Contrast and autoshaping in multiple schedules varying reinforcer rate and duration

Thirteen master pigeons were exposed to multiple schedules in which reinforcement frequency (Experiment I) or duration (Experiment II) was varied. In Phases 1 and 3 of Experiment I, the values of the first and second components' random-interval schedules were 33 and 99 seconds, respectively. In Phase 2, these values were 99 seconds for both components. In Experiment II, a random-interval 33-second schedule was associated with each component. During Phases 1 and 3, the first and second components had hopper durations of 7.5 and 2.5 seconds respectively. During Phase 2, both components' hopper durations were 2.5 seconds. In each experiment, positive contrast obtained for about half the master subjects. The rest showed a rate increase in both components (positive induction). Each master subject's key colors and reinforcers were synchronously presented on a response-independent basis to a yoked control. Richer component key-pecking occurred during each experiment's Phases 1 and 3 among half these subjects. However, none responded during the contrast condition (unchanged component of each experiment's Phase 2). From this it is inferred that autoshaping did not contribute to the contrast and induction findings among master birds. Little evidence of local contrast (highest rate at beginning of richer component) was found in any subject. These data show that (a) contrast can occur independently from autoshaping, (b) contrast assays during equal-valued components may produce induction, (c) local contrast in multiple schedules often does not occur, and (d) differential hopper durations can produce autoshaping and contrast.     

The effects of brief-stimulus presentations in fixed-ratio second-order schedules

Pigeons' responses were reinforced according to a three-component multiple schedule. In Component 1, key pecks produced food according to a fixed-ratio second-order schedule with fixed-ratio units. Here, a fixed number of fixed-ratio units produced food, and the brief stimulus terminating each unit also accompanied food. Responses in Component 2 produced food on an identical schedule except that the brief stimulus was not paired with food. Component 3 contained a simple fixed-ratio schedule whose response requirement equaled that of Components 1 and 2. Across conditions the size of the fixed-ratio unit (five, ten, twenty, forty, and eighty responses) and the total number of responses per reinforcement were parametrically manipulated. The highest response rates and shortest preratio pauses were observed in Component 3 (no brief stimulus). The lowest rates and longest pauses were found in the component with paired brief-stimulus presentations, indicating that the food-paired brief stimulus suppressed responding. The suppressive effects were greatest when the fixed-ratio units were small (e.g., fixed-ratio 5) and the total fixed-ratio requirement was large (e.g., fixed-ratio 160). Under no conditions did the paired brief stimulus facilitate responding. The nonpaired brief stimulus also suppressed responding but to a lesser extent. The suppressive effects of nonpaired brief stimuli were greatest when the fixed-ratio units were small and the total response requirement was large. These data suggest that the suppressive effects of the brief stimuli may have masked the conditioned-reinforcing effects reported in other studies, and that conditions that maximize suppression in second-order schedules involve the use of fixed-ratio schedule units and the presentation of many brief stimuli per reinforcer.     

THE RELATIVE EFFICACY OF METHYLPHENIDATE (RITALIN) AND BEHAVIOR-MODIFICATION TECHNIQUES IN THE TREATMENT OF A HYPERACTIVE CHILD

Drug versus placebo effects were contrasted with those of contingency management in the treatment of a hyperactive child. Several criterion behaviors were monitored in two different settings to gauge the breadth and generalizability of drug and behavior-management effects. Medication and contingency management effects were both found to be situation specific. No interaction effects were found. Accuracy of task performance, amount of eye contact with the experimenters, frequency of repetitive hand movements, and distractible behavior were apparently unaffected by medication (Ritalin versus placebo) within the clinic. A multiple-baseline design incorporating contingency reversals revealed the reinforcement contingencies to be the crucial variable controlling behavior within the clinic. Medication effects were shown to be significant within the home setting where reinforcement contingencies were not changed. While aggressive behavior decreased as a function of Ritalin, repetitive hand movements increased.     

TRAINING FUNCTIONAL EXPRESSIVE LANGUAGE: THE ACQUISITION AND GENERALIZATION OF FIVE-ELEMENT SYNTACTIC RESPONSES1

A single-subject multiple-baseline design using within- and across-subject replication was employed to study the acquisition of expanded “agent-action-object” sentences and the spontaneous generation of this form in the natural environment. Three young language-delayed subjects were trained to describe various agent-action-object relationships with a five-element syntactical form. The language training strategy was a synthesis of the developmental-psycholinguistic and behavioral models. Dynamic interactions between familiar persons and objects were the stimulus events that the children mapped. A five-element syntactical form, previously absent from the children's language repertoires, was trained during individual sessions. Concurrent with baseline, training, and followup, each subject's language was monitored in another setting, the classroom during free play. After onset of training, the core elements of the complex syntactic form were spontaneously emitted by the child in its natural environment. The free-play data reflect individual differences in the emergence and frequency of each child's spontaneous use of the agent-action-object form. The acquisition and maintenance of the specific lexicon and syntax trained were tested by posttraining probes and responses to videotape presentations. These probes revealed generalization and maintenance of both the lexical and syntactical forms acquired in treatment. The main purpose of any language-training procedure should be to provide language that is functional for the child in the natural environment. This study, which documented the spontaneous usage of the core agent-action-object syntactical form in the natural environment, effectively trained a functional syntactical rule.     

EFFECTS OF A PROCEDURE DERIVED FROM THE OVERCORRECTION PRINCIPLE ON MANIPULATED AND NONMANIPULATED BEHAVIORS

Positive practice overcorrection has been shown to be effective in reducing stereotypic self-stimulatory behaviors displayed by retarded and autistic individuals. In addition, the procedure also may increase the occurrence of appropriate behavior through intensive practice. In the present study, several stereotypic and one appropriate behavior (appropriate toy play) displayed by two autistic children were measured before and during treatment by a positive practice in appropriate toy play overcorrection procedure. Overcorrection was introduced for each of the targeted inappropriate behaviors in succession for both children. Results showed that overcorrection reduced all stereotypic behaviors displayed by both children. In addition, one subject displayed marked increases in the behavior practised during overcorrection, appropriate toy play, relative to its baseline rate of occurrence. The results indicate that for some individuals, overcorrection may be effective in teaching and motivating appropriate forms of behavior as well as in reducing stereotypy.     

On the effects of component durations and component reinforcement rates in multiple schedules

Four experiments, each using the same six pigeons, investigated the effects of varying component durations and component reinforcement rates in multiple variable-interval schedules. Experiment 1 used unequal component durations in which one component was five times the duration of the other, and the shorter component was varied over conditions from 120 seconds to 5 seconds. The schedules were varied over five values for each pair of component durations. Sensitivity to reinforcement rate changes was the same at all component durations. In Experiment 2, both component durations were 5 seconds, and the schedules were again varied using both one and two response keys. Sensitivity to reinforcement was not different from the values found in Experiment 1. In Experiment 3, various manipulations, including body-weight changes, reinforcer duration changes, blackouts, hopper lights correlated with keylights, and overall reinforcement rate changes were carried out. No reliable increase in reinforcement sensitivity resulted from any manipulation. Finally, in Experiment 4, reinforcement rates in the two components were kept constant and unequal, and the component durations were varied. Shorter components produced significantly increased response rates normally in the higher reinforcement rate component, but schedule reversals at short component durations eliminated the response rate increases. The effects of component duration on multiple schedule performance cannot be interpreted as changing sensitivity to reinforcement nor to changing bias.     

Effects of methamphetamine and scopolamine on variability of response location.

Methamphetamine and scopolamine were studied in monkeys responding under a multiple fixed-ratio fixed-interval schedule of reinforcement. A response on any one of six levers could satisfy the schedule requirements. Variability of response location was evaluated in terms of switches, where a switch was defined as a response on one lever followed by a response on a different lever. Under baseline conditions the fixed-ratio schedule generated a high rate of responding and a low level of variability, while the fixed-interval schedule generated a low rate of responding and a high level of variability. Both methamphetamine (0.1 to 0.5 mg/kg) and scopolamine (2.4 to 240 microgram/kg) decreased overall response rate and increased variability of response location in each component of the multiple schedule with increasing doses of drug. At lower doses both drugs were found to decrease rate without affecting response variability.     

Test-retest reliability of retrospective self-reports in three populations of alcohol abusers

The reliability of alcohol abusers' retrospective self-reports was evaluated using a time-line follow-back interview technique. Independent groups of male subjects were interviewed in three different treatment settings (outpatient,n=12; inpatient,n=12; residential,n=12) on two separate occasions to assess the test-retest reliability of their self-reports of daily drinking and related events occurring 1 year prior to treatment. Correlational and scatterplot analyses generally showed a high correlation and low discrepancy between the two sets of interview responses for all groups. However, since some population differences were found in the reliability of reports for some variables, further research is needed to delineate the conditions under which reliable and valid retrospective self-reports can be obtained from different populations of alcohol abusers.This research was supported, in part, by Grant No. AA07072 from the National Institute on Alcohol Abuse and Alcoholism to Vanderbilt University.     

Some Effects Of Intertrial Interval Duration On Discrete-trial Choice

Pigeons were trained in Experiment 1 on a discrete-trial concurrent variable-interval (VI) 1-min VI 3-min schedule, and in Experiment 2 on a discrete-trial concurrent VI 1.5-min VI 1.5-min schedule. In each experiment, the intertrial-interval durations (ITIs) were 0 s, 6 s, 22 s, and 120 s, and the schedules were both independent and interdependent. The purpose of the research was to determine whether lengthening the ITI would disrupt any local control that existed, measured with respect to relative response rate and changeover probability. In Experiment 1, with the independent schedules, both preference and obtained relative reinforcement rate approximated .75 at short ITIs, but then decreased toward .50 with longer ITIs. With interdependent schedules, both preference and obtained relative reinforcement rate approximated .75 at all ITIs. In both experiments, with both independent and interdependent schedules, changeover probabilities for each response in a sequence of up to five successive responses to a given schedule were variable for individual birds. The average changeover probabilities for all birds suggested perseveration rather than a systematic increase within a given ITI or a systematic trend toward chance responding as ITI duration increased. Finally, the changeover functions did not differ when a sequence of responses was calculated to begin anew after reinforcement rather than with the first response on a schedule. Taken together, the data were inconsistent with a theory holding that only local processes underlie choice in discrete-trial procedures.     

中国古代心理测验及其特色与价值

文章对中国古代心理测验历史进行反思,认为中国古代心理测验是以知人观为其理论依据,渊远流长,内容丰富,既有类似于现代西方的小时空心理测验,也有西方至今尚未充分关注的大时空心理测验。文章还阐释了中国古代心理测验的几个具体特色;置测验于生活实际中;文化与超文化测验井存;测验与选拨、训练、教学、娱乐相结合;精于定性,疏于定量。