This is a two-alternative, forced choice, backward masking, visual discrimination task. It was used to assess speed of elementary visual processing. The inspection time task was replicated as closely as possible from the one described in a previous study [61], but with a longer instruction period and more practice trials. The participants were required to make a simple visual discrimination: to indicate, with no pressure on response time, which of two parallel, vertical lines of markedly different lengths was longer. The inspection time test was constructed, run, and analyzed using E-Prime (Psychology Software Tools, Pittsburgh, PA). The stimulus lines were 5 cm for the longer line and 2.5 cm for the shorter line. They were joined at the top with a 2.5 cm crossbar. The lines were about 1.6 mm wide. The backward mask was constructed of a jumble of vertical lines 1.6 mm wide that overwrote the vertical lines in the stimulus. Participants were seated comfortably, with their eyes about 75 cm from a computer screen, though this was not fixed. A small fixation cross preceded the stimulus. This
