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Biomedical subjects

J J Boren

Publications and source records attributed to J J Boren.

18 recordsLinked to original sources
PubMed1990

Preference among research cigarettes with varying nicotine yields.

Cigarette smokers (N = 18), primarily women, chose, under double blind conditions, among three research cigarettes with nicotine yields of 0.17, 0.89 and 2.02 mg. Choices were made daily for 12 days following an initial 24-hour forced exposure to each cigarette type. Each subject developed a clear and stable preference for one cigarette type. Of 211 total choice opportunities analyzed, 46% were for the highest nicotine yield cigarette, 29% were for the medium yield, and 25% of the total dose selections were for the low yield cigarettes, suggesting a weak effect of dose. Across subjects, however, the preferences which developed were not significantly related to nicotine yield: low and medium yield cigarette were each preferred by 5 subjects; the remaining 8 subjects came to prefer the high yield cigarette. There was no consistent relationship between nicotine yield of the preferred experimental cigarette and that of the subjects' usual brand. In general, the cigarette choice data are consistent with the behavior of smokers in nonlaboratory settings who also tend to develop stable brand preferences. Specifically, within the range of cigarettes evaluated in this study, nicotine yield is not a strong determinant of cigarette type/brand preference.

Choice Behavior↗
PubMed1979

Effects of cocaine and d-amphetamine on the repeated acquisition and performance of conditional discriminations.

The acute and chronic effects of cocaine and d-amphetamine on food-reinforced behavior were investigated in pigeons responding on a two-component multiple schedule. In one component, the behavioral task consisted of the same chain of conditional discriminations each session (performance). In the other component, the chain of conditional discriminations was changed from session to session (learning). In comparison to control sessions, both acute cocaine and d-amphetamine increased errors in each component of the multiple schedule. Responding in the learning component, however, was generally disrupted at lower doses than those that affected responding in the performance component. At high doses, both drugs produced pauses in responding in each component in three of the four subjects. Pausing engendered by d-amphetamine was approximately twice as long as that under cocaine. Upon chronic administration, both the pausing and error-increasing effects of each drug diminished. Drug-induced changes in timeout responding, however, did not decrease during chronic administration. Redeterminations of the d-amphetamine dose-effect curves following chronic cocaine administration suggested the existence of cross-tolerance between cocaine and d-amphetamine. Both the acute and chronic data are consistent with the view that conditions of stimulus control may modulate the behavioral effects of drugs.

Animals↗
PubMed1978

Effects of d-amphetamine and cocaine on repeated acquisition with timeout from avoidance.

The acute effects of d-amphetamine and cocaine on a repeated acquisition baseline with timeout from avoidance were investigated in two rats. Each session the animals acquired one of two different three-member response sequences. Each sequence member was associated with a different response lever. The first two correct responses of each sequence postponed shock for a fixed period of time. The third correct response initiated a signalled timeout (30 sec) from avoidance. Incorrect responses did not postpone shock. The baseline performance was characterized by a decrease in errors within each session, similar to patterns of repeated acquisition maintained by food. In comparison to control sessions, both d-amphetamine and cocaine increased errors and altered the pattern of within-session acquisition. d-Amphetamine increased the rate of sequence completion and the rate of shock delivery in both animals. Cocaine increased the rate of sequence completion in one animal and increased the rate of shock delivery for the other.

Animals↗
PubMed1978

Repeated acquisition of conditional discriminations.

A new technique was developed to study the repeated acquisition of conditional discriminations. Using a discrete trial procedure, pigeons were required to learn during each session a different two-member chain of conditional discriminations. Key color and geometric forms were used as stimuli. After the pigeons had reached a steady state of relearning (40 to 60 sessions), the technique was used to investigate variables that have previously been shown to affect the repeated acquisition of response sequences. Various (0 to 90 seconds) durations of timeout for errors were investigated in Experiment I. The stimulus change associated with a timeout, rather than its duration, was found to be the critical variable in acquisition of the discrimination. Extended training on a single chain was found to reduce total errors across sessions in Experiment II. Extended training (three sessions) did not, however, change the pattern of within-session error reduction. In some cases, extended training facilitated acquisition of a partially reversed discrimination. In Experiment III, color rather than chain position was found to control behavior, for three of the four birds, as the second stimulus dimension in the conditional situation. The results of these experiments replicate and extend previous findings concerning some of the variables that affect the repeated acquisition of response sequences.

Journal Article↗
PubMed1978

Variability of response location on fixed-ratio and fixed-interval schedules of reinforcement.

Variability of response location was studied in monkeys performing in a six-lever chamber. Fixed-ratio schedules, ranging from FR 1 to FR 300, generated a high degree of stereotypy of response location. In contrast, fixed-interval schedules of comparable reinforcement frequencies (0.06 to 4 minutes) generated much greater variability. These results failed to confirm any simple relationship between response variability and intermittence of reinforcement. Rather, variability seems to be determined by the particular characteristics of the reinforcement schedule.

Journal Article↗
PubMed1976

Sequential reacquisition as a function of timeout from avoidance.

Rats learned to reacquire four similar three-member response sequences. Each sequence member was associated with a different response lever, and the correct sequence of levers (i.e., 3-1-2, 2-1-3, 1-3-2, and 2-3-1) changed each session. The first two correct responses of each sequence postponed shock for a fixed period of time. The third correct response initiated a signalled timeout from avoidance. Incorrect responses did not affect the shock interval or reset the sequence. The effects of manipulating timeout duration on the sequential reacquisition baseline were investigated. All subjects displayed biphasic reacquisition performances similar to those controlled by food. The phases were characterized by an initial increase in accuracy, which reached a stable level during the latter portion of each session. Timeout duration affected rate of sequence completion and shock density, but not percentage of errors. Rate of sequence completion was fastest with intermediate timeouts (15 to 60 sec), and slowest with extreme durations (1 or 120 sec). Shock densities peaked with extreme durations and were at minimum with intermediate timeout values. The percentage of errors was the same across timeout durations. These data extend the generality of sequential reacquisition as a procedure for studying learning, and demonstrate timeout from avoidance to be a controlling variable.

Journal Article↗
PubMed1970

Some experiments on reinforcement principles within a psychiatric ward for delinquent soldiers.

Several experiments exploring the effects of certain behavioral procedures were performed on a psychiatric ward for delinquent soldiers. Within the context of a point economy, the behavioral procedures were examined for their applicability to this patient group in a hospital-ward setting. The following procedures were studied: (1) use of points as consequences for specific behaviors compared with demonstration of "model" behavior by a ward officer; (2) punishment by a point-fine to control undesired behavior; (3) use of a chaining-type reinforcement contingency to increase desired behavior; (4) differential reinforcement of the individual versus the group to increase the frequency of a verbal performance; and (5) reinforcement of reports of personal problems versus impersonal problems.

Journal Article↗
PubMed1969

An information system for measuring patient behavior and its use by staff.

A behavioral measurement system was designed around a point economy for a psychiatric ward of delinquent patients. The characteristics of the system were: (1) the records of points earned for appropriate patient behavior formed the primary data. (2) After the points were recorded in a data matrix, graphs were prepared to show the behavior of individual patients, the participation of the patient group in the various ward activities, and an overall index of ward operation. (3) Several techniques were devised for reviewing the graphs so that the ward staff could evaluate the success of their procedures over substantial time periods.

Journal Article↗
PubMed1969

Some variables affecting the superstitious chaining of responses.

This study was based upon a repeated acquisition technique that systematically generated superstitious chains of responses. Several procedures were investigated in an effort to modify the amount of superstitious chaining. The effects of a large work requirement, a stimulus correlated with non-reinforcement after inappropriate responses, an equivalent time delay after inappropriate responses, and extensive training were examined. The presentation of a stimulus correlated with non-reinforcement was found to be the most effective technique for reducing superstitious chaining; the time delay was the least effective.

Journal Article↗
PubMed1968

The repeated acquisition of behavioral chains.

Monkeys were trained with food reinforcement in a chamber containing four groups of three levers. For each session the monkey's task was to learn a new four-response chain by pressing the correct lever in each group. A stable pattern of learning resulted, and the number of errors reached a steady state from session to session. The technique was then used to determine how various durations of timeouts, following errors, affected the acquisition of new chains. With no timeout, the monkeys made a great many errors, due in large part to superstitious responses within the reinforced chain. Timeout durations ranging from 1 sec to 4 min reduced the number of errors substantially. A second experiment investigated the effects upon acquisition errors of presenting a single light (an "instruction" stimulus) over the correct lever. When this light did not influence the monkeys' responses to the three alternatives, the chains were learned as without it. When the light did control responding, the monkey pressed the appropriate sequence of levers but did not learn the sequence. Thus, when the light was removed, the monkey performed as if learning that sequence for the first time.

Journal Article↗
PubMed1966

An experimental social relation between two monkeys.

A technique was developed for studying the reinforcement of one organism by another. Two pairs of monkeys served as subjects in adjoining but separate lever-pressing chambers. However, they were in visual, aural, and tactile contact with each other. After both pairs were trained to tolerate delays of reinforcement and one pair was trained under stimulus control to exchange reinforcements, monkey A of each pair pressed a lever to feed monkey B, and monkey B pressed to feed monkey A. The experiment sought to determine if this social interaction could be maintained. With a free responding procedure where the monkeys could work at any time in any order, the social relation proved unstable. After several oscillations in which one monkey did most of the responding and the other monkey did most of the eating, the reinforcement frequency for both pairs of animals decreased to very low levels. The final outcome would have been starvation had the experimenter not intervened.

Animals↗