Figure 4.

Single-trial simultaneous depth profiles of the local field potential, V(t), and the current source density, −Δ²V(z, t)/Δz², in response to a looming ball. (A) (Left) Schematic of the location of the two Si-based arrays in dorsal-area D2, one caudal (C) and one rostral (R) relative to the centroid of the 20-Hz response (Fig. 2E). (Right) Schematic of the Si-based multielectrode arrays through the depth of cortex. (B) Single-trial measurement of the local field potentials at the two locations in A. The 4-s period of the loom is indicated by the thick bar. (C) The current source density, calculated from the data in B. Note that the lower two rostral traces and the lower three caudal traces have been multiplied by a factor of 2.