Trial · NCT07877389
Registered outcomes16
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
1 to 16 of 16
Download this page as JSON| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Weighted Accuracy During the Final Four Minutes of the Main Cognitive Task | 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. |
| Secondary | Weighted Accuracy Across the Main Cognitive Task | During four consecutive 4-minute windows (0-240, 240-480, 480-720, and 720-960 seconds) of the 16-minute main 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. |
| Secondary | Change in Weighted Accuracy From the End of the Main Task to the Post-Rest Task | During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main 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. |
| Secondary | Median Correct-Response Reaction Time Across Task Phases | 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. | 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. |
| Secondary | Standard Deviation of Correct-Response Reaction Time Across Task Phases | 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. | 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. |
| Secondary | Number of Incorrect Responses Across Task Phases | 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 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. |
| Secondary | Number of Required-Response Omissions Across Task Phases | 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 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. |
| Secondary | Self-Reported Mental Fatigue Across the Study Visit | 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. | 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. |
| Secondary | Perceived Workload on the Unweighted NASA Task Load Index | Immediately after the 16-minute main task and before the start of the five-minute seated rest. | 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. |
| Secondary | Heart Rate Variability During Baseline, Cognitive Load, and Rest | 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. | 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. |
| Secondary | Mean Skin Conductance During Baseline, Cognitive Load, and Rest | 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). | 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. |
| Other | Heart Rate During the Post-Rest Cognitive Task | During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main task. | Mean heart rate, in beats per minute, derived from quality-controlled electrocardiographic data during the four-minute post-rest task. The value is compared with the final four minutes of the main task to explore the autonomic response during task resumption at the same calibrated presentation interval. |
| Other | Heart Rate Variability During the Post-Rest Cognitive Task | During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main task. | Root mean square of successive differences between normal-to-normal heartbeat intervals (RMSSD), in milliseconds, calculated from continuous valid segments of the electrocardiographic recording during the four-minute post-rest task. The value is compared with the final four minutes of the main task to explore the autonomic response during task resumption. |
| Other | Skin Conductance During the Post-Rest Cognitive Task | During the entire 4-minute task after five minutes of seated rest; compared with seconds 720-960 of the 16-minute main task. | Mean skin conductance, in microsiemens, calculated from valid electrodermal samples during the four-minute post-rest task. The value is compared with the final four minutes of the main task to explore the autonomic response during task resumption. The measure includes tonic level and contributions from phasic responses. |
| Other | Individually Verified Stimulus Presentation Interval | At successful completion of the adaptive calibration, which lasts no longer than five minutes and precedes the 16-minute main task. | Stimulus presentation interval accepted after successful calibration of the Time Load Dual-back task, in milliseconds. Permitted values range from 400 to 1600 ms in 100-ms increments. The interval must satisfy the weighted-accuracy criterion in a separate verification block and is then fixed for both the main and post-rest tasks. Lower values indicate a faster task pace, not an intelligence score. This measure is used in supplementary analyses; no interval is assigned if calibration is unsuccessful. |
| Other | Standard Deviation of Normal-to-Normal Heartbeat Intervals | During seconds 60-300 of baseline, each consecutive 4-minute window of the 16-minute main task, seconds 60-300 of seated rest, and the entire 4-minute post-rest task. | Standard deviation of normal-to-normal heartbeat intervals (SDNN), in milliseconds, derived from quality-controlled electrocardiographic data. This supplementary measure is calculated separately within the four-minute physiological assessment windows. Higher values indicate greater overall heartbeat-interval variability within the window. SDNN is supplementary to the prespecified RMSSD measure and is not substituted for RMSSD in the primary predictive model. |
Source ClinicalTrials.govtrials-2026-11-12-0.5.0
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this list from software.
Twenty rows a page, as JSON. No key.
GET https://conductscience.org/api/trials/v1/NCT07877389/registered