Imagery of errors in typing.

Using a typing task we investigated whether insufficient imagination of errors and error corrections is related to duration differences between execution and imagination. In Experiment 1 spontaneous error imagination was investigated, whereas in Experiment 2 participants were specifically instructed to imagine errors. Further, in Experiment 2 we manipulated correction instructions (whether or not to correct errors) and controlled for visual feedback in executed typing (letters appearing on the screen or not). Participants executed and imagined typing proverbs of different lengths. Errors and error corrections explained a significant amount of variance of execution minus imagination differences in Experiment 1, and in Experiment 2 when participants were instructed to correct errors, but not when participants were instructed not to correct errors. In Experiment 2 participants corrected and reported more errors with than without visual feedback. However, the relation between execution-imagination duration differences and errors and error corrections was unaffected by visual feedback. The types of errors reported less often in imagination than in execution were related to processes in typing execution. We conclude that errors and error corrections are not spontaneously imagined during motor imagery, and that even when attention is drawn to their occurrence only some are imagined. This may be due to forward models not predicting all aspects of an action, imprecise forward models, or a neglect of monitoring error signals during motor imagery.