In two experiments, we examined the behavioural and electro-physiological effects of errors in touch-typing. The effect of errors on skilled actions is an under-studied area in cognitive psychology. The available evidence suggests that errors have different effects on discrete vs. skilled and continuous actions. Our primary aim was to study the behavioural and electro-physiological effects of errors, and explore any interactions between them such as event-related potentials (ERP) and error correction via the backspace. We asked touch-typists to type 100 sentences in the absence of visual feedback. We recorded electro-encephalogram (EEG) as well as typing performance of touch-typists. We analysed the data using independent component analysis (ICA), with an emphasis on the difference between correct and error key-presses as well as corrected and uncorrected error key-presses. We found that the error (corrected and uncorrected) key-presses in typing were slowed, and were followed by slowed key-presses. In the EEG record, we found a considerable increase in the power of theta oscillations (3-8Hz) as well as classic ERP findings (i.e. Error related negativity (ERN) and positivity (Pe). Importantly, these effects were much stronger during corrected errors compared to uncorrected errors. Our results suggest that even in a skilled action which involves more than 7 key-presses every second, it is possible to detect one's errors before the error action is completed, and that error correction can be predicted by the strength of error induced changes in the EEG record.