Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Reflex Activity01:08

Reflex Activity

4.8K
A reflex activity is an automatic, involuntary response to specific stimuli. It is a part of our survival mechanism, designed to protect us from potential harm. For example, when a bright light suddenly shines into our eyes, we instinctively close them or look away. This is a simple reflex activity orchestrated by the nervous system without conscious thought or effort.
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
4.8K
Somatic Spinal Reflexes01:22

Somatic Spinal Reflexes

7.6K
Somatic spinal reflexes are rapid, involuntary muscular responses to external stimuli that involve the somatic musculature and the spinal cord.
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
7.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Dissociating the behavioral and computational features of implicit motor learning and explicit perturbation detection.

bioRxiv : the preprint server for biology·2026
Same author

Dissociating variability from error-based processes in observational learning.

Human movement science·2026
Same author

What Is the StartReact Effect?

Acta physiologica (Oxford, England)·2026
Same author

Imitation performance biases are moderated by perceived accuracy in golf putting.

Scientific reports·2025
Same author

Dual agonist and antagonist muscle vibration produces a bias in end point with no change in variability.

Experimental brain research·2025
Same author

Causal inference, prediction and state estimation in sensorimotor learning.

Proceedings. Biological sciences·2025

Related Experiment Video

Updated: Mar 30, 2026

A Modified Lean and Release Technique to Emphasize Response Inhibition and Action Selection in Reactive Balance
07:19

A Modified Lean and Release Technique to Emphasize Response Inhibition and Action Selection in Reactive Balance

Published on: March 19, 2020

6.5K

Voluntary reaction time and long-latency reflex modulation.

Christopher J Forgaard1, Ian M Franks1, Dana Maslovat2

  • 1School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; and.

Journal of Neurophysiology
|November 6, 2015
PubMed
Summary
This summary is machine-generated.

Muscle stretch reflexes in the upper limb show increased long-latency responses (M2) when actively compensating for perturbations. This enhancement is partly due to instruction-dependent reflex gain modulation, not just voluntary response overlap.

Keywords:
M2StartReact effectlong-latency reflexreaction timesuperposition

More Related Videos

An Emerging Target Paradigm to Evoke Fast Visuomotor Responses on Human Upper Limb Muscles
09:27

An Emerging Target Paradigm to Evoke Fast Visuomotor Responses on Human Upper Limb Muscles

Published on: August 25, 2020

4.8K
The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task
10:39

The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task

Published on: May 3, 2018

9.2K

Related Experiment Videos

Last Updated: Mar 30, 2026

A Modified Lean and Release Technique to Emphasize Response Inhibition and Action Selection in Reactive Balance
07:19

A Modified Lean and Release Technique to Emphasize Response Inhibition and Action Selection in Reactive Balance

Published on: March 19, 2020

6.5K
An Emerging Target Paradigm to Evoke Fast Visuomotor Responses on Human Upper Limb Muscles
09:27

An Emerging Target Paradigm to Evoke Fast Visuomotor Responses on Human Upper Limb Muscles

Published on: August 25, 2020

4.8K
The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task
10:39

The "Motor" in Implicit Motor Sequence Learning: A Foot-stepping Serial Reaction Time Task

Published on: May 3, 2018

9.2K

Area of Science:

  • Neuroscience
  • Human Motor Control
  • Biomedical Engineering

Background:

  • Stretching upper limb muscles triggers short (M1) and long-latency (M2) reflexes.
  • Active compensation for perturbations increases M2 size, followed by a voluntary response.
  • The cause of M2 increase (reflex gain vs. voluntary overlap) is unclear due to timing overlap.

Purpose of the Study:

  • To investigate whether M2 reflex enhancement is due to reflex gain modulation or voluntary response superposition.
  • To differentiate between reflex and voluntary contributions to electromyographic activity during M2.
  • To analyze the influence of response accuracy and complexity on M2 modulation.

Main Methods:

  • Participants performed active compensation for upper limb perturbations under varying accuracy and complexity conditions.
  • Electromyographic (EMG) activity during the M2 period was analyzed.
  • Passive conditions were used as a baseline for comparison.

Main Results:

  • M2 was significantly larger in all active conditions compared to the passive condition.
  • M2 changes began early (around 50 ms), preceding significant voluntary overlap.
  • While voluntary response latency affected later M2 activity, early M2 changes were independent of voluntary response timing.

Conclusions:

  • Instruction-dependent reflex gain modulation significantly contributes to M2 period EMG changes.
  • Voluntary responses can occur at short latencies (<100 ms) following upper limb perturbations.
  • The study successfully delineated reflex and voluntary contributions to M2 modulation.