Optimizing SSVEP Detection in Reduced-Channel BCI-EEG Devices: Synchronization and Power Dynamics Across Brain Regions

Steady-state visual evoked potentials (SSVEP) are widely used in EEG-based brain-computer interfaces (BCIs) due to their fast response times and minimal subject training requirements. These signals, elicited by visual stimuli at specific frequencies, enable users to interact with external systems by focusing on flickering stimuli. SSVEP responses are strongest in occipital, though contributions from other brain areas, such as the parietal, frontal and central regions, are also relevant. With the growing adoption of portable EEG devices, understanding channel performance across brain regions is essential, especially given the limitations of fewer channels and reduced signal quality. In this paper, we evaluated the synchronization and power dynamics of EEG channels using Phase Locking Value (PLV) and Event-Related Spectral Perturbation (ERSP) metrics. Using a public dataset with limited subjects and two frequency stimuli (8 Hz and 14 Hz), the study offers insights into optimal channel selection and regional contributions, enhancing future SSVEP-based BCI design and performance. From this study, it was concluded that the 3 best channels according to their respective stimulus frequencies (8 Hz and 14 Hz) and PLV+ERSP values were as follows (Oz: 0.813 0.757, C4: 0.823 0.706, C5: 0.818 0.713).