Finger somatotopy is preserved after tetraplegia but deteriorates over time

Kikkert, Sanne; Pfyffer, Dario; Verling, Michaela; Freund, Patrick; Wenderoth, Nicole

doi:10.7554/elife.67713

Cited by 23 publications

(43 citation statements)

References 93 publications

(192 reference statements)

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“…More specifically, there was stronger index compared to little finger activity on the lateral part of S1, while there was stronger little compared to index finger activity medial of S1. These S1 activity maps are in line with previous findings on finger somatotopy which is highly specific within S1 (Besle et al, 2013;Kikkert et al, 2021;Kolasinski et al, 2016;Martuzzi et al, 2014;Sanchez Panchuelo et al, 2018;Sanders et al, 2019). Finally, we assessed whether finger-specific activity was sustained within these finger-specific maps during the delay period.…”

Section: Vibrotactile Working Memory Recruits a Distributed Brain Networksupporting

confidence: 83%

Finger representations in primary somatosensory cortex are modulated by a vibrotactile working memory task

Rabe

Kikkert

Wenderoth

2021

Preprint

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It is well-established that vibrotactile stimulations elicit Blood-oxygen-level-dependent (BOLD) responses in somatotopically organized brain regions. Whether these somatotopic maps are modulated by working memory (WM) is still unknown. In our WM experiment, participants had to compare frequencies that were separated by a delay period. Vibrotactile stimuli were sequentially applied to either their right index or little finger. Using functional MRI, we investigated whether vibrotactile WM modulated neural activity in primary somatosensory (S1), an area that is known to contain individual finger representations. Our mass-univariate results revealed the well-described network of brain regions involved in WM. Interestingly, our mass-univariate results did not demonstrate S1 to be part of this network. However, when we parametrically modulated the time-binned regressors in our GLM we found that the delay activity in S1 and secondary somatosensory cortex (S2) was reflected in a U-shaped manner. Using multi-voxel pattern analysis (MVPA), an analysis technique that is more sensitive to subtle activity differences, we found finger-specific patterns of activation in the S1 hand area during the WM delay period. These results indicate that processes underlying WM modulate finger-specific representations during our discrimination task.

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Section: Vibrotactile Working Memory Recruits a Distributed Brain Networksupporting

confidence: 83%

Finger representations in primary somatosensory cortex are modulated by a vibrotactile working memory task

Rabe

Kikkert

Wenderoth

2021

Preprint

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“…Consistent with this notion, previous functional magnetic resonance imaging (fMRI studies have not detected the presence of planning-related information in this area Gallivan et al, 2011a ; Gallivan et al, 2011b , Gallivan et al, 2016 ; Gallivan et al, 2013 ; although see Gale et al, 2021 ). However, challenging this notion, in the past years research has shown that S1 can be somatotopically activated even in the absence of tactile inputs, for instance during touch observation ( Kuehn et al, 2014 ), attempted movements without afferent tactile inputs ( Kikkert et al, 2021 ), and through attentional shifts ( Puckett et al, 2017 ). Moreover, a recent human electrocorticography (ECoG) study suggested a possible role for S1 in cognitive-motor imagery ( Jafari et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Motor planning brings human primary somatosensory cortex into action-specific preparatory states

Ariani

Pruszynski

Diedrichsen

2022

eLife

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Motor planning plays a critical role in producing fast and accurate movement. Yet, the neural processes that occur in human primary motor and somatosensory cortex during planning, and how they relate to those during movement execution, remain poorly understood. Here we used 7T functional magnetic resonance imaging (fMRI) and a delayed movement paradigm to study single finger movement planning and execution. The inclusion of no-go trials and variable delays allowed us to separate what are typically overlapping planning and execution brain responses. Although our univariate results show widespread deactivation during finger planning, multivariate pattern analysis revealed finger-specific activity patterns in contralateral primary somatosensory cortex (S1), which predicted the planned finger action. Surprisingly, these activity patterns were as informative as those found in contralateral primary motor cortex (M1). Control analyses ruled out the possibility that the detected information was an artifact of subthreshold movements during the preparatory delay. Furthermore, we observed that finger-specific activity patterns during planning were highly correlated to those during execution. These findings reveal that motor planning activates the specific S1 and M1 circuits that are engaged during the execution of a finger press, while activity in both regions is overall suppressed. We propose that preparatory states in S1 may improve movement control through changes in sensory processing or via direct influence of spinal motor neurons.

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“…was highly similar to the inter-finger representational distance patterns that we and others have described previously in fMRI experiments using individual finger movements (Ejaz et al, 2015;Kikkert et al, 2021Kikkert et al, , 2016Sanders et al, 2019;Wesselink et al, 2019) or individual finger tactile stimulation (Sanders et al, 2019). The inter-finger representational distances were averaged across finger pairs within each participant to obtain an estimate for average interfinger representational separability (see Figure 5C), or 'representation strength'.…”

Section: Finger Representationsmentioning

confidence: 53%

“…3 participants were stimulated on the right side of the face and their right thumb. We included thumb stimulation in these runs as the thumb representation borders the face area in S1 (Kikkert et al, 2021(Kikkert et al, , 2016Kolasinski et al, 2016;Penfield and Rasmussen, 1950;Roux et al, 2018). To uncover face somatotopy we used a blocked design consisting of 5 conditions: Stimulation conditions for each of the three face locations and for the thumb, as well as a rest (no stimulation) condition.…”

Section: Face Stimulation Runsmentioning

confidence: 99%

Hand and face somatotopy shown using MRI-safe vibrotactile stimulation with a novel Soft Pneumatic Actuator (SPA)-Skin interface

Kikkert

Sonar²,

Freund

et al. 2021

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The exact somatotopy of the human facial representation in the primary somatosensory cortex (S1) remains debated. One reason that progress has been hampered is due the methodological challenge of how to apply automated vibrotactile stimuli to face areas in a manner that is: 1) reliable despite different curvature depending on the face location; and 2) MR-compatible and free of MR-interference artefacts when applied in the MR head-coil. Here we overcame this challenge by using soft pneumatic actuator (SPA) technology. SPAs are made of a soft silicon material and can be in- or deflated by means of airflow, have a small diameter, and are flexible in structure, enabling good skin contact even on curved body surfaces (as on the face). Here, we aimed to provide a methodological advance by providing automated tactile vibration stimulation inside the head-coil of the MRI. As a sanity check, we first mapped the well-characterised S1 finger layout using this novel device. We found that tactile stimulation of the fingers elicited characteristic somatotopic finger activations in S1, validating the use of our SPA-setup to map somatotopic representations. Ultimately, we used the device to automatically and systematically deliver somatosensory stimulation to different face locations. We found that the forehead representation was least distance from the representation of the hand. Within the face representation, we found that the lip representation is most distant from the forehead representation, with the chin represented in between. Together our results show that, by providing vibrotactile stimulation using the SPA-technology, we are able to reveal clear somatotopic representational patterns.

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Finger somatotopy is preserved after tetraplegia but deteriorates over time

Cited by 23 publications

References 93 publications

Finger representations in primary somatosensory cortex are modulated by a vibrotactile working memory task

Finger representations in primary somatosensory cortex are modulated by a vibrotactile working memory task

Motor planning brings human primary somatosensory cortex into action-specific preparatory states

Hand and face somatotopy shown using MRI-safe vibrotactile stimulation with a novel Soft Pneumatic Actuator (SPA)-Skin interface

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