Role of feedback in the development and maintenance of complex skill

Three experiments examined the role of various sources of feedback in the development and maintenance of a complex ballistic skill, dart throwing, using extended practice. Even a brief delay of visual feedback initially affected accuracy and consistency adversely, though with practice performance gradually recovered. A total absence of visual feedback impelled subjects to use subtle cues such as crude auditory localization. When these cues were available, accuracy suffered to the same extent as with delayed visual feedback, but consistency in this case was unaffected. When all external feedback was removed, with subjects throwing in the dark at a luminous dot without hearing the dart land, consistency remained unimpaired, but accuracy suffered. However, on returning to full visual feedback both accuracy and consistency were found to have improved when compared to a control group. The independence of accuracy and consistency is discussed in terms of fixed and variable parameters of the skill. The effect of delayed visual feedback is attributed to the failure to integrate visual information with the fading proprioceptive trace. Central importance is attached to improvement in compentence when no external feedback is available, and possible underlying mechanisms for this improvement are described.