Figure 1.

The paired-bar stimulus protocol and example complex cell responses. A, Example stimulus frames for the paired-bar protocol. All possible pairs of ON and OFF bars were flashed at 45% contrast along with individual bars of both polarities at 45 and 90% contrast. B, Complex cell responses to part of a paired-bar protocol. Bars were flashed for 60 ms with 240 ms of succeeding blank time. This cell depolarized in response to almost all combinations of bars, regardless of polarity. C, Responses to ON and OFF bars at 90% contrast for the complex cell in B. The similarity between ON and OFF responses at each position clearly marked this cell as being complex. pos, Position.