Table 1.

Description of precision, recall, and F measures applied to the latent inhibition and discriminating conditioning task

	PER
	Extended	Not extended
	True positive (tp)	False positive (fn)
Reinforced odor (A+)	P ↑	P ○
	R ↑	R ↓
	F ↑	F ↓
	False positive (tp)	True negative (tn)
Unreinforced odor (X−)	P ↓	P ○
	R ○	R ○
	F ↓	F ○

Precision (P) = tp/(tp + fp); ↑ increase; ○ no change; Recall (R) = tp/(tp + fn); ↓ decrease; F = 2 × (P × R)/(P + R). Level of inhibition of PER is relatively low or relatively high .