Figure 1.

Delayed letter recognition (DLR) task data for each of the 4 dependent variables. Solid lines are data from Day 1 (pre-sleep deprivation) and dotted lines are data from Day 2 (post sleep deprivation). “L,” “M,” and “H,” indicate low, medium, and high levels of the stimulus degradation manipulation, respectively. The effect of Day is significant for all variables. The effect of Degradation is significant only for mean reaction time (RT) (Panel A), although there are no significant interactions of Day and Degradation for RT or any other variable.