(a).

Drugs	Photocell beam breaks ± SEM (60 min)
Vehicle	588.9 ± 61.20
JWH 133 (0.25 mg/kg)	611.7 ± 25.11
JWH 133 (0.5 mg/kg)	644.2 ± 74.15
JWH 133 (1.0 mg/kg)	606.5 ± 45.15
JWH 133 (2.0 mg/kg)	621.3 ± 47.77