the measurement phases. Receives: Behavioral: Individually Calibrated Time Load Dual-back Task With Seated Rest |
What is being measured
The primary outcome is the main question the study is designed to answer.
Weighted Accuracy During the Final Four Minutes of the Main Cognitive Task
Weighted accuracy (WAcc) on the Time Load Dual-back task is calculated as 0.65 x letter accuracy + 0.35 x digit accuracy, with both component accuracies expressed as percentages. Letter accuracy includes correct responses to matching letters and correct withholding of responses to nonmatching letters. Digit accuracy is the percentage of correct odd/even classifications. Errors and required-response omissions are scored as incorrect. The first letter of each new sequence and technically excluded trials are removed from the relevant denominators; analytical windows do not reset the letter reference. Scores range from 0 to 100%, with higher scores indicating better performance. The primary endpoint is the late-task score; initial accuracy is included as a predictor, rather than subtracted to define this endpoint.
Measured: During seconds 720-960 (the final four minutes) of the 16-minute main task, within a single study visit.
Secondary outcomes (10)
Weighted Accuracy Across the Main Cognitive Task
Weighted accuracy is calculated separately for each consecutive four-minute window as 0.65 x percentage letter accuracy + 0.35 x percentage digit accuracy. Correct letter responses include both target detections and correct withholding on non-target trials. The scoring and exclusion rules are identical to those for the primary outcome. Scores range from 0 to 100%, with higher scores indicating better performance. The repeated scores describe the course of performance during sustained cognitive load.
Measured: During four consecutive 4-minute windows (0-240, 240-480, 480-720, and 720-960 seconds) of the 16-minute main task.
Change in Weighted Accuracy From the End of the Main Task to the Post-Rest Task
Weighted accuracy during the entire four-minute post-rest task minus weighted accuracy during the final four minutes of the main task, expressed in percentage points. Both scores use the same weighting (0.65 x letter accuracy + 0.35 x digit accuracy), scoring rules, and individually calibrated presentation interval. The difference ranges from -100 to +100 percentage points. Positive values indicate better accuracy after rest. This comparison describes change after the break without attributing the change solely to rest.
Measured: During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main task.
Median Correct-Response Reaction Time Across Task Phases
Within-participant median time from stimulus onset to the first keypress on a correctly scored response-required trial, in milliseconds, calculated separately for each assessment window. Only correct trials requiring a response are included; correct withholding on non-target letter trials has no reaction time. Responses earlier than 100 ms and technically excluded trials are not included. Response times must fall within the stimulus response window. Main-task trajectories and post-rest versus late-main-task values will be compared. Shorter times indicate faster responses and will be interpreted together with accuracy.
Measured: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Standard Deviation of Correct-Response Reaction Time Across Task Phases
Within-participant sample standard deviation of correct-response reaction times, in milliseconds, calculated separately for each assessment window. The same eligible responses are used as for median correct-response reaction time: correct keypresses from 100 ms after stimulus onset to the end of the response window. Correct withholding, anticipations, incorrect responses, and technically excluded trials are not included. Higher values indicate greater variability in response speed. Main-task trajectories and post-rest versus late-main-task values will be compared.
Measured: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Number of Incorrect Responses Across Task Phases
Number of trials with an incorrect keypress in each assessment window, including responses to non-target letters, incorrect response keys on letter-target or digit trials, and anticipatory responses earlier than 100 ms. A trial is scored once according to the first-keypress rule. Required-response trials without a keypress are counted separately as omissions; correct withholding on non-target letters is not an error. Technically excluded trials and the first reference-setting letter of each sequence are omitted. Counts will be interpreted with the number of eligible trials, which varies with the calibrated presentation interval. Lower counts indicate fewer incorrect responses.
Measured: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Number of Required-Response Omissions Across Task Phases
Number of letter-target and digit trials in which no keypress is recorded within the response window. Correct withholding on non-target letter trials is not an omission. Trials with anticipatory or incorrect keypresses are classified as incorrect responses rather than omissions. Technically excluded trials and the first reference-setting letter of each sequence are omitted. Counts will be interpreted with the number of eligible response-required trials. Main-task trajectories and post-rest versus late-main-task values will be compared. Lower counts indicate fewer omissions.
Measured: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Self-Reported Mental Fatigue Across the Study Visit
Single-item rating of current mental fatigue from 0 (no mental fatigue) to 100 (extreme mental fatigue). Ratings are obtained before baseline, after calibration immediately before the main task, immediately after the main task, after the full five-minute rest before the post-rest task, and after the post-rest task. Repeated ratings describe fatigue during preparation, sustained task performance, rest, and task resumption. Higher scores indicate greater fatigue.
Measured: Before baseline; after calibration/before the main task; immediately after the 16-minute main task; after five minutes of rest/before the post-rest task; and immediately after the 4-minute post-rest task, within one visit.
Perceived Workload on the Unweighted NASA Task Load Index
Unweighted mean of the six ratings on the National Aeronautics and Space Administration Task Load Index (NASA-TLX): mental demand, physical demand, temporal demand, performance, effort, and frustration. Each dimension is scored from 0 to 100. The performance dimension is oriented from success to failure so that higher values on every dimension indicate greater workload or a less favorable assessment. The overall score ranges from 0 to 100, with higher scores indicating greater perceived workload. Ratings refer only to the 16-minute main task. Pairwise weighting is not used.
Measured: Immediately after the 16-minute main task and before the start of the five-minute seated rest.
Heart Rate Variability During Baseline, Cognitive Load, and Rest
Root mean square of successive differences between normal-to-normal heartbeat intervals (RMSSD), in milliseconds, calculated from quality-controlled electrocardiographic recordings using continuous valid segments. Values are calculated separately for each assessment window. The natural logarithm of RMSSD is used in the predictive model; early reactivity is the first main-task window minus baseline on that logarithmic scale. Resting recovery compares the final four minutes of seated rest with the final four minutes of the main task and baseline. Higher RMSSD indicates greater successive-interval variability, without implying better cognitive performance.
Measured: During seconds 60-300 of the 5-minute baseline, each consecutive 4-minute window of the 16-minute main task, and seconds 60-300 of the 5-minute seated rest.
Mean Skin Conductance During Baseline, Cognitive Load, and Rest
Mean skin conductance, in microsiemens, calculated from valid electrodermal samples in each assessment window. This measure includes both tonic level and contributions from phasic responses; it is not a decomposed tonic-only measure. The predictive model uses ln(1 + the numerical skin conductance value in microsiemens), with early reactivity calculated as the first main-task window minus baseline on this scale. Resting recovery compares the final four minutes of seated rest with the final four minutes of the main task and baseline. Higher values indicate greater skin conductance, without implying better or worse cognitive performance. The first minute of rest is additionally examined to describe the initial transition.
Measured: During seconds 60-300 of baseline, each consecutive 4-minute window of the 16-minute main task, and the 5-minute rest (initial 60 seconds and final 240 seconds).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Oct 2026
- Study startDec 2026 (estimated)
- Primary completionDec 2026 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Mental FatigueStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Prospective, single-arm laboratory study with repeated measurements within participants. All participants are assigned to the same single-visit protocol: resting baseline, task familiarization, individual calibration, a 16-minute Time Load Dual-back (TloadDback) task, post-task ratings, five minutes of seated rest, and a four-minute post-rest task. The individually verified stimulus presentation interval remains unchanged during the main and post-rest tasks. There is no randomization or separate control group.
- Masking
- None (open label)
- Enrolment
- 250 participants (estimated)
Sponsor and investigators
- Lead sponsor
- DSW Ideis University
- Sponsor type
- University, hospital or other
- Collaborators
- Wroclaw University of Health and Sport Sciences
- Responsible party
- Principal investigator, Maciej Lachowicz, PhD, DSW Ideis University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07877389
- Sponsor's protocol ID
- COG-PRED-2026-01
- Acronym
- COG-PRED
- Status last verified
- Oct 2026
- First submitted
- 9 Oct 2026
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the results reported in each publication will be made publicly available as supplementary data accompanying that publication. Shared datasets will contain the relevant participant-level behavioral, questionnaire, and derived physiological measures, together with a data dictionary. Direct identifiers and raw physiological recordings will not be included. Datasets will undergo a review of re-identification risk before release.
Publications
Laborde S, Mosley E, Thayer JF. Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research - Recommendations for Experiment Planning, Data Analysis, and Data Reporting. Front Psychol. 2017 Feb 20;8:213. doi: 10.3389/fpsyg.2017.00213. eCollection 2017.
PubMed 28265249Lim J, Kwok K. The Effects of Varying Break Length on Attention and Time on Task. Hum Factors. 2016 May;58(3):472-81. doi: 10.1177/0018720815617395. Epub 2015 Dec 29.
PubMed 26715686Matuz A, van der Linden D, Kisander Z, Hernadi I, Kazmer K, Csatho A. Enhanced cardiac vagal tone in mental fatigue: Analysis of heart rate variability in Time-on-Task, recovery, and reactivity. PLoS One. 2021 Mar 3;16(3):e0238670. doi: 10.1371/journal.pone.0238670. eCollection 2021.
PubMed 33657124Matuz A, van der Linden D, Darnai G, Csatho A. Generalisable machine learning models trained on heart rate variability data to predict mental fatigue. Sci Rep. 2022 Nov 21;12(1):20023. doi: 10.1038/s41598-022-24415-y.
PubMed 36414673O'Keeffe K, Hodder S, Lloyd A. A comparison of methods used for inducing mental fatigue in performance research: individualised, dual-task and short duration cognitive tests are most effective. Ergonomics. 2020 Jan;63(1):1-12. doi: 10.1080/00140139.2019.1687940. Epub 2019 Nov 18.
PubMed 31680632Hrabovecky JM, De Tiege X, Samyn C, Borragan G, Peigneux P, Strauss M, Slama H. Is a single calibration for the TloadDback cognitive fatigue induction task reliable? Front Psychol. 2025 Jul 24;16:1561819. doi: 10.3389/fpsyg.2025.1561819. eCollection 2025.
PubMed 40777221Borragan G, Slama H, Bartolomei M, Peigneux P. Cognitive fatigue: A Time-based Resource-sharing account. Cortex. 2017 Apr;89:71-84. doi: 10.1016/j.cortex.2017.01.023. Epub 2017 Feb 3.
PubMed 28237888Borragan G, Slama H, Destrebecqz A, Peigneux P. Cognitive Fatigue Facilitates Procedural Sequence Learning. Front Hum Neurosci. 2016 Mar 3;10:86. doi: 10.3389/fnhum.2016.00086. eCollection 2016.
PubMed 26973501
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prediction of Cognitive Performance Decline Based on Autonomic Activity and Subjective State During Sustained Cognitive Load
- ClinicalTrials.gov ID
- NCT07877389
- Acronym / sponsor ID
- COG-PRED / COG-PRED-2026-01
- Conditions
- Mental Fatigue, Cognitive Performance
- Keywords
- Sustained Cognitive Load, Time Load Dual-back (TloadDback), Working Memory, Sustained Attention, Heart Rate Variability, Electrodermal Activity, Skin Conductance, Cognitive Performance Prediction
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 250 participants (estimated)
- Lead sponsor
- DSW Ideis UniversityUniversity, hospital or other
- Collaborators
- Wroclaw University of Health and Sport Sciences
- Study start
- Dec 2026 (estimated)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 16 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will investigate whether heart activity and changes in the skin's ability to conduct electricity can help predict performance during a demanding computer task. These signals reflect how the body responds to mental effort. The main question is whether measurements taken at rest and near the beginning of the task help predict later accuracy, beyond information about sleep the previous night, current sleepiness, and initial task performance.
Healthy young adults will attend one visit lasting approximately 50-60 minutes. Participants will complete a questionnaire and wear sensors that record heart activity and skin responses. After a five-minute resting measurement, participants will learn a computer task involving letters and numbers. The task requires remembering the previous letter and deciding whether numbers are odd or even. A short calibration will adjust the presentation speed to each participant.
Participants will then perform the task for 16 minutes at the selected speed and rate their fatigue and the demands of the task. After these ratings, participants will rest quietly for five minutes and repeat the task for four minutes at the same speed.
The researchers will also examine how performance, fatigue, and body responses change during the task and after rest. The study is intended to improve understanding of sustained mental effort and is not a medical diagnostic assessment.
Detailed description
COG-PRED is a prospective, single-group laboratory study of cognitive performance during sustained mental effort. Subjective fatigue, autonomic responses, and task performance may change at different rates. The study will examine whether resting autonomic activity and early physiological responses provide information about subsequent performance beyond that available from sleep duration, sleepiness, and initial task accuracy. All participants will follow the same sequence of procedures, without randomization or a separate control group.
Cognitive load will be induced using a study-specific implementation of the Time Load Dual-back (TloadDback) task. Letters and digits will alternate on the screen. Participants will respond when a letter matches the preceding letter and withhold a response when it does not. For digits, participants will classify each number as odd or even. Responses will be made with the dominant hand, while the hand carrying the skin conductance electrodes remains supported.
Following familiarization, a shortened adaptive calibration will identify an individual presentation interval using a criterion of at least 85% weighted accuracy. Search blocks will contain 30 stimuli, and the selected interval will be checked in a separate 40-stimulus verification block. Calibration will last no longer than five minutes. Participants who do not obtain a verified interval will not proceed to the main task. Once verified, the interval will remain fixed throughout the main task and the post-rest task. Individual calibration adjusts task pace but does not assume identical subjective workload across participants.
Physiological recording will cover the resting measurement, task phases, and recovery period. Cardiac and skin conductance signals will be synchronized with stimulus and response events. Resting features will be derived from the final four minutes of the five-minute baseline. Early task responses will be characterized by changes from this baseline during the first four minutes of the main task.
Prespecified linear regression models will assess later task accuracy while accounting for initial accuracy. A reference model containing previous-night sleep duration, pretask sleepiness, and initial accuracy will be compared with an expanded model that additionally includes resting heart rate, heart rate variability, skin conductance, and their early task changes. Predictive performance will be assessed using 10-fold cross-validation at the participant level. Physiological information recorded after the prediction window will not be used as an early predictor.
Immediately after the main task, participants will rate mental fatigue and complete the six dimensions of the National Aeronautics and Space Administration Task Load Index (NASA-TLX), scored as an unweighted mean. These assessments will precede the full five-minute seated rest. Participants will then rate fatigue and perform a four-minute task with a new stimulus sequence at the same calibrated speed. The total interval between the main task and the post-rest task will be recorded.
Secondary analyses will describe performance and physiological changes over time and compare the final four minutes of the main task with the four-minute post-rest task. Relationships between autonomic recovery and changes in performance will be explored separately. Because there is no no-rest control condition, changes after the break will not be interpreted as effects attributable solely to rest.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Prospective, single-arm laboratory study with repeated measurements within participants. All participants are assigned to the same single-visit protocol: resting baseline, task familiarization, individual calibration, a 16-minute Time Load Dual-back (TloadDback) task, post-task ratings, five minutes of seated rest, and a four-minute post-rest task. The individually verified stimulus presentation interval remains unchanged during the main and post-rest tasks. There is no randomization or separate control group.
| Arm | Type | Receives |
|---|---|---|
| Calibrated Cognitive Load and Post-Rest Assessment | Experimental | Behavioral: Individually Calibrated Time Load Dual-back Task With Seated RestParticipants undergo a five-minute seated baseline, task familiarization, and individual calibration of the Time Load Dual-back (TloadDback) task. After successful calibration, participants complete a 16-minute task combining letter matching with odd/even digit classification. Task pace remains fixed at the individually verified level. Immediately afterward, participants rate mental fatigue and perceived workload, followed by five full minutes of seated rest. Participants then rate fatigue and complete a four-minute post-rest task at the same pace, followed by final fatigue and well-being ratings. Cardiac activity and skin conductance are recorded throughout the measurement phases. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Age 18-30 years.
- Good general health according to self-report.
- Normal or corrected-to-normal vision and ability to read the letters and digits presented on the screen.
- Ability to understand instructions in Polish and perform the computer task.
- Provision of voluntary informed consent.
Key exclusion criteria (6 listed)
- Neurological, psychiatric, or cardiovascular conditions that significantly affect participant safety, task performance, or heart rhythm.
- Use of medications or substances that significantly affect heart rhythm, arousal, or cognitive performance.
- Acute infection, fever, feeling unwell, or skin damage that makes sensor placement difficult.
- Failure to understand the task after repetition of the instructions and practice, or unsuccessful calibration.
- Caffeine or nicotine use within four hours, alcohol consumption within 24 hours, or intense physical exercise within 12 hours before the visit.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Individually Calibrated Time Load Dual-back Task With Seated RestParticipants perform the Time Load Dual-back task, alternating letter 1-back matching with odd/even digit classification. A study-specific adaptive calibration starts at 1400 ms and tests presentation intervals between 400 and 1600 ms. Search blocks contain 30 stimuli; the selected interval must achieve at least 85% weighted accuracy in a separate 40-stimulus verification block. Calibration is limited to five minutes; participants without a verified interval do not proceed to the main task. The verified interval is used for a 16-minute main task and a four-minute post-rest task. Fatigue and workload ratings follow the main task, before five full minutes of quiet seated rest. A fatigue rating precedes the post-rest task. Task pace remains fixed after calibration. | Behavioural | Calibrated Cognitive Load and Post-Rest Assessment |
Primary outcome
Weighted Accuracy During the Final Four Minutes of the Main Cognitive Task
Time frame: During seconds 720-960 (the final four minutes) of the 16-minute main task, within a single study visit.
Weighted accuracy (WAcc) on the Time Load Dual-back task is calculated as 0.65 x letter accuracy + 0.35 x digit accuracy, with both component accuracies expressed as percentages. Letter accuracy includes correct responses to matching letters and correct withholding of responses to nonmatching letters. Digit accuracy is the percentage of correct odd/even classifications. Errors and required-response omissions are scored as incorrect. The first letter of each new sequence and technically excluded trials are removed from the relevant denominators; analytical windows do not reset the letter reference. Scores range from 0 to 100%, with higher scores indicating better performance. The primary endpoint is the late-task score; initial accuracy is included as a predictor, rather than subtracted to define this endpoint.
10 secondary outcomes
Weighted Accuracy Across the Main Cognitive Task
Time frame: During four consecutive 4-minute windows (0-240, 240-480, 480-720, and 720-960 seconds) of the 16-minute main task.
Change in Weighted Accuracy From the End of the Main Task to the Post-Rest Task
Time frame: During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main task.
Median Correct-Response Reaction Time Across Task Phases
Time frame: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Standard Deviation of Correct-Response Reaction Time Across Task Phases
Time frame: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Number of Incorrect Responses Across Task Phases
Time frame: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Number of Required-Response Omissions Across Task Phases
Time frame: During each of four consecutive 4-minute windows of the 16-minute main task and during the entire 4-minute post-rest task, within one visit.
Self-Reported Mental Fatigue Across the Study Visit
Time frame: Before baseline; after calibration/before the main task; immediately after the 16-minute main task; after five minutes of rest/before the post-rest task; and immediately after the 4-minute post-rest task, within one visit.
Perceived Workload on the Unweighted NASA Task Load Index
Time frame: Immediately after the 16-minute main task and before the start of the five-minute seated rest.
Heart Rate Variability During Baseline, Cognitive Load, and Rest
Time frame: During seconds 60-300 of the 5-minute baseline, each consecutive 4-minute window of the 16-minute main task, and seconds 60-300 of the 5-minute seated rest.
Mean Skin Conductance During Baseline, Cognitive Load, and Rest
Time frame: During seconds 60-300 of baseline, each consecutive 4-minute window of the 16-minute main task, and the 5-minute rest (initial 60 seconds and final 240 seconds).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Oct 2026.
- Background: PubMed 28265249Laborde S, Mosley E, Thayer JF. Heart Rate Variability and Cardiac Vagal Tone in Psychophysiological Research - Recommendations for Experiment Planning, Data Analysis, and Data Reporting. Front Psychol. 2017 Feb 20;8:213. doi: 10.3389/fpsyg.2017.00213. eCollection 2017.
- Background: PubMed 26715686Lim J, Kwok K. The Effects of Varying Break Length on Attention and Time on Task. Hum Factors. 2016 May;58(3):472-81. doi: 10.1177/0018720815617395. Epub 2015 Dec 29.
- Background: PubMed 33657124Matuz A, van der Linden D, Kisander Z, Hernadi I, Kazmer K, Csatho A. Enhanced cardiac vagal tone in mental fatigue: Analysis of heart rate variability in Time-on-Task, recovery, and reactivity. PLoS One. 2021 Mar 3;16(3):e0238670. doi: 10.1371/journal.pone.0238670. eCollection 2021.
- Background: PubMed 36414673Matuz A, van der Linden D, Darnai G, Csatho A. Generalisable machine learning models trained on heart rate variability data to predict mental fatigue. Sci Rep. 2022 Nov 21;12(1):20023. doi: 10.1038/s41598-022-24415-y.
- Background: PubMed 31680632O'Keeffe K, Hodder S, Lloyd A. A comparison of methods used for inducing mental fatigue in performance research: individualised, dual-task and short duration cognitive tests are most effective. Ergonomics. 2020 Jan;63(1):1-12. doi: 10.1080/00140139.2019.1687940. Epub 2019 Nov 18.
- Background: PubMed 40777221Hrabovecky JM, De Tiege X, Samyn C, Borragan G, Peigneux P, Strauss M, Slama H. Is a single calibration for the TloadDback cognitive fatigue induction task reliable? Front Psychol. 2025 Jul 24;16:1561819. doi: 10.3389/fpsyg.2025.1561819. eCollection 2025.
- Background: PubMed 28237888Borragan G, Slama H, Bartolomei M, Peigneux P. Cognitive fatigue: A Time-based Resource-sharing account. Cortex. 2017 Apr;89:71-84. doi: 10.1016/j.cortex.2017.01.023. Epub 2017 Feb 3.
- Background: PubMed 26973501Borragan G, Slama H, Destrebecqz A, Peigneux P. Cognitive Fatigue Facilitates Procedural Sequence Learning. Front Hum Neurosci. 2016 Mar 3;10:86. doi: 10.3389/fnhum.2016.00086. eCollection 2016.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the results reported in each publication will be made publicly available as supplementary data accompanying that publication. Shared datasets will contain the relevant participant-level behavioral, questionnaire, and derived physiological measures, together with a data dictionary. Direct identifiers and raw physiological recordings will not be included. Datasets will undergo a review of re-identification risk before release.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Maciej Lachowicz Vice Dean of the Instute of Health, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Individually Calibrated Time Load Dual-back Task With Seated Rest in people with Mental Fatigue and Cognitive Performance, run by DSW Ideis University at 1 site in Poland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 16 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Poland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Maciej Lachowicz Vice Dean of the Instute of Health, PhD (+48532670867, maciej.lachowicz@ideis.pl), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Weighted Accuracy During the Final Four Minutes of the Main Cognitive Task (time frame: During seconds 720-960 (the final four minutes) of the 16-minute main task, within a single study visit.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07877389, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Oct 2026.