It's all about time: precision and accuracy of Emotiv event-marking for ERP research.

摘要: Background The use of consumer-grade electroencephalography (EEG) systems for research purposes has become more prevalent. In event-related potential (ERP) research, it is critical that these have precise and accurate timing. aim the current study was to investigate timing reliability event-marking solutions used with Emotiv commercial EEG systems. Method We conducted three experiments. Experiment 1 we established a jitter threshold (i.e. point at which made an method unreliable). To do this, introduced statistical noise temporal position event-marks pre-existing ERP dataset (recorded research-grade system, Neuroscan SynAmps2 1,000 Hz using parallel-port event-marking) calculated level waveform peaks differed statistically from original waveform. 2 identify 'true' events when event should appear in data). did this by inserting into data custom-built 'Airmarker', marks triggering voltage spikes two channels. lag between Airmarker generated as reference comparisons 3. 3 measured precision accuracy types generating events, s apart. variability (standard deviation ms) mean difference true events. methods tested were: (1) Parallel-port-generated TTL triggers; (2) Arduino-generated (3) Serial-port triggers. Methods auxiliary device, Extender, incorporate triggers data. across configurations systems: EPOC+ sampling 128 Hz; 256 EPOC Flex Hz. Results found smaller P1 N1 were attenuated lower levels relative larger P2 peak (21 ms, 16 45 ms P1, N1, P2, respectively). 2, average 30.96 3, some all configurations. However, exhibited less than single sample, serial-port-marking most paired Conclusion All enough each would provide waveforms equivalent research-standard system. Though inaccuracy, researchers could easily account during processing.