Monkey V1 epidural field potentials provide detailed information about stimulus location, size, shape, and color

Brain signal recordings with epidural microarrays constitute a low-invasive approach for recording distributed neuronal signals. Epidural field potentials (EFPs) may serve as a safe and highly beneficial signal source for a variety of research questions from basic and applied neuroscience, but wider use is constrained by limited data on their information content. Leveraging the high spatial resolution and columnar organization of macaque primary visual cortex (V1), the authors tested whether and to what extent EFPs preserve information about visual stimulus features spanning different spatial scales of cortical organization. Two monkeys viewed combinations of stimulus location, size, shape, and color (375 conditions). EFPs were highly specific for stimulus location and were significantly modulated by small differences in size, shape, and color, enabling high single-trial classification. These results indicate that EFPs provide detailed and reliable information about constituent stimulus features, supporting their value as a low-invasive signal source for long-term recordings in medical and basic research.

Benjamin Fischer, Detlef Wegener