title: Open Ephys electroencephalography (Open Ephys  +  EEG): a modular, low-cost, open-source solution to human neural recording.
abstract: Electroencephalography (EEG) offers a unique opportunity to study human neural activity non-invasively with millisecond resolution using minimal equipment in or outside of a lab setting. EEG can be combined with a number of techniques for closed-loop experiments, where external devices are driven by specific neural signals. However, reliable, commercially available EEG systems are expensive, often making them impractical for individual use and research development. Moreover, by design, a majority of these systems cannot be easily altered to the specification needed by the end user. We focused on mitigating these issues by implementing open-source tools to develop a new EEG platform to drive down research costs and promote collaboration and innovation.
  
  
  
  Here, we present methods to expand the open-source electrophysiology system, Open Ephys (www.openephys.org), to include human EEG recordings. We describe the equipment and protocol necessary to interface various EEG caps with the Open Ephys acquisition board, and detail methods for processing data. We present applications of Open Ephys  +  EEG as a research tool and discuss how this innovative EEG technology lays a framework for improved closed-loop paradigms and novel brain-computer interface experiments.
  
  
  
  The Open Ephys  +  EEG system can record reliable human EEG data, as well as human EMG data. A side-by-side comparison of eyes closed 8-14 Hz activity between the Open Ephys  +  EEG system and the Brainvision ActiCHamp EEG system showed similar average power and signal to noise.
  
  
  
  Open Ephys  +  EEG enables users to acquire high-quality human EEG data comparable to that of commercially available systems, while maintaining the price point and extensibility inherent to open-source systems.
authors.affiliation: Center for Biomedical Engineering, Brown University, Providence, RI, United States of America.
authors.forename: Christopher
authors.initials: C
authors.lastname: Black
authors.forename: Jakob
authors.initials: J
authors.lastname: Voigts
authors.forename: Uday
authors.initials: U
authors.lastname: Agrawal
authors.forename: Max
authors.initials: M
authors.lastname: Ladow
authors.forename: Juan
authors.initials: J
authors.lastname: Santoyo
authors.forename: Christopher
authors.initials: C
authors.lastname: Moore
authors.forename: Stephanie
authors.initials: S
authors.lastname: Jones
mesh_terms: D000465:Algorithms; D000669:Amplifiers, Electronic; D000703:Analog-Digital Conversion; D001921:Brain / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D004569:Electroencephalography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006260:Head Protective Devices; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012984:Software; D014584:User-Computer Interface