Detecting Error-Related Negativity During a Motor Task
Abstract
When a person makes a mistake while executing a motor task and recognizes making the mistake, an error-related potential (ErrP) occurs. ErrP is a neural signature of error processing and a form of event-related potential [1]. An important component of ErrP is a frontocentral potential, termed error-related negativity (ERN) [2]. The negative frontocentral potential peaks at 50–100 ms after an erroneous response, which can be the consequence of making either an execution error or an outcome error. An execution error happens due to inaccurate feedback during the motion [1]. An outcome error happens when the outcome is different from the desired goal of an action [2]. The goal of this study is to determine whether we can detect an ERN in a motor task where a participant tries to reach the target but experiences perturbation. We hypothesize that perturbation will cause an execution or an outcome error, which is why we will be able to detect an ERN.
Methods
Two subjects participated in the preliminary study and we plan to include additional 6 subjects for the main experiment. We used a visuomotor paradigm where the participants performed arm-reaching movements. They were sitting in a chair and moving the handle of a haptic robot. On the screen above, the participants saw their starting position and the target that was located 10 cm away from the starting point.
The aim of the motor task was to hit the target on a screen with a cursor that was controlled by the motion of the hand. The motion of the participant’s hand was displayed on the screen as a cursor. Participants performed 300 trials. There were two types of trials: unperturbed and perturbed. During perturbed trials, the cursor underwent a visuomotor rotation, for 25° or 45°. While participants executed the task, their brain activity was measured using EEG with 64 electrodes (Brain Products GmbH, Gilching, Germany). The data we collected will be analysed to determine whether an ERN can be detected during trials where participants experienced errors.
We expect the perturbation will cause the participants to make an execution or an outcome error that will be reflected in the ERN. Based on the previous studies we expect to detect the ERN at the Cz electrode location. The ability to detect the perceived motor errors from brain activity will allow us to determine when a person experiences errors and enable further contributions towards the understanding of different motor errors connected to distinct motor learning processes. Moreover, these findings have a potential to help with developing algorithms for brain-computer interfaces [1].
References
[1] M. Spüler and C. Niethammer, “Error- related potentials during continuous feedback: using EEG to detect errors of different type and severity,” Frontiers in Human Neuroscience, vol. 9, 2015, doi: 10.3389/fnhum.2015.00155.
[2] M. Benyamini, I. Demchenko, and M. Zacksenhouse, “Error related EEG potentials evoked by visuo-motor rotations,” Brain Research, vol. 1769, p. 147606, 2021, doi: 10.1016/j.brainres.2021.147606.
