An analysis of the utility of differential outcome procedures in drug discrimination research.
In differential outcomes procedures, the correlation of unique reinforcers with distinct discriminative stimuli can decrease the amount of time needed for response acquisition and improve terminal accuracy of responding. The drug discrimination assay is widely used to categorize psychoactive drugs as similar or dissimilar and to describe underlying neurochemical changes associated with drug administration. Because the drug discrimination assay relies heavily upon initial response acquisition and continuing terminal accuracy, a procedure successful at shortening acquisition time and improving terminal accuracy would be beneficial. The present studies examined differences in acquisition of drug stimulus control between rats exposed to differential outcome procedures and rats exposed to the outcomes, in a non-systematic way, in two experiments. The first experiment examined acquisition of control by (+/-)-3,4-methylenedioxymethamphetamine (MDMA), D-amphetamine and saline; the second examined control by MDMA, (+)-lysergic acid diethylamide (LSD) and saline. Neither initial acquisition nor terminal accuracy was influenced by differential outcomes in either experiment. Although the differential outcome effect has been demonstrated in many situations, it does not appear to be useful in the drug discrimination assay. Possible reasons for the lack of an observed effect are discussed.
Goodwin
A K
AK
rtment of Psychology, Western Michigan Unversity, Kalamazoo, 49008, USA.
Baker
L E
LE
D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology; D004192:Discrimination, Psychological / Q000187:drug effects*; D006213:Hallucinogens / Q000494:pharmacology; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule
D000697:Central Nervous System Stimulants; D006213:Hallucinogens; D011619:Psychotropic Drugs; D008238:Lysergic Acid Diethylamide; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D003913:Dextroamphetamine