Effects of Cognitive Fatigue on Gait

The goal of this study is to comprehend how mental fatigue could affect human gait. The main questions to answer are:

• Does mental fatigue change how people walk?
• How long does it take for walking patterns to return to normal after mental fatigue sets in?
• What role do constructs like boredom, sleepiness, and motivation play in this relationship?

To achieve this, participants will take part in the experiment, split into two sessions:

Day 1 (online, about 25 minutes): Practice session. Participants will practice a computer task that will be used to induce mental fatigue in the next session.

Day 2 (in-person, about 1.5 to 2 hours): Participants will wear several wearable sensors: motion sensors on their legs, feet, and back, sensor insoles in their shoes, a cap that measures brain activity, and glasses that track eye movement. After sensor placement, participants will walk in a straight line for 10 meters to measure their normal walking pattern. They will then complete a 32-minute computer task designed to induce mental fatigue. Afterward, participants will walk in a straight line for 10 meters again, rest for 3 minutes, and repeat this walk-and-rest cycle 3 more times. Participants will also answer short questions about how tired, bored, and alert they feel throughout the session.

Study Overview

• Status: Not yet recruiting
• Conditions: Mental Fatigue
• Intervention / Treatment: Other: Mental fatigue

Detailed Description

Background:

Most prior research on mental fatigue and gait has examined concurrent dual-task walking, in which a cognitive task and walking occur simultaneously. It remains unclear whether gait is altered following (rather than during) a mentally fatiguing task. This study addresses that gap using TloadDback, an adaptive N-back paradigm (Borragán et al., 2016) that individually calibrates cognitive demand to maintain consistent task difficulty across participants, as the mental fatigue induction method.

Design:

This is a within-subject, repeated-measures design. All primary analyses will be conducted on data collected during the in-person session. Sample size (up to 30 enrolled, target N = 24) was determined via a power analysis using pilot data (N = 5; within-subject design, α = 0.05, power = 0.90).

Mental Fatigue Induction Task:

TloadDback is administered as a single continuous 32-minute block. Participants view a continuous sequence of number-letter-number stimuli and respond via keypress (odd/even number), when seeing a number, or spacebar (letter repeat), when seeing a letter. Stimulus-presentation speed is individually calibrated during the practice session to the maximum speed at which the participant maintains greater than 85% accuracy, ensuring standardized cognitive demand across participants during the main session.

Sensor:

Inertial measurement units (IMUs): 8 units, placed at the shanks (2), thighs (2), feet (2), upper spine (1), and lower back (1), capturing spatiotemporal and kinematic gait parameters.

Pressure-sensing insoles: worn inside participants' shoes to detect gait events (heel strike, toe-off), complementing IMU-derived timing data.

Eye tracker: recording pupil diameter, blink rate, and fixation duration.

EEG cap: records brain's electrical voltage fluctuaction to obtain metrics such as frequency band analysis and neural signals related.

IMUs and insoles are used primarily to obtain gait parameters, whereas eye tracking and EEG are used only during the mental fatigue-inducing computer task, serving as physiological metrics to corroborate fatigue.

Procedures

Practice session (remote, online via PsychoPy/Pavlovia): Participants complete a familiarization run of TloadDback for individual speed calibration

In-person session pipeline:

Demographic questionnaire. Sensor placement: IMUs and insoles Baseline gait trial (10-meter straight-line walk). A 3-minute Psychomotor Vigilance Task (PVT), in which participants respond as quickly as possible by pressing the spacebar each time a visual stimulus (a dot) appears at random inter-stimulus intervals.

Sensor placement: Eye tracker and EEG. TloadDback task (32 minutes continuous). Repeat the 3-minute Psychomotor Vigilance Task (PVT). Take off the Eye Tracker and EEG. Post-task gait and recovery assessment: repeated cycles of a straight-line walk trial followed by a 3-minute rest, for a total of 4 post-task walk assessments.

Visual Analog Scale (VAS) ratings (fatigue, boredom) are collected at multiple points across the session to track the time course of fatigue and alertness.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alexis M Gomez Hernandez; Phone Number: PhD Candidate 330-554-0868; Email: agomezhe@buffalo.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 18-60 years.
• Neurotypical individuals with no self-reported history of neurological or cognitive disorders.
• Able to walk independently, without an assistive device.
• Fluent in English.
• Recruitment will aim for gender balance across the sample.
• For Day 2, participants must arrive with clean, dry hair, free of styling products (e.g., gels, oils), to ensure adequate EEG electrode contact.

Exclusion Criteria:

• Outside the age range of 18-60 years.
• Self-reported history of neurological or cognitive disorders (e.g., epilepsy, multiple sclerosis, stroke/traumatic brain injury).
• Any musculoskeletal condition or injury affecting normal gait.
• Use of an assistive device for walking (e.g., cane, walker, brace).
• Self-reported photosensitive epilepsy or seizure disorder triggered by screen/visual stimuli.
• Non-English speaking.
• Day 2 restrictions: less than 6 hours of sleep the night before; caffeine within 2 hours of the session; alcohol within 24 hours of the session.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Mental fatigue; Day 1 (remote): online familiarization session with the TloadDback cognitive task to individually calibrate stimulus speed. Day 2 (in-person): gait (spatiotemporal parameters and kinematics) is assessed using wearable motion sensors and pressure-sensing insoles, before and repeatedly after a computer task (32-minute TloadDback session), used to induce mental fatigue. Eye tracking and EEG are recorded during the task as physiological fatigue indices. Subjective (VAS) and behavioral (PVT) measures of fatigue and alertness are also collected throughout the session.

Other: Mental fatigue; Participants will undergo a mental fatigue induction protocol to examine its effects on gait parameters.; Other Names: Cognitive fatigue

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective fatigue (VAS fatigue rating)	Change in self-reported mental fatigue from baseline (PRE) to immediately after the mental fatigue induction task (POST), measured using the Visual Analog Scale for Fatigue (VAS). The VAS is a single-item, self-report scale ranging from 0 to 10, where 0 indicates "not tired at all" and 10 indicates "extremely tired." Higher scores indicate greater self-reported mental fatigue.	Right at the beginning of the experiment and right after the 32-minutes TloadDback task
Change in Mean Reaction Time of the Psychomotor Vigilance Task (PVT)	Change in mean reaction time on the Psychomotor Vigilance Task from PRE to POST TloadDback, used as a behavioral indicator of mental fatigue-related vigilance decrement. Slower reaction time in the POST, compared to PRE, means more mentally fatigued.	Right at the beginning and right after the 32-minute TloadDback cognitive task.
Change in Gait Velocity	Change in gait velocity (meters/second), comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. Here, there is no clear pattern; however, we expect participants to slow their gait spede after the fatigue intervention.	Right at the beginning and right after the 32-minute TloadDback cognitive task.
Change in Gait Cadence	Change in gait cadence (steps/minute), comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. There is no clear pattern here; however, we are expecting the cadence (steps/minute) to decrease after the fatigue intervention.	Immediately before and immediately after the 32-minute TloadDback task
Change in Stance and Swing Phase Duration	Change in stance phase duration and swing phase duration, each expressed as a percentage of the gait cycle, comparing baseline (PRE) walking trials to post-task (POST) walking trials, measured using inertial measurement units and pressure-sensing insoles. Stance phase refers to the portion of the gait cycle when the foot is in contact with the ground, while swing phase refers to the portion when the foot is off the ground and advancing forward. An increase in stance phase duration (with a corresponding decrease in swing phase duration) is generally associated with a more cautious, conservative gait pattern. A decrease in stance phase duration (with a corresponding increase in swing phase) may reflect a faster, less guarded walking pattern.	Immediately before and immediately after the 32-minute TloadDback task
Change in Lower Extremity Joint Angles (Hip, Knee, Ankle)	Change in peak hip, knee, and ankle joint angles (degrees) during walking, comparing baseline (PRE) walking trials to post-task (Post) walking trials, measured using inertial measurement units. Joint angles reflect the range of motion at each joint during the gait cycle. A reduction in joint angle range (i.e., smaller peak flexion/extension excursions) is commonly interpreted in the literature as a more restricted or cautious movement strategy, sometimes associated with reduced motor control.	Immediately before and immediately after the 32-minute TloadDback task

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gait Velocity During Post-Task Recovery	Gait velocity (meters/second), measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how walking speed changes as participants rest and recover from mental fatigue. Values will be reported separately for each timepoint. We will be expecting the gait velocity to increase after resting.	3, 6, 9, and 12 minutes after the 32-minute TloadDback task
Gait Cadence During Post-Task Recovery	Gait cadence (steps/minute), measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how stepping rate changes as participants rest and recover from mental fatigue. Values will be reported separately for each time point.	3, 6, 9, and 12 minutes after the 32-minute TloadDback task
Stance and Swing Phase Duration During Post-Task Recovery	Stance phase duration and swing phase duration, each expressed as a percentage of the gait cycle, measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how the distribution of gait phases changes as participants rest and recover from mental fatigue. Values will be reported separately for stance and swing phase at each timepoint. Stance phase is the gait phase where the foot is on the ground, while swing phase is the gait phase where the foot is moving forward (off the ground).	3, 6, 9, and 12 minutes after the 32-minute TloadDback task
Lower Extremity Joint Angles During Post-Task Recovery (Hip/Knee/Ankle)	Peak hip, knee, and ankle joint angles (degrees) during walking, measured at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how the joint range of motion changes as participants rest and recover from mental fatigue. Values will be reported separately for hip, knee, and ankle at each time point.	3, 6, 9, and 12 minutes after the 32-minute TloadDback task
Self-Reported Mental Fatigue During Post-Task Recovery	Self-reported mental fatigue, measured using the Visual Analog Scale for Fatigue (VAS), at 3, 6, 9, and 12 minutes after the TloadDback task, where participants will rest for 3 minutes, walk 10 meters, and repeat this cycle 4 times. The idea is to examine whether and how perceived fatigue changes as participants rest and recover. The VAS ranges from 0 to 10, where 0 indicates "not tired at all" and 10 indicates "extremely tired"; higher scores indicate greater fatigue. Values will be reported separately for each time point.	3, 6, 9, and 12 minutes after the 32-minute TloadDback task
Change in electroencephalography (EEG) Band Spectral Power	Change in relative electroencephalography (EEG) spectral power (%) in theta and alpha frequency bands, recorded during the TloadDback task, providing physiological confirmation of mental fatigue induction. Increases in theta and alpha power, particularly over central and posterior regions, are commonly reported in the literature as indicators of cognitive fatigue accumulation. Values will be reported separately for each frequency band.	During the 32-minute TloadDback task
Change in Pupil Diameter	Change in pupil diameter (millimeters), recorded during the TloadDback task using eye-tracking, providing physiological confirmation of mental fatigue induction. A decrease in pupil diameter over the course of the task is commonly reported in the literature as an indicator of increasing mental fatigue.	During the 32-minute TloadDback task
Change in Blink Rate	Change in blink rate (blinks per minute), recorded during the TloadDback task using eye-tracking, providing physiological confirmation of mental fatigue induction. An increase in blink rate over the course of the task is commonly reported in the literature as an indicator of increasing mental fatigue.	During the 32-minute TloadDback task

Collaborators and Investigators

• Sponsor: State University of New York at Buffalo
• Investigators: Study Chair: Lora Cavuoto, PhD, University at Buffalo

Publications and helpful links

General Publications

• Al-Yahya E, Dawes H, Smith L, Dennis A, Howells K, Cockburn J. Cognitive motor interference while walking: a systematic review and meta-analysis. Neurosci Biobehav Rev. 2011 Jan;35(3):715-28. doi: 10.1016/j.neubiorev.2010.08.008. Epub 2010 Sep 15.
• Behrens M, Gube M, Chaabene H, Prieske O, Zenon A, Broscheid KC, Schega L, Husmann F, Weippert M. Fatigue and Human Performance: An Updated Framework. Sports Med. 2023 Jan;53(1):7-31. doi: 10.1007/s40279-022-01748-2. Epub 2022 Oct 18.
• Borragan 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.

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: July 6, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Fatigue; Cognitive Fatigue; Mental fatigue
• Additional Relevant MeSH Terms: Behavioral Symptoms; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Fatigue; Mental Fatigue
• Other Study ID Numbers: STUDY00010729

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: A decision on data sharing has not yet been finalized. I intend to complete the IRB review process first, incorporating any feedback or requirements related to data collection, de-identification, and storage. Once IRB approval is obtained, a formal individual participant data (IPD) sharing plan will be developed, taking into account any applicable restrictions on data publication and participant privacy protections.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No