The Relationships Between Neural Correlates of Effort Perception and Physical Activity Engagement (EffortLESS)

Functional MRI Protocols for Studying the Neural Correlates of Effort Perception and the Effects of Targeted RTMS Protocols on Perceived Effort and Effort-based Decision-making

Objectives and research hypothesis Physical inactivity is a major health concern that has been linked to a variety of chronic diseases, including obesity, diabetes, cancer, cardiovascular diseases, and mental disorders. Recent studies have shown that regular physical activity can decrease the risk of SARS-CoV-2 infection, and severe COVID-19 illnesses, as well as improve antibody response to vaccine. As such, the adoption of a physically active lifestyle carries potential health benefits and has even been referred to as a "miracle cure" by the Academy of Royal Medical Colleges. Despite the implementation of policies that aimed to encourage regular physical activity, the prevalence of insufficient physical activity in high-income countries has increased since 2001 (32% in 2001 vs. 37% in 2018). Given the limited impact of health policies on physical activity engagement, it is essential to explore other avenues of research that can contribute to understanding this high level of inactivity and driving innovative strategies for encouraging physical activity. In this context, the automatic attraction of individuals toward activities associated with low-effort exertion is thought to play a key role in physical inactivity. Physical activity involves exerting physical effort, i.e., intensifying physical energy to achieve certain goals, such as increasing the force to lift a heavy object. This physical intensification is associated with the phenomenological experience of energy exertion. Higher effort perception is thought to be aversively valued by inactive individuals, inhibiting their engagement in regular physical activity. However, there is a lack of knowledge regarding the neural correlates of effort perception and how they relate to physical inactivity. It is crucial to gain insights into these neural correlates, especially to enhance our comprehension of the significance of effort minimization in physical inactivity. This project aims to decrease effort perception and improve the valuation of effort, incentivize regular physical activity, and improve overall health outcomes.

Objective 1. Despite ongoing research, there is a lack of agreement on the neural mechanisms underlying effort perception as well as the role of sensorial feedback. Tasks EEG and fMRI aim to address this issue with original experimental methods in order to identify this neural mechanism.

Hypothesis 1. Following A) muscle vibration and B) Induced ischemic paralysis and anesthesia, we expect decreased effort perception associated with a lower cortical S1 activation, unchanged activation in premotor structures, and preserved functional connectivity between premotor regions and S1.

Objective 2. To unravel the neural interaction between efference copy and reafferent muscle spindle signals that contribute to effort perception Hypothesis 2. The neural correlates of effort perception involve interactions between premotor and sensory brain structures. Neural activation patterns of the brain regions implicated in effort perception vary depending on an individual's inclination to engage in physical activity.

Objective 3. Task 3 will examine the potential of non-invasive brain stimulation techniques (TMS) to reduce effort perception in turn increase its perceived value quantified with the CR100 scale, the outcome variable of this study.

Hypothesis 3. Vibration-induced desensitization of muscle spindles and the SMA cTBS reduce effort perception and improve the subjective value of physical effort.

Study Overview

• Status: Recruiting
• Conditions: Motor Task; Transcranial Magnetic Stimilation; EEG Brain Oscillations; FMRI Research; Ischemic Nerve Block (INB); Muscle Vibration Protocol
• Intervention / Treatment: Device: Transcranial Magnetic Stimulation Sham

Detailed Description

Our society is currently facing a pandemic of physical inactivity that is responsible for numerous chronic diseases and deaths. Despite the implementation of policies aimed at encouraging regular physical activity, the prevalence of physical inactivity remains high. It then seems necessary to explore other areas of research that could explain this level of inactivity and guide the implementation of new strategies to make the population more active. In this context, the tendency of most individuals to gravitate towards activities associated with a low perception of effort seems to play a central role in many barriers to engaging in physical activity. The perception of effort, which refers to the perception of the physical resources invested in a physical task, seems to be evaluated aversively by inactive individuals, limiting their engagement in physical activity. However, the neuropsychological bases of effort perception and how they are involved in physical inactivity remain poorly understood today. Therefore, clarifying the neural substrates involved in this perception and understanding how they determine engagement in physical activity is essential to help increase the population's level of physical activity. The hypothesis guiding this project is that reducing the perception of effort so that a particular intensity physical activity is perceived as less demanding facilitates engagement and the maintenance of a physically active lifestyle. In this context, the primary objective of this project will be to clarify the neural substrates involved in the perception of effort through a functional MRI study and to identify whether neuropsychological mechanisms related to the perception of effort differentiate individuals who have an aversion or an attraction to physical activity. Based on these results, the second objective will be to evaluate whether repetitive transcranial magnetic stimulation techniques targeting key nerve structures and reducing the perception of effort improve the value of effort and engagement in regular physical activity.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Florian MONJO; Phone Number: 0479758123; Email: florian.monjo@univ-smb.fr
• Study Contact Backup: Name: Diego LOMBARDO; Phone Number: 0479758123; Email: diego-martin.lombardo-vera@univ-smb.fr

Study Locations

• France
  • La TRONCHE, France, 38700
    • Recruiting
    • Plateforme IRMaGe
    • Contact: Emilie COUSIN; Phone Number: 0476825876; Email: emilie.cousin@univ-grenoble-alpes.fr
    • Contact: Florian MONJO

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Normal subjects all ranges age
• Exclusion Criteria:
• Neurologic conditions that may bias the EEG or fMRI results such as epilepsy, tumors; stroke; which can be a casual MRI finding during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Transcranial Magnetic Stimulation Sham; Participants will engage in 4 cycling exercise visits and 4 effort-discounting task visits. Each of these 8 visits will be associated with one of the 4 stimulation conditions: vibration condition, sham vibration condition, cTBS over SMA. These 8 visits will be randomized across participant	Device: Transcranial Magnetic Stimulation Sham; cTBS over SMA and cTBS over precuneus (control site)
Placebo Comparator: TMS; cTBS over precuneus (control site).	Device: Transcranial Magnetic Stimulation Sham; cTBS over SMA and cTBS over precuneus (control site)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Effort perception	Physical effort scale Category (C)-Ratio (R) (CR) scaling 100 or Borg centiMax® Scale (CR100) is a measure from 0 to 100 to rate the intensity of effort perception, where 0 means "nothing at all" (i.e. "no perception of effort at all") and 100 means "Maximal", that is, the maximal perception of effort experienced.	From enrollment up to 12 months after

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Resting-state and task fMRI functional connectivity	Task fMRI condition A) induce ischemic paralysis and anesthesia: an MRI-compatible two chamber cuff will be placed over participants' upper arm outside the scanner and inflated to 250 mmHg until total abolishment of light touch sensation below the elbow is achieved46. This generally takes 20-40 min B) Task fMRI control condition. They will perform voluntary isometric handgrip contractions at moderate and strong perceived effort intensities based on the CR100 with their dominant hand. These two intensities were chosen to assess the impact of perceived effort level on brain activity, while avoiding excessive head movement that could occur at higher intensities and controlling for the development of neuromuscular fatigue C) Resting-state fMRI: 10-min resting-state fMRI scan to assess functional connectivity between different brain regions.	From enrollment to 15 weeks after 60 healthy subjects will be assessed (4 subjects per week)
EEG event related synchronization	ERSP analyses will allow us to examine changes in alpha (8-13 Hz) and beta (13-30 Hz) neural oscillations within predetermined regions of interest during spindle desensitization. This will be done trougth the application of vibration at the myotendinous junction of the biceps brachii using a custom-made vibrator. Following the successful methodology of the PI in PoC1 and 2, we will apply the vibration for a 10-min period with a frequency of 100 Hz and an amplitude of approximately 2 mm in the vibration condition.	From enrollment to 40 weeks after

Collaborators and Investigators

• Sponsor: University Hospital, Grenoble
• Collaborators: IRMage
• Investigators: Principal Investigator: Florian MONJO, Université de Chambéry

Publications and helpful links

General Publications

• Cheval B, Boisgontier MP. The Theory of Effort Minimization in Physical Activity. Exerc Sport Sci Rev. 2021 Jul 1;49(3):168-178. doi: 10.1249/JES.0000000000000252.
• Pageaux B. Perception of effort in Exercise Science: Definition, measurement and perspectives. Eur J Sport Sci. 2016 Nov;16(8):885-94. doi: 10.1080/17461391.2016.1188992. Epub 2016 May 30.
• Inzlicht M, Shenhav A, Olivola CY. The Effort Paradox: Effort Is Both Costly and Valued. Trends Cogn Sci. 2018 Apr;22(4):337-349. doi: 10.1016/j.tics.2018.01.007. Epub 2018 Feb 21.
• Hallam J, Jones T, Alley J, Kohut ML. Exercise after influenza or COVID-19 vaccination increases serum antibody without an increase in side effects. Brain Behav Immun. 2022 May;102:1-10. doi: 10.1016/j.bbi.2022.02.005. Epub 2022 Feb 5.
• Christensen MS, Lundbye-Jensen J, Geertsen SS, Petersen TH, Paulson OB, Nielsen JB. Premotor cortex modulates somatosensory cortex during voluntary movements without proprioceptive feedback. Nat Neurosci. 2007 Apr;10(4):417-9. doi: 10.1038/nn1873. Epub 2007 Mar 18.
• Cheval B, Sieber S, Maltagliati S, Millet GP, Formanek T, Chalabaev A, Cullati S, Boisgontier MP. Muscle strength is associated with COVID-19 hospitalization in adults 50 years of age or older. J Cachexia Sarcopenia Muscle. 2021 Oct;12(5):1136-1143. doi: 10.1002/jcsm.12738. Epub 2021 Aug 6.

Study record dates

Study Major Dates

• Study Start (Actual): February 13, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: November 7, 2024
• First Submitted That Met QC Criteria: November 14, 2024
• First Posted (Actual): November 15, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 18, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: Perception of effort
• Other Study ID Numbers: 38RC23.0416

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be stored in a secure server (NetExplorer, managed by the SFRI of the USMB). Access to the database will be limited with specific rights assigned to the different people involved in the project. Data extraction will automatically de-identified data
• IPD Sharing Time Frame: During the study
• IPD Sharing Access Criteria: Researchers and technicians involved in the project will have access to the data by a sharing lin
• IPD Sharing Supporting Information Type: ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No