O objetivo do presente trabalho foi investigar os efeitos da interferência contextual em função das dificuldades funcional e nominal da tarefa. Participaram do estudo 160 adultos de ambos os sexos. Os participantes divididos em grupos de experientes e inexperientes praticaram uma tarefa simples ou complexa de timing coincidente, sob regime aleatório ou por blocos, totalizando oito grupos experimentais. As medidas de desempenho foram os erros absoluto, variável e constante. Os resultados não mostraram diferenças entre os grupos de prática aleatória e por blocos em nenhuma das condições de dificuldade (nominal e funcional). Sendo assim, concluiu-se que o efeito da interferência contextual não é dependente das dificuldades funcional e nominal da tarefa / The objective of this study was to investigate the effect of contextual interference due to the lack of functional and nominal task. The study included 160 adults of both sexes. Participants were divided in groups of experience and inexperience, which performed a simple or complex task of coincident timing, under random or blocked schedule. It resulted in eight experimental groups. Performance measures were the absolute, variable, and constant errors. Results did not show differences between random and blocked groups in all conditions of difficult (nominal and functional). Therefore, it was conclude that the effect of contextual interference is not dependent of the nominal and functional difficulties of the task

É sabido que a população idosa vem aumentando em números relativamente altos, gerando preocupações em relação aos cuidados que necessitam. Uma forma de idosos se manterem ativos é através da aprendizagem de novas habilidades motoras. Neste sentido, foram encontrados poucos estudos envolvendo a população idosa e o efeito da interferência contextual, particularmente estudos que utilizassem habilidades esportivas como tarefa. O objetivo do estudo foi investigar se há o efeito da interferência contextual na aprendizagem de uma habilidade esportiva em idosos. Foram selecionados para participar do estudo quarenta idosos (65-80 anos), fisicamente ativos, que foram divididos aleatoriamente em dois grupos: prática variada aleatória; e prática variada em blocos. A tarefa praticada foi o arremesso a ponto do jogo de bocha e bola deveria atingir três alvos nas distâncias de 2, 4 e 6 metros. A prática constou de 120 tentativas divididas em duas sessões de prática. Foram realizados dois testes de Retenção (10min e 24h) e também dois testes de Transferência (24 horas), sendo um realizado com a mão preferencial e outro com a mão não preferencial do participante, com o alvo à 5 metros. As medidas de desempenho utilizadas foram o erro radial, o desvio padrão do erro radial e a frequência de erros grosseiros. Também foram realizadas medidas cinemáticas, como amplitude, velocidade média e pico de aceleração de deslocamento da bola no forwardswing; e velocidade de soltura da bola. Na comparação entre os grupos de prática, não foi encontrada diferença no erro radial ou no desvio padrão do erro (p > 0,05), mas na frequência de erros grosseiros houve diferença entre os grupos apenas na fase de aquisição (p < 0,05). Além disso, as análises inferenciais referentes às medidas cinemáticas nos testes de retenção e transferência, tanto da velocidade média como da velocidade de soltura, mostraram que os idosos de ambos os grupos mudaram a velocidade nos testes (p < 0,05), provavelmente procurando ajustar o movimento. Correlações de Pearson foram realizadas entre medidas de desempenho e medidas cinemáticas e observou-se apenas uma correlação fraca entre o erro radial e a amplitude de deslocamento da bola no teste de transferência com a mão não preferencial (p < 0,05). Em conjunto, os resultados mostraram que os grupos apresentaram desempenho semelhante em ambas as estruturas de prática (aleatória e blocos) e, portanto, não houve efeito da interferência contextual na aprendizagem de idosos nesta habilidade esportiva. No entanto, pode ser argumentado que o controle adequado de força necessário no arremesso a ponto possa exigir maior tempo de prática para ser adquirido / It is known that the elderly population is increasing in relatively high numbers, generating concerns about the care they need. A form of seniors remain active is through the learning of new motor skills. In this sense, few studies involving the elderly population and the contextual interference effect have been found, particularly, studies that used sports skills as task. The objective of this study was to investigate if there is the contextual interference effect on sports skill learning in elderly. We selected 40 old persons (65-80 years old), physically active, which were divided randomly into two groups: random varied practice; and practice varied in blocks. The task was the throwing practiced at the bocce game, in which the ball should reach three targets at distances of 2, 4 and 6 meters. The practice consisted of 120 attempts divided into two practice sessions. Two Retention tests were conducted (10 min and 24 hours) and also two Transfer tests (24 hours), being performed with the preferential hand and also with the non-preferential hand of the participant, with the target at 5 meters. The performance measures used were the radial error, the standard deviation of radial error and frequency of gross errors. Kinematic measures were also used, such as amplitude, average speed and peak of acceleration in the displacement of the ball on the forwardswing; and also, speed of release of the ball. Comparisons between the practice groups, found no difference in the radial error or the standard deviation of the error (p > 0.05), but in the frequency of gross errors, there was a difference between the groups only at the acquisition phase (p < 0.05). In addition, the inferential analysis on retention and transfer tests, both the average speed as the speed of release, showed that the elderly of both groups have changed the speed (p < 0.05), probably trying to adjust the movement. Pearson correlations were performed between performance and kinematic measures and there was only a weak correlation between the radial error and amplitude on the transfer test with the non-preferential hand (p < 0.05). Overall, the results showed that the groups have similar performance on both practice structures (random and blocks) and, therefore, there was no effect of contextual interference in learning this sport skill by the elderly. However, it can be argued that the proper control of force needed in this task may require more practice time to be acquired

De acordo com o efeito da interferência contextual (EIC), a prática variada aleatória ou prática com alta interferência contextual (abcbcacbabac) proporciona pior desempenho de aquisição, porém melhor transferência e retenção em comparação à prática variada em blocos ou prática com baixa interferência contextual (aaaabbbbcccc). Entretanto, muitas pesquisas não confirmaram totalmente o EIC, o que põe em dúvida a aplicação do princípio no domínio motor. Através de um procedimento metodológico que prolongou a transferência (aumento do número de tentativas), o objetivo do presente estudo foi verificar se o EIC é um fator duradouro, temporário ou inexistente. Trinta e seis escolares do sexo feminino, com idades entre 12 e 14 anos, foram distribuídas em dois grupos de prática variada em função dos resultados de um teste de entrada: grupo aleatório e grupo em blocos. As tarefas de aquisição foram os saques de voleibol por baixo e por cima, a dois alvos afixados no solo. A tarefa de transferência foi o saque japonês a um terceiro alvo. Todos os saques foram executados a cinco metros da rede. O experimento constou de quatro fases: teste de entrada (oito tentativas), fase de aquisição (288 tentativas), fase de transferência (84 tentativas) e fase de retenção (12 tentativas). Os resultados das medidas de precisão e de padrão de movimento mostraram que não houve diferenças estatisticamente significantes entre os grupos em nenhum dos blocos do experimento. Logo, a estrutura da prática variada não influiu de forma significante no desempenho da tarefa nova. Ademais, os resultados não deram suporte à hipótese de MAGILL & HALL (1990), segundo a qual o EIC ocorre quando as variações da tarefa pertencem a programas motores diferentes. Ainda, o presente estudo reforçou a tendência de que o EIC não ocorre com crianças e com a utilização de tarefas de campo. / According to the contextual interference effect (CIE), practicing several motor skills under random practice or high contextual interference practice (abcbcacbabac) facilitates retention and transfer in comparison to practicing the same tasks under blocked practice or low contextual interference practice (aaaabbbbcccc). This learning phenomenon has led to a considerable amount of research. However, no definite trend in the results has been found, which makes its acceptance in the motor learning domain questionable. By extending the transfer phase (increasing the number of transfer trials), the aim of this study was to assess whether the CIE is temporary, lasting or non-existent. Accordingly, based on the scores of the pre-test, thirty-six schoolgirls (12 -14 years of age) were allocated to either a blocked or a random group. The acquisition tasks were the underhand and overhand volleyball serves, to two targets placed on the floor. The transfer task was the round house (Asian floater) volleyball serve to a third target. All serves were performed five meters away from the net. The experimental design consisted of four phases: pre-test (eight trials), acquisition (288 trials), transfer (84 trials) and retention (12 trials). The results of precision and movement pattern measures did not provide support to the CIE, since there were no significant statistical differences between the groups in any of the phases. The structure of variable practice did not affect the performance of the new task. Likewise, there was no support to the MAGILL & HALL (1990) hypothesis that, when task variations involve learning of different motor programs, the benefit of random practice over blocked practice would be found. Moreover, the present study reinforced the trend that the CIE does not take place in children as well as with field tasks.

De acordo com o efeito da interferência contextual (EIC), a prática variada aleatória ou prática com alta interferência contextual (abcbcacbabac) proporciona pior desempenho de aquisição, porém melhor transferência e retenção em comparação à prática variada em blocos ou prática com baixa interferência contextual (aaaabbbbcccc). Entretanto, muitas pesquisas não confirmaram totalmente o EIC, o que põe em dúvida a aplicação do princípio no domínio motor. Através de um procedimento metodológico que prolongou a transferência (aumento do número de tentativas), o objetivo do presente estudo foi verificar se o EIC é um fator duradouro, temporário ou inexistente. Trinta e seis escolares do sexo feminino, com idades entre 12 e 14 anos, foram distribuídas em dois grupos de prática variada em função dos resultados de um teste de entrada: grupo aleatório e grupo em blocos. As tarefas de aquisição foram os saques de voleibol por baixo e por cima, a dois alvos afixados no solo. A tarefa de transferência foi o saque japonês a um terceiro alvo. Todos os saques foram executados a cinco metros da rede. O experimento constou de quatro fases: teste de entrada (oito tentativas), fase de aquisição (288 tentativas), fase de transferência (84 tentativas) e fase de retenção (12 tentativas). Os resultados das medidas de precisão e de padrão de movimento mostraram que não houve diferenças estatisticamente significantes entre os grupos em nenhum dos blocos do experimento. Logo, a estrutura da prática variada não influiu de forma significante no desempenho da tarefa nova. Ademais, os resultados não deram suporte à hipótese de MAGILL & HALL (1990), segundo a qual o EIC ocorre quando as variações da tarefa pertencem a programas motores diferentes. Ainda, o presente estudo reforçou a tendência de que o EIC não ocorre com crianças e com a utilização de tarefas de campo. / According to the contextual interference effect (CIE), practicing several motor skills under random practice or high contextual interference practice (abcbcacbabac) facilitates retention and transfer in comparison to practicing the same tasks under blocked practice or low contextual interference practice (aaaabbbbcccc). This learning phenomenon has led to a considerable amount of research. However, no definite trend in the results has been found, which makes its acceptance in the motor learning domain questionable. By extending the transfer phase (increasing the number of transfer trials), the aim of this study was to assess whether the CIE is temporary, lasting or non-existent. Accordingly, based on the scores of the pre-test, thirty-six schoolgirls (12 -14 years of age) were allocated to either a blocked or a random group. The acquisition tasks were the underhand and overhand volleyball serves, to two targets placed on the floor. The transfer task was the round house (Asian floater) volleyball serve to a third target. All serves were performed five meters away from the net. The experimental design consisted of four phases: pre-test (eight trials), acquisition (288 trials), transfer (84 trials) and retention (12 trials). The results of precision and movement pattern measures did not provide support to the CIE, since there were no significant statistical differences between the groups in any of the phases. The structure of variable practice did not affect the performance of the new task. Likewise, there was no support to the MAGILL & HALL (1990) hypothesis that, when task variations involve learning of different motor programs, the benefit of random practice over blocked practice would be found. Moreover, the present study reinforced the trend that the CIE does not take place in children as well as with field tasks.

I outline a framework for researching the effects of practice schedule on skill acquisition, based upon stage theories of information processing and stage theories of skill acquisition. Skilled performance requires stimulus identification, response selection, and response execution. I hypothesize that practice schedule affects learning in two types of information processing stages: stimulus-oriented and response-oriented stages. The loci of these effects differ based on the stage. In stimulus-oriented stages, practice schedule affects concept and categorization learning via contiguity of exemplars and feature saliency. In response-oriented stages, practice schedule affects the efficiency with which individuals produce a response by affecting response preparation. I evaluated this framework and theory with 4 experiments that manipulated practice schedule and amount of practice, in 2 domains with different information processing demands. Experiments~1~and~2 focused on response-oriented stages via a task that required participants to execute a multisegment movement according to a target time. Experiments~3~and~4 focused on stimulus-oriented stages via a task that required participants to categorize football play diagrams. Within the 2 task domains the amount of acquisition practice was manipulated to test whether different durations of acquisition training changed how practice schedules affected retention and transfer performance. The practice schedule manipulation had reliable effects on performance and learning when task performance involved either response preparation or induction of categorization rules. Practice schedule did not affect performance or learning when task performance involved categorization decisions, after the rules had been learned. Additionally, I report a novel method for quantifying amount of practice that allows comparisons across task domains.

Feedback, Trainingsplan und individuelle Unterschiede zwischen Lernern sind drei Faktoren die den motorischen Fertigkeitserwerb beeinflussen und wurden in der vorliegenden Dissertation untersucht. Ein besonderer Fokus lag auf den zugrundeliegenden Gehirnprozessen von Feedbackverarbeitung und Handlungsvorbereitung, die mittels ereigniskorrelierter Potenziale (EKPs) untersucht wurden. 120 Teilnehmer trainierten auf virtuelle Zielscheiben zu werfen und wurden in einer Folgesitzung auf Abruf und Transfer getestet. Der Trainingsplan verursachte entweder hohe contextual interference (CI) (randomisiert) oder niedrige CI (geblockt). In einer anschließenden Onlinestudie, bearbeiteten 80% der Teilnehmer eine Untermenge der Raven advanced progressive matrices, die schlussfolgerndes Denken (SD) erfassen. Unter hoher CI hängt besseres SD mit größerem Zuwachs im Training und höherer Performanz in Abruf und Transfer zusammen. Ähnliche Effekte von SD im späten Trainingsverlauf unter niedriger CI lassen darauf schließen, dass Variabilität eine notwendige Voraussetzung für positive Effekte von SD ist. Wir folgern, dass CI das Ausmaß an Praxisvariabilität über den Trainingsverlauf beeinflusst und darüber moduliert, ob Regeln abstrahiert werden (Studie 1). Diese Interpretation wird durch differenzielle Lerneffekte auf EKPs in der Vorbereitungsphase gestützt. Hohe CI führt zu einer stärkeren Abnahme von aufmerksamkeits- und kontrollbezogenen EKPs während der Vorbereitungsphase. Die CNV Amplitude, als Maß motorischer Vorbereitungsaktivität nimmt zu, wenn die Anforderungen in Training und Abruf gleich sind, wie bei niedriger CI. Das spricht für zwei parallele Mechanismen motorischen Lernens, die gemeinsam zur CNV Amplitude beitragen (Studie 2). Wir zeigten außerdem, dass sich graduelle Verarbeitung positiven Performanz-Feedbacks in der Variation der Amplitude der Reward Positivity widerspiegelt (Studie 3). / Feedback, training schedule and individual differences between learners influence the acquisition of motor skills and were investigated in the present thesis. A special focus was on brain processes underlying feedback processing and motor preparation, investigated using event related potentials (ERPs). 120 participants trained to throw at virtual targets and were tested for retention and transfer. Training schedule was manipulated with half of the participants practicing under high contextual interference (CI) (randomized training) and the other half under low CI (blocked training). In a follow-up online study, 80% of the participants completed a subset of the Raven advanced progressive matrices, testing reasoning ability. Under high CI, participants’ reasoning ability was related to higher performance increase during training and higher subsequent performance in retention and transfer. Similar effects in late stages of low CI training indicate, that variability is a necessary prerequisite for beneficial effects of reasoning ability. We conclude, that CI affects the amount of variability of practice across the course of training and the abstraction of rules (Study 1). Differential learning effects on ERPs in the preparatory phase foster this interpretation. High CI shows a larger decline in attention- and control-related ERPs than low CI. CNV amplitude, as a measure of motor preparatory activity, increases with learning only, when attention demands of training and retention are similar, as in low CI training. This points to two parallel mechanisms in motor learning, with a cognitive and a motor processor, mutually contributing to CNV amplitude (Study 2). In the framework of the “reinforcement learning theory of the error related negativity”, we showed, that positive performance feedback is processed gradually and that this processing is reflected in varying amplitudes of reward positivity (Study 3). Together these results provide new insights on motor learning.

<p>Two studies were conducted to examine the effects of learner-adapted practice on the self-efficacy beliefs, acquisition and retention of a motor task. Through a discovery process all participants learned to perform several keypress patterns, with the goal of completing each sequence as fast and accurate as possible. The first experiment had learners practice the keypress sequences in one of two adaptive schedules, which utilized either a ‘WinSwitch’ or ‘WinRepeat’ task switching algorithm, or follow a pre-determined order of tasks (two yoked-control groups). The purpose of this experiment was to determine if adaptive schedules were effective because they were tailored to a learner’s performance characteristics or due to the nature of the contextual interference employed by the switching algorithm when the 'winning' criterion was satisfied. To examine the psychological factors involved in adaptive practice, the second experiment had all groups practice in a ‘WinSwitch Adaptive’ schedule and manipulated the social-comparative feedback that was provided (positive, negative or control). Together these studies revealed that the effectiveness of adaptive schedules may not necessarily be due to the fact that they are tailored to a learner's performance characteristics. They also suggest that learning is facilitated by a switching algorithm that involves some blocked practice towards the beginning and mostly random practice towards the end of acquisition (WinRepeat schedule). However, providing positive social-comparative feedback can override the negative effects of the opposite schedule (WinSwitch) and result in more effective learning and increases in self-efficacy beliefs. These findings are discussed in reference to contextual interference effects and the self-efficacy framework.</p> / Master of Science in Kinesiology

Tidigare forskning har visat att hög contextual interference försämrar den omedelbara prestationen vid ackvisitionen av en färdighet, men främjar inlärning jämfört med låg contextual interference. Resultaten från tillämpad forskning är dock mångtydig och det råder oklarhet i när och i vilka sammanhang effekten uppstår. Syftet med denna positivistiska studie var att jämföra två övningsstrategier med olika grad av contextual interference vid inlärning av rudiments för trumspel. Vuxna musikhögskolestudenter (N=17) med begränsad erfarenhet av trumspel delades in i två grupper – seriell (n=8) och blockindelad (n=9). Uppgiften var att lära sig spela tre rudiment. Den blockindelade gruppen övade sex minuter på varje rudiment en gång, medan den seriella gruppen övade en minut på varje rudiment sex gånger. Deltagarnas retention testades direkt efter och 48 timmar efter övningen. Båda grupperna spelade signifikant snabbare mellan förtest och retentionstesten (p&lt;.01) men det fanns ingen signifikant interaktion mellan grupp och mättillfälle (p=.96) vilket betyder att båda grupper blev lika mycket bättre. I diskussionen redovisas ett antal möjliga förklaringar till varför effekten inte visade sig i denna studie. / Previous research has found that high contextual interference hinders performance at acquisition but promotes learning compared to low contextual interference. The findings in applied research is however ambiguous and there’s uncertainty of when and in which contexts the effect occurs. The purpose of this study was to compare two practice strategies with different levels of contextual interference. Adult college music students (N=17) with limited experience playing drums were divided in to two treatment groups – serial (n=8) and blocked (n=9). The task was to learn to play three drum rudiments. The blocked group practiced each rudiment for six minutes one time while the serial group practice each rudiment for one minute six times. Retention tests were performed immediately after and 48 hours after acquisition. Both groups played significantly faster at retention compared to pre-test (p&lt;.01) but there was no significant interaction between group and test (Pre-test to retention) (p=.96) meaning both groups improved equally. In the discussion a number possible of explanations as to why the effect wasn’t observed are presented.