Figure 1. Sixty sector dartboard consisting of 6 concentric rings (A). Pattern reversal and pattern pulse modes drove the presentation in each sector modulated by a binary m-sequence. Rings of same eccentricity (B). R1 is the inner ring and R6 is the outer ring. Pattern reversal mode: m-step 1 showed a chessboard pattern during a frame interval, m-step -1 showed the reversed chessboard pattern during a frame interval (C). Pattern pulse mode: m-step 1 showed a chessboard pattern during a frame interval, m-step -1 showed a zero contrast field during a frame interval (C).