scholarly journals Predictive attenuation of touch and tactile gating are distinct perceptual phenomena

2020 ◽  
Author(s):  
Konstantina Kilteni ◽  
H. Henrik Ehrsson
Keyword(s):  
Voluntary Movement ◽  
Voluntary Movements ◽  
Intensity Attenuation ◽  
Suppression Process

In recent decades, research on somatosensory perception has led to two important observations. First, self-generated touches that are predicted by voluntary movements become attenuated compared to externally generated touches of the same intensity (attenuation). Second, externally generated touches feel weaker and are more difficult to detect during movement compared to rest (gating). Researchers today often consider gating and attenuation to be the same suppression process; however, this assumption is unwarranted because, despite more than forty years of research, no study has combined them in a single paradigm. We quantified how people perceive self-generated and externally generated touches during movement and rest. We demonstrate that whereas voluntary movement gates the precision of both self-generated and externally generated touch, the amplitude of self-generated touch is selectively attenuated compared to externally generated touch. We further show that attenuation and gating neither interact nor correlate, and we conclude that they represent distinct perceptual phenomena.

scholarly journals Predictive attenuation of touch and tactile gating are distinct perceptual phenomena

2020 ◽  
Author(s):  
Konstantina Kilteni ◽  
H. Henrik Ehrsson
Keyword(s):  
Voluntary Movement ◽  
Voluntary Movements ◽  
Intensity Attenuation ◽  
Suppression Process

Abstract In recent decades, research on somatosensory perception has led to two important observations. First, self-generated touches that are predicted by voluntary movements become attenuated compared to externally generated touches of the same intensity (attenuation). Second, externally generated touches feel weaker and are more difficult to detect during movement compared to rest (gating). Researchers today often consider gating and attenuation to be the same suppression process; however, this assumption is unwarranted because, despite more than forty years of research, no study has combined them in a single paradigm. We quantified how people perceive self-generated and externally generated touches during movement and rest. We demonstrate that whereas voluntary movement gates the precision of both self-generated and externally generated touch, the amplitude of self-generated touch is selectively attenuated compared to externally generated touch. We further show that attenuation and gating neither interact nor correlate, and we conclude that they represent distinct perceptual phenomena.

scholarly journals What We Think before a Voluntary Movement

2013 ◽  
Vol 25 (6) ◽  
pp. 822-829 ◽  
Author(s):  
Logan Schneider ◽  
Elise Houdayer ◽  
Ou Bai ◽  
Mark Hallett
Keyword(s):  
Real Time ◽  
False Positive ◽  
Voluntary Movement ◽  
False Positive Rate ◽  
Central Feature ◽  
Voluntary Movements ◽  
Eeg Signal ◽  
Positive Rate ◽  
Multiple Variables ◽  
The Brain

A central feature of voluntary movement is the sense of volition, but when this sense arises in the course of movement formulation and execution is not clear. Many studies have explored how the brain might be actively preparing movement before the sense of volition; however, because the timing of the sense of volition has depended on subjective and retrospective judgments, these findings are still regarded with a degree of scepticism. EEG events such as beta event-related desynchronization and movement-related cortical potentials are associated with the brain's programming of movement. Using an optimized EEG signal derived from multiple variables, we were able to make real-time predictions of movements in advance of their occurrence with a low false-positive rate. We asked participants what they were thinking at the time of prediction: Sometimes they were thinking about movement, and other times they were not. Our results indicate that the brain can be preparing to make voluntary movements while participants are thinking about something else.

Directional Bias of Limb Tremor Prior to Voluntary Movement

2007 ◽  
Vol 18 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Rajal G. Cohen ◽  
David A. Rosenbaum
Keyword(s):  
Voluntary Movement ◽  
Visual Fixation ◽  
Horizontal Axis ◽  
Voluntary Movements ◽  
Simple Task ◽  
Directional Bias ◽  
Vertical Movements ◽  
Manual Pointing ◽  
Preparatory Activity ◽  
Subsequent Target

Taking a cue from recent discoveries of directional bias in microsaccades during visual fixation, we investigated directional bias in tremor during manual pointing. Subjects memorized and then performed patterns of alternating postures and voluntary movements. The directions of the tiny movements occurring during periods of intended stillness were predictive of subsequent target-directed movements such that in the horizontal axis, relative to baseline, the frequency of tremor decreased and the amplitude of tremor increased before horizontal movements, but not before vertical movements. This effect was less pronounced in the finger than in the arm, forearm, and hand. Possible explanations of the effect are based on eye-limb coupling, decreasing stiffness in the axis of forthcoming movement, and release of inhibition. The discovery of directionally specific preparatory activity suggests that the simple task of holding still before moving may provide a new window into the processes that allow for the translation of intentions into actions.

scholarly journals Voluntary movement initiation is not coupled to optimal sensorimotor oscillatory phases

2019 ◽  
Author(s):  
Sara J Hussain ◽  
Mary K Vollmer ◽  
Romain Quentin ◽  
Iñaki Iturrate ◽  
Leonardo G. Cohen
Keyword(s):  
Human Brain ◽  
Voluntary Movement ◽  
List Type ◽  
Voluntary Movements ◽  
Movement Initiation ◽  
Healthy Human ◽  
Strongly Coupled ◽  
Motor Behaviors ◽  
Brain States ◽  
Time Point

AbstractSuccessful initiation of a voluntary movement requires transmission of descending motor commands from the primary motor cortex (M1) to the spinal cord and effector muscles. M1 activity alternates between brief excitatory and inhibitory brain states in the form of oscillatory phases that correlate with single neuron spiking rates and population-level neuronal activity. The influence of these brief brain states on fundamental motor behaviors, like movement initiation, is not known. Here, we asked if voluntary movement initiation occurs during specific oscillatory phases of sensorimotor rhythms using a combination of transcranial magnetic stimulation (TMS), electroencephalography (EEG), and behavioral testing. To address this, we empirically determined the time point at which M1 released the motor command required to produce a simple finger movement during a self-paced movement initiation task. We then probabilistically modeled the oscillatory phase at this time point in the mu (8-12 Hz) and beta (13-30 Hz) ranges, and at each frequency between 8 and 50 Hz, determining each subject’s preferred movement initiation phase for each frequency. After pooling the identified phases across subjects, we identified no significant clustering of preferred movement initiation phases within mu or beta frequencies, or at any other frequency between 8 and 50 Hz. These results demonstrate that movements were not preferentially initiated during optimal oscillatory phases at any frequency. Thus, we conclude that initiation of self-paced voluntary movements is not strongly coupled to optimal sensorimotor oscillatory phases in the healthy human brain. It remains to be determined if more complex aspects of motor behavior like action selection occur during optimal oscillatory phases.Key points summaryMotor cortical activity alternates between periods of excitation and inhibition, but the influence of these brain states on fundamental motor behaviors like movement initiation is unknown.We examined whether self-paced voluntary movements are preferentially initiated during optimal sensorimotor oscillatory phases.Our results showed no evidence that voluntary movements were predominantly initiated during optimal phases across a range of frequencies.We conclude that initiation of voluntary, self-paced movements is not strongly coupled to optimal sensorimotor oscillatory phases in the healthy human brain.

scholarly journals Differentiating tic electrophysiology from voluntary movement in the human thalamocortical circuit

2020 ◽  
Vol 91 (5) ◽  
pp. 533-539 ◽  
Author(s):  
Jackson N Cagle ◽  
Michael S Okun ◽  
Enrico Opri ◽  
Stephanie Cernera ◽  
Rene Molina ◽  
...  
Keyword(s):  
Tourette Syndrome ◽  
Voluntary Movement ◽  
Thalamic Nucleus ◽  
Neurodevelopmental Disorder ◽  
Low Frequency ◽  
Voluntary Movements ◽  
Physiological Signal ◽  
Electrophysiological Recordings ◽  
Beta Power ◽  
Mri Scans

ObjectivesTourette syndrome is a neurodevelopmental disorder commonly associated with involuntary movements, or tics. We currently lack an ideal animal model for Tourette syndrome. In humans, clinical manifestation of tics cannot be captured via functional imaging due to motion artefacts and limited temporal resolution, and electrophysiological studies have been limited to the intraoperative environment. The goal of this study was to identify electrophysiological signals in the centromedian (CM) thalamic nucleus and primary motor (M1) cortex that differentiate tics from voluntary movements.MethodsThe data were collected as part of a larger National Institutes of Health-sponsored clinical trial. Four participants (two males, two females) underwent monthly clinical visits for collection of physiology for a total of 6 months. Participants were implanted with bilateral CM thalamic macroelectrodes and M1 subdural electrodes that were connected to two neurostimulators, both with sensing capabilities. MRI scans were performed preoperatively and CT scans postoperatively for localisation of electrodes. Electrophysiological recordings were collected at each visit from both the cortical and subcortical implants.ResultsRecordings collected from the CM thalamic nucleus revealed a low-frequency power (3–10 Hz) increase that was time-locked to the onset of involuntary tics but was not present during voluntary movements. Cortical recordings revealed beta power decrease in M1 that was present during tics and voluntary movements.ConclusionWe conclude that a human physiological signal was detected from the CM thalamus that differentiated tic from voluntary movement, and this physiological feature could potentially guide the development of neuromodulation therapies for Tourette syndrome that could use a closed-loop-based approach.

Hippocampus: memory, habit and voluntary movement

1985 ◽  
Vol 308 (1135) ◽  
pp. 87-99 ◽  
Keyword(s):  
Voluntary Movement ◽  
Habit Formation ◽  
Visual Stimuli ◽  
Voluntary Movements ◽  
Simple Generalization ◽  
Hippocampal Lesions ◽  
The One ◽  
Environmental Events ◽  
General Method

A general method for studying monkeys’ memories is to teach the animals memory-dependent performance rules: for example, to choose, out of two visual stimuli, the one that flashed last time the animal saw it. One may thus assess the animal’s memory for any arbitrarily chosen event such as flashing even if the event itself has no intrinsic importance for the animal. The method also allows assessment of an animal’s memory of the animal’s own previous behaviour. The use of these methods has revealed a simple generalization about the function of the hippocampus in memory: hippocampal lesions impair memory of the voluntary movement that a stimulus previously elicited, but leave intact memory for relations between environmental events other than voluntary movements. The impairment in memory for voluntary movements produces deficits in exploration and in habit formation.

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