The perils of the first try: experimental evidence for visuomotor calibration in darts and hammering.

Task such as hammering or throwing darts involve intentional actions performed with the anticipation of a desired effect that requires precision to achieve success. Visual perception of the goal, defined in an external frame of reference, plays a crucial role in specifying movement parameters in a body-centered frame of reference. Physical interruption of the task decouples the internal and external frames of reference leading to rapid performance decrements. Motor calibration, as noted by the 'Calibration Effect', is the fine-tuning of motor commands following performance-related feedback in the external frame of reference. Here we test the calibration effect with non-skilled populations in both a sport specific and an everyday type of task, darts and hammering. Participants performed 20 rounds of five attempts of hitting a goal with a stable bodily position. Between rounds they moved around to perturb the fine tuning. The first repetition within a round of repeated attempts was less accurate than the subsequent attempts within that same round, even if controlling for gradual learning effects. Thus, the calibration effect, a rapid component of warm-up, is present both in professional athletes and unskilled dart players as well as in everyday activities such as hammering.