Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Single-unit example in A (X-on cell, bright spot size 3), averaged data of five Y-cells and seven X-cells in B and C. Otherwise, the same conventions are used as in Fig. 6.
