Figure 4.

1-CSRTT assessed after drug self-administration. Premature responses were recorded twice (i.e., ITI Triad Sets #3 and #4) and averaged for each rat at ITI values of 5, 7.5, and 10 seconds. Rats are subdivided into sex (left column), impulsivity (middle column), drug responder (right column), and self-administered drug (MDPV, top row; cocaine, bottom row). A subject’s baseline was considered to be the average of premature responses over a 5-day period after reaching stability criteria and immediately before starting ITI Triad Set #3. Abscissa: ITI value (seconds). Ordinate: Premature responses. *P < 0.05 between mid-responder and high-responder points. Total MDPV rats: n=9 (females n=4, males n=5; HI-MDPV = 3, MI-MDPV = 4, LI-MDPV = 2; HR-MDPV = 3, MR-MDPV = 3, LR-MDPV = 3). Total cocaine rats: n=9 (females n= 5, males n= 4; HI-COC = 2, MI-COC = 5, LI-COC = 2; HR-COC = 3, MR-COC = 3, LR-COC = 3).