Stimulus control in the use of landmarks by pigeons in a touch-screen task

Pigeons were tested in a search task on the surface of a monitor on which their responses were registered by a touch-sensitive device. A graphic landmark array was presented consisting of a square outline (the frame) and a colored “landmark.” The unmarked goal, pecks at which produced reward, was located near the center of one edge of the frame, and the landmark was near it. The entire array was displaced without rotation on the monitor from trial to trial. On occasional no-reward tests, the following manipulations were made to the landmark array: (a) either the frame or the landmark was removed; (2) either one edge of the frame or the landmark was shifted; and (3) two landmarks were presented with or without the frame present. On these two-landmark tests, the frame, when present, defined which was the “correct” landmark. When the frame was absent, the “correct” landmark was arbitrarily determined. Results showed that pecks of 2 pigeons were controlled almost solely by the landmark, pecks of 3 were controlled primarily by the landmark but the frame could distinguish the correct landmark, and 1 bird's behavior was controlled primarily by the frame. Stimulus control in this search task is thus selective and differs across individuals. Comparisons to other search tasks and to other stimulus control experiments are made.     

Interactive effects of dispositional mindfulness and PETTLEP imagery training on basketball shooting performance: A randomized controlled trial

The purpose of this study was to examine the interactive effects of dispositional mindfulness and visualized PETTLEP imagery training on basketball mid-range shooting performance and retention. Seventy-three participants (M age = 20.32 ± 1.09) with high/low dispositional mindfulness (high n = 35; low n = 38) selected out of 302 college students were randomly assigned into the following six groups: (a) high mindfulness internal imagery (H-II, n = 13); (b) high mindfulness external imagery (H-EI, n = 11); (c) high mindfulness control (H–CO, n = 11); (d) low mindfulness internal imagery (L-II, n = 13); (e) low mindfulness external imagery (L-EI, n = 12); and (f) low mindfulness control (L-CO, n = 13). Participants engaged in a pretest to measure their basketball shooting performance, then participated in a 6-week (3 times/per-week) intervention, plus a posttest and retention test. A three-way 2 (high/low mindfulness) X 3 (treatments: internal-, external imagery, and control) X 3 (measurement time: pretest, posttest, and retention) mixed ANOVA statistical analysis found dispositional mindfulness interacted with treatments and measurement time. The main effects showed high dispositional mindfulness performed better than low dispositional mindfulness, and internal imagery training performed better than external imagery training on mid-range basketball performance at retention. The 3–way interaction indicated that when using either internal or external imagery, high dispositional mindfulness performed better than low mindfulness on retention but not posttest. For 2-way interaction, high dispositional mindfulness performed better than low dispositional mindfulness on retention but not posttest. Our results extended current knowledge on sport imagery and dispositional mindfulness and gained several theoretical implications for researchers. The limitations, future research directions, and practical implications were also discussed.     

Discrimination of methadone and cocaine by pigeons without explicit discrimination training.

Pigeons were trained to peck a key on a variable-interval 2-min schedule of food reinforcement. Prior to each session, either 2.0 mg/kg methadone (n = 3), 3.0 mg/kg cocaine (n = 4), or 5.6 mg/kg cocaine (n = 2) was administered. When each pigeon's rate of pecking was stable, a range of doses of the training drug and saline were administered prior to 20-min extinction sessions separated by at least four training sessions. Rate of pecking during these extinction tests was generally an increasing function of dose, with the lowest rates obtained following saline and low doses and the highest rates obtained following doses near the training doses. Dose functions from pigeons trained with 5.6 mg/kg cocaine were steeper than those from pigeons trained with 3.0 mg/kg cocaine. Pigeons trained with methadone or 3.0 mg/kg cocaine were then given discrimination training, in which food reinforcement followed drug administration and 20-min extinction sessions followed saline administration. Rates of pecking under these conditions quickly diverged until near-zero rates were obtained following saline and high rates were obtained following drug. Discrimination training steepened dose functions for the training drugs, and the effects of several other substituted drugs depended on the pharmacology of the training drug. The pigeons trained with 5.6 mg/kg cocaine were tested with d-amphetamine, methadone, and morphine prior to discrimination training. d-Amphetamine increased rates dose dependently, and methadone and morphine did not. The results suggest that discriminative control by methadone and cocaine was established without explicit discrimination training.     

Characteristics and consequences of help-giving practices in contrasting human services programs

Relationships between human services program models and help-giving practices, and between both program models and help-giving practices and help-seeker control appraisals were examined in a study of 107 low socioeconomic background families. Three kinds of human services agencies were included in the study, each of which differed in terms of their implicit and explicit assumptions about the families they served and the roles professionals and families played as part of helping relationships. Results support the hypotheses that (a) a program philosophy that was family centered would be associated with more empowering help-giving practices compared to more professionally centered philosophies and (b) a family-centered program philosophy and empowering help-giving practices would be related to an enhanced sense of personal control over needed supports and resources from a target help-giver.     

A comparison of multiple versus single examples of the correct stimulus on task acquisition and generalization by persons with developmental disabilities

In teaching discriminations to persons with retardation, we often presume we will improve acquisition and generalization if we use multiple examples of boththe correct and incorrect stimuli. Two experiments were conducted to test this hypothesis. In the first experiment, 7 persons with moderate retardation learned to discriminate between functional words under two conditions. In one condition, Multiple Example of S- Only,1 example of the correct stimulus (S+) and 10 examples of the incorrect stimulus (S-) were used during acquisition. In the other condition, Multiple Examples of S+ and S-,10 examples of the S+ and 10 examples of the S- were used. Results showed that the condition which presented only a single example of S+ was superior 16 times and inferior 4 times during acquisition, generalization, and maintenance. A second experiment was conducted to (a) replicate the methodology and procedures in Experiment 1 with different participants, (b) determine whether the results were replicable, and (c) obtain efficiency data. Results replicated the findings of the first experiment. The condition which presented only a single example of S+ was superior on measures of (a) trials to criterion, (b) percent correct during acquisition, and (c) minutes to criterion. On measures of generalization, the two conditions were relatively equal. Thus, the condition which presented only a single example of the correct stimulus was more efficient and was just as effective in generalization as the condition which presented multiple examples of both the S+ and S-. These surprising results were discussed in terms of stimulus control, why students performed just as well during generalization when only one example of the S+ was used, why acquisition was also poorer for this condition, and how future studies might address these points.     

Control across the life span: A model for understanding self-direction

A comprehensive four-factor interactive model on physical, psychological, and environmental processes related to the sense of control is presented for adult development with an emphasis on later life. The four experienced components are (1) control from within oneself, (2) control over oneself, (3) control over the environment, and (4) control from the environment. Control over oneself and over the environment measure self-directed control, while control from within oneself and from the environment measure nonself-directed control. Coping (a bidimensional control scale) measures control from powerlessness and suicide to overcontrolling. Findings confirm a significant loss of coping in an older cohort group from a white, rural sample composed primarily of single subjects with low coping representing a significant drop in self-directed behavior. A discussion of the relationship between self-direction and health in the older cohort group follows.     

父母心理控制与小学生的欺负行为:敌意归因和冷酷无情的作用检验

采用班级整群抽样法选取1847名3~6年级小学生（男生987名;平均年龄10.73±1.16岁）及其家长为被试,采用问卷法考察父母心理控制与小学生欺负行为的关系,同时探讨敌意归因和冷酷无情的中介作用。结果发现：（1）父母心理控制显著正向预测小学生的欺负行为;（2）冷酷无情在父母心理控制与小学生欺负行为间的关系中存在中介作用,敌意归因不发挥中介作用;（3）父母心理控制对小学生欺负行为影响的中介机制不存在显著的性别差异和学段差异。本研究结果表明,冷酷无情是父母心理控制影响小学生欺负行为的重要机制,但敌意归因不是。研究者和实践者应注重对欺负者情感加工能力的关注和干预。     

Temporal control of behavior: schedule interactions

In Experiment I the response that terminated the postreinforcement pauses occurring under a fixed-interval 60-second schedule was reinforced, if the pause duration exceeded 30 seconds. The percentage of such pauses, rather than increasing, decreased. There were complex effects on the discriminative control of the pause by the reinforcer terminating the previous fixed interval, depending on whether the fixed interval and the added reinforcer were the same or different. In Experiments II(a) and II(b), each reinforcement initiated an alternative fixed-interval interresponse-time-greater-than-t-sec schedule, the schedule values being systematically varied. When the response following a pause exceeding a given duration was reinforced, fewer such pauses occurred than when they were not reinforced, i.e., on the comparable simple fixed-interval schedule. There was no systematic relationship between mean interrinforcement interval and duration of the postreinforcement pause. The pause duration initiated by reinforcement was directly related to the dependency controlling the shortest pause at that time, regardless of changes in mean interreinforcement interval.     

Reaction times of pigeons on a wavelength discrimination task

After extensive pretraining, three pigeons were exposed in 2-second trials to a random series of 14 light wavelengths, ranging in one nanometer (nm) steps from 575 nanometers to 589 nanometers. Responses to one of the wavelengths, 582 nanometers, were intermittently reinforced. The relative frequency of response approached 1.0 at 582 nanometers, and decreased with progressively higher and lower wavelengths. Reaction times shorter than about 0.2 second occurred with a low frequency that was largely independent of wavelength. Wavelength controlled the frequency of longer reaction times, but did not affect the distribution of these reaction times. Consequently, receiver-operating characteristic curves constructed by using reaction time as a rating measure did not conform to the signal-detection model, in contrast to such conformity when response rate is used in a similar way. The data suggest that stimulus onset as such triggers early response emission with some small probability; the probability of responses with longer latency is controlled by wavelength, but their time of emission is controlled by some independent process.