Methods and findings in an analysis of a vocal operant

The relations among acoustic parameters of a vocal operant were considered and some methods for their measurement are described. Four human subjects (Ss) and one chick were employed in an experiment on the relations among vocal rate, vocal topography, and schedules of reinforcement. The earlier finding that schedules of reinforcement control human and infra-human vocal responding as they do other operants was replicated and extended to the case of variable-interval reinforcement. An analysis of response amplitude, pitch, and duration showed that the mean and variance of these parameters typically increase from CRF to VI, from VI to EXT and, for a second group of Ss, from CRF to EXT. The topography of the chick's vocal response appears to stand in the same relation to reinforcement operations as does the human vocal response.     

Operant control of vocal behavior in the cat

Evidence of operant control of vocal behavior in the cat is presented: (1) On mult FR 12 S^Δ schedule, cats miaowed rapidly during periods of S^D and much less or not at all during S^Δ. (2) This control was re-established following reversal of stimuli. (3) The frequency distribution of response durations was shifted to both shorter and longer values by the differential reinforcement of shorter or longer response durations respectively. Since both the frequency and duration of vocal responses were shown to be under the control of the schedule of reinforcement, it is concluded that at least some of the vocal behavior of the cat is susceptible to operant control.     

Behavioral effects of pairing an SD with a decreasing limited-hold reinforcement schedule

Four pigeons were trained on a multiple reinforcement schedule consisting of two limited-hold schedules, one in which a discriminative stimulus (S^D) accompanied the periodic reinforcement contingency, and one in which the discriminative stimulus was omitted. The duration of the limited-hold in each component of the multiple schedule was reduced in parallel steps. It was shown that behavioral differences between the two schedules were attenuated by this manipulation of temporal parameters. When S^D was reduced in duration, three out of four pigeons responded with extremely high S^Δ rates, despite the regular pairing of S^Δ with the reinforcement contingency. These high rates qualitatively resembled the rapid rates emitted on the analogous no-S^D component.     

Delayed Alternation to Non-Positional Cues in Chimpanzee

Three subjects were exposed to fixed-ratio schedules of reinforcement in a two-phase experiment. In the first phase, sessions were terminated after a fixed number of responses had been emitted. In the second phase, sessions were terminated after a fixed length of time (equivalent to the mean of session lengths when steady state responding occurred in Phase 1). A comparison of response rates showed higher rates for all subjects in Phase 2.     

The development of imitation by reinforcing behavioral similarity to a model

This research demonstrated some of the conditions under which retarded children can be taught to imitate the actions of adults. Before the experiment, the subjects were without spontaneous imitative behavior, either vocal or motor. Each subject was taught, with food as reinforcement, a series of responses identical to responses demonstrated by an experimenter; i.e., each response was reinforced only if it was identical to a prior demonstration by an experimenter. Initially, intensive shaping was required to establish matching responses by the subjects. In the course of acquiring a variety of such responses, the subjects' probability of immediate imitation of each new demonstration, before direct training, greatly increased. Later in the study, certain new imitations, even though perfect, were never reinforced; yet as long as some imitative responses were reinforced, all remained at high strength. This imitativeness was then used to establish initial verbal repertoires in two subjects.     

Graded differential reinforcement: Response-dependent reinforcer amount

After key pecking had been autoshaped, six pigeons were exposed to a condition in which the duration of grain availability at the end of an 8-second trial depended on the number of responses emitted during the trial (0.25-second access to grain per response). This procedure, called correlated reinforcement, alternated across conditions with the automaintenance baseline in which the 8-second trial terminated with a constant 2.5-second access to grain. Two control procedures were run; in both, the reinforcer durations were yoked to those obtained in the last correlated session. In the yoked control no responses were required, but in the single-response yoked control at least one response was required to receive the yoked duration. The correlated condition maintained response rates above those produced by the two control conditions. These results may be accounted for by differential reinforcement.     

Instrumental performance on negative schedules

Three experiments examined the performance of rats pressing a lever for food reinforcement on a schedule in which high rates of response resulted in lowered rates of reinforcement (i.e. a schedule with a negative component). In Experiment 1, rats responded on a variable interval (VI) schedule with a conjoint component such that every 30 responses a reinforcement programmed by the VI schedule was cancelled. These subjects generally emitted a lower response rate than rats responding on a VI schedule yoked to the former subjects with respect to the delivery of reinforcement, although response rate differences were sometimes not large. Similar response-rate effects were obtained in Experiment 2 using a within-subject yoking procedure. In Experiment 3, reinforced interresponse times were matched on negative and VI schedules yoked in terms of reinforcement rate, and the response rate emitted in these conditions were similar. These results give support to theories of instrumental conditioning that stress the strengthening and shaping properties of reinforcement.     

The dissociation of discriminative and conditioned reinforcing functions of stimuli with changes in deprivation

Pigeons were studied in two experiments designed to explore the effects of deprivation level upon responding in each link of a two-link chained schedule. The stimulus associated with the terminal link of the chain can be both a discriminative stimulus (S^D) for responding in the presence of the stimulus and a conditioned reinforcer (S^r) for responding in the preceding link. Previous findings have indicated that the S^r function was more readily weakened by satiation than was the S^D function, i.e., the rate of responding decreased more rapidly in the initial link of the chain than in the terminal link. The first of the present experiments, in which tests were conducted after a series of sessions, produced different results: rates of responding in the two links declined simultaneously. The second experiment supported the hypothesis that the effects of satiation interact with the duration of maintenance on the satiation procedure: in early sessions the S^r function was more readily disrupted, but in later sessions the rates of responding in the two links declined simultaneously. Subsequent to this extensive series of identical sessions, the pigeons' deprivation level was altered before a session by pre-feeding the pigeons up to their normal post-session weights. The rates of responding failed to reflect fully this change in deprivation in the first such session, suggesting that the pigeons' behavior had become partially independent of deprivation level.     

The effects of prompting,fading, and differential reinforcement on vocal mands in non‐verbal preschool children with autism spectrum disorders

There are few procedures to teach non‐vocal children vocal mands. This study evaluated the effects of prompting, fading, and differential reinforcement on eye contact, pointing, vocal approximations, independent requests and immature mands in three children with Autism Spectrum Disorders who in baseline emitted almost no independent vocal mands. This procedure resulted in a large and socially valid increase in independent vocal mands, other appropriate responses and near elimination of immature mands. Copyright © 2010 John Wiley & Sons, Ltd.     

Functional Communication Training and Demand Fading Using Concurrent Schedules of Reinforcement

Demand fading, a schedule thinning procedure for escape-maintained behaviors, typically includes an escape extinction component. The purpose of this study was to examine the effectiveness of demand fading with alternative reinforcement utilizing concurrent reinforcement schedules without extinction. During demand fading, aggression and requests emitted prior to meeting the task completion criterion were reinforced with short, low-quality breaks, but requests emitted following the task completion criterion were reinforced with long, high-quality breaks. Results suggest that concurrent schedules of reinforcement may be an effective alternative to extinction as a component of demand fading.     

Effects of vicarious consequences on imitation and recall: Some developmental findings

Two experiments were conducted using a multiple-item list in which each item consisted of a pair of pictures. The model indicated which member of each pair she preferred and was either positively reinforced, negatively reinforced, or received neutral consequences. The S then indicated his preferences (imitation test). Following the imitation test, each S was asked to recall the model's choices. Age was an independent variable in both experiments. Imitation scores of the children, preschool to sixth-grade age range, were strongly influenced by differential vicarious reinforcement. Vicarious reward increased imitation and vicarious punishment decreased it. College students' imitation scores were only minimally influenced by differential vicarious reinforcement. Within- and between-subjects variations of vicarious reinforcement had similar effects. Recall scores were surprisingly high and were not significantly influenced by differential vicarious reinforcement. Interestingly, age and percentage of correct recall were negatively correlated.     

Effects of reinforcing preselected approximations on the topography of the rat's bar press

The effects of different shaping approximations on the topography of the rat's bar press were investigated in two experiments. Behavior was classified into discrete components, and changes in components and their sequential organization were analyzed. Experiment 1 examined response form early in training and found that specific components reinforced during shaping were incorporated into press sequences. Experiment 2 investigated how response form changed when a shaping contingency was relaxed later in training. Two topographies were selected for reinforcement, and both appeared in the press sequences of all subjects by the end of shaping. Subsequently, all variations of bar pressing were reinforced, and neither topography was necessary to satisfy the contingency. Although the frequency of the topographies reinforced during shaping declined for 3 of 4 subjects during this phase, the most frequent press sequence for 2 rats at the end of training included both unnecessary topographies. Variability in press topographies declined when all emitted variants were reinforced. However, all subjects emitted novel response forms throughout training. The results demonstrate that specific response-reinforcer contingencies influence response form by modulating component availability and organization.     

Procedure for operant conditioning of the dog

Most reports arising from operant conditioning procedures have little or no emphasis on the actual behavior shaping or acquisition phase of the responses which are the cumulative frequency of the well-practiced act. There is a need for more detail for beginners or those desiring a clearer understanding of procedures leading to the finally reported data. The procedure reported here is typically used to compare animal subjects or conditions, such as drugs, both in the acquisition and final phases of behavior. Beginning with an unconditional response (e.g. feeding) a bridging stimulus is paired in classical conditioning fashion. From that point on the bridging stimulus and UCS (feeding—or shock) are used immediately as reward or reinforcement only for responses “in the direction of the final desired behavior. The number of timed standardized behavior shaping sessions to criterion is the best index of acquisition phase performance and the total number bar presses or the rate of bar pressing (slope) is the usual index of operant responding. With timid animals it is often necessary to administer tranquilizers.     

Biofeedback and reinforcement to increase heterosexual arousal in homosexuals

Relatively few procedures exist for developing heterosexual arousal in the treatment of sexual deviation (Barlow, 1973) although several recent studies suggest this is a necessary component of treatment (Feldman and MacCulloch, 1971; Bancroft, 1970; Barlow, 1974).In recent years, biofeedback techniques have been applied to many types of disorders (Blanchard and Young, 1974). Basic to biofeedback technology is the notion that providing a person with feedback (or immediate information) of a bioelectric response enables him to learn (gain) self-control of that response. These responses traditionally have been considered involuntary and include heart rate (Scott et al., 1973a). blood pressure (Benson et al., 1971), stomach acid pH (Welgan. 1972), and electroencephalographic activity (Sterman, 1972), In the present experiments, biofeedback and its attendant technology was applied to the problem of generating heterosexual arousal in homosexual males.Frequently, in biofeedback research, reinforcement has been used in addition to feedback in attempting to teach self-control of a response. In fact, an alternate way of conceptualizing and describing the biofeedback research is in terms of operant conditioning (e.g., Weiss and Engel, 1971: Scott et al., 1973b). In one sense, however, feedback and reinforcement are inextricably confounded: the delivery or non-delivery of a reinforcer provides the S with information about the rightness or wrongness of his response and hence, binary feedback about it. Likewise, if feedback or knowledge of whether the response has reached a criterion level or not is effective in leading to a change in the response, then feedback functions as a reinforcer. Reinforcement, however, may be viewed as providing both information about the response (feedback) plus an incentive to change it in the desired direction in addition to any incentive provided by successful performance of a task. Thus, if one provides Ss with a separate, functionally defined reinforcer in such a way that no additional information about the response is conveyed, it becomes possible to detect additive effects of reinforcement over feedback effects. Such was the second purpose of this study.Several recent analogue experiments with volunteers have reported success in modifying erections through feedback and/or reinforcement. Price (1973) found that heterosexual volunteers who received analogue visual feedback as well as binary feedback, provided by a colored light once the needle had passed a pre-set criterion, showed a shorter latency to peak erection and maintained criterion erection longer than a control group receiving no feedback. Both groups were listening to erotic audio tapes. Rosen (1973) demonstrated significant suppression of tumescence in a group of heterosexual volunteers provided with response contingent signal lights. A group receiving non-contingent feedback did not show this effect. In a technical paper, Laws and Pawlowski (1973) have suggested audio feedback of tumescence as a treatment for deficits in sexual arousal.In the clinic, Harbison, Quinn and McAllister (1970), in an uncontrolled case study, reported increasing heterosexual responsiveness in homosexuals through reinforcement of erection. In one of their homosexual patients they were able, over a long series of trials, to increase erection to a heterosexual stimulus (female slide) through rewarding progressively larger responses with sips of iced lime after the patient was water deprived. In addition to the reinforcement, this S was given feedback, of sorts, in that a light was flashed for each successful trial. A second homosexual patient was similarly rewarded for maintaining progressively longer and clearer fantasies of heterosexual behavior. Since other treatments were also applied and no experimental analysis was performed, it is not possible to evaluate the effectiveness of the procedure.In the present experiment the separate effects of feedback and reinforcement to increase heterosexual arousal in homosexuals was experimentally evaluated using single case experimental design methodology (Barlow and Hersen, 1973). Since each experiment was somewhat different in design and purpose, each will be described separately.     

Effects of reinforcement magnitude on pigeons' preference for different fixed-ratio schedules of reinforcement

In concurrent, two-member chains, the completion of one or the other of two initial percentage fixed-interval 90-sec links produced a terminal link in which the completion of a fixed ratio produced food reinforcement. The fixed ratios and the duration of reinforcement in the terminal links were varied. Relative response rate in initial links was proportional to the relative reinforcement duration per ratio response (reinforcement duration divided by fixed ratio) in terminal links. The rate of responding in the terminal fixed-ratio links was insensitive to both ratio size and reinforcement duration and therefore did not vary sufficiently to distinguish between responses per reinforcement and immediacy of reinforcement as controlling variables in terminal links.     

Response-initiated imaging of operant behavior using a digital camera

A miniature digital camera, QuickCam Pro 3000, intended for use with video e-mail, was modified so that snapshots were triggered by operant behavior emitted in a standard experimental chamber. With only minor modification, the manual shutter button on the camera was replaced with a simple switch closure via an I/O interface controlled by a PC computer. When the operant behavior activated the I/O switch, the camera took a snapshot of the subject's behavior at that moment. To illustrate the use of the camera, a simple experiment was designed to examine stereotypy and variability in topography of operant behavior under continuous reinforcement and extinction in 6 rats using food pellets as reinforcement. When a rat operated an omnidirectional pole suspended from the ceiling, it also took a picture of the topography of its own behavior at that moment. In a single session after shaping of pole movement (if necessary), blocks of continuous reinforcement, in which each response was reinforced, alternated with blocks of extinction (no reinforcement), with each block ending when 20 responses had occurred. The software supplied with the camera automatically stored each image and named image files successively within a session. The software that controlled the experiment also stored quantitative data regarding the operant behavior such as consecutive order, temporal location within the session, and response duration. This paper describes how the two data types--image information and numerical performance characteristics-can be combined for visual analysis. The experiment illustrates in images how response topography changes during shaping of pole movement, how response topography quickly becomes highly stereotyped during continuous reinforcement, and how response variability increases during extinction. The method of storing digital response-initiated snapshots should be useful for a variety of experimental situations that are intended to examine behavior change and topography.     

Continuous, fixed-ratio, and fixed-interval reinforcement in honey bees

Bees learned to enter a Plexiglas tube and to suck small portions of sugar solution; every entry or every fifth entry was reinforced. During an extinction phase, the bees on the fixed-ratio schedule emitted twice as many responses as did those given continuous reinforcement. Bees on a fixed-interval schedule of reinforcement emitted lower response rates than did those given fixed-ratio reinforcement. By extending the conditioning procedure for several days, it was possible to maintain responding with fixed-ratio schedules requiring 30 responses per reinforcement and with fixed-interval values up to 90 sec. Under fixed-interval schedules, response rates did not increase toward the end of the reinforcement intervals.     

Psychophysics of key-peck duration in the pigeon

The duration of the pigeon's key peck was differentially reinforced in either a trials or a free-operant procedure. Mean emitted peck duration was a power function of the duration required for food delivery to occur. The exponents of the power function differed considerably from those observed in earlier research involving longer duration responses in pigeons and other species. The coefficients of variation also did not correspond with those of the earlier research on other responses, nor did consideration of the durations actually reinforced resolve the differences. Duration was neither a function of response rate nor of intermittency of reinforcement. Key-peck duration was changed in an orderly way by differential reinforcement. However, it appeared to be more strongly determined by its duration in the absence of differential reinforcement than were longer duration responses.     

The distribution of observing responses in a mixed FI-FR schedule,

In Exp I, three pigeons were trained on an observing response procedure where observing responses produced a stimulus correlated either with FI or with FR. Stimulus duration was 30 sec. During FR, the subjects completed the ratio before the stimulus terminated. During FI, the subjects usually observed the stimulus only once. Observing responses occurred immediately after food reinforcement. In Exp II, stimulus duration was shortened to 5 sec and the FR for food was increased. The results were similar to those of Exp 1. During most FIs and FRs, only one observing response occurred. The results of both experiments could be interpreted in a response competition framework. Immediately after food reinforcement, observing behavior is strong. When behavior on the food key begins it competes with further observing behavior.