Fig. 2.

Illustration of the Main Events (a), Response Categories and Outcome (b) of the SAT as Used in Rats and Illustration of Performance Data From SAT and dSAT Sessions (c–h; base task performance: black lines, squares; distractor condition: orange lines, triangles; data from Wistar rats; the presence of the distractor in blocks 2 and 3 is indicated by the oranges block on the abscissa). The performance in signal and nonsignal trials is collapsed into one measure of performance, the SAT/dSAT scores (h). SAT/dSAT scores are calculated for each signal duration (eg, 500, 50, 25 ms; SAT/dSAT_500,50,25) on the basis of the relative number of hits (h) and false alarms (f), in accordance with this formula: (SAT/dSAT = [(h − f)/2(h + f) − (h + f)²]) and then averaged over all signal durations, yielding a single overall score (h). The formula is a variation of the nonparametric calculation of signal sensitivity. Signal intensity is based on the probabilities for hits and false alarms. In contrast, the calculation of SAT/dSAT scores is based on the relative number of hits and false alarms, thereby removing the confounding effects of omissions from this performance measure. SAT/dSAT scores range from −1 to +1. Values of 0 indicate randomized lever section, +1 indicates perfect response accuracy in signal and nonsignal trials, and −1 indicates complete inaccuracy. The scores shown in (h) are averaged over all signal durations and depicted by block to visualize the contrast between SAT and dSAT scores.