scholarly journals Somatosensory signals from the controllers of an extra robotic finger support motor learning

2021 ◽  
Author(s):  
Elena Amoruso ◽  
Lucy Dowdall ◽  
Mathew Thomas Kollamkulam ◽  
Obioha Ukaegbu ◽  
Paulina Kieliba ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor Learning ◽  
Pressure Sensors ◽  
Motor Task ◽  
Body Part ◽  
Control Group ◽  
Body Parts ◽  
Position Information ◽  
Somatosensory Information ◽  
Alternative Means

Considerable resources are being invested to provide bidirectional control of substitutive and augmentative motor interfaces through artificial somatosensory feedback. Here, we investigated whether intrinsic somatosensory information, from body part(s) proportionally controlling an augmentation device, can be utilised to infer the device state and position, to better support motor control and learning. In a placebo-controlled design, we used local anaesthetic to attenuate somatosensory inputs to the big toes while participants learned to operate a toe-controlled robotic extra finger (Third Thumb) using pressure sensors. Motor learning outcomes were compared against a control group who received sham anaesthetic. The availability of somatosensory cues about the amount of exerted pressure generally facilitated acquisition, retention and transfer of motor skills, and performance under cognitive load. Motor performance was not impaired by anaesthesia when tasks involved close collaboration with the biological fingers, indicating that the brain could close the gap of the missing pressure signals by alternative means, including feedback from other body parts involved in the motor task. Together, our findings demonstrate that there are intrinsic natural avenues to provide surrogate position information to support motor control of an artificial body part, beyond artificial extrinsic signalling.

scholarly journals Intrinsic somatosensory feedback supports motor control and learning to operate artificial body parts

2022 ◽  
Author(s):  
Elena Amoruso ◽  
Lucy Dowdall ◽  
Mathew Thomas Kollamkulam ◽  
Obioha Ukaegbu ◽  
Paulina Kieliba ◽  
...  
Keyword(s):  
Motor Control ◽  
Motor System ◽  
Pressure Sensors ◽  
Body Part ◽  
Skill Learning ◽  
The Body ◽  
Control Group ◽  
Body Parts ◽  
Somatosensory Feedback ◽  
Somatosensory Information

Abstract Objective Considerable resources are being invested to enhance the control and usability of artificial limbs through the delivery of unnatural forms of somatosensory feedback. Here, we investigated whether intrinsic somatosensory information from the body part(s) remotely controlling an artificial limb can be leveraged by the motor system to support control and skill learning. Approach In a placebo-controlled design, we used local anaesthetic to attenuate somatosensory inputs to the big toes while participants learned to operate through pressure sensors a toe-controlled and hand-worn robotic extra finger. Motor learning outcomes were compared against a control group who received sham anaesthetic and quantified in three different task scenarios: while operating in isolation from, in synchronous coordination, and collaboration with, the biological fingers. Main results Both groups were able to learn to operate the robotic extra finger, presumably due to abundance of visual feedback and other relevant sensory cues. Importantly, the availability of displaced somatosensory cues from the distal bodily controllers facilitated the acquisition of isolated robotic finger movements, the retention and transfer of synchronous hand-robot coordination skills, and performance under cognitive load. Motor performance was not impaired by toes anaesthesia when tasks involved close collaboration with the biological fingers, indicating that the motor system can close the sensory feedback gap by dynamically integrating task-intrinsic somatosensory signals from multiple, and even distal, body- parts. Significance Together, our findings demonstrate that there are multiple natural avenues to provide intrinsic surrogate somatosensory information to support motor control of an artificial body part, beyond artificial stimulation.

scholarly journals A Novel Multiple Person Pose Estimation Optimization Model Utilizing Genetic Algorithm

2021 ◽  
Vol 2129 (1) ◽  
pp. 012027
Author(s):  
Qing Zhang ◽  
Lei Ding ◽  
Kai Qing Zhou ◽  
Jian Feng Li
Keyword(s):  
Genetic Algorithm ◽  
Pose Estimation ◽  
Human Body ◽  
Optimization Model ◽  
Body Part ◽  
Body Parts ◽  
Position Information ◽  
Assembly Method ◽  
Optimal Value ◽  
Human Pose

Abstract For traditional human pose estimation models rely on a large amount of human body feature information, this paper proposes an optimization model using genetic algorithm to solve the problem of multiple person body part assembly. Different from other human body parts assembly method. The method proposed in this paper depends on the joints position information, namely the sum of the connection distances between the joints as the objective function, and finds the optimal value to obtain the best human pose assembly information. The simulation results show that compared with the traditional OpenPose model, the model proposed in this paper can obtain the same human skeleton using less position information.

scholarly journals Visual and somatosensory information contribute to distortions of the body model

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Valeria Peviani ◽  
Lucia Melloni ◽  
Gabriella Bottini
Keyword(s):  
Estimation Error ◽  
Body Part ◽  
Spatial Dimension ◽  
Line Length ◽  
Judgment Task ◽  
The Body ◽  
Body Parts ◽  
Tactile Acuity ◽  
Body Model ◽  
Somatosensory Information

Abstract Distorted representations of the body are observed in healthy individuals as well as in neurological and psychiatric disorders. Distortions of the body model have been attributed to the somatotopic cerebral representation. Recently, it has been demonstrated that visual biases also contribute to those distortions. To better understand the sources of such distortions, we compared the metric representations across five body parts affording different degrees of tactile sensitivity and visual accessibility. We evaluated their perceived dimensions using a Line Length Judgment task. We found that most body parts were underestimated in their dimensions. The estimation error relative to their length was predicted by their tactile acuity, supporting the influence of the cortical somatotopy on the body model. However, tactile acuity did not explain the distortions observed for the width. Visual accessibility in turn does appear to mediate body distortions, as we observed that the dimensions of the dorsal portion of the neck were the only ones accurately perceived. Coherent with the multisensory nature of body representations, we argue that the perceived dimensions of body parts are estimated by integrating visual and somatosensory information, each weighted differently, based on their availability for a given body part and a given spatial dimension.

scholarly journals Flexible motor adjustment of pecking with an artificially extended bill in crows but not in pigeons

2017 ◽  
Vol 4 (2) ◽  
pp. 160796 ◽  
Author(s):  
Hiroshi Matsui ◽  
Ei-Ichi Izawa
Keyword(s):  
Motor Control ◽  
Tool Use ◽  
Motor Adaptation ◽  
Body Part ◽  
Visuomotor Control ◽  
Conversion Process ◽  
Body Parts ◽  
Extended Body ◽  
Foraging Skills

The dextrous foraging skills of primates, including humans, are underpinned by flexible vision-guided control of the arms/hands and even tools as body-part extensions. This capacity involves a visuomotor conversion process that transfers the locations of the hands/arms and a target in retinal coordinates into body coordinates to generate a reaching/grasping movement and to correct online. Similar capacities have evolved in birds, such as tool use in corvids and finches, which represents the flexible motor control of extended body parts. However, the flexibility of avian head-reaching and bill-grasping with body-part extensions remains poorly understood. This study comparatively investigated the flexibility of pecking with an artificially extended bill in crows and pigeons. Pecking performance and kinematics were examined when the bill extension was attached, and after its removal. The bill extension deteriorated pecking in pigeons in both performance and kinematics over 10 days. After the bill removal, pigeons started bill-grasping earlier, indicating motor adaptation to the bill extension. Contrastingly, pecking in crows was deteriorated transiently with the bill extension, but was recovered by adjusting pecking at closer distances, suggesting a quick adjustment to the bill extension. These results indicate flexible visuomotor control to extended body parts in crows but not in pigeons.

scholarly journals Promoting Motor Variability During Robotic Assistance Enhances Motor Learning of Dynamic Tasks

2021 ◽  
Vol 14 ◽  
Author(s):  
Özhan Özen ◽  
Karin A. Buetler ◽  
Laura Marchal-Crespo
Keyword(s):  
Motor Learning ◽  
Sense Of Agency ◽  
Control Group ◽  
Haptic Guidance ◽  
Movement Variability ◽  
Robotic Training ◽  
Motor Variability ◽  
End Effector ◽  
Dynamic Task ◽  
Somatosensory Information

Despite recent advances in robot-assisted training, the benefits of haptic guidance on motor (re)learning are still limited. While haptic guidance may increase task performance during training, it may also decrease participants' effort and interfere with the perception of the environment dynamics, hindering somatosensory information crucial for motor learning. Importantly, haptic guidance limits motor variability, a factor considered essential for learning. We propose that Model Predictive Controllers (MPC) might be good alternatives to haptic guidance since they minimize the assisting forces and promote motor variability during training. We conducted a study with 40 healthy participants to investigate the effectiveness of MPCs on learning a dynamic task. The task consisted of swinging a virtual pendulum to hit incoming targets with the pendulum ball. The environment was haptically rendered using a Delta robot. We designed two MPCs: the first MPC—end-effector MPC—applied the optimal assisting forces on the end-effector. A second MPC—ball MPC—applied its forces on the virtual pendulum ball to further reduce the assisting forces. The participants' performance during training and learning at short- and long-term retention tests were compared to a control group who trained without assistance, and a group that trained with conventional haptic guidance. We hypothesized that the end-effector MPC would promote motor variability and minimize the assisting forces during training, and thus, promote learning. Moreover, we hypothesized that the ball MPC would enhance the performance and motivation during training but limit the motor variability and sense of agency (i.e., the feeling of having control over their movements), and therefore, limit learning. We found that the MPCs reduce the assisting forces compared to haptic guidance. Training with the end-effector MPC increases the movement variability and does not hinder the pendulum swing variability during training, ultimately enhancing the learning of the task dynamics compared to the other groups. Finally, we observed that increases in the sense of agency seemed to be associated with learning when training with the end-effector MPC. In conclusion, training with MPCs enhances motor learning of tasks with complex dynamics and are promising strategies to improve robotic training outcomes in neurological patients.

Masked Auditory Feedback Affects Speech Motor Learning of a Plosive Duration Contrast

Motor Control ◽  
2011 ◽  
Vol 15 (1) ◽  
pp. 68-84
Author(s):  
Silvia C. Lipski ◽  
Stefanie Unger ◽  
Martine Grice ◽  
Ingo G. Meister
Keyword(s):  
Motor Control ◽  
Motor Learning ◽  
Auditory Feedback ◽  
Auditory Perception ◽  
Sensory Feedback ◽  
Learning Capacity ◽  
Somatosensory Feedback ◽  
Somatosensory Information ◽  
Speech Motor Learning ◽  
Speech Motor

Adult speakers have developed precise forward models of articulation for their native language and seem to rely less on auditory sensory feedback. However, for learning of the production of new speech sounds, auditory perception provides a corrective signal for motor control. We assessed adult German speakers’ speech motor learning capacity in the absence of auditory feedback but with clear somatosensory information. Learners were presented with a nonnative singleton-geminate duration contrast of voiceless, unaspirated bilabial plosives /p/ vs. /pp/ which is present in Italian. We found that the lack of auditory feedback had no immediate effect but that deviating productions emerged during the course of learning. By the end of training, speakers with masked feedback produced strong lengthening of segments and showed more variation on their production than speakers with normal auditory feedback. Our findings indicate that auditory feedback is necessary for the learning of precise coordination of articulation even if somatosensory feedback is salient.

Corticostriatal transformations in the primate somatosensory system. Projections from physiologically mapped body-part representations

1991 ◽  
Vol 66 (4) ◽  
pp. 1249-1263 ◽  
Author(s):  
A. W. Flaherty ◽  
A. M. Graybiel
Keyword(s):  
Basal Ganglia ◽  
Receptive Fields ◽  
Somatosensory System ◽  
Body Part ◽  
The Body ◽  
Saimiri Sciureus ◽  
Body Parts ◽  
Cortical Areas ◽  
Somatosensory Information ◽  
Multiple Regions

1. The basal ganglia of primates receive somatosensory input carried largely by corticostriatal fibers. To determine whether map-transformations occur in this corticostriatal system, we investigated how electrophysiologically defined regions of the primary somatosensory cortex (SI) project to the striatum in the squirrel monkey (Saimiri sciureus). Receptive fields in the hand, mouth, and foot representations of cortical areas 3a, 3b, and 1 were mapped by multiunit recording; and small volumes of distinguishable anterograde tracers were injected into different body-part representations in single SI areas. 2. Analysis of labeled projections established that at least four types of systematic remapping occur in the primate corticostriatal system. 1) An area of cortex representing a single body part sends fibers that diverge to innervate multiple regions in the putamen, forming branching, patchy fields that are densest in the lateral putamen. The fields do not form elongated cylindrical forms; rather, they are nearly as extended mediolaterally as they are rostrocaudally. 2) Cortical regions representing hand, mouth, and foot send globally somatotopic, nonoverlapping projections to the putamen, but regions with closely related representations (such as those of the thumb and 5th finger in area 3b) send convergent, overlapping corticostriatal projections. The overlap is fairly precise in the caudal putamen, but in the rostral putamen the densest zones of the projections do not overlap. 3) Regions representing homologous body parts in different SI cortical areas send projections that converge in the putamen. This was true of paired projections from areas 3a and 3b, and from areas 3b and 1. Thus corticostriatal inputs representing distinct somatosensory submodalities can project to the same local regions within the striatum. Convergence is not always complete, however: in the rostral putamen of two cases comparing projections from areas 3a and 1, the densest zones of the projections did not overlap. 4) All projections from SI avoid striosomes and innervate discrete zones within the matrix. 3. These experiments demonstrate that the somatosensory representations of the body are reorganized as they are projected from SI to the somatosensory sector of the primate putamen. This remapping suggests that the striatal representation of the body may be functionally distinct from that of each area of SI. The patchy projections may provide a basis for redistribution of somatosensory information to discrete output systems in the basal ganglia. Transformations in the corticostriatal system could thus be designed for modulating different movement-related programs.

scholarly journals A Short-Term Intervention of High-Intensity Exercise and Anodal-tDCS on Motor Learning in Middle-Aged Adults: An RCT

2021 ◽  
Vol 15 ◽  
Author(s):  
Clare Quinlan ◽  
Ben Rattray ◽  
Disa Pryor ◽  
Joseph M. Northey ◽  
James Coxon ◽  
...  
Keyword(s):  
Motor Learning ◽  
High Intensity ◽  
Exercise Intervention ◽  
Motor Task ◽  
High Intensity Exercise ◽  
Future Research ◽  
Control Group ◽  
Middle Aged ◽  
Short Term ◽  
Middle Aged Adults

High-intensity exercise has enhanced motor learning in healthy young adults. Anodal-transcranial direct current stimulation (a-tDCS) may optimize these effects. This study aimed to determine the effects of a short-term high-intensity interval exercise intervention either with or without a-tDCS on the learning and retention of a novel motor task in middle-aged adults. Forty-two healthy middle-aged adults (age = 44.6 ± 6.3, female = 76%) were randomized into three groups: exercise and active a-tDCS, exercise and sham a-tDCS, and a non-exercise and sham a-tDCS control. Participants completed a baseline testing session, followed by three intervention sessions 48-h apart. The exercise groups completed 20-min of high-intensity exercise followed by a novel sequential visual isometric pinch task (SVIPT) while receiving 20-min of 1.5 mA a-tDCS, or sham tDCS. The control group completed 20-min of reading before receiving sham a-tDCS during the SVIPT. Learning was assessed by skill change within and between intervention sessions. Participants returned 5–7 days after the final intervention session and performed the SVIPT task to assess retention. All three groups showed evidence of learning on the SVIPT task. Neither group displayed enhanced overall learning or retention when compared to the control group. High-intensity exercise with or without a-tDCS did not improve learning or retention of a novel motor task in middle-aged adults. The methodological framework provides direction for future research to investigate the potential of differing exercise intensity effects on learning and retention.

scholarly journals Interactive effect of acute pain and motor learning acquisition on sensorimotor integration and motor learning outcomes

2016 ◽  
Vol 116 (5) ◽  
pp. 2210-2220 ◽  
Author(s):  
Erin Dancey ◽  
Bernadette Murphy ◽  
Danielle Andrew ◽  
Paul Yielder
Keyword(s):  
Motor Learning ◽  
Learning Outcomes ◽  
Acute Pain ◽  
Sensorimotor Integration ◽  
Interactive Effect ◽  
Motor Task ◽  
Learning Task ◽  
Control Group ◽  
Complex Motor ◽  
Acquisition Task

Previous work has demonstrated differential changes in early somatosensory evoked potentials (SEPs) when motor learning acquisition occurred in the presence of acute pain; however, the learning task was insufficiently complex to determine how these underlying neurophysiological differences impacted learning acquisition and retention. To address this limitation, we have utilized a complex motor task in conjunction with SEPs. Two groups of 12 participants ( n = 24) were randomly assigned to either a capsaicin (capsaicin cream) or a control (inert lotion) group. SEP amplitudes were collected at baseline, after application, and after motor learning acquisition. Participants performed a motor acquisition task followed by a pain-free retention task within 24–48 h. After motor learning acquisition, the amplitude of the N20 SEP peak significantly increased ( P < 0.05) and the N24 SEP peak significantly decreased ( P < 0.001) for the control group while the N18 SEP peak significantly decreased ( P < 0.01) for the capsaicin group. The N30 SEP peak was significantly increased ( P < 0.001) after motor learning acquisition for both groups. The P25 SEP peak decreased significantly ( P < 0.05) after the application of capsaicin cream. Both groups improved in accuracy after motor learning acquisition ( P < 0.001). The capsaicin group outperformed the control group before motor learning acquisition ( P < 0.05) and after motor learning acquisition ( P < 0.05) and approached significance at retention ( P = 0.06). Improved motor learning in the presence of capsaicin provides support for the enhancement of motor learning while in acute pain. In addition, the changes in SEP peak amplitudes suggest that early SEP changes reflect neurophysiological alterations accompanying both motor learning and mild acute pain.

Mechanisms and consequences of head injuries in soccer: a study of 451 patients

2011 ◽  
Vol 31 (5) ◽  
pp. E1 ◽  
Author(s):  
Malgorzata A. Kolodziej ◽  
Stephan Koblitz ◽  
Christopher Nimsky ◽  
Dieter Hellwig
Keyword(s):  
Head Injury ◽  
Head Injuries ◽  
Body Part ◽  
Physical Symptoms ◽  
The Body ◽  
Control Group ◽  
Case Group ◽  
Body Parts ◽  
Injury Group ◽  
Complicated Course

Object The goal of this study was to evaluate the incidence and mechanisms of head injury during soccer games and to describe the results after spontaneous resolution of symptoms or after treatment. Methods In a retrospective study from 2005, records on 451 players from the German Soccer Association who had suffered various injuries were collected. The study used a questionnaire in which the player described the accident and the playing situation as well as the clinical course after trauma. This questionnaire also included information about the physical symptoms of the players and the length of their rehabilitation. Two groups were formed: one with head injuries (case group), and the other with injuries of other body parts (control group). Results Of the injuries reported, 108 (23.9%) were related to the head, 114 (25.3%) to the knee, 58 (13%) to the ankle, 56 (12%) to the calf, and 30 (7%) to the shoulder. The areas of the head most frequently involved were the facial and occipital regions. In the head injury group, the head duel was the most common playing action to lead to trauma. In those cases, the body part that hit the injured player was the elbow, arm, or head of the opponent. The most common playing situation was combat in the penalty area. The median hospitalization time after the trauma was 2 days for the case group and 5 days for the control group. The rehabilitation time for the case group was also shorter (median 6.5 days) than for the control group (median 30 days). Conclusions Trivial head injuries in soccer can have a long and complicated course. Nevertheless, the temporary disability is shorter in most cases than for players with injuries to other parts of the body. Modifying the rules of play would be necessary to reduce the incidence of head trauma.

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