The Stimulus Transduction Artifact from Headphones in hdEEG during the ASSR Experiments: a Phantom Study

The auditory steady-state response is considered to be a biomarker of neuropsychiatric diseases in electroencephalography. Many studies use headphones to deliver a click train stimulus (40 Hz) to evoke the brain oscillations. However, headphones can generate a stimulus transduction artifact. The aim of this study is to investigate a stimulus transducer artifact due to click train stimulation. We further describe the influence of the artifact to final data analysis. We recorded hdEEG from a human head phantom to control the experimental conditions. The intertrial phase clustering was computed to evaluate phase locking across trials before and during stimulation by headphones and speakers (control condition). Results show, that headphones generated artifact in higher harmonic components of 40 Hz. Time-frequency analysis proves that the artifact doe to headphones is phase locked to stimulation onset. On the other hand, the speakers did not create this artifact. In future work, we will compare our results with results on human subjects.