scholarly journals Analogous adaptations in speed, impulse and endpoint stiffness when learning a real and virtual insertion task with haptic feedback

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Atsushi Takagi ◽  
Giovanni De Magistris ◽  
Geyun Xiong ◽  
Alain Micaelli ◽  
Hiroyuki Kambara ◽  
...  
Keyword(s):  
Motor Learning ◽  
Virtual Environment ◽  
Tool Use ◽  
Haptic Feedback ◽  
Movement Speed ◽  
Trial Duration ◽  
Dynamic Interactions ◽  
Diverse Range ◽  
Endpoint Stiffness ◽  
The Brain

AbstractHumans have the ability to use a diverse range of handheld tools. Owing to its versatility, a virtual environment with haptic feedback of the force is ideally suited to investigating motor learning during tool use. However, few simulators exist to recreate the dynamic interactions during real tool use, and no study has compared the correlates of motor learning between a real and virtual tooling task. To this end, we compared two groups of participants who either learned to insert a real or virtual tool into a fixture. The trial duration, the movement speed, the force impulse after insertion and the endpoint stiffness magnitude decreased as a function of trials, but they changed at comparable rates in both environments. A ballistic insertion strategy observed in both environments suggests some interdependence when controlling motion and controlling interaction, contradicting a prominent theory of these two control modalities being independent of one another. Our results suggest that the brain learns real and virtual insertion in a comparable manner, thereby supporting the use of a virtual tooling task with haptic feedback to investigate motor learning during tool use.

ATP-binding cassette transporters and neurodegenerative diseases

2021 ◽  
Author(s):  
Jared S. Katzeff ◽  
Woojin Scott Kim
Keyword(s):  
Neurodegenerative Diseases ◽  
Abc Transporters ◽  
Brain Diseases ◽  
Atp Binding ◽  
Future Directions ◽  
Diverse Range ◽  
The Brain ◽  
Lateral Sclerosis ◽  
Atp Binding Cassette

Abstract ATP-binding cassette (ABC) transporters are one of the largest groups of transporter families in humans. ABC transporters mediate the translocation of a diverse range of substrates across cellular membranes, including amino acids, nucleosides, lipids, sugars and xenobiotics. Neurodegenerative diseases are a group of brain diseases that detrimentally affect neurons and other brain cells and are usually associated with deposits of pathogenic proteins in the brain. Major neurodegenerative diseases include Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. ABC transporters are highly expressed in the brain and have been implicated in a number of pathological processes underlying neurodegenerative diseases. This review outlines the current understanding of the role of ABC transporters in neurodegenerative diseases, focusing on some of the most important pathways, and also suggests future directions for research in this field.

Resilience

2019 ◽  
pp. 286-303 ◽  
Author(s):  
Rebecca Alexander ◽  
Justine Megan Gatt
Keyword(s):  
Well Being ◽  
Neural Systems ◽  
Dynamic Interactions ◽  
Control Networks ◽  
Effective Interventions ◽  
Adaptive Recovery ◽  
The Brain ◽  
Insight Into ◽  
Over Time

Resilience refers to the process of adaptive recovery following adversity or trauma. It is likely to include an intertwined series of dynamic interactions between neural, developmental, environmental, genetic, and epigenetic factors over time. Neuroscientific research suggests the potential role of the brain’s threat and reward systems, as well as executive control networks. Developmental research provides insight into how the environment may affect these neural systems across the lifespan towards greater risk or resilience to stress. Genetic work has revealed numerous targets that alter key neurochemical systems in the brain to influence mental health. Current challenges include ambiguities in the definition and measurement of resilience and a simplified focus on resilience as the absence of psychopathology, irrespective of levels of positive mental functioning. Greater emphasis on understanding the protective aspects of resilience and related well-being outcomes are important to delineate the unique neurobiological factors that underpin this process, so that effective interventions can be developed to assist vulnerable populations and resilience promotion.

scholarly journals Visual delay affects force scaling and weight perception during object lifting in virtual reality

2019 ◽  
Vol 121 (4) ◽  
pp. 1398-1409 ◽  
Author(s):  
Vonne van Polanen ◽  
Robert Tibold ◽  
Atsuo Nuruki ◽  
Marco Davare
Keyword(s):  
Virtual Reality ◽  
Multisensory Integration ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Visual Signals ◽  
Visual Events ◽  
Object Lifting ◽  
Relative Weighting ◽  
The Brain ◽  
Visual Delay

Lifting an object requires precise scaling of fingertip forces based on a prediction of object weight. At object contact, a series of tactile and visual events arise that need to be rapidly processed online to fine-tune the planned motor commands for lifting the object. The brain mechanisms underlying multisensory integration serially at transient sensorimotor events, a general feature of actions requiring hand-object interactions, are not yet understood. In this study we tested the relative weighting between haptic and visual signals when they are integrated online into the motor command. We used a new virtual reality setup to desynchronize visual feedback from haptics, which allowed us to probe the relative contribution of haptics and vision in driving participants’ movements when they grasped virtual objects simulated by two force-feedback robots. We found that visual delay changed the profile of fingertip force generation and led participants to perceive objects as heavier than when lifts were performed without visual delay. We further modeled the effect of vision on motor output by manipulating the extent to which delayed visual events could bias the force profile, which allowed us to determine the specific weighting the brain assigns to haptics and vision. Our results show for the first time how visuo-haptic integration is processed at discrete sensorimotor events for controlling object-lifting dynamics and further highlight the organization of multisensory signals online for controlling action and perception. NEW & NOTEWORTHY Dexterous hand movements require rapid integration of information from different senses, in particular touch and vision, at different key time points as movement unfolds. The relative weighting between vision and haptics for object manipulation is unknown. We used object lifting in virtual reality to desynchronize visual and haptic feedback and find out their relative weightings. Our findings shed light on how rapid multisensory integration is processed over a series of discrete sensorimotor control points.

scholarly journals Hierarchical Complexity of the Macro-Scale Neonatal Brain

2020 ◽  
Author(s):  
Manuel Blesa ◽  
Paola Galdi ◽  
Simon R Cox ◽  
Gemma Sullivan ◽  
David Q Stoye ◽  
...  
Keyword(s):  
Functional Specialization ◽  
Newborn Period ◽  
Diverse Range ◽  
Sensorimotor Processing ◽  
Macro Scale ◽  
Hierarchical Complexity ◽  
Connectivity Patterns ◽  
Cognitive Information ◽  
The Brain ◽  
Atypical Brain Development

Abstract The human adult structural connectome has a rich nodal hierarchy, with highly diverse connectivity patterns aligned to the diverse range of functional specializations in the brain. The emergence of this hierarchical complexity in human development is unknown. Here, we substantiate the hierarchical tiers and hierarchical complexity of brain networks in the newborn period, assess correspondences with hierarchical complexity in adulthood, and investigate the effect of preterm birth, a leading cause of atypical brain development and later neurocognitive impairment, on hierarchical complexity. We report that neonatal and adult structural connectomes are both composed of distinct hierarchical tiers and that hierarchical complexity is greater in term born neonates than in preterms. This is due to diversity of connectivity patterns of regions within the intermediate tiers, which consist of regions that underlie sensorimotor processing and its integration with cognitive information. For neonates and adults, the highest tier (hub regions) is ordered, rather than complex, with more homogeneous connectivity patterns in structural hubs. This suggests that the brain develops first a more rigid structure in hub regions allowing for the development of greater and more diverse functional specialization in lower level regions, while connectivity underpinning this diversity is dysmature in infants born preterm.

When a robot teaches humans: Automated feedback selection accelerates motor learning

2019 ◽  
Vol 4 (27) ◽  
pp. eaav1560 ◽  
Author(s):  
Georg Rauter ◽  
Nicolas Gerig ◽  
Roland Sigrist ◽  
Robert Riener ◽  
Peter Wolf
Keyword(s):  
Motor Learning ◽  
Haptic Feedback ◽  
Robotic Systems ◽  
Control Group ◽  
Training Sequences ◽  
Automated Feedback ◽  
Experimental Group ◽  
And Training ◽  
Main Shortcoming ◽  
Selection Of

A multitude of robotic systems have been developed to foster motor learning. Some of these robotic systems featured augmented visual or haptic feedback, which was automatically adjusted to the trainee’s performance. However, selecting the type of feedback to achieve the training goal usually remained up to a human trainer. We automated this feedback selection within a robotic rowing simulator: Four spatial errors and one velocity error were considered, all related to trunk-arm sweep rowing set as the training goal to be learned. In an alternating sequence of assessments without augmented feedback and training sessions with augmented, concurrent feedback, the experimental group received feedback, thus addressing the main shortcoming of the previous assessment. With this approach, each participant of the experimental group received an individual sequence of 10 training sessions with feedback. The training sequences from participants in the experimental group were consecutively applied for participants in the control group. Both groups were able to reduce spatial and velocity errors due to training. The learning rate of the requested velocity profile was significantly higher for the experimental group compared with the control group. Thus, our robotic rowing simulator accelerated motor learning by automated feedback selection. This demonstration of a working, closed-loop selection of types of feedback, i.e., training conditions, could serve as the basis for other robotic trainers incorporating further human expertise and artificial intelligence.

scholarly journals Successful auditory motor adaptation requires task-relevant auditory errors

2019 ◽  
Vol 122 (2) ◽  
pp. 552-562 ◽  
Author(s):  
Ayoub Daliri ◽  
Jonathan Dittman
Keyword(s):  
Motor Learning ◽  
Categorical Perception ◽  
Production Systems ◽  
State Space Model ◽  
Motor Adaptation ◽  
Auditory Information ◽  
Speech Motor Learning ◽  
Task Irrelevant ◽  
The Brain ◽  
Speech Motor

When we produce speech movements, we also predict the auditory consequences of the movements. We use discrepancies between our predictions and incoming auditory information to modify our future movements (adapt). Although auditory errors are crucial for speech motor learning, not all perceived auditory errors are consequences of our own actions. Therefore, the brain needs to evaluate the relevance of perceived auditory errors. In this study, we examined error assessment processes involved in auditory motor adaptation by systematically manipulating the correspondence between speech motor outputs and their auditory consequences during speaking. Participants ( n = 30) produced speech while they received perturbed auditory feedback (e.g., produced “head” but heard a word that sounded like “had”). In one condition, auditory errors were related to participants’ productions (task-relevant errors). In another condition, auditory errors were defined by the experimenter and had no correspondence with participants’ speech output (task-irrelevant errors). We found that the extent of adaptation and error sensitivity (derived from a state-space model) were greater in the condition with task-relevant auditory errors compared with those in the condition with task-irrelevant auditory errors. Additionally, participants with smaller perceptual targets (derived from a categorical perception task) adapted more to auditory perturbations, and participants with larger perceptual targets adapted less. Similarly, participants with smaller perceptual targets were more sensitive to errors in the condition with task-relevant auditory errors. Together, our results highlight the intricate mechanisms, involving both perception and production systems, that the brain uses to optimally integrate auditory errors for successful speech motor learning. NEW & NOTEWORTHY Feedback monitoring is essential for accurate speech production. By providing empirical results and a computational framework, we show that 1) the brain evaluates relevance of auditory errors and responds more to relevant errors, and 2) smaller perceptual targets are associated with more sensitivity to errors and more auditory motor adaptation.

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