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Biomedical subjects

D F Hake

Publications and source records attributed to D F Hake.

At least 19 recordsLinked to original sources
PubMed1984

Stimulus control of schedule-induced activity in pigeons during multiple schedules.

Stimulus control of schedule-induced general activity was demonstrated with pigeons using multiple schedules of response-independent food delivery. In Experiment 1, the introduction of food during a multiple variable-time 30-second variable-time 30-second schedule produced a tenfold increase in activity above the no-food baseline. Each pigeon developed stable differential activity rates during the components (correlated with red and green lights) of a multiple variable-time 30-second extinction schedule. Lengthening the extinction component from 1 to 7 minutes increased the rate differences and produced a reliable pattern of responding during S- (the stimulus correlated with extinction): Activity rate was high immediately following the change from S+ (the stimulus correlated with variable-time 30-second) to S-, then decreased abruptly and remained low throughout the middle of the interval, and subsequently showed a positively accelerated increase until the stimulus changed to S+. In Experiment 2, three pigeons were exposed to a mixed variable-time extinction schedule prior to a multiple variable-time extinction schedule. Auditory rather than visual stimuli were used to determine the generality of Experiment 1 results. The multiple- versus mixed-schedule results indicated that stimulus control of activity occurred for two of the birds, but rate differences between S+ and S- were much less than those demonstrated with visual stimuli. A direct comparison of visual and auditory stimulus control in Experiment 3 supported this conclusion. These parallels between the stimulus control of reinforced responding and that of schedule-induced activity suggest that the stimulus control of induced activity may be a factor in operant stimulus control.

Journal Article↗
PubMed1983

Analysis of discriminative control by social behavioral stimuli.

Visual discriminative control of the behavior of one rat by the behavior of another was studied in a two-compartment chamber. Each rat's compartment had a food cup and two response keys arranged vertically next to the clear partition that separated the two rats. Illumination of the leader's key lights signaled a "search" period when a response by the leader on the unsignaled and randomly selected correct key for that trial illuminated the follower's keys. Then, a response by the follower on the corresponding key was reinforced, or a response on the incorrect key terminated the trial without reinforcement. Accuracy of following the leader increased to 85% within 15 sessions. Blocking the view of the leader reduced accuracy but not to chance levels. Apparent control by visual behavioral stimuli was also affected by auditory stimuli and a correction procedure. When white noise eliminated auditory cues, social learning was not acquired as fast nor as completely. A reductionistic position holds that behavioral stimuli are the same as nonsocial stimuli; however, that does not mean that they do not require any separate treatment. Behavioral stimuli are usually more variable than nonsocial stimuli, and further study is required to disentangle behavioral and nonsocial contributions to the stimulus control of social interactions.

Journal Article↗
PubMed1983

Fast acquisition of cooperation and trust: A two-stage view of trusting behavior.

Trustful behavior was defined in terms of the consecutive numbers of matching-to-sample problems worth money that each subject worked during sessions that ended in an equitable distribution. Two stages of acquisition are inherent in this definition; the first stage requires acquisition of an equitable method of distributing reinforcers (cooperation) to show that the within-session deviations (trust) from equity that develop during the second stage are temporary and are not part of an inequitable method of distributing reinforcers. Previous research has indicated that a contingency to trust is necessary to override the aversiveness of the inequity inherent in trusting and to produce consistent and maximal trust (half of the problems worked consecutively by each subject). The present experiment examined such a contingency. The trust contingency was an increased requirement for changing the direction of problem allocation. Only the subject who had been allocated a problem could change that allocation, by pulling a lever 45 or more times. On the other hand, no separate responses were required to allow the person who worked the last problem to also work the next one (passive trust). Hence, giving a problem was the only way to increase the distribution of problems to the other person and hence prevent oneself from receiving all of the reinforcers. All eight pairs of subjects cooperated from the outset. Trusting behavior developed for all four pairs exposed to the contingency to trust and expanded to maximal levels by the second session for three of the four pairs.

Journal Article↗
PubMed1981

Acquisition and maintenance of trusting behavior.

This study determined whether a two-person exchange situation contained natural contingencies for trusting behavior or whether external contingencies were necessary. Pairs of college students worked matching-to-sample problems for money. On each trial there was one problem and the subjects determined which of them would solve it. Trusting behavior was defined as an increase in the number of consecutive problems each subject allowed his partner to work during sessions that also ended with an equitable distribution. Simply, trust was a temporary deviation from equity. A subject could give the problem to the other person (cooperate), or not respond and let the other person take the problem (share). Other possibilities were for both subjects to try to take the problem (complete), or for neither subject to respond and thereby let the person who worked the last problem also work the next one (passive trust). When only four lever pulls were required to distribute a problem (no external contingencies to reach either equity or trust) subjects reached equity, but only minimal trust (strict alternation of single problems) developed in 18 sessions. When 30 or 60 lever pulls were required to distribute a problem (smaller response requirement for passive trust and therefore a contingency for trust), trusting behavior developed after a few sessions (fixed ratio 30) or after several trials of the first session (fixed ratio 60) and it ordinarily expanded gradually to 10 to 15 consecutive problems through passive trust. The aversiveness of the inequity involved in trusting appears to necessitate a contingency for acquisition. Once trust develops, however, this aversiveness is reduced as subjects learn the inequity is only temporary (e.g., once trust was acquired at fixed ratio 60 it was maintained at fixed ratio 4, which would not initially produce it), and the direction of the inequity appears to become of questionable importance (e.g., being behind was alternated over rather than within sessions and usually not in a systematic manner).

Journal Article↗
PubMed1980

Some relations between classically conditioned aggression and conditioned suppression in squirrel monkeys.

During three experiments with squirrel monkeys, stimulus and shock pairings were given in the presence of a bite tube. Experiments 1 and 2 used a conditioned-suppression procedure in which bar pressing was reinforced with food. A transparent shield prevented biting of the bar. When the stimulus was paired with shock, bar pressing decreased (conditioned suppression) and tube biting increased during the stimulus (classically conditioned aggression). When the bite tube was removed on alternate sessions in Experiment 2, there was more suppression when the tube was present, thus suggesting that biting competed with bar pressing. However, this simple competing-response interpretation was complicated by the findings of Experiment 3 where, with naive monkeys, bar pressing was never reinforced with food, yet bar pressing was induced during the stimulus and was highest when the bite tube was absent. The fact that stimulus-induced bar pressing developed inciated that bar pressing in conditioned-suppression procedures, suppressed or not, may be maintained by two types of control--the food reinforcer and induced CS control. The higher rate of induced bar pressing during the stimulus with the bite tube absent confounds a simple competing response interpretation of conditioned suppression. It suggests that shock-induced responses during conditioned suppression could be both contributing to and competing with responding maintained by food, with the net effect depending on specific but ill-defined features of the situation.

Aggression↗
PubMed1979

Operant and nonoperant vocal responding in the mynah: Complex schedule control and deprivation-induced responding.

Several recent studies have been concerned with operant responses that are also affected by nonoperant factors, (e.g., biological constraints, innate behavior patterns, respondent processes). The major reason for studying mynah vocal responding concerned the special relation of avian vocalizations to nonoperant emotional and reflexive systems. The research strategy was to evaluate operant and nonoperant control by comparing the schedule control obtained with the vocal response to that characteristic of the motor responses of other animals. We selected single, multiple, and chain schedules that ordinarily produce disparate response rates at predictable times. In multiple schedules with one component where vocal responding ("Awk") was reinforced with food (fixed-ratio or fixed-interval schedule) and one where the absence of vocal responding was reinforced (differential reinforcement of other behavior), response rates never exceeded 15 responses per minute, but clear schedule differences developed in response rate and pause time. Nonoperant vocal responding was evident when responding endured across 50 extinction sessions at 25% to 40% of the rate during reinforcement. The "enduring extinction responding" was largely deprivation induced, because the operant-level of naive mynahs under food deprivation was comparable in magnitude, but without deprivation the operant level was much lower. Food deprivation can induce vocal responding, but the relatively precise schedule control indicated that operant contingencies predominate when they are introduced.

Journal Article↗
PubMed1977

Gasoline conservation: a procedure for measuring and reducing the driving of college students.

The study sought to motivate college students to reduce the number of miles they drove each day and thus save gasoline. Students in two psychology classes were divided by class into two groups. The experimental group was offered various combinations of prizes such as cash, a tour of a mental-health facility, car servicing, and a university parking sticker for reducing driving. The value of the prize received was scaled in terms of per cent reduction in driving. The contrast group received no inducements. The condition in which the experimental group's mileage reduction was reinforced was counterbalanced by two baseline conditions. Several special recording procedures were used to reduce and detect the possibility of subjects altering their odometers, the source of the driving data. Experimental subjects reduced their average daily mileage by 20% relative to the initial baseline; the contrast group did not change. During the one-month reinforcement condition, the 12 experimental subjects saved some 170 gallons (worth $102) of gasoline.

Journal Article↗
PubMed1976

Producing a change from competition to sharing: effects of large and adjusting response requirements.

Pairs of high-school students matched-to-sample for money. On each trial, the first pair member to complete a fixed ratio of knob-pulling responses could work the matching problem on that trial. Competition occurred when both pair members responded for the problem. Sharing occurred when only one pair member responded on each trial, and the subjects alternated trials. Hence, sharing requires less responding and still allows a moderate number of reinforcers for each subject. Recent research has shown that increasing the response requirement to the point that it may have aversive properties will produce a change from competition to sharing. A related variable is an adjusting schedule that adjusts the subjects' response requirements so that their abilities to take reinforcers are equal. In this way, subjects might learn that competition requires more responding but produces no more reinforcers. However, recent research also suggests that competition decreases over sessions without experimental manipulations. Because of this possibility of a time-related variable, ratio size and an adjusting schedule were studied in a group design. Competition did decrease for all groups over sessions, but the large-ratio groups switched from competition to sharing sooner than the low-ratio groups. The adjusting schedule had a similar but smaller effect.

Journal Article↗
PubMed1975

The measurement of sharing and cooperation as equity effects and some relationships between them.

The initial objective was to determine whether an increase in cooperative responses (minimal cooperation) was also accompanied by an increase in the degree of correspondence in the number of reinforcers of the two subjects (maximal cooperation). Correct matching-to-sample responses of seven pairs of male adolescents were reinforced with money. On each trial, a subject could (1) give the matching-to-sample problem to his coactor (give or cooperative responses), or (2) take the problem for himself (take responses). The first member of the pair to respond made the choice. Correspondence did increase under this procedure as compared to a baseline where problems were distributed randomly. However, the increased correspondence usually resulted from take responses rather than cooperative give responses. This equitable method of problem distribution, designated as sharing, was characterized by the subjects alternately taking problems. The spacing of daily sessions may have been partly responsible for the high degree of correspondence, because correspondence did not increase within the usual number of sessions when the sessions were massed, i.e., all in one day. Daily sessions require cooperative responses, i.e., each subject has to show up each day for the other to earn money, and this dependency upon the coactor's behavior may facilitate some sharing or cooperation to ensure the coactor's attendance.

Journal Article↗
PubMed1975

Switching from competition to sharing or cooperation at large response requirements: competition requires more responding.

Two pairs of high-school students matched-to-sample for money. On each trial, a subject could either respond on one lever to take the matching-to-sample problem himself (taking response) or respond on a second lever to give the problem to his coactor (giving response). The first subject to complete the response requirement determined the distribution of the problem. Competition maximizes the amount of responding over trials, i.e., both subjects make taking responses on each trial. Sharing and cooperation minimize responding: only one subject makes a taking response (sharing) or a giving response (cooperation) on each trial, and the subjects alternate responding such that there is an equitable distribution of responses and reinforcers over trials. Large increases in the fixed-ratio response requirement to distribute problems produced: (1) a switch from competition to sharing or cooperation, (2) the expected concomitant change from inequitable to equitable distributions of reinforcers, and (3) a reduction in the amount of responding for three of the four subjects. Previous animal research has shown that large response requirements may have aversive properties. Switching from competition to sharing or cooperation at large response requirements allows a reduction in responding and, at the same time, a moderate number of reinforcers for each subject.

Journal Article↗
PubMed1974

Effects of the difference between self and coactor scores upon the audit responses that allow access to these scores.

An audit response allows access to an existing score from a subject's own performance (self audit) or from his coactor's performance (coactor audit). A previous study found that social stimuli (coactor present) increased audits relative to a non-social (no coactor) condition. The increase, designated a social-stimulus effect, was found to be due more to the coactor's score than to his mere presence. This finding suggested that the difference between self and coactor scores might affect the size of the social-stimulus effect. In the present study, six pairs of human subjects matched-to-sample for points that were exchangeable for money. During a session, matching-to-sample problems were distributed so that a subject's score was ahead, behind, or about even with his coactor's score. The even condition produced the largest social-stimulus effects, i.e., the most audits that could not be attributed to non-social variables such as time or number of problems. The even condition may have produced the largest social-stimulus effects because it was the only condition where the major social reinforcer (being ahead) could be both present or absent and, consequently, the even condition was the only one where audits had a discriminative function with respect to the presence of the major social reinforcer.

Journal Article↗
PubMed1973

Analysis of the control exerted by a complex cooperation procedure.

The study examined the effects of the availability of a non-cooperative response on cooperative responding when cooperation did not have to result in an equal distribution of work or reinforcers. Also, an attempt was made to determine if the cooperative responding was under the control of the cooperation procedure. Pairs of institutionalized retardates were tested in full view of each other. For each subject, reinforcers (money) were contingent upon responses on each of two panels: (1) a matching panel for working matching-to-sample problems, and (2) a sample panel for producing the sample stimulus. The matching panels of the two subjects were 6 m apart, but a subject's sample panel could be placed at different distances from his matching panel. For each subject, either his own or his partner's sample panel could be nearest his matching panel such that less walking was required to reach one sample panel than the other. Subjects could work either individually, by producing their own sample stimulus, or cooperatively, by producing the sample stimulus for their partner. Subjects selected whichever solution involved the least amount of walking. The importance of testing for control by the cooperation procedure was indicated by the findings that cooperative-like responses were not always under the control of the cooperation procedure.

Adult↗
PubMed1973

Audit responses: responses maintained by access to existing self or coactor scores during non-social, parallel work, and cooperation procedures.

Human subjects, mostly between 11 and 16 yr old, matched to sample for points that were exchangeable for money. An audit response was defined as a response maintained by allowing a subject access to an existing score on his own (self audit) or a coactor's (coactor audit) performance. In Experiment I, changes from non-social procedures (no coactor) to social procedures (coactor present) increased self and coactor audits. Since both types of audits occurred at about the same rates during cooperation and parallel work procedures, the increases did not depend on the subjects' response interactions. Although Experiment I did not demonstrate that subjects were comparing scores, the frequent occurrence of each kind of audit within a brief time period (interpersonal audit) did indicate that it was reinforcing to have both scores at the same time. These interpersonal audits suggested that the coactor's score increased self audits during social procedures. Experiment II supported this notion: relative to a non-social procedure, self audits increased more during a parallel work procedure when the coactor's score was accessible than when it was not accessible. Thus, increases in other behaviors that occur in the presence of a coactor, i.e., social facilitation, may also result from or be increased by providing a coactor's score.

Journal Article↗
PubMed1972

Characteristics and response-displacement effects of shock-generated responding during negative reinforcement procedures: pre-shock responding and post-shock aggressive responding.

Bar-pressing (Experiment I) or key-pressing (Experiments II and III) responses of monkeys were reinforced according to a fixed-interval schedule of negative reinforcement: the first response after a fixed interval of time terminated regularly spaced shocks for a fixed time designated as the reinforcement period. During extinction, shocks continued during the reinforcement period. That there were two types of responding generated by shock alone was indicated by (1) the level of responding maintained during extinction relative to conditions without shock, (2) the stability of two between-shock response patterns across reinforcement and extinction conditions, and (3) the development of these two between-shock patterns without a history of reinforcement. Subjects developed either a pre-shock or a post-shock response pattern when only the bar was available. However, when both a bite tube, an operandum requiring an aggressive topography, and a recessed key, an operandum that did not require an aggressive topography, were provided, the post-shock pattern was observed in tube biting and the pre-shock pattern was observed in key pressing. Removal of the bite tube produced post-shock key responding similar to that observed when only the bar was available. The displacement of post-shock, aggression-motivated responding confirmed the confounding effect of shock-generated responding in negative reinforcement procedures, and suggests that the use of concurrent response alternatives would reduce such confounding.

Aggression↗
PubMed1972

A classification and review of cooperation procedures.

The definition of cooperation allows many procedural variations, as revealed by examination of the cooperation literature which includes procedures differing so greatly that it is surprising that all of them are considered under the same topic. This paper attempts to provide a framework for organizing that literature by (1) indicating some procedural dimensions along which cooperation procedures can be classified, (2) classifying and reviewing briefly the research at the extremes of these procedural dimensions, and (3) indicating the behavioral effects that are necessary to demonstrate control by the various cooperation procedures.

Cooperative Behavior↗
PubMed1971

Reduction of dangerously aggressive behavior in a severely retarded resident through a combination of positive reinforcement procedures.

A severely retarded resident was released from a timeout chair only occasionally for brief periods of time. Under the timeout contingency alone, the subject made a choke response within minutes of being released. Attention, such as hugs, smiles, and candy was then increased, first by providing it non-contingently and continuously as long as there were no aggressive responses and then, by making it contingent upon incompatible responses. Under conditions of timeout plus increased attention, choking decreased aburptly. Grabbing responses, which increased when choking was reduced, were also reduced under conditions of timeout plus attention. Unrestrained time was gradually increased and all extra attention, i.e., more scheduled attention than provided other residents, was gradually withdrawn. When the resident was unrestrained all day and all extra attention was withdrawn, grabs and, to a lesser extent, chokes increased. Both were again reduced to a manageable level by scheduling several brief periods of attention each day. Hence, the program resulted in quick reductions that endured when the program was largely withdrawn. The changes in aggressive responding as a function of the presence and absence of extra attention suggest the importance of extra "positive reinforcement" in programs based upon positive reinforcement procedures and dealing with retarded residents for whom positive reinforcers may be scarce.

Journal Article↗
PubMed1970

An extinction-induced increase in an aggressive response with humans.

Nine subjects, 14 to 18 yr old, pulled a knob on a schedule of monetary reinforcement. Concurrently, they escaped or avoided periodic presentations of a tone by pressing a button that required 1.5 lb (6.67 N) of force or by punching a padded cushion that required 20 lb (88.96 N) of force. The punching response was designated as an aggressive response because the force of this response together with its topography was comparable to responses of humans that deface objects and produce escape or counter aggression from other humans. It was found that button pressing was the preferred concurrent avoidance response and there were few punches. However, when the monetary reinforcer was discontinued (extinction) punching increased for seven of the nine subjects, but there was no consistent change in the rate of button pressing. When the punching response was replaced by another non-preferred but non-aggressive response, neither this response nor button pressing increased during extinction. Hence, the increase in punching during extinction cannot be attributed solely to the fact that it was a concurrent response or a non-preferred response.

Adolescent↗