ENTRE LÁGRIMAS E RISADAS: O ENSINO DO PERÍODO MÉDICI ATRAVÉS DAS CHARGES D’O PASQUIM

O presente trabalho abordara o ensino da ditadura civil-militar brasileira, com especial ênfase no período de governo do ditador Emílio Médici (30/10/1969 a 15/03/1974), com o auxílio de algumas charges selecionadas do semanário O Pasquim, enfatizando as possibilidades de utilização do discurso visual pela história

ENTRE LÁGRIMAS E RISADAS: O ENSINO DO PERÍODO MÉDICI ATRAVÉS DAS CHARGES D' O PASQUIM

Este trabalho pretende analisar o uso de charges políticas no ensino de História, especificamente para o estudo do período do general Médici, que vai do ano de 1969 ao ano de 1974. Nesse período, certas práticas coercitivas como a tortura, o extermínio e os “desaparecimentos” tornaram-se sistemáticas. Para realizar esse estudo, foram escolhidas as charges do semanário O Pasquim, criado em junho de 1969, justamente em função da decretação do Ato Institucional nº. 5 (AI-5)

Ventrolateral Prefrontal Cortex Contributes to Human Motor Learning

This study assesses the involvement in human motor learning, of the ventrolateral prefrontal cortex (BA 9/46v), a somatic region in the middle frontal gyrus. The potential involvement of this cortical area in motor learning is suggested by studies in nonhuman primates which have found anatomic connections between this area and sensorimotor regions in frontal and parietal cortex, and also with basal ganglia output zones. It is likewise suggested by electrophysiological studies which have shown that activity in this region is implicated in somatic sensory memory and is also influenced by reward. We directly tested the hypothesis that area 9/46v is involved in reinforcement-based motor learning in humans. Participants performed reaching movements to a hidden target and received positive feedback when successful. Before the learning task, we applied continuous theta burst stimulation (cTBS) to disrupt activity in 9/46v in the left or right hemisphere. A control group received sham cTBS. The data showed that cTBS to left 9/46v almost entirely eliminated motor learning, whereas learning was not different from sham stimulation when cTBS was applied to the same zone in the right hemisphere. Additional analyses showed that the basic reward-history-dependent pattern of movements was preserved but more variable following left hemisphere stimulation, which suggests an overall deficit in somatic memory for target location or target directed movement rather than reward processing per se. The results indicate that area 9/46v is part of the human motor learning circuit. © 2022 Kumar et al

RECOMMENDATIONS FOR MINIMUM TRIAL NUMBERS DURING WALKING GAIT

In a rehabilitation context, athletes may not be able to complete large numbers of trials during testing due to joint edema and pain. The purpose of this research was to determine the minimum number of trials needed to achieve a negligibly fluctuating temporal variance profile during walking gait. The time-series kinematics of the hip, knee and ankle were recorded from 10 participants, completing 11 trials each. The time-series variance of each kinematic variables were calculated for ten trials and used as a reference. Using a two-sample SPM1D {t} (α=0.05), all variance combinations (9, 8, 7, ... 3 of 11 trials) from the same participants were compared to the reference. Results showed a minimum of 7 trials were needed to achieve ’stable‘ kinematic variance during walking gait. This study provides evidence for selecting an appropriate number of walking trials in gait analysis, especially in early-stage rehabilitation for patients with joint pain or edema

On the somatosensory and reinforcement bases of human motor learning

Humans have a remarkable capability to adapt and learn new things, including new motor skills. For example, one can learn to play a short sequence of musical notes by navigating one's fingers on a piano or a guitar. Often, motor skill learning involves a goal-directed pointing or reaching to a clearly-defined visual target, such as making a purchase using a touch screen. In cases such as swimming or skiing, however, visual information is often limited or occluded. In order to successfully learn the task, one has to rely primarily on somatosensory information to form sensory goals or targets, or in effect to discover what it feels like to make a successful movement. In search for actions that are successful, one learns through trial and error and exploration, which leads to either unsuccessful or successful movements. Naturally, an efficient way of learning is to avoid committing the same mistakes, and instead, try to perform repeatedly successful actions. Assuming that moment-to-moment sensory information is important, the best possible candidate for such a mechanism would be a working memory store. This thesis examines the role of reinforcement and somatosensory information in the initial phases of motor learning using arm-reaching tasks as a model. The tasks involve making reaching movements to a hidden visual target. Binary positive feedback is provided throughout training as a form of reinforcement. Such learning brings about changes in functional networks in specific brain regions. More specifically, increases in functional connectivity related to reduction of movement error were found in sensorimotor areas of the brain, including supplementary motor area and second somatosensory cortex. In contrast, connectivity increases related to the number of successful trials (and thus, reinforcement) were observed in the ventral striatum and ventromedial prefrontal cortex. Thus, learning involves both sensorimotor and reward-related areas of the brain. Trial-by-trial changes in motor behavior (and hence variability) were also examined in this study, where it was found that variability was less following a successful trial than an unsuccessful trial, presumably reflecting a sign of exploration. Changes in connectivity involving putamen and sensorimotor cortices were observed that varied systematically with the magnitude of trial-by-trial variability. Changes in connectivity that were related to motor exploration following unsuccessful trial were also found in second somatosensory cortex and lateral prefrontal cortex, regions known to be involved in somatic working memory and decision-making. The role of somatic working memory in motor learning was assessed in a second study. In two separate experiments, it was found that individual differences in somatosensory working memory performance were reliably related to the amount of learning. Performance of somatosensory working memory was shown to decay as a function of the number of sequential items in the memory list, where the overall capacity was estimated to be around 2 items. Another experiment measures working memory by using subject's own movements. During learning period, working memory preferentially stores reinforced movements more than non-reinforced ones. The findings point to the critical roles of somatosensory working memory in reinforcement-based in motor learning.Les humains ont une capacité remarquable à s'adapter et à apprendre de nouvelles choses, y compris de nouvelles compétences motrices. Par exemple, on peut apprendre à jouer une courte séquence de notes de musique en bougeant ses doigts sur un piano ou une guitare. Souvent, l'apprentissage d'habiletés motrices implique un pointage ciblé vers un objectif ou une cible visuelle clairement définie, comme effectuer une sélection sur un écran tactile. Dans des cas tels que la natation ou le ski, les informations visuelles ne sont souvent pas disponibles ou occultées. Pour réussir à apprendre la tâche, il faut utiliser les informations somatosensorielles pour former des objectifs ou des cibles sensorielles, ou pour découvrir ce que cela signifie de réussir un mouvement. À la recherche d'actions réussies, on traverse une série d'essais et erreurs ainsi que d'exploration. Ces processus entraînent des mouvements à la fois infructueux et réussis. Naturellement, un moyen efficace d'apprendre est d'éviter de répéter les mêmes erreurs et, au contraire, de ne mener à bien que des actions réussies. En supposant qu'un stockage sensoriel instantané soit impliqué, le meilleur candidat possible pour un tel mécanisme est la mémoire de travail. Cette thèse examine le rôle du renforcement et de l'information somatosensorielle dans les phases initiales de l'apprentissage moteur en utilisant des tâches de mouvement d'atteinte avec le bras. Les tâches impliquent de faire des mouvements vers une cible visuelle cachée. Une renforcement positif binaire a été fournie tout au long de l'entraînement. Il a été constaté que le renforcement positif et les informations somatosensorielles étaient importants pour mener l'apprentissage en l'absence d'une cible visuelle claire. Un tel apprentissage entraîne des changements dans les réseaux fonctionnels de régions spécifiques du cerveau. On a constaté que les augmentations de la connectivité fonctionnelle varient en fonction du nombre d'essais réussis. Un schéma similaire a également été observé avec une augmentation de la connectivité impliquant le striatum ventral et le cortex préfrontal ventromédian. Les modifications du comportement moteur effectuées au cours des essais ont également été examinées en fonction des résultats des essais antérieurs, où, comparativement à un essai infructueux, un essai réussi a entraîné une plus faible variabilité des mouvements successifs. Les changements de connectivité variant avec la quantité de variabilité ont été identifiées comme comprenant le putamen et le cortex sensorimoteur. Aussi, les changements de connectivité variant avec la quantité d'exploration après un essai infructueux ont été identifiées comme comprenant le second cortex somatosensoriel et le cortex préfrontal latéral, régions connues pour être impliquées dans la mémoire de travail somatique et les tâches décisionnelles.Le rôle de la mémoire de travail somatique dans l'apprentissage moteur a été démontré dans une deuxième étude. Dans deux expériences distinctes, il a été constaté que les différences individuelles dans la performance de la mémoire de travail somatosensorielle étaient liées de manière fiable à l'ampleur de l'apprentissage. Pendant l'apprentissage, cette mémoire de travail se souvient préférentiellement des mouvements renforcés par rapport aux mouvements non renforcés. Ces résultats mettent en évidence le rôle critique de la mémoire de travail somatosensorielle dans l'apprentissage par le renforcement du moteur

Robotic-based ACTive somatoSENSory (Act.Sens) retraining on upper limb functions with chronic stroke survivors : study protocol for a pilot randomised controlled trial

Background: Prior studies have established that senses of the limb position in space (proprioception and kinaesthesia) are important for motor control and learning. Although nearly one-half of stroke patients have impairment in the ability to sense their movements, somatosensory retraining focusing on proprioception and kinaesthesia is often overlooked. Interventions that simultaneously target motor and somatosensory components are thought to be useful for relearning somatosensory functions while increasing mobility of the affected limb. For over a decade, robotic technology has been incorporated in stroke rehabilitation for more controlled therapy intensity, duration, and frequency. This pilot randomised controlled trial introduces a compact robotic-based upper-limb reaching task that retrains proprioception and kinaesthesia concurrently.Methods: Thirty first-ever chronic stroke survivors (> 6-month post-stroke) will be randomly assigned to either a treatment or a control group. Over a 5-week period, the treatment group will receive 15 training sessions for about an hour per session. Robot-generated haptic guidance will be provided along the movement path as somatosensory cues while moving. Audio-visual feedback will appear following every successful movement as a reward. For the same duration, the control group will complete similar robotic training but without the vision occluded and robot-generated cues. Baseline, post-day 1, and post-day 30 assessments will be performed, where the last two sessions will be conducted after the last training session. Robotic-based performance indices and clinical assessments of upper limb functions after stroke will be used to acquire primary and secondary outcome measures respectively. This work will provide insights into the feasibility of such robot-assisted training clinically. Discussion: The current work presents a study protocol to retrain upper-limb somatosensory and motor functions using robot-based rehabilitation for community-dwelling stroke survivors. The training promotes active use of the affected arm while at the same time enhances somatosensory input through augmented feedback. The outcomes of this study will provide preliminary data and help inform the clinicians on the feasibility and practicality of the proposed exercise.Published versionThis study is supported by the Rehabilitation Research Institute of Singapore, Research Fellowship Program (RFP/19002)

A Comprehensive Appraisal of Meta-Analyses of Exercise-Based Stroke Rehabilitation with Trial Sequential Analysis

Meta-analysis is a common technique used to synthesise the results of multiple studies through the combination of effect size estimates and testing statistics. Numerous meta-analyses have investigated the efficacy of exercise programmes for stroke rehabilitation. However, meta-analyses may also report false-positive results because of insufficient information or random errors. Trial sequential analysis (TSA) is an advanced technique for calculating the required information size (RIS) and more restrictive statistical significance levels for the precise assessment of any specific treatment. This study used TSA to examine whether published meta-analyses in the field of stroke rehabilitation reached the RIS and whether their overall effect sizes were sufficient. A comprehensive search of six electronic databases for articles published before May 2022 was conducted. The intervention methods were divided into four primary groups, namely aerobic or resistance exercise, machine-assisted exercise, task-oriented exercise, and theory-based exercise. The primary outcome measure was gait speed and the secondary outcome measure was balance function. The data were obtained either from the meta-analyses or as raw data from the original cited texts. All data analysis was performed in TSA software. In total, 38 articles with 46 analysable results were included in the TSA. Only 17 results (37.0%) reached the RIS. In conclusion, meta-analysis interpretation is challenging. Clinicians must consider the RIS of meta-analyses before applying the results in real-world situations. TSA can provide accurate evaluations of treatment effects, which is crucial to the development of evidence-based medicine

A micro motion sensing system for micromanipulation tasks

An optical-based motion sensing system has been developed for real-time sensing of instrument motion in micromanipulation. The main components of the system consist of a pair of position sensitive detectors (PSDs), lenses, an infrared (IR) diode that illuminates the workspace of the system, a non-reflective intraocular shaft, and a white reflective ball attached at the end of the shaft. The system calculates 3D displacement of the ball inside the workspace using the centroid position of the IR rays that are reflected from the ball and strike the PSDs. In order to eliminate inherent nonlinearity of the system, calibration using a feedforward neural network is proposed and presented. Handling of different ambient light and environment light conditions not to affect the system accuracy is described. Analyses of the whole optical system and effect of instrument orientation on the system accuracy are presented. Sensing resolution, dynamic accuracies at a few different frequencies, and static accuracies at a few different orientations of the instrument are reported. The system and the analyses are useful in assessing performance of hand-held microsurgical instruments and operator performance in micromanipulation tasks