Author
Herbert Ugrinowitsch
Other affiliations: University of São Paulo
Bio: Herbert Ugrinowitsch is an academic researcher from Universidade Federal de Minas Gerais. The author has contributed to research in topics: Motor learning & Motor skill. The author has an hindex of 13, co-authored 115 publications receiving 750 citations. Previous affiliations of Herbert Ugrinowitsch include University of São Paulo.
Papers published on a yearly basis
Papers
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TL;DR: In conclusion, distinct neural processes are engendered by different practice conditions and the integration of behavioral and neurophysiological findings promotes a more comprehensive view of the phenomenon.
85 citations
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TL;DR: The results showed that random practice induced greater cognitive effort than constant practice when task engagement was analyzed, and the increased demand for sensory processing observed in random practice opens a new exciting field of study in practice organization.
Abstract: Explanatory hypotheses proposed in behavioral studies assumed that less repetitive practice schedules, such as random practice, seem to demand greater cognitive effort than more repetitive types of practice organization, such as constant. All of these hypotheses emphasize the enhanced demand to memory processes promoted by less repetitive practice schedules. In the present study, we investigated the cognitive effort involved in random and constant practice schedules with an electrophysiological approach. Twenty-one male participants practiced a sequential key-pressing task with two goals: learning the relative timing dimension and learning the absolute timing dimension. Sixty trials were performed in a constant practice schedule (only one absolute timing goal), and sixty trials were performed in random order (three absolute timing goals). Two electroencephalography based measures of cognitive states were used: (a) task engagement (sensory processing and attention resources) and (b) mental workload (working memory load). The results showed that random practice induced greater cognitive effort than constant practice when task engagement was analyzed. Throughout practice, both task engagement and mental workload decreased more in the constant practice condition than in the random practice condition. The increased demand for sensory processing observed in random practice opens a new exciting field of study in practice organization.
36 citations
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TL;DR: An outline of a non-equilibrium model, in which motor learning is explained as a continuous process of stabilization and adaptation, is presented, and propositions derived from this model have been tested and discussed.
Abstract: This article presents an outline of a non-equilibrium model, in which motor learning is explained as a continuous process of stabilization and adaptation. The article also shows how propositions derived from this model have been tested, and discusses possible practical implications of some supporting evidence to the teaching of motor skills. The stabilization refers to a process of functional stabilization that is achieved through negative feedback mechanisms. Initially, inconsistent and incorrect responses are gradually reduced, leading to a spatial-temporal patterning of the action. The adaptation is one in which new skills are formed from the reorganization of those already acquired through the flexibility of the system, reorganization of the skill structure, or self-organization. In order to provide learners with competency for adaptation, teachers should (a) guide students to learn motor skills taking into account that the stabilization of performance is just a transitory state that must be dismantled to achieve higher levels of complexity; (b) be clear which parts (micro) compose the skills and how they interact in order to form the whole (macro); (c) manipulate the skills in terms of their temporal, spatial, and/or spatiotemporal dimensions; (d) organize practice initially in a constant way, and then in a varied regimen (random) when the motor skills involve requirements of time and force; and, inversely for motor skills with spatial demands; and (e), provide a moderate frequency of feedback.
34 citations
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TL;DR: The results showed that the execution of brief interceptive movements was not affected by the range of OPs used in the experiments, which indicates that the whole movement was prepared in advance and triggered by a visual stimulus event that occurred at about 150 ms before onset.
Abstract: Continuous perceptuo-motor models have been widely favoured to describe the control mechanisms which underlie all types of interceptive actions. However, different interceptive tasks and types of interception (hitting or catching) may involve distinct control processes. Adopting an alternative version of the operational timing hypothesis developed by Tresilian (2005), we tested the assumptions that for hitting actions with brief movement times, timing control may not be possible post movement onset and therefore that movement parameterization must occur prior to the initiation of action. The aims of the two experiments reported here were twofold. Firstly, we investigated whether in a brief hitting task the preferred mode of control is offline instead of continuous. Secondly, we sought to verify what types of strategies, if any, are employed to attain the task goal. In experiment 1, eight participants performed brief hitting movements (180ms of duration) towards a moving target under five viewing conditions. Hitting movement was constrained to one degree of freedom (1df) via a slide rail. In the control condition the participants had full-vision of the target. In the occlusion conditions, vision of the target was suppressed for 200ms by liquid-crystal visual occlusion goggles from three different times before the expected movement onset (600, 400, and 200ms) as well as during movement execution (occlusion began at 0ms). In the second experiment, eight participants performed their movements under the same viewing conditions used in experiment 1 but this time the hitting movements were constrained to a horizontal plane (2df hitting task). Since directional movements were allowed, a chasing strategy was possible which would effectively increase the time window available in which to hit the target. The results of both experiments showed that performance deteriorated only when the participants had their vision occluded 200ms prior to movement onset. These results indicate that the remaining time until the target reached the striking zone (≈200ms) was not enough for feedback mechanisms to be effectively employed. The results imply that brief hitting movements were controlled offline by motor programs and that visual information 200ms prior to movement onset is paramount to trigger the motor program at the correct time.
31 citations
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01 Dec 2005
TL;DR: In this article, simple reaction time (RT) and movement time (MT) of young indoor soccer players (13.8 ± 0.5 years, n = 16) were measured using Multipsy 821 apparatus with a button pressing movement as an answer to a light stimulus.
Abstract: The aim of the study was to verify the level of association between simple reaction time (RT) and movement time (MT) of young indoor soccer (futsal) players (13.8 ± 0.5 years, n = 16). Simple RT was measured using the Multipsy 821 apparatus with a button pressing movement as an answer to a light stimulus. MT, turning the body to the left or right, was measured by a system composed of a contact carpet, fixed on the ground, and two pairs of doubled-photocells. The beginning of the movement was registered by loss of contact with the contact carpet and the end of the movement was recorded when the player passed through the pair of doubled-photocells. The distance between the contact carpet and the first pair of photocells was 1.45 m. Statistical analysis did not indicate significant correlation for both variables. The results can be explained by differences in the structure of the used tests and by RT and MT measurement in different motor skills. Moreover, these movements have distinct demands related to body mass. To conclude, TR performance cannot be associated with the potentiality of an athlete to perform rapid body rotation movements.
30 citations
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01 Jan 2016
TL;DR: The using multivariate statistics is universally compatible with any devices to read, allowing you to get the most less latency time to download any of the authors' books like this one.
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14,604 citations
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3,248 citations
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TL;DR: This work aims to unify the neuroscientific literature relevant to the recovery process and rehabilitation practice in order to provide a synthesis of the principles that constitute an effective neurorehabilitation approach.
Abstract: What are the principles underlying effective neurorehabilitation? The aim of neurorehabilitation is to exploit interventions based on human and animal studies about learning and adaptation, as well as to show that the activation of experience-dependent neuronal plasticity augments functional recovery after stroke. Instead of teaching compensatory strategies that do not reduce impairment but allow the patient to return home as soon as possible, functional recovery might be more sustainable as it ensures a long-term reduction in impairment and an improvement in quality of life. At the same time, neurorehabilitation permits the scientific community to collect valuable data, which allows inferring about the principles of brain organization. Hence neuroscience sheds light on the mechanisms of learning new functions or relearning lost ones. However, current rehabilitation methods lack the exact operationalization of evidence gained from skill learning literature, leading to an urgent need to bridge motor learning theory and present clinical work in order to identify a set of ingredients and practical applications that could guide future interventions. This work aims to unify the neuroscientific literature relevant to the recovery process and rehabilitation practice in order to provide a synthesis of the principles that constitute an effective neurorehabilitation approach. Previous attempts to achieve this goal either focused on a subset of principles or did not link clinical application to the principles of motor learning and recovery. We identified 15 principles of motor learning based on existing literature: massed practice, spaced practice, dosage, task-specific practice, goal-oriented practice, variable practice, increasing difficulty, multisensory stimulation, rhythmic cueing, explicit feedback/knowledge of results, implicit feedback/knowledge of performance, modulate effector selection, action observation/embodied practice, motor imagery, and social interaction. We comment on trials that successfully implemented these principles and report evidence from experiments with healthy individuals as well as clinical work.
167 citations