Figure 2.  .

Reduced or reversed right minus left gradient in visual detection when the nonviewing eye is rotated to the left compared with the right. The laterality index was calculated as (H_R − H_L)/(H_R + H_L), where H_R and H_L were hit rates for right and left targets, respectively, and for reaction times (RT_L − RT_R)/(RT_R + RT_L). The index has values between +1 and −1; the more positive the value, the larger the rightward bias and the more negative, the larger the leftward bias. The symbols correspond to each participant 1, █, 2, ⧫, 3, ×, 4, ○. Participants 3 and 4 were naïve to the purpose of the experiment.