- The laboratory houses a 64-channel BioSemi ActiveTwo system from Cortech Solutions. This system includes a compact ActiveTwo AD-box, into which sensor-signals attach. In addition to the 64 scalp-signals, the AD-box is also outfitted to receive channels from the face as well as from basic psychophysiological monitors.
- Each AD-box channel consists of a low noise DC coupled post-amplifier, with a first order anti-aliasing filter, followed by a Delta-Sigma modulator with an oversampling rate of 64, and decimation filter with a steep fifth order sinc response and high resolution 24-bit output. The digital outputs of all the AD converters (up to 256) are digitally multiplexed and sent to the PC via a single optical fiber without any compression or other form of data reduction.
- There is a USB2 Receiver which converts the optical data coming from the AD-box to an USB2 output. This receiver also has a trigger port with 16 independent trigger inputs and outputs. This setup keeps the stimulation setup galvanically isolated from the subject. The trigger inputs allow easy setup of ERP measurements and event logging.
- The BioSemi headcaps (we have three different sizes of headcap to accommodate all adults) include the the electrode holders. This allows for fast placement of the active electrodes (approximately 15 minutes for a 64 channel headcap).
- The BioSemi "Pin-type" Active electrode has been designed for mounting in BioSemi headcap's. The electrode has a sintered Ag-AgCl electrode tip, providing very low noise, low offset voltages and very stable DC performance. The electrode is completely resistant to long term water and alcohol submergence enabling easy cleaning and disinfecting. The electrodes are numbered with water-proof stickers for easy channel recognition. Because of the Active electrode principle, high electrode impedances do not influence the signal quality.
- One benefit of this system is that it does not require scalp abrasion (and is therefore useful for older adults and children with fragile scalps)
- We currently only have adult head-caps (if interested in collecting data from special populations (e.g., children) additional caps should be purchased by the PI of the lab, each additional cap costs ~$1500)
General EEG analysis how to:
- Here is a great online course to learn how to collect and analyze EEG/ERP data
- The above linked website offers a great set of videos and quizzes (it the virtual version of the ERP bootcamp offered by NIMH/UC Davis)
- For a great set of information on all things EEG/ERP see this webpage from the ERP bootcamp offered by NIMH/UC Davis: https://erpinfo.org/resources
- Want to know how to collect clean EEG data? See here for a detailed protocol
- In the Human Neuroscience laboratory, we recommend using the EEGLAB and ERPLAB toolbox for all analyses