The impact of ROI extraction method for MEG connectivity estimation: practical recommendations for the study of resting state data.

Magnetoencephalography and electroencephalography (M/EEG) seed-based connectivity analysis requires the extraction of measures from regions of interest (ROI). M/EEG ROI-derived source activity can be treated in different ways. It is possible, for instance, to average each ROI's time series prior to calculating connectivity measures.

Tele-Impedance control of a virtual avatar based on EMG and M-IMU sensors: a proof-of-concept.

The broad spread of cooperative robots into many application domains has resulted in a demand for intuitive and effective solutions for teleoperated control. A relevant role in teleoperation has been assumed by impedance controllers, that allow the increase of stability and accuracy during interaction. This paper aims to test a teleoperation method based on an impedance controller, namely tele-impedance control, that is usable in unstructured environments since it relies only on wearable sensors.

Experiencing an Elongated Limb in Virtual Reality Modifies the Tactile Distance Perception of the Corresponding Real Limb.

In measurement, a reference frame is needed to compare the measured object to something already known. This raises the neuroscientific question of which reference frame is used by humans when exploring the environment. Previous studies suggested that, in touch, the body employed as measuring tool also serves as reference frame.

Intracortical and interhemispheric excitability changes in arm amputees: A TMS study.

Objective: To evaluate cortical circuits and excitability of the motor cortex in the hemisphere contralateral to the affected (AH) and to the unaffected arm (UH), in upper limb amputees.

Methods: Motor evoked potentials (MEP) were recorded in 17 subjects who had upper limb amputation: 11 trans-radial (TR) and 6 trans-humeral (TH). Motor thresholds (MT), short interval intracortical inhibition (SICI), and interhemispheric inhibition (IHI) in the available arm muscles of the stump were evaluated.

Integration of proprioception in upper limb prostheses through non-invasive strategies: a review.

Proprioception plays a key role in moving our body dexterously and effortlessly. Nevertheless, the majority of investigations evaluating the benefits of providing supplemental feedback to prosthetics users focus on delivering touch restitution. These studies evaluate the influence of touch sensation in an attempt to improve the controllability of current robotic devices.

From rubber hands to neuroprosthetics: Neural correlates of embodiment.

Our interaction with the world rests on the knowledge that we are a body in space and time, which can interact with the environment. This awareness is usually referred to as sense of embodiment. For the good part of the past 30 years, the rubber hand illusion (RHI) has been a prime tool to study embodiment in healthy and people with a variety of clinical conditions.

Exploring crossmodal correspondences for future research in human movement augmentation.

"Crossmodal correspondences" are the consistent mappings between perceptual dimensions or stimuli from different sensory domains, which have been widely observed in the general population and investigated by experimental psychologists in recent years. At the same time, the emerging field of human movement augmentation (i.e.

Comparing end-effector position and joint angle feedback for online robotic limb tracking.

Somatosensation greatly increases the ability to control our natural body. This suggests that supplementing vision with haptic sensory feedback would also be helpful when a user aims at controlling a robotic arm proficiently. However, whether the position of the robot and its continuous update should be coded in a extrinsic or intrinsic reference frame is not known.

Wrist redundancy management during pointing tasks remains stable over time and in presence of a visuomotor perturbation.

Pointing at a screen using wrist and forearm movements is a kinematically redundant task, and the Central Nervous System seems to manage this redundancy by using a simplifying strategy, named Donders' Law for the wrist. In this work we investigated (1) whether this simplifying approach is stable over time and (2) whether a visuomotor perturbation provided in the task space influences the strategy used to solve the redundancy problem. We conducted two experiments asking participants to perform the same pointing task in four different days (first experiment), and providing a visual perturbation, i.

Upper limb home-based robotic rehabilitation in chronic stroke patients: A pilot study.

Introduction: Robotic therapy allow to propose sessions of controlled and identical exercises, customizing settings, and characteristics on the individual patient. The effectiveness of robotic assisted therapy is still under study and the use of robots in clinical practice is still limited. Moreover, the possibility of treatment at home allows to reduce the economic costs and time to be borne by the patient and the caregiver and is a valid tool during periods of pandemic such as covid.

Reduced connectivity of primary auditory and motor cortices during exposure to auditory white noise.

Auditory white noise (WN) is widely used in daily life for inducing sleep, and in neuroscience to mask unwanted environmental noise and cues. However, WN was recently reported to influence corticospinal excitability and behavioral performance. Here, we expand previous preliminary findings on the influence of WN exposure on cortical functioning, and we hypothesize that it may modulate cortical connectivity.

High-frequency oscillations-based precise temporal resolution of short latency afferent inhibition in the human brain.

Objective: Sensorimotor integration is a crucial process for adaptive behaviour and can be explored non-invasively with a conditioned transcranial magnetic stimulation (TMS) paradigm - i.e. short-latency afferent inhibition (SAI).

Stimulation with acoustic white noise enhances motor excitability and sensorimotor integration.

Auditory white noise (WN) is widely used in neuroscience to mask unwanted environmental noise and cues, e.g. TMS clicks.

Embodying an artificial hand increases blood flow to the investigated limb.

The autonomic nervous system is the main determinant of the blood flow directed towards a body part, and it is tightly connected to the representation of the body in the brain; would the experimental modulation of the sense of ownership of the limb affect its blood perfusion? In healthy participants, we employed the rubber hand illusion paradigm to modulate limb ownership while we monitored the brachial artery blood flow and resistance of the investigated limb. In all conditions with brush-stroking, we found an initial drop in the blood flow due to tactile stimulation. Subsequently, in the illusion condition where both the rubber and real hand experience synchronous brush-stroking, the blood flow rose significantly faster and reached significantly higher values.

Design of multi-pad electrotactile system envisioned as a feedback channel for supernumerary robotic limbs.

Background: Providing real-time haptic feedback is an important, but still not sufficiently explored aspect of the use of supernumerary robotic limbs (SRLs). We present a multi-pad electrode for conveying multi-modal proprioceptive and sensory information from SRL to the user's thigh and propose a method for stimuli calibration.

Methods: Within two pilot tests, we investigated return electrode configuration and active electrode discrimination in three healthy subjects to select the appropriate electrode pad topology.

A Soft Zwitterionic Hydrogel as Potential Coating on a Polyimide Surface to Reduce Foreign Body Reaction to Intraneural Electrodes.

Invasive intraneural electrodes can control advanced neural-interfaced prostheses in human amputees. Nevertheless, in chronic implants, the progressive formation of a fibrotic capsule can gradually isolate the electrode surface from the surrounding tissue leading to loss of functionality. This is due to a nonspecific inflammatory response called foreign-body reaction (FBR).

Principles of human movement augmentation and the challenges in making it a reality.

Augmenting the body with artificial limbs controlled concurrently to one's natural limbs has long appeared in science fiction, but recent technological and neuroscientific advances have begun to make this possible. By allowing individuals to achieve otherwise impossible actions, movement augmentation could revolutionize medical and industrial applications and profoundly change the way humans interact with the environment. Here, we construct a movement augmentation taxonomy through what is augmented and how it is achieved.

polymorphism and interhemispheric balance of motor cortex excitability: a preliminary study.

Preclinical studies have demonstrated that brain-derived neurotrophic factor (BDNF) plays a crucial role in the homeostatic regulation of cortical excitability and excitation/inhibition balance. Using transcranial magnetic stimulation techniques, we investigated whether BDNF polymorphism could influence cortical excitability of the left and right primary motor cortex in healthy humans. Twenty-nine participants were recruited and genotyped for the presence of the BDNF Val66Met polymorphism, namely homozygous for the valine allele (Val/Val), heterozygotes (Val/Met), and homozygous for the methionine allele (Met/Met).

Sensorimotor integration within the primary motor cortex by selective nerve fascicle stimulation.

The integration of sensory inputs in the motor cortex is crucial for dexterous movement. We recently demonstrated that a closed-loop control based on the feedback provided through intraneural multichannel electrodes implanted in the median and ulnar nerves of a participant with upper limb amputation improved manipulation skills and increased prosthesis embodiment. Here we assessed, in the same participant, whether and how selective intraneural sensory stimulation also elicits a measurable cortical activation and affects sensorimotor cortical circuits.

Resting state network connectivity is attenuated by fMRI acoustic noise.

Introduction: During the past decades there has been an increasing interest in tracking brain network fluctuations in health and disease by means of resting state functional magnetic resonance imaging (rs-fMRI). Rs-fMRI however does not provide the ideal environmental setting, as participants are continuously exposed to noise generated by MRI coils during acquisition of Echo Planar Imaging (EPI). We investigated the effect of EPI noise on resting state activity and connectivity using magnetoencephalography (MEG), by reproducing the acoustic characteristics of rs-fMRI environment during the recordings.

Neurophysiology of slip sensation and grip reaction: insights for hand prosthesis control of slippage.

Sensory feedback is pivotal for a proficient dexterity of the hand. By modulating the grip force in function of the quick and not completely predictable change of the load force, grabbed objects are prevented to slip from the hand. Slippage control is an enabling achievement to all manipulation abilities.