ROC analysis of an example neuron (T2 cell). A, Spike rasters and PSTH for single-target (left column) and the choice (right column) task. Trials to the preferred target (T2, dark) and nonpreferred target (T1, light) are presented separately. Activity in the choice task is aligned on the second target (T2). The neuron is responsive to T2. B, ROC information graph (thick curve) indicating the level of predictability an ideal observer would have in predicting the selection of the animal (preferred or nonpreferred target) at each moment in time when evaluating the neural activity in the most recent 200 ms time interval. Horizontal line, Chance level (0.5 bit). Thin vertical line, Separation time, defined as the time when the ROC curve consistently exceeds the 95% confidence limit for chance (dotted lines) (see Materials and Methods). Other conventions as in Figure 3.