This study investigates the information content of epidural field potentials (EFPs) in macaque primary visual cortex (V1) regarding visual stimulus features. Two monkeys were presented with various combinations of location, size, shape, and color. Results show EFPs are highly specific for location and significantly modulated by size, shape, and color, enabling high stimulus classification rates even at the single-trial level. This suggests EFPs are a valuable, minimally invasive signal source for long-term recordings in both basic and applied neuroscience.
