Huang, L.; Varlet, M.; Grootswagers, T.

High-density EEG recording enhances spatial resolution for neural signal decoding, yet the relationship between electrode density and decoding performance, as well as the minimum number of electrodes required for effective decoding, remains unclear. To address this, we systematically investigated the decoding accuracy of neural signals across varying electrode densities (16, 32, 64, 96, and 128 electrodes) using visual grating stimuli characterized by orientation, contrast, spatial frequency, and color. Our findings showed that accurate decoding of these visual grating features was achievable even with as few as 16 electrodes, highlighting the robustness of decodable neural signals. To test the generalization of these results to more complex natural stimuli, we conducted a similar analysis with a diverse set of naturalistic images categorizable into living/non-living and moving/non-moving. The results consistently showed that effective decoding persists even with only 16 electrodes, demonstrating robust decoding efficacy even for complex naturalistic stimuli. This work provides valuable insights into the efficient neural decoding offered by low-density EEG and robustness of neural signal representation.