Layers of the monkey visual cortex are selectively modulated during electrical stimulation
Fig 3
Layer-specific phase dependency of LFP components during electrical stimulation.
Phase dependency of the amplitude of LFP components, P1 and N1, to external stimulation. The P1 and N1 components were sorted into 20 phase bins, followed by taking trial- and phase bin-averages for each layer. The gray lines represent the mean direction of the phase preference of LFP amplitudes. A) Illustration of the sorting of LFP components based on the AC phase. For instance, in a single trial, the visual stimulus was presented at a time corresponding to an AC phase of 90° (left). For each trial, the amplitudes of the P1 and N1 components were calculated and sorted into the phase bin that includes 90° (right). B) Circular distributions of P1 and N1 amplitudes according to the AC phase show a bimodal characteristic for monkey 1. C) Circular distributions show a unimodal characteristic for monkey 2. A permutation test revealed significant directional preferences in P1 and N1 amplitudes with respect to the phase of AC only within deeper layers (layers 4–6) (*p < 0.05) for both capuchin monkeys.