A neural signature of error processing in motor learning measured as error-related negativity

The error-related negativity (ERN) is a component of brain activity that appears around 100 ms after a motor error, serving as an indicator of cognitive error detection. This study investigates the relationship between error magnitude and ERN during motor learning tasks—specifically, a reaching exercise. We induced ERN through two methods: by generating a force field (Force task) and by altering the visual trajectory towards a target (Visual task). By analysing EEG data, we identified a correlation between error magnitude and ERN signal strength, which intensifies as errors increase. Additionally, we observed that the brain region where ERN is detected varies with the type of error. These findings highlight how different sensory manipulations during motor tasks can influence error processing in the brain.