scholarly journals Exploring Disturbance as a Force for Good in Motor Learning

2019 ◽  
Author(s):  
Jack Brookes ◽  
Faisal Mushtaq ◽  
Earle Jamieson ◽  
Aaron J. Fath ◽  
Geoffrey P. Bingham ◽  
...  
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Formal Model ◽  
The Novel ◽  
Active Inference ◽  
Random Group ◽  
Energy Principle ◽  
Before And After ◽  
Entropy Reduction ◽  
Haptic Assistance

AbstractDisturbance forces facilitate motor learning, but theoretical explanations for this counterintuitive phenomenon are lacking. Smooth arm movements require predictions (inference) about the force-field associated with a workspace. The Free Energy Principle (FEP) suggests that such ‘active inference’ is driven by ‘surprise’. We used these insights to create a formal model that explains why disturbance helps learning. In two experiments, participants undertook a continuous tracking task where they learned how to move their arm in different directions through a novel 3D force field. We compared baseline performance before and after exposure to the novel field to quantify learning. In Experiment 1, the exposure phases (but not the baseline measures) were delivered under three different conditions: (i) robot haptic assistance; (ii) no guidance; (iii) robot haptic disturbance. The disturbance group showed the best learning as our model predicted. Experiment 2 further tested our FEP inspired model. Assistive and/or disturbance forces were applied as a function of performance (low surprise), and compared to a random error manipulation (high surprise). The random group showed the most improvement as predicted by the model. Thus, motor learning can be conceptualised as a process of entropy reduction. Short term motor strategies (e.g. global impedance) can mitigate unexpected perturbations, but continuous movements require active inference about external force-fields in order to create accurate internal models of the external world (motor learning). Our findings reconcile research on the relationship between noise, variability, and motor learning, and show that information is the currency of motor learning.

scholarly journals Observing motor learning produces somatosensory change

2013 ◽  
Vol 110 (8) ◽  
pp. 1804-1810 ◽  
Author(s):  
Nicolò F. Bernardi ◽  
Mohammad Darainy ◽  
Emanuela Bricolo ◽  
David J. Ostry
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Observational Learning ◽  
Human Subjects ◽  
Somatosensory System ◽  
Visual Observation ◽  
Video Observation ◽  
Physical Practice ◽  
Before And After ◽  
Somatosensory Function

Observing the actions of others has been shown to affect motor learning, but does it have effects on sensory systems as well? It has been recently shown that motor learning that involves actual physical practice is also associated with plasticity in the somatosensory system. Here, we assessed the idea that observational learning likewise changes somatosensory function. We evaluated changes in somatosensory function after human subjects watched videos depicting motor learning. Subjects first observed video recordings of reaching movements either in a clockwise or counterclockwise force field. They were then trained in an actual force-field task that involved a counterclockwise load. Measures of somatosensory function were obtained before and after visual observation and also following force-field learning. Consistent with previous reports, video observation promoted motor learning. We also found that somatosensory function was altered following observational learning, both in direction and in magnitude, in a manner similar to that which occurs when motor learning is achieved through actual physical practice. Observation of the same sequence of movements in a randomized order did not result in somatosensory perceptual change. Observational learning and real physical practice appear to tap into the same capacity for sensory change in that subjects that showed a greater change following observational learning showed a reliably smaller change following physical motor learning. We conclude that effects of observing motor learning extend beyond the boundaries of traditional motor circuits, to include somatosensory representations.

Optimization of a New Reactive Force Field for Silver - Based Materials

2020 ◽  
Author(s):  
Clément Dulong ◽  
Bruno Madebène ◽  
Susanna Monti ◽  
Johannes Richardi
Keyword(s):  
Force Field ◽  
Self Assembled Monolayers ◽  
The Novel ◽  
Reactive Force ◽  
Reactive Force Field ◽  
Energetic Properties ◽  
Extended Training ◽  
Geometrical Features ◽  
Assembled Monolayers ◽  
Gold Thiolate

<div><div><div><p>A new reactive force field based on the ReaxFF formalism is effectively parametrized against an extended training set of quantum chemistry data (containing more than 120 different structures) to describe accurately silver- and silver-thiolate systems. The results obtained with this novel representation demonstrate that the novel ReaxFF paradigm is a powerful methodology to reproduce more appropriately average geometric and energetic properties of metal clusters and slabs when compared to the earlier ReaxFF parametrizations dealing with silver and gold. ReaxFF cannot describe adequately specific geometrical features such as the observed shorter distances between the under-coordinated atoms at the cluster edges. Geometric and energetic properties of thiolates adsorbed on a silver Ag20 pyramid are correctly represented by the new ReaxFF and compared with results for gold. The simulation of self-assembled monolayers of thiolates on a silver (111) surface does not indicate the formation of staples in contrast to the results for gold-thiolate systems.</p></div></div></div>

More Alike Than Unalike: Cross-language Similarity Influences Novel Word Lexicalization in Bilingual Individuals

2020 ◽  
Author(s):  
Pauline Palma ◽  
Marie-France Marin ◽  
k onishi ◽  
Debra Titone
Keyword(s):  
Lexical Decision ◽  
Lexical Decision Task ◽  
Decision Task ◽  
The Novel ◽  
Lexical Representations ◽  
Before And After ◽  
Word Forms ◽  
Explicit Recognition ◽  
Novel Word Learning ◽  
Cross Language

Although several studies have focused on novel word learning and consolidation in native (presumably monolingual) speakers, less is know about how bilinguals add novel words to their mental lexicon. Here, we trained 33 English-French bilinguals on novel word-forms that were neighbors to “hermit” English words (i.e., words with no existing neighbors). Importantly, these English words varied in terms of orthographic overlap with their French translation equivalent (i.e., cognates vs. noncognates). We measured explicit recognition of the novel neighbors and the interaction between novel neighbors and English words through a lexical decision task, both before and after a sleep interval. In the lexical decision task, we found evidence of immediate facilitation for English words with novel neighbors, and evidence of competition after a sleep interval for cognate words only. These results suggest that higher quality of existing lexical representations predicts an earlier onset for novel word lexicalization.

A CRITICAL ASSESSMENT OF THE NOVEL «ASSEMBLY HALL» BY HERMANN KANT IN THE REUNIFIED GERMANY (AFTER 1991)

2020 ◽  
pp. 144-152
Author(s):  
Rimma Gurevich
Keyword(s):  
Critical Assessment ◽  
The Novel ◽  
Aesthetic Appreciation ◽  
Party Position ◽  
Creative Personality ◽  
Before And After

H. Kant’s novel received a high literary and aesthetic appreciation in criticism and wide recognition by readers. Criticism (before and after the unification of Germany) concerns mainly one aspect viz. authenticity of the events depicted in the novel and the charcters’ images. Opponents argue that Kant’s ideological views, his consistent socialist and party position have prompt him to embellish reality, create simulacra, and the idyllic world of socialist Biedermeyer. The article shows that these assessments ignore the nature of his talent, especially his creative personality peculiarities such as journalistic orientation of the motivated «political» person and writer.

Syntax Stimulation Revisited

1995 ◽  
Vol 4 (4) ◽  
pp. 99-104 ◽  
Author(s):  
Ruth B. Fink ◽  
Myrna F. Schwartz ◽  
Elizabeth Rochon ◽  
Jessica L. Myers ◽  
Gail Simon Socolof ◽  
...  
Keyword(s):  
Multiple Baseline ◽  
Structure Modeling ◽  
The Novel ◽  
Connected Speech ◽  
Language Program ◽  
Nonfluent Aphasia ◽  
Coding Scheme ◽  
Narrative Production ◽  
Before And After ◽  
Picture Description

A multiple-probes variant of the multiple-baseline across-behaviors design was used to study the extent of generalization associated with syntax stimulation (SS) training. To assess whether acquisition of specific structures generalized across tasks, we used a specially designed sentence elicitation probe, Picture Description with Structure Modeling (PDSM; Fink et al., 1994). To assess whether training enhanced morphosyntactic production in connected speech, we used the coding scheme developed by Saffran, Berndt, and Schwartz (1989). Four subjects with chronic nonfluent aphasia were trained to produce active, passive, and embedded sentences using materials and procedures from the Helm Elicited Language Program for Syntax Stimulation (Helm-Estabrooks, 1981). These sentence structures were trained in successive phases with generalization probes administered before and after each phase. Three subjects with aphasia served as controls. Strong within-task generalization was observed and, in contrast to previous studies, generalization to the novel sentence elicitation task (PDSM). SS training did not yield measurable gains in narrative production.

scholarly journals A Variational Approach to Scripts

2021 ◽  
Vol 12 ◽  
Author(s):  
Mahault Albarracin ◽  
Axel Constant ◽  
Karl J. Friston ◽  
Maxwell James D. Ramstead
Keyword(s):  
Social Order ◽  
Formal Model ◽  
Behavioral Modeling ◽  
Integrative Model ◽  
Action Perception ◽  
Active Inference ◽  
Modeling Framework ◽  
Dual Nature ◽  
The Social ◽  
Action Sequences

This paper proposes a formal reconstruction of the script construct by leveraging the active inference framework, a behavioral modeling framework that casts action, perception, emotions, and attention as processes of (Bayesian or variational) inference. We propose a first principles account of the script construct that integrates its different uses in the behavioral and social sciences. We begin by reviewing the recent literature that uses the script construct. We then examine the main mathematical and computational features of active inference. Finally, we leverage the resources of active inference to offer a formal model of scripts. Our integrative model accounts for the dual nature of scripts (as internal, psychological schema used by agents to make sense of event types and as constitutive behavioral categories that make up the social order) and also for the stronger and weaker conceptions of the construct (which do and do not relate to explicit action sequences, respectively).

scholarly journals Motor learning in reaching tasks leads to homogenization of task space error distribution

2021 ◽  
Author(s):  
Puneet Singh ◽  
Oishee Ghosal ◽  
Aditya Murthy ◽  
Ashitava Ghodal
Keyword(s):  
Motor Learning ◽  
Force Field ◽  
Error Distribution ◽  
Task Space ◽  
Field Perturbation ◽  
Directional Dependence ◽  
Reaching Tasks ◽  
Space Error ◽  
Human Arm ◽  
Point To Point

A human arm, up to the wrist, is often modelled as a redundant 7 degree-of-freedom serial robot. Despite its inherent nonlinearity, we can perform point-to-point reaching tasks reasonably fast and with reasonable accuracy in the presence of external disturbances and noise. In this work, we take a closer look at the task space error during point-to-point reaching tasks and learning during an external force-field perturbation. From experiments and quantitative data, we confirm a directional dependence of the peak task space error with certain directions showing larger errors than others at the start of a force-field perturbation, and the larger errors are reduced with repeated trials implying learning. The analysis of the experimental data further shows that a) the distribution of the peak error is made more uniform across directions with trials and the error magnitude and distribution approaches the value when no perturbation is applied, b) the redundancy present in the human arm is used more in the direction of the larger error, and c) homogenization of the error distribution is not seen when the reaching task is performed with the non-dominant hand. The results support the hypothesis that not only magnitude of task space error, but the directional dependence is reduced during motor learning and the workspace is homogenized possibly to increase the control efficiency and accuracy in point-to-point reaching tasks. The results also imply that redundancy in the arm is used to homogenize the workspace, and additionally since the bio-mechanically similar dominant and non-dominant arms show different behaviours, the homogenizing is actively done in the central nervous system.

scholarly journals Increase in weighting of vision vs. proprioception associated with force field adaptation

2019 ◽  
Author(s):  
Brandon M. Sexton ◽  
Yang Liu ◽  
Hannah J. Block
Keyword(s):  
Force Field ◽  
Position Sense ◽  
Multisensory Perception ◽  
Hand Position ◽  
Null Field ◽  
Before And After ◽  
Force Field Adaptation ◽  
Perceptual Changes ◽  
The Brain ◽  
Straight Ahead

AbstractHand position can be encoded by vision, via an image on the retina, and proprioception (position sense), via sensors in the joints and muscles. The brain is thought to weight and combine available sensory estimates to form an integrated multisensory estimate of hand position with which to guide movement. Force field adaptation, a form of cerebellum-dependent motor learning in which reaches are systematically adjusted to compensate for a somatosensory perturbation, is associated with both motor and proprioceptive changes. The cerebellum has connections with parietal regions thought to be involved in multisensory integration; however, it is unknown if force adaptation is associated with changes in multisensory perception. One possibility is that force adaptation affects all relevant sensory modalities similarly, such that the brain’s weighting of vision vs. proprioception is maintained. Alternatively, the somatosensory perturbation might be interpreted as proprioceptive unreliability, resulting in vision being up-weighted relative to proprioception. We assessed visuo-proprioceptive weighting with a perceptual estimation task before and after subjects performed straight-ahead reaches grasping a robotic manipulandum. Each subject performed one session with a clockwise or counter-clockwise velocity-dependent force field, and one session in a null field to control for perceptual changes not specific to force adaptation. Subjects increased their weight of vision vs. proprioception in the force field session relative to the null field session, regardless of force field direction, in the straight-ahead dimension (F1,44 = 5.13, p = 0.029). This suggests that force field adaptation is associated with an increase in the brain’s weighting of vision vs. proprioception.

scholarly journals Sex in Stencil Novels Case Study: Readers' Reception of Enny Arrow's Stencil Novel in Surakarta

2021 ◽  
Vol 04 (01) ◽  
Author(s):  
Ariska Puspita Anggraini ◽  
Keyword(s):  
Data Analysis ◽  
Psychological Factors ◽  
Reception Theory ◽  
The Novel ◽  
Social Psychological ◽  
Modern Humans ◽  
Erotic Literature ◽  
Before And After ◽  
New Perspective

The phenomenon of sex has always been novel in every era. In Indonesia, for example, Enny Arrow’s stencil novel has been circulating, which has been named as a legend of Indonesian erotic literature. Along with the development of technology, the existence of stencil novels was replaced by DVDs or VCDs, which then continued with the emergence of various sites providing access to pornography. This difference in phenomena certainly makes the meaning of sex for each individual different. This research will analyze the meaning of sex in the stencil novel by Enny Arrow in the eyes of millennial men. The data analysis will focus on social psychological factors using Normand Holland’s literary reception theory. From the data analysis, it can be concluded that there are different views on sexual relations before and after reading the novel. This research is expected to provide a new perspective on the picture of sexuality for modern humans.

scholarly journals What is mood? A computational perspective

2018 ◽  
Vol 48 (14) ◽  
pp. 2277-2284 ◽  
Author(s):  
James E Clark ◽  
Stuart Watson ◽  
Karl J Friston
Keyword(s):  
Mood Disorders ◽  
Active Inference ◽  
Simple Formulation ◽  
Energy Principle ◽  
Free Energy Principle ◽  
New Approach ◽  
Functional Brain ◽  
Bayesian Brain ◽  
Multiple Levels ◽  
Computational Pathology

AbstractThe neurobiological understanding of mood, and by extension mood disorders, remains elusive despite decades of research implicating several neuromodulator systems. This review considers a new approach based on existing theories of functional brain organisation. The free energy principle (a.k.a. active inference), and its instantiation in the Bayesian brain, offers a complete and simple formulation of mood. It has been proposed that emotions reflect the precision of – or certainty about – the predicted sensorimotor/interoceptive consequences of action. By extending this reasoning, in a hierarchical setting, we suggest mood states act as (hyper) priors over uncertainty (i.e. emotions). Here, we consider the same computational pathology in the proprioceptive and interoceptive (behavioural and autonomic) domain in order to furnish an explanation for mood disorders. This formulation reconciles several strands of research at multiple levels of enquiry.

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