TRS-TMS: An EEGLAB plugin for the reconstruction of onsets in EEG-TMS datasets

The analysis of EEG evoked potentials strongly relies on the correct alignment of different segments of the recorded EEG activity. The alignment of segments is needed in order to extract event related waves hidden in the background EEG activity. Commonly, the information on onsets is provided by the acquisition system. However, wrong configuration of the recording system or human errors during the acquisition or storage of data may make this information unavailable. Usually, these errors are discovered during the datasets analysis stage, and this stage can take place even several months after the acquisition of datasets. Unluckily, changes on patients status and the expensiveness of EEG registrations make unfeasible to repeat the acquisitions. In this paper we present and evaluate two mechanisms that we included in an EEGLAB plugin for the automatic reconstruction of onsets in EEG-TMS recordings. The methods of the TMS Triggers Reconstruction Software (TRS-TMS) plugin are discussed and evaluated obtaining guidelines for their correct configuration in the routine usage.