International audienceThis study examined how imagery ability could affect motor improvement following motor imagery training in tennis. Skilled tennis players were divided into 3 groups with regard to their MIQ scores (good imager, poor imager and control group). During a pre-test, participants physically performed 15 service returns towards a target. The motor imagery training period was included during physical training for 15 sessions and each session consisted of 2 series of 15 imagined trials and 15 physical trials. Some of the participants were required to use internal visual imagery (good and poor imager groups) while others were given a reading task (control group). Finally, 48 hours after the last training session, participants were submitted to a post-test similar to the pre-test. Results indicated that motor imagery improved service return, and that this improvement was better in good imagers than in poor imagers. The impact of motor imagery practice on motor performance, for skilled tennis players, is discussed

A complex sequence learning task was used to determine if the type of coding acquired through physical practice (PP), observation of the stimulus (Obs-S), or observation of stimulus and action (Obs-SA) differs between conditions and whether the type of observation influences subsequent learning of the task when physical practice was permitted. Participants in the Obs-S group were permitted to watch the sequentially illuminated stimuli on the screen. In the Obs-SA group participants could see both flexion-extension movements of the model's arm performing the sequence and the sequentially illuminated stimuli on the screen. Participants in the PP group actually performed the 16-element sequence with their dominant right arm. Delayed retention tests and two inter-manual transfer tests were completed following each of two acquisition sessions. First, the data indicated that learning the sequence structure, as revealed by response time per element, occurred similarly irrespective of the initial practice condition. Secondly, the movement sequence appeared to be coded in abstract visual-spatial coordinates resulting in effector-independent performance. Finally, observing the model's action and sequential stimuli allows participants to transfer the perceived aspects of the movement sequence into efficient coordination patterns when additional physical practice is permitted.

The perception of a human actor performing movements may involve processes related to action execution. This resonance of the motor system may support observational learning and imitation, and could also explain the fact that observers'/actors' movements are disturbed by the observation of a human model making different movements (Kilner et al., 2003). In this study, we tried to specify what information available in the model's behaviour triggers this influence on an observer's behaviour. In two experiments, we had participants make horizontal or vertical arm movements while observing similar movements. In the first experiment, the observers' pattern of behaviour was affected by the observation of a human model making incongruent movements. In the second experiment, similar results were obtained with participants observing a moving dot depicting either biological or non-biological motion. Movement execution was affected differentially by biological and non-biological motion observation. These results show that an observer's behaviour is sensitive to information available in biological motion.

There is evidence indicating that an individual can learn a motor skill by observing a model practising it. In the present study we wanted to determine whether observation would permit one to learn the relative timing pattern required to perform a new motor skill. Also, we wanted to determine the joint effects of observation and of physical practice on the learning of that relative timing pattern. Finally, we were interested in finding whether there was an optimal type of model, advanced or beginner, which would lead better to observational learning. Data from two experiments indicated that observation of either a beginner or an advanced model resulted in modest learning of a constrained relative timing pattern. Observation also resulted in significant parameterization learning. However, a combination of observation followed by physical practice resulted in significant learning of the constrained relative timing pattern. These results suggest that observation engages one in cognitive processes similar to those occurring during physical practice.