EEG Experiment Flow Control using FPGA as an Alternative to Commercial Devices

Traditionally, Electroencephalography (EEG) experiments requiring precise timestamp analysis of a subject’s exposure to stimuli involve the inclusion of timestamp marks within EEG records. This is typically achieved through the use of EEG amplifiers capable of receiving external triggers and synchronizing them with the EEG data. However, such equipment is often sourced as a compatible accessory from either thirdparty vendors or acquired separately from the original vendor after-sales, incurring in significant additional costs. This paper describes in detail the methodology and considerations taken into account for the design and cost-effective construction of an EEG signal-stimuli synchronization equipment, compatible with EEG devices equipped to record external triggers, making the development of such systems more accessible and affordable. Furthermore, it showcases a successful case study involving participants exposed to auditory stimuli, where stimuli-coherent timestamps, referred to as “onset triggers”, were used. This data configuration is in high demand in neuropsychology research and our work demonstrates its attainability through the development and integration of custom-engineered components. These components are not only adaptable but are also open to enhancements and low-cost replication. Finally, a discussion about the significance of this alternative approach is presented, particularly for emerging neuropsychology and brain researchers exploring new paradigms through experimental setups that require flexibility and higher data manipulation capabilities.