Biomedical subjects

G Galbicka

Publications and source records attributed to G Galbicka.

22 records · Page 2Linked to original sources

PubMed1984

Interresponse-time punishment: a basis for shock-maintained behavior.

Lever pressing of squirrel monkeys postponed brief electric shock according to a free-operant shock-postponement procedure. Pressing also produced shock with a probability proportional to the duration of the current interresponse time in some conditions, or to the fifth ordinally-preceding interresponse time in others. These conditions provided equal frequencies and temporal distributions of response-produced shocks either contingent on or independent of the current interresponse-time duration, respectively. Shock delivered contingent on the current interresponse-time duration resulted in shorter mean interresponse times and higher overall response rates that shock delivered independent of the current interresponse time. In subsequent conditions, response-produced shocks were sufficient to maintain responding following suspension of the postponement procedure only when those shocks were contingent on the current interresponse time. Presenting shock independent of the current interresponse time, conversely, suppressed response rate and ultimately led to cessation of responding in the absence of a conjoint shock-postponement procedure. These results demonstrate interresponse-time punishment in the absence of any indirect avoidance contingencies based on overall shock-frequency reduction, and strongly support similar interpretation at the more local level of shock-frequency reduction correlated with particular interresponse times. Differential punishment of long interresponse times also provides both an a priori basis for predicting whether a schedule of shock presentation will maintain or suppress responding and a framework for interpreting many of the functional relations between overall response rate and parameters of consequent shock presentation. Finally, these results and others indicate the importance of response-consequence contiguity above and beyong any notion of noncontiguous contingency in the control of behavior.

Animals↗

PubMed1983

Stimulus-food relations and free-operant postponement of timeout from response-independent food presentation.

Grain was briefly presented to food-deprived pigeons intermittently and response-independently except during signaled timeouts. During Experiment 1, key pecks postponed the next timeout for a specified interval. Rates of pecking during time in were inversely related to the length of time pecking postponed the next timeout. Response-independent presentation of temporal distributions of timeouts exactly matched to a preceding postponement condition decreased pecking rates during Experiment 2. These results indicate that key pecking of pigeons can be controlled by response-dependent postponement of timeout, but that responses elicited by stimulus-reinforcer relations inherent in timeout-postponement procedures may substantially modify rates and patterns of pecking.

Journal Article↗

PubMed1981

Selective punishment of interresponse times.

Lever pressing by two squirrel monkeys was maintained under a variable-interval 60-second schedule of food presentation. When response-dependent electric shock was made contingent on comparatively long interresponse times, response rate increased, and further increases were obtained when the minimum interresponse-time requirement was decreased. When an equal proportion of responses produced shock without regard to interresponse time, rates decreased. Thus, shock contingent on long interresponse times selectively decreased the relative frequency of those interresponse times, and increased the relative frequency of shorter interresponse times, whereas shock delivered independent of interresponse times decreased the relative frequency of shorter interresponse times while increasing the frequency of longer ones. The results provide preliminary evidence that interresponse times may be differentiated by punishment, further supporting the notion that interresponse times may be considered functional units of behavior.

Journal Article↗

PubMed1980

Schedule-dependent tolerance to behavioral effects of delta 9-tetrahydrocannabinol when reinforcement frequencies are matched.

Squirrel monkeys pressed a lever under a multiple interresponse-time greater than 28-sec, modified random-interval schedule which provided comparable frequencies and temporal distributions of food pellet presentation in the two components. Daily intramuscular administration of either 0.25 or 1.00 mg/kg delta 9-tetrahydrocannabinol resulted initially in suppression and/or disruption of responding and concomitant decreases in the frequency of food presentation in both components. Responding in both components next increased, resulting in recovery of baseline frequencies of pellet delivery during the random-interval component, but continued depression during the interresponse-time schedule. The drug-induced changes in responding under the interresponse-time schedule diminished with repeated injections, whereas response rates during the random-interval schedule sometimes remained elevated. Interresponse-time distributions under the interresponse-time schedule showed that with repeated administration of the drug only those characteristics which had the greatest effect on reinforcement frequency recovered to baseline levels. When drug injections were replaced by daily injections of the vehicle, responding was greatly disrupted only during the random-interval component. These findings are only partially consistent with other results which suggest aht tolerance development to the behavioral effects of delta 9-tetrahydrocannabinol is greatly enhanced if the drug initially produces reinforcement loss.

Animals↗