scholarly journals Dynamic temporal modulation of somatosensory processing during reaching

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dimitris Voudouris ◽  
Katja Fiehler
Keyword(s):  
Time Course ◽  
Feedforward Control ◽  
Human Action ◽  
Somatosensory Processing ◽  
Directed Movement ◽  
Feedback Processing ◽  
Target Hand ◽  
Maximal Speed ◽  
Online Feedback ◽  
Critical Moments

AbstractSensorimotor control of human action integrates feedforward policies that predict future body states with online sensory feedback. These predictions lead to a suppression of the associated feedback signals. Here, we examine whether somatosensory processing throughout a goal-directed movement is constantly suppressed or dynamically tuned so that online feedback processing is enhanced at critical moments of the movement. Participants reached towards their other hand in the absence of visual input and detected a probing tactile stimulus on their moving or static hand. Somatosensory processing on the moving hand was dynamically tuned over the time course of reaching, being hampered in early and late stages of the movement, but, interestingly, recovering around the time of maximal speed. This novel finding of temporal somatosensory tuning was further corroborated in a second experiment, in which larger movement amplitudes shifted the absolute time of maximal speed later in the movement. We further show that the release from suppression on the moving limb was temporally coupled with enhanced somatosensory processing on the target hand. We discuss these results in the context of optimal feedforward control and suggest that somatosensory processing is dynamically tuned during the time course of reaching by enhancing sensory processing at critical moments of the movement.

Author response for "Automatic postural responses are scaled from the association between online feedback and feedforward control"

2019 ◽  
Author(s):  
Luis Augusto Teixeira ◽  
Nametala Maia Azzi ◽  
Júlia Ávila de Oliveira ◽  
Caroline Ribeiro de Souza ◽  
Lucas da Silva Rezende ◽  
...  
Keyword(s):  
Feedforward Control ◽  
Author Response ◽  
Postural Responses ◽  
Online Feedback ◽  
Automatic Postural Responses

Author response for "Automatic postural responses are scaled from the association between online feedback and feedforward control"

2019 ◽  
Author(s):  
Luis Augusto Teixeira ◽  
Nametala Maia Azzi ◽  
Júlia Ávila de Oliveira ◽  
Caroline Ribeiro de Souza ◽  
Lucas da Silva Rezende ◽  
...  
Keyword(s):  
Feedforward Control ◽  
Author Response ◽  
Postural Responses ◽  
Online Feedback ◽  
Automatic Postural Responses

scholarly journals Learning feedback and feedforward control in a mirror-reversed visual environment

2015 ◽  
Vol 114 (4) ◽  
pp. 2187-2193 ◽  
Author(s):  
Shoko Kasuga ◽  
Sebastian Telgen ◽  
Junichi Ushiba ◽  
Daichi Nozaki ◽  
Jörn Diedrichsen
Keyword(s):  
Feedback Control ◽  
Visual Information ◽  
Feedforward Control ◽  
Control Policy ◽  
Movement Direction ◽  
Common Mechanism ◽  
Central Target ◽  
Online Corrections ◽  
Online Feedback ◽  
Initial Movement

When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers.

scholarly journals Auditory feedback is used for adaptive control of timing in speech

2020 ◽  
Author(s):  
Robin Karlin ◽  
Benjamin Parrell ◽  
Chris Naber
Keyword(s):  
Adaptive Control ◽  
Real Time ◽  
Auditory Feedback ◽  
Feedforward Control ◽  
Vowel Duration ◽  
Washout Phase ◽  
Vowel Formants ◽  
Temporal Perturbation ◽  
Online Feedback ◽  
Perturbation Magnitude

Real-time altered auditory feedback has demonstrated a key role for auditory feedback in both online feedback control and in updating feedforward control for future utterances. Much of this research has examined control in the spectral domain, and has found that speakers compensate for perturbations to vowel formants, intensity, and fricative center of gravity. The aim of the current study is to examine adaptation in response to temporal perturbation, using real-time perturbation of ongoing speech. Word-initial consonant targets (VOT for /k, g/ and fricative duration for /s, z/) were lengthened and the following stressed vowel (/æ/) was shortened. Overall, speakers did not adapt to lengthened consonants, but did lengthen vowels by nearly 100\% of the perturbation magnitude in response to shortening. Vowel lengthening showed continued aftereffects during a washout phase when perturbation was abruptly removed. Although speakers did not actively adapt consonant durations, the adaptation in vowel duration leads to the consonant taking up an overall smaller proportion of the syllable, aligning with previous research that suggests that speakers attend to proportional durations rather than absolute durations. These results indicate that speakers actively monitor duration and update upcoming plans accordingly.

Visual Feedback Processing and Goal-Directed Movement in Adults with Down Syndrome

1995 ◽  
Vol 12 (2) ◽  
pp. 176-186 ◽  
Author(s):  
Nicola J. Hodges ◽  
Sheri J. Cunningham ◽  
James Lyons ◽  
Tracey L. Kerr ◽  
Digby Elliott
Keyword(s):  
Down Syndrome ◽  
Visual Feedback ◽  
Mental Disabilities ◽  
Disabled People ◽  
Directed Movement ◽  
Feedback Processing ◽  
Aiming Movements ◽  
Mentally Disabled ◽  
Vision Condition ◽  
Different Diameters

Frith and Frith (1974) suggested that adults with Down syndrome have difficulty planning goal-directed movements and therefore are more reliant on feedback than other mentally disabled people. The purpose of the study was to examine this hypothesis directly through the manipulation of visual feedback. Twelve adults with Down syndrome, 12 mentally disabled adults without Down syndrome, and 12 nondisabled adults performed simple aiming movements to targets of three different diameters. While the target was always visible, on half the trial blocks vision of the movement was occluded upon response initiation. Subjects with Down syndrome exhibited longer movement times than other subjects, regardless of vision condition. In terms of target-aiming consistency, subjects with Down syndrome were actually less affected by the elimination of visual feedback than subjects in the other mentally disabled group. While adults with mental disabilities appear to be more reliant on visual feedback for the control of goal-directed movement, this dependence is not a specific characteristic of Down syndrome.

Automatic postural responses are scaled from the association between online feedback and feedforward control

2019 ◽  
Vol 51 (10) ◽  
pp. 2023-2032 ◽  
Author(s):  
Luis Augusto Teixeira ◽  
Nametala Azzi ◽  
Júlia Ávila de Oliveira ◽  
Caroline Ribeiro de Souza ◽  
Lucas Rezende ◽  
...  
Keyword(s):  
Feedforward Control ◽  
Postural Responses ◽  
Online Feedback ◽  
Automatic Postural Responses

Time Course of Oculomotor Inhibition Revealed by Saccade Trajectory Modulation

2006 ◽  
Vol 96 (3) ◽  
pp. 1420-1424 ◽  
Author(s):  
Eugene McSorley ◽  
Patrick Haggard ◽  
Robin Walker
Keyword(s):  
Time Course ◽  
Saccade Latency ◽  
Saccade Target ◽  
Inhibitory Process ◽  
Directed Movement ◽  
Local Competition ◽  
Inhibitory Processes ◽  
Behavioral Evidence ◽  
Saccade Trajectory ◽  
Gap Paradigm

Selecting a stimulus as the target for a goal-directed movement involves inhibiting other competing possible responses. Both target and distractor stimuli activate populations of neurons in topographic oculomotor maps such as the superior colliculus. Local inhibitory interconnections between these populations ensure only one saccade target is selected. Suppressing saccades to distractors may additionally involve inhibiting corresponding map regions to bias the local competition. Behavioral evidence of these inhibitory processes comes from the effects of distractors on oculomotor and manual trajectories. Individual saccades may initially deviate either toward or away from a distractor, but the source of this variability has not been investigated. Here we investigate the relation between distractor-related deviation of trajectory and saccade latency. Targets were presented with, or without, distractors, and the deviation of saccade trajectories arising from the presence of distractors was measured. A fixation gap paradigm was used to manipulate latency independently of the influence of competing distractors. Shorter-latency saccades deviated toward distractors and longer-latency saccades deviated away from distractors. The transition between deviation toward or away from distractors occurred at a saccade latency of around 200 ms. This shows that the time course of the inhibitory process involved in distractor related suppression is relatively slow.

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