Combining muscle-computer interface guided training with bihemispheric tDCS improves upper limb function in patients with chronic stroke.

Transcranial direct current stimulation (tDCS) may facilitate neuroplasticity but with a limited effect when administered while patients with stroke are at rest. Muscle-computer interface (MCI) training is a promising approach for training patients with stroke even if they cannot produce overt movements. However, using tDCS to enhance MCI training has not been investigated.

A usability study on mobile EMG-guided wrist extension training in subacute stroke patients-MyoGuide.

Background: Effective stroke rehabilitation requires high-dose, repetitive-task training, especially during the early recovery phase. However, the usability of upper-limb rehabilitation technology in acute and subacute stroke survivors remains relatively unexplored. In this study, we introduce subacute stroke survivors to MyoGuide, a mobile training platform that employs surface electromyography (sEMG)-guided neurofeedback training that specifically targets wrist extension.

Exploring the Feasibility of Computer Vision for Detecting Post-Stroke Compensatory Movements.

Compensatory movements are commonly observed post-stroke and can negatively affect long-term motor recovery. In this context, a system that monitors movement quality and provides feedback would be beneficial. In this study, we aimed to detect compensatory movements during seated reaching using a conventional tablet camera and an open-source markerless body pose tracking algorithm called MediaPipe [1].

Characterization and wearability evaluation of a fully portable wrist exoskeleton for unsupervised training after stroke.

Background: Chronic hand and wrist impairment are frequently present following stroke and severely limit independence in everyday life. The wrist orientates and stabilizes the hand before and during grasping, and is therefore of critical importance in activities of daily living (ADL). To improve rehabilitation outcomes, classical therapy could be supplemented by novel therapies that can be applied in unsupervised settings.

Assessing Rhythmic Visual Entrainment and Reinstatement of Brain Oscillations to Modulate Memory Performance.

The human brain's ability to store information and remember past events is thought to be orchestrated by the synchronization of neuronal oscillations in various frequency bands. A vast amount of research has found that neural oscillations in the theta (∼4-7 Hz) and alpha (∼8-12 Hz) bands play an important role in memory formation. More specifically, it has been suggested that memory performance benefits if the same oscillatory pattern is present during encoding and retrieval.

Reinstating verbal memories with virtual contexts: Myth or reality?

When learning new information, contextual information about the encoding situation is stored in addition to the focal memory content. Later, these strings of extra information can help retrieve the learned content as demonstrated by experiments where contextual cues from an encoding situation facilitate remembering and improve memory performance when reinstated during retrieval. This context-dependent memory effect has been investigated over the course of several decades and has been demonstrated with many different types of contexts.

Age-Dependent Modulations of Resting State Connectivity Following Motor Practice.

Recent work in young adults has demonstrated that motor learning can modulate resting state functional connectivity. However, evidence for older adults is scarce. Here, we investigated whether learning a bimanual tracking task modulates resting state functional connectivity of both inter- and intra-hemispheric regions differentially in young and older individuals, and whether this has behavioral relevance.

Training wrist extensor function and detecting unwanted movement strategies in an EMG-controlled visuomotor task.

Stroke patients often suffer from severe upper limb paresis. Rehabilitation treatment typically targets motor impairments as early as possible, however, muscular contractions, particularly in the wrist and fingers, are often too weak to produce overt movements, making the initial phase of rehabilitation training difficult. Here we propose a new training tool whereby electromyographic (EMG) activity is measured in the wrist extensors and serves as a proxy of voluntary corticomotor drive.

The eWrist - A wearable wrist exoskeleton with sEMG-based force control for stroke rehabilitation.

Chronic wrist impairment is frequent following stroke and negatively impacts everyday life. Rehabilitation of the dysfunctional limb is possible but requires extensive training and motivation. Wearable training devices might offer new opportunities for rehabilitation.

GriFT: A Device for Quantifying Physiological and Pathological Mirror Movements in Children.

Goal: Mirror movements (MM) occur during unilateral actions and manifest as involuntary muscle activity of the passive limb, "mirroring" voluntary actions executed by the contralateral homologous body part. They are a normal motor feature in young children that gradually disappears. In children suffering from neurological disorders, e.

Structural and Functional Cortical Connectivity Mediating Cross Education of Motor Function.

Cross-education (CE) is the process whereby training with one limb leads to subsequent improvement in performance by the opposite untrained limb. We used multimodal neuroimaging in humans to investigate the mediating neural mechanisms by relating quantitative estimates of functional and structural cortical connectivity to individual levels of interlimb transfer. Resting-state (rs)-fMRI and diffusion weighted imaging (DWI) scans were undertaken before unilateral ballistic wrist flexion training.

Reconsolidation of Motor Memories Is a Time-Dependent Process.

Reconsolidation is observed when a consolidated stable memory is recalled, which renders it transiently labile and requires re-stabilization. Motor memory reconsolidation has previously been demonstrated using a three-day design: on day 1 the memory is encoded, on day 2 it is reactivated and experimentally manipulated, and on day 3 memory strength is tested. The aim of the current study is to determine specific boundary conditions in order to consistently degrade motor memory through reconsolidation paradigms.

Virtual water maze learning in human increases functional connectivity between posterior hippocampus and dorsal caudate.

Recent work has demonstrated that functional connectivity between remote brain regions can be modulated by task learning or the performance of an already well-learned task. Here, we investigated the extent to which initial learning and stable performance of a spatial navigation task modulates functional connectivity between subregions of hippocampus and striatum. Subjects actively navigated through a virtual water maze environment and used visual cues to learn the position of a fixed spatial location.

Gone for 60 seconds: reactivation length determines motor memory degradation during reconsolidation.

When a stable memory is reactivated it becomes transiently labile and requires restabilization, a process known as reconsolidation. Animal studies have convincingly demonstrated that during reconsolidation memories are modifiable and can be erased when reactivation is followed by an interfering intervention. Few studies have been conducted in humans, however, and results are inconsistent regarding the extent to which a memory can be degraded.

Changes in corticomotor excitability and intracortical inhibition of the primary motor cortex forearm area induced by anodal tDCS.

Objective: Previous studies have investigated how tDCS over the primary motor cortex modulates excitability in the intrinsic hand muscles. Here, we tested if tDCS changes corticomotor excitability and/or cortical inhibition when measured in the extensor carpi radialis (ECR) and if these aftereffects can be successfully assessed during controlled muscle contraction.

Methods: We implemented a double blind cross-over design in which participants (n = 16) completed two sessions where the aftereffects of 20 min of 1 mA (0.

Distinct and simultaneously active plasticity mechanisms in mouse hippocampus during different phases of Morris water maze training.

Although the Morris water maze (MWM) is the most frequently used protocol to examine hippocampus-dependent learning in mice, not much is known about the spatio-temporal dynamics of underlying plasticity processes. Here, we studied molecular and cellular hippocampal plasticity mechanisms during early and late phases of spatial learning in the MWM. Quantitative in situ hybridization for the immediate early genes zif268 and Homer1a (H1a) revealed phase-dependent differences in their expression between areas CA1 and CA3.

Aging effects on the resting state motor network and interlimb coordination.

Both increases and decreases in resting state functional connectivity have been previously observed within the motor network during aging. Moreover, the relationship between altered functional connectivity and age-related declines in bimanual coordination remains unclear. Here, we explored the developmental dynamics of the resting brain within a task-specific motor network in a sample of 128 healthy participants, aged 18-80 years.

Underconnectivity of the superior temporal sulcus predicts emotion recognition deficits in autism.

Neurodevelopmental disconnections have been assumed to cause behavioral alterations in autism spectrum disorders (ASDs). Here, we combined measurements of intrinsic functional connectivity (iFC) from resting-state functional magnetic resonance imaging (fMRI) with task-based fMRI to explore whether altered activity and/or iFC of the right posterior superior temporal sulcus (pSTS) mediates deficits in emotion recognition in ASD. Fifteen adults with ASD and 15 matched-controls underwent resting-state and task-based fMRI, during which participants discriminated emotional states from point light displays (PLDs).

Combinatorial brain decoding of people's whereabouts during visuospatial navigation.

Complex behavior typically relies upon many different processes which are related to activity in multiple brain regions. In contrast, neuroimaging analyses typically focus upon isolated processes. Here we present a new approach, combinatorial brain decoding, in which we decode complex behavior by combining the information which we can retrieve from the neural signals about the many different sub-processes.

Homologous involvement of striatum and prefrontal cortex in rodent and human water maze learning.

The multiple memory systems hypothesis posits that dorsal striatum and hippocampus are central nodes in independent memory systems, supporting response-based and place-based learning, respectively. Although our understanding of the function of hippocampus within this framework is relatively well established, the contribution of dorsal striatum is less clear. This in part seems to be due to the heterogeneous nature of dorsal striatum, which receives extensive topographically organized projections from higher cortical areas.

Movement observation improves early consolidation of motor memory.

Practicing a motor task can induce neuroplastic changes in the human primary motor cortex (M1) that are subsequently consolidated, leading to a stable memory trace. Currently, little is known whether early consolidation, tested several minutes after skill acquisition, can be improved by behavioral interventions. Here we test whether movement observation, known to evoke similar neural responses in M1 as movement execution, can benefit the early consolidation of new motor memories.

Visual target separation determines the extent of generalisation between opposing visuomotor rotations.

Here we investigated the influence of angular separation between visual and motor targets on concurrent adaptation to two opposing visuomotor rotations. We inferred the extent of generalisation between opposing visuomotor rotations at individual target locations based on whether interference (negative transfer) was present. Our main finding was that dual adaptation occurred to opposing visuomotor rotations when each was associated with different visual targets but shared a common motor target.

Visual guidance modulates hemispheric asymmetries during an interlimb coordination task.

The cerebral hemispheres of humans exhibit functional asymmetries. It is generally thought that the left hemisphere contributes to higher order planning of demanding motor tasks, while the right hemisphere plays an important role in processing visual or proprioceptive stimuli and controls spatial attention. Few studies have directly investigated which aspects of motor control increase the involvement of right-lateralized areas.

Sex differences in human virtual water maze performance: novel measures reveal the relative contribution of directional responding and spatial knowledge.

Sex differences in humans on virtual water maze navigation are well established when overall performance is measured, e.g., by the total time taken to find the hidden platform, total path length, or quadrant dwell time during probe trials.

The synergistic organization of muscle recruitment constrains visuomotor adaptation.

Reaching to visual targets engages the nervous system in a series of transformations between sensory information and motor commands. That which remains to be determined is the extent to which the processes that mediate sensorimotor adaptation to novel environments engage neural circuits that represent the required movement in joint-based or muscle-based coordinate systems. We sought to establish the contribution of these alternative representations to the process of visuomotor adaptation.