Biomedical subjects

F A Gonzalez

Publications and source records attributed to F A Gonzalez.

41 records · Page 3Linked to original sources

PubMed1976

Effects of a delay-reinforcement procedure on performance under IRT>t schedules.

Water-deprived rats were studied under a compound schedule that prescribed that responses terminating interresponse times (IRTs) greater than a fixed value t(1) (IRT > t(1) component schedule) initiated a delay of reinforcement interval t(2), at the end of which water was presented if the subject did not respond (R > t(2) component schedule). If the subject responded before the t(2) interval elapsed, the IRT > t(1) component schedule was re-initiated and water was not presented. The IRT > t(1) and R > t(2) component schedules were not differentially correlated with distinctive stimuli. Rate of responding during the IRT > t(1) component decreased as a function of the value of t(2). The magnitude of the decreases in response rate appeared to be proportional to the subject's rate under the IRT > t schedule with no delay of reinforcement (t(2) = 0 sec). The effects were independent of the parameter value of the IRT > t(1) component schedule and of the rate of reinforcement. The results suggested that "efficiency" of performance under IRT > t schedules can be increased by appropriately arranging brief delays of reinforcement.

Journal Article↗

PubMed1976

Effects of propranolol on behavior maintained under fixed-ratio schedules of cocaine injection or food presentation in squirrel monkeys.

Behavior of squirrel monkeys was maintained under comparable 30-response fixed-ratio schedules of cocaine injection or fooc presentation. Every 30th key press in the presence of a green light produced an intravenous injection of 25 mug/kg of cocaine in one group of monkeys or delivery of a food pellet in a second group of monkeys. Each cocaine injection or food presentation was followed by a 1-minute timeout period, during which the green light was absent and responses had no programmed consequences. Responding at a mean rate of more than 1/sec was maintained in the presence of the green light during each daily session. Propranolol doses from 0.3 to 3.0 mg/kg i.m. had no effect on food-maintained responding but decreased cocaine-maintained responding by approximately 30%. The selective disruption of cocaine-maintained responding by propranolol appeared to depend on the cumulative cocaine dose. Decreases in cocaine-maintained responding after propranolol became increasingly pronounced as the session progressed. Similar progressive decreases in cocaine-maintained responding were produced by increasing the dose of cocaine per injection.

Animals↗

PubMed1974

Handwriting as an operant.

An apparatus was designed to monitor handwriting behavior. Two subjects were studied under various schedules of monetary reinforcement for handwriting. The different schedules engendered and maintained distinctive response patterns but the rates of sustained responding did not vary across schedules. The development of fixed-interval performance following continuous reinforcement resembled the same transition in lower animals. In one subject, availability of reading material interacted with the schedule to determine response pattern. It was suggested that handwriting may be a more appropriate response for the experimental analysis of human behavior than the more frequently used button-pushing or lever-pulling responses.

Journal Article↗

PubMed1974

Effects of varying the percentage of key illuminations paired with food in a positive automaintenance procedure.

Three pigeons were exposed to a positive automaintenance procedure in which each trial began with a brief tone followed by the transillumination of a small central area of the response key for 10 sec. Key illumination was followed by food on 100%, 50%, 25%, 12.5%, and 0% of the trials. The effects depended on the dependent variable observed. The mean rate of responding during key illumination rapidly increased and then decreased slightly as the percentage of key illuminations paired with food increased. The number of key illuminations during which at least one response occurred increased as a negatively accelerating function of the percentage of key illuminations paired with food, and the mean latency to the first response during the key illuminations decreased as a negatively decelerating function of the percentage condition. The mean rate of sustained responding during key illumination was not systematically affected by changes in the percentage conditions.

Journal Article↗

PubMedDate not supplied

Ultrasound.

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Female↗