Ethanol and isopropanol effects on schedule-controlled responding.

The effects of ethanol and isopropanol were studied on responding by pigeons under multiple fixed-ratio (FR), fixed-interval (FI) schedules of food presentation and under a fixed-interval (FI) schedule of food presentation where responding was decreased by punishment. The ethanol was rapidly absorbed into blood and decreased responding within 15 min after intubation to the opening of the proventriculus. Dose-effect determinations of the effects of ethanol showed that ethanol decreased responding in both the FR and FI components of the multiple schedules at similar doses, but there were increases in responding under an FR 100 schedule at lower doses. Isopropanol tended to decrease FR responding at doses that either increased FI responding or did not affect FI responding. Both ethanol and isopropanol (1 g/kg) produced effects on the local rates of responding within the FI which were rate-dependent in that they increased low rates while not affecting or actually decreasing the high rates of responding. Both ethanol and isopropanol increased punished responding if it was not severely suppressed by the punishment procedures.