RESUMO
Three experiments using rats in an appetitive conditioning procedure analyzed the effect of short and long (50s vs. 1440s) intertrial intervals (ITI) over the acquisition of conditioned stimulus (CS), context (Ctxt), and unconditioned stimulus (US) associations, as well as the effect on the extinction and renewal of the conditioned response to the CS. Experiment 1 revealed more contextual conditioned responses in groups trained with the short ITIs, however the renewal effect was not observed during test phase with either ITI condition. When subjects were pre-exposed to the contexts before the acquisition phase (Experiment 2) renewal of the conditioned response (CR) was only observed in long ITI group. However, when the acquisition context was extinguished (Experiment 3) the renewal effect observed in the Experiment 2 was weakened. In all three experiments subjects showed a similar number of responses to the tone predicting food, however they showed a clear contextual conditioning effect only for the groups trained with short ITIs. It is noteworthy that the acquisition context showed high levels of the CR in the renewal test only for groups trained with short ITIs (Experiment 2) but these responses were absent if additional contextual extinction was imposed before such test (Experiment 3). In general, all groups showed similar acquisition curves for the CS but only Short groups had an increase in the CR during the pre-CS. Also, context conditioning does not interfere with the conditioning of the CS and context pre-exposure prior to acquisition is essential in order to observe the renewal effect when long ITIs are used.
Assuntos
Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Aprendizagem/fisiologia , Ratos/fisiologia , Animais , Comportamento Apetitivo/fisiologia , Feminino , Masculino , Ratos Wistar , Fatores de TempoRESUMO
O fornecimento de conhecimento de resultados (CR) envolve os aspectos temporais, que consistem no momento em que o CR é fornecido além de se relacionar a três intervalos: Pré-CR, Pós-CR e o intervalo intertentativas. O presente estudo investigou esses intervalos em três diferentes experimentos. 90 voluntários desempenharam uma tarefa de posicionamento com sequência e tempo alvo pré-estabelecidos. Testes de transferência imediata e atrasada foram realizados em nova sequência e tempo alvo, sem CR. O teste de transferência atrasada foi realizado 24h após a fase de aquisição. Os três experimentos foram conduzidos para investigar os efeitos do pré-CR, intervalo pós-CR e o intervalo intertentativas, respectivamente. Os resultados mostraram diferenças entre os grupos na condição do intervalo pré-CR e intervalo intertentativas. Concluiu-se que os efeitos do intervalo pré-CR e intervalo intertentativas podem ser mais efetivos para a aprendizagem motora que o intervalo pós-CR.
The supply of knowledge of results (KR) involves temporal aspects, which is the moment when KR is provided, and it is composed by three intervals: delay KR, post-KR interval, and intertrial interval. This study investigated these intervals in three different experiments. Ninety volunteers performed a positioning task with sequence and target time pre-established. Immediate and delayed transfer tests were performed in a new sequence and target time, without KR. A delayed transfer test was carried out 24 hours after acquisition phase. Three experiments were conducted to investigate the effects of KR delay, post-KR interval, and intertrial interval, respectively. The results showed differences among groups in KR delay and intertrial interval conditions. We conclude that the effects of KR delay and intertrials interval can be more effective for motor learning than the post-KR interval.
RESUMO
O aspecto temporal do Conhecimento de Resultados (CR) é composto por três intervalos: pré-CR, pós-CR e o intervalo intertentativas. Um problema sobre este tópico é que a manipulação de um intervalo implica na alteração dos outros, o que sugere uma análise conjunta desses intervalos. O presente estudo investigou os efeitos dos intervalos de tempo de apresentação de CR na aquisição de habilidades motoras. Foi utilizada uma tarefa de posicionamento manual, que consistia em transportar três bolas de tênis entre seis recipientes em ordem e tempo alvo pré-estipulados. O instrumento continha uma plataforma com seis recipientes e uma central de controle ligada ao microcomputador. O estudo teve a fase de aquisição, com 30 tentativas com a sequência (4-2/5-3/6-1) e tempo alvo (3000 ms) definidos pelo experimentador. Dez minutos após o término da fase de aquisição foi aplicado o teste de transferência imediata e, após 24 horas, o teste de transferência atrasada. Ambos os testes tiveram de 15 tentativas de prática, de uma nova sequência de movimento (6-1/5-3/4-2) e tempo alvo (4000 ms), sem fornecimento de CR. Noventa universitários foram divididos em nove grupos (n = 10): três grupos com quatro segundos, três grupos com oito segundos e três grupos com 16 segundos de intervalo intertentativas, todos com intervalos pré e pós-CR distintos. Os resultados mostraram que menores intervalos intertentativas tiveram melhor desempenho nos testes. Isto sugere que o tempo para processamento de informação não deve ser longo, o que aumentaria a demanda de atenção e a exigência de memória.
The temporal locus of the Knowledge of Results (KR) is composed by three intervals: pre KR, post-KR, and inter trial interval. A problem regarding this topic is that the manipulation of one interval implies in changing the others, suggesting that the intervals may be combined for analysis. The present study investigated the effects of temporal locus of the KR in the motor skills acquisition. A manual positioning task consisting of the transport of three tennis balls between six containers in a specific sequence and time was used. The apparatus was comprised of a platform with six containers and a central controller connected to a computer. An acquisition phase of 30 trials using the 4-2/5-3/6-1 sequence and a 3,000 msec target time was allowed. The immediate transfer tests and the delayed transfer tests were performed ten minutes and twenty four hours after the completion of the acquisition phase, respectively. Both tests were preceded by 15 practice trials in a previously unknown movement sequence (6-1/5-3/4-2) and target time (4,000 msec.) without any KR. Ninety undergraduate students were allocated into nine groups (n = 10). Three groups had a four-second interval between trials; three groups had an eight-second intertrial interval; the reaming three groups had a sixteen-second intertrial interval. All groups had distinct pre and post-KR intervals. The results showed that smaller intertrial intervals resulted in better testing performance. It suggests that the time for information processing should not be long, as it increases both the attention and memory demands.