Imitation Learning Errors Are Affected by Visual Cues in Both Performance and Observation Phases.

Mechanisms of action imitation were examined. Previous studies have suggested that success or failure of imitation is determined at the point of observing an action. In other words, cognitive processing after observation is not related to the success of imitation; 20 university students participated in each of three experiments in which they observed a series of object manipulations consisting of four elements (hands, tools, object, and end points) and then imitated the manipulations. In Experiment 1, a specific intially observed element was color coded, and the specific manipulated object at the imitation stage was identically color coded; participants accurately imitated the color coded element. In Experiment 2, a specific element was color coded at the observation but not at the imitation stage, and there were no effects of color coding on imitation. In Experiment 3, participants were verbally instructed to attend to a specific element at the imitation stage, but the verbal instructions had no effect. Thus, the success of imitation may not be determined at the stage of observing an action and color coding can provide a clue for imitation at the imitation stage.

Physical imitation and verbal description of modeled movements engage different encoding processes.

The present study analyzed the effects of performing a specified sequence of movements in imitation of a model, and examined the characteristics of the encoding involved in the process. Thirty-two college students were presented with a movement model that consisted of five elements and performed imitation tasks in which they either reproduced the movement sequence physically or described it verbally. During the period from the onset of the movement model to the imitation response, participants performed articulation suppression, movement suppression, and spatial suppression tasks, and their effects on the imitation response were analyzed. The results showed that the encoding processes for conversion to movement and to language were different, and that movements associated with articulations or planning of articulations and spatial processing were involved in converting the model to movement. In addition, imitation-specific goal selection was partially supported in movement conversion, but not in language conversion.

Imitation of modeled manipulation of objects by children and adults.

Prior studies have investigated imitation by extracting a hierarchy of goals from the key elements of action models. The theoretical model is that all ages practice a method of imitation in which goal or target elements are more easily imitated correctly, while nontarget elements are not. The present study compared error responses among 32 children and 32 adults when imitating an action model for manipulating concrete objects constructed of five elements. The results indicated that the elements for which error responses were easily produced and those for which error responses were more difficult to produce were approximately the same in children and adults. It showed that the imitation mechanisms were similar in children and adults. In addition, children had higher omissions and error responses than adults. This result suggests that imitation and differences in working memory capacity may be related.

Children's imitations of movements are goal-directed and context-specific.

Previous research indicates that imitation of gestures in preschool children is goal-directed. A goal may be a salient feature from a presented movement; that goal may be imitated correctly, but other features were ignored, resulting in observable errors. Objects (e.g., a dot on the table) can become the most salient features and presence or absence of objects influences imitation responses. Imitation responses were examined under conditions in which objects could not be used directly as the most salient feature. 60 children (M age = 5:6) were assigned to Gestural, Dot, No-dot, and Un-dot conditions, and they were asked to imitate 20 movements. The type of presented movement and the occurrence of correct, mirror, and error responses were examined. Responses in the Un-dot condition were similar to those in the Dot condition. Error responses in the Un-dot condition were related to age. Children may extract a more abstract feature in a context without visible objects. This ability is associated with a cognitive mechanism developed in preschool years.