The skill and knowledge that is involved in the performance of electrodiagnostic medicine is a process where it's an accumulation of knowledge over time and a sound basis of the fundamentals, both from an electronic and clinical perspective that becomes an essential component for all future training and experience. My electrodiagnostic training back in the mid-eighties stressed these fundamentals of bio-medical electronics, amplification (differential amplification), analog signal and what would come with digital manipulation. Because if there isn't a clear understanding of these basic electrical principals than all the skills necessary to properly trouble shoot and recognize all types of signals, whether it be artifact, anomalous or patient generated, are never sound in the mind of the provider. I believe it was this training where students would take Grass amplifiers and EEG equipment apart and reassemble that allows for the highest level of expertise when caring for your patients. 

* Grass Brand of EEG equipment was the most commonly relied upon type of electrodiagnostic equipment in this time period.