Amphetamine effects on unconditional and conditional instrumental responses with alimentary and social rewards in dogs.

The effect of amphetamine dose (0.5 mg per 1 kg) on conditional and unconditional responses based on alimentary and social motivation was investigated in two groups of dogs. Amphetamine resulted in a significant decrease of conditional instrumental responses (CRs) in both groups but did not attenuate significantly the dogs' need for food or petting. On the contrary, the drug drastically increased the dogs' need for petting, and its anorectic effect was mild. The deteriorating effect of amphetamine on mnemonic processes and its facilitatory effect on behaviors directed to get more than the usual amount of pleasant tactile stimulation might underlie the behavioral changes described in this study.