THE EFFECTIVENESS OF VERBAL INSTRUCTION ON TEACHING BEHAVIOR-MODIFICATION SKILLS TO NONPROFESSIONALS1

The effectiveness of a mastery criterion, lecture-based training program for teaching behavior modification to sheltered workshop personnel was evaluated. Staff performance was assessed in terms of: (1) verbal proficiency, as determined from a pre- and posttraining written exam, and (2) application proficiency, as measured by the frequency and appropriateness of staff responses to client behaviors. A direct count was made of the number of positive, negative, and neutral statements following client appropriate and inappropriate behaviors, and the number and type of client behaviors ignored. Thus, it was possible to determine the extent of generalization from classroom to applied settings, as well as the appropriateness of lectures for training specific performance skills. Lecture units introduced stimulus control procedures, shaping-chaining, and contingency management. Characteristic features of the training program were frequent testing, study objectives, immediate remediation, and contingent reinforcement. Verbal instruction was shown to be effective in improving subjects' verbal skills concerning behavior-modification principles, while only partially effective in improving application skills. There was an increase in the total number of staff-client interactions observed for all subjects, but only two of the response classes emphasized in the training program (reinforcing desirable client behavior and ignoring undesirable behavior) showed considerable improvement over pretraining levels. Despite this partial improvement, verbal instruction alone was shown to be insufficient for teaching the full range of behavior-modification skills required to function effectively in applied settings.     

Application of timeout from positive reinforcement for increasing the efficiency of speech training

Language training procedures, which involved positive reinforcement for verbal imitation, were applied to increase the appropriate verbal behavior of an almost non-verbal, brain damaged, 5-yr-old boy. Two experiments assessed the effectiveness of timeout from positive reinforcement as a training procedure viewed as having potential punishing and negatively reinforcing functions. In both experiments, timein, termination of timeout and resumption of training, was arranged to have reinforcing properties in that it presented an opportunity to receive positive reinforcers. In Exp. I, the procedure consisted of temporarily halting language training (timeout) following verbal jargon and resuming it (timein) contingent upon the boy sitting quietly in his chair for approximately 30 sec. The jargon declined to almost zero for an extended period each time the procedure was employed. In Exp. II, the procedure consisted of halting language training (timeout) after emission of undesired verbal responses which previously had been reinforced as the desired approximation to the target verbal behavior. Resumption of training (timein) was made contingent upon the emission of the then-desired approximation of the target verbal behavior. In each experiment, the contingent timeout and timein of the language training that involved positive reinforcement effectively reduced the undesired and increased the desired responses.     

Conjoint control of performance in conditional discriminations by successive and simultaneous stimuli.

In a conditional discrimination, reinforcement of pigeons' responses to pairs of simultaneously presented wavelength stimuli depended on the orientation of white lines superimposed on the wavelengths. Over different conditions in Experiment 1, three wavelength differences were combined with two differences between successively presented line orientations. Measures of stimulus discriminability increased with increases in the difference between both orientation and wavelength stimuli. Conditional-discrimination performance was thus conjointly determined by stimulus disparity in the successive and simultaneous discriminations. In Experiment 2, ratios of rates of reinforcement contingent upon the two categories of correct responses were varied over several conditions for difficult and easy discriminations. Ratios of responses to wavelength pairs were sensitive to variations in the reinforcement ratio to a greater extent for the more difficult orientation discrimination than for the easier orientation discrimination. Performance in the conditional discrimination was therefore determined by the interacting effects of stimulus disparity and the relative rates of reinforcement contingent upon the two correct choices. It was concluded that the effect of temporally distant reinforcement on behavior in a prevailing schedule component is attenuated to an extent that depends on similarity of stimuli that delineate the successive components.     

Emergence of symmetry in a visual conditional discrimination by chimpanzees (Pan troglodytes)

In Exp. 1, three young chimpanzees were trained to match red to a cross and green to a circle in an arbitrary matching-to-sample task. After acquisition of this task, they were tested for the emergence of associative symmetry of these conditional relations using the trials on which shapes were presented as samples and colors as comparisons. One of the three chimpanzees showed statistically significant accuracy on these test trials. This successful subject served in Exp. 2, in which an auditory-visual stimulus appeared contingent upon red and a cross while another auditory-visual stimulus was contingent upon green and a circle. This subject showed higher accuracies in symmetry tests than in Exp. 1, which suggested the facilitative effects of these events common to sample and correct comparison on the development of symmetry. In Exp. 3, subsequent tests in which only these stimuli were presented as samples indicated that these stimuli might have become the members of equivalence classes.     

INCREASING VERBAL INTERACTION AMONG ELDERLY SOCIALLY ISOLATED MENTALLY RETARDED ADULTS: A GROUP LANGUAGE TRAINING PROCEDURE

The present study examined the effectiveness of a group language training procedure for directly increasing and generalizing the rate of verbal interaction among four elderly, socially isolated, moderately mentally retarded men. A withdrawal of treatment design was used to examine the effect of the procedure that used verbal prompts, behavioral rehearsal, and contingent social praise. Changes in behavior were examined in two generalization settings, one similiar to the training environment (Generalization I) and the other arranged as part of the subjects' daily routine (Generalization II). Baseline data indicated no verbal interaction among the subjects. During treatment the training procedure increased the rate of subjects' verbal interactions not only in the training situation, but also in the two generalization settings. An analysis of the data obtained during the Generalization II situation indicated that subjects' verbal interaction increased not only among themselves, but with nonsubject peers present in this setting. Follow-up data showed that increases in rates of verbal interaction were maintained four months after the cessation of training. The implications of the results for program generalization and work with the language deficient individual is discussed.     

Attentional capture is contingent on the interaction between task demand and stimulus salience

The aim of this research was to investigate the potential impacts of task demand and stimulus salience on the stimulus-driven attentional capture effect. The participants performed an inefficient visual search task while an irrelevant luminance singleton was present. In Experiment 1, the task demand was manipulated while the stimulus salience of the irrelevant singleton was fixed. With the same salient singleton, the attentional capture effect was observed in the low-difficulty condition but disappeared in the high-difficulty condition. In Experiment 2, the stimulus salience was manipulated while the task demand was fixed. With the same task, the highly salient singleton captured attention, whereas the relatively lowly salient singleton could not. In Experiment 3, both task demand and stimulus salience were manipulated simultaneously. The stimulus-driven attentional capture effect by the irrelevant singleton increased not only as the task demand decreased but also as the stimulus salience increased. The present study might provide a way to reconcile conflicting findings in the attentional capture literature; the underlying neural mechanism is discussed. 2009 The Psychonomic Society, Inc.     

Effects of auditory stimulation upon non-nutritive sucking by premature infants.

Changes in non-nutritive sucking contingent upon presentation of an auditory stimulus previously found capable of eliciting heart-rate acceleration was investigated in a sample of 24 premature infants. Across 30 10-sec. presentations of the stimulus, only transient changes in sucking rate during the first 6 trials were observed, and these effects obtained primarily for those infants showing few abnormalities in their non-nutritive sucking behavior. These results were discussed as reflecting possible differences in infants' attention associated with sucking pathology and the dependence of psychological assessment upon the specific response index used.     

ACQUISITION OF EXPRESSIVE SIGNING BY AUTISTIC CHILDREN: AN EVALUATION OF THE RELATIVE EFFECTS OF SIMULTANEOUS COMMUNICATION AND SIGN-ALONE TRAINING

Two methods of training autistic children to use manual signs were compared. Two children, one mute and one capable of some verbal imitation, were taught to use signs as expressive labels for pictures of objects. Using an alternating treatments design, speed of sign acquisition was compared across two training conditions in which signs were presented either accompanied by, or without, the corresponding verbal label. In both conditions, the training procedure incorporated reinforcement, modeling, prompting, fading, and stimulus rotation. The efficacy of training in both treatment conditions was demonstrated by the use of a multiple baseline control across signs, but no clear differences in acquisition speed across conditions were apparent. Posttests conducted to assess stimulus control of signing, and learning of verbal labels when these were present in training, showed that the behavior of the imitative, but not the mute, child was controlled by the verbal stimuli. The implications of the results both for understanding deficits characteristic of autistic children and for developing appropriate language training procedures are discussed.     

Exteroceptive control of fixed-interval responding

Two pigeons were exposed to several fixed-interval schedules of food reinforcement. In some cases, exteroceptive stimuli associated with the passage of time were present. Such visual "clock" stimuli were found to gain almost complete control over the behavior, although at the longest fixed interval studied, the superposition of a new temporal discrimination upon the visual discrimination was observed. Where clock stimuli were made contingent upon the birds' behavior, a new form of responding was generated. This behavior was discussed in terms of positive and negative response-tendencies resulting from several stimulus factors: Some of these functioned as S(Delta)'s and secondary negative reinforcers; some functioned as S(D)'s and secondary positive reinforcers; and some were ambiguous with respect to reinforcement conditions. A "pure temporal" discrimination was superimposed upon these factors, but its exact nature was indeterminate from the present data.     

Baseline training sequence affects speed of emergent conditional discriminations

We examined the effects of baseline training sequence on the emergence of conditional discriminations in an intraverbal naming task. Thirty‐two college students were randomly assigned to two groups. The tact‐intraverbal (TI) group first learned to vocally tact eight visual stimuli using a unique verbal label for each stimulus, and then to intraverbally relate four pairs of verbal labels. The intraverbal‐tact (IT) group received the same training but in the opposite sequence. Both groups then received a match‐to‐sample test involving the visual stimuli alone. On average, the TI group had significantly shorter reaction times than the IT group throughout all four test blocks, even when controlling for intraverbal retention, which was lower in the IT group. Accuracy on the MTS test did not differ significantly between groups when controlling for intraverbal retention. However, MTS accuracy and intraverbal retention were strongly correlated in the IT group but uncorrelated in the TI group. We suggest the effect of training sequence reflects different sources of stimulus control available to subjects in different groups when confronted with the novel MTS trials.     

Reinforcer frequency and restricted stimulus control.

Stimulus control was evaluated in 3 individuals with moderate to severe mental retardation by delayed identity matching-to-sample procedures that presented either one or two discrete forms as sample stimuli on each trial. On pretests, accuracy scores on one-sample trials were uniformly high. On two-sample trials, the correct stimulus (i.e., the one that subsequently appeared in the comparison array) varied unpredictably, and accuracy scores were substantially lower, suggesting that both sample stimuli did not exert stimulus control on every trial. Subjects were then given training sessions with the one-sample task and with a new set of four stimuli. For two of the stimuli, correct matching responses were followed by reinforcers on a variable-ratio schedule that led to a high reinforcer rate. For the other two stimuli, correct responses were followed by reinforcers on a variable-ratio schedule that led to a substantially lower reinforcer rate. Results on two-sample tests that followed showed that (a) on trials in which comparison arrays consisted of one high reinforcer-rate and one low reinforcer-rate stimulus, subjects most often selected the high-rate stimulus; and (b) on trials in which the comparison arrays were either two high reinforcer-rate stimuli or two low reinforcer-rate stimuli and the samples were one high reinforcer- and one low reinforcer-rate stimulus, accuracy was higher on trials with the high-rate comparisons. These results indicate that the frequency of stimulus control by high reinforcer-rate samples was greater than that by low reinforcer-rate samples. Following more training with the one-sample task and reversed reinforcement schedules for all stimuli, the differences in stimulus control frequencies on two-sample tests also reversed. These results demonstrate experimental control by reinforcement contingencies of which of two sample stimuli controlled selections in the two-sample task. The procedures and results may prove to be relevant for understanding restricted stimulus control and stimulus overselectivity.     

The effect of logarithmic transformation on estimating the parameters of the generalized matching law

This study examined stimulus class membership established via stimulus-reinforcer relations. Mentally retarded subjects learned conditional discriminations with four two-member sets of visual stimuli (A, B, C, and D). On arbitrary-matching trials, they selected comparison stimuli B1 and B2 conditionally upon samples A1 and A2, respectively, and C1 and C2 conditionally upon B1 and B2, respectively. On identity-matching trials, they selected all stimuli as comparisons conditionally upon identical stimuli as samples. Throughout training, correct selections of A1, B1, C1, and D1 were followed by one reinforcer, R1, and those of A2, B2, C2, and D2 were followed by another, R2. Subsequent tests documented the formation of two four-member stimulus classes, A1-B1-C1-D1 and A2-B2-C2-D2. The class membership of the A, B, and C stimuli could have been based on equivalence relations that resulted from the arbitrary-matching training. D1 and D2 had never appeared on arbitrary-matching trials, however. Their class membership must have been based on relations with R1 and R2, respectively. Results thus confirm a previous finding that stimulus classes can be expanded via stimulus-reinforcer relations. They also define more precisely the potential nature of those classes and the conditions under which class membership can be established.     

Stimulus control in the experimental study of cooperation

The cooperative responses of pairs of human subjects were reinforced under several stimulus conditions in two settings designed to require a "social" response, i.e., where at least one of the two persons is responding to the behavior of the other. The first task, designed by Lindsley and Cohen, required individual responses within 0.5 sec of one another for reinforcement. The second (modified) task required a delay of 3 sec between individual responses. To determine dependence of cooperation on social stimuli, rates of cooperative behavior on these tasks were compared in the presence and absence of a stimulus indicating to each subject the other's response and a stimulus which indicated the duration of the timeout after reinforcement. The results indicated that only in the modified task was a high rate of cooperation always contingent upon the presence of the social stimuli.     

Reduction of kindergarten children's disruptive behavior with delayed feedback and delayed contingent access to play

After measuring the amount of disruptive behavior exhibited by nine kindergarten children in a lunchroom, delayed feedback about the disruptive behaviors engaged in was given to each child after he left the lunchroom, but there were no additional differential consequences for any behaviors. This delayed feedback alone had little effect on the rates of disruptive behavior. When the delayed feedback was paired with contingent access to play, the rates of disruptive behaviors of six of the children was substantially reduced. A more elaborate form of feedback, still paired with contingent access to play, was later found to be effective in reducing the rates of disruptive behavior of the other three children. When contingencies and feedback were removed, the rates of disruptive behavior of the three children who required the extended feedback increased, but the rates of disruptive behavior for the other six children did not increase upon termination of contingencies and feedback. However, when disruptive behavior was differentially reinforced, the rates of disruptive behavior of all of the children increased.     

Stereopsis with opposite contrast contours

The effects of incidental stimuli, defined as visual stimuli not under verbal control, upon a selection task were observed as a function of feedback contingency. Ss judged letter pairs to be valid or invalid completions of preceding letter parts. During the presentation of the letter parts, the response pair or an alternative pair of letters was intermittently presented at a threshold value individually determined for each S. One group of Ss received a light feedback of performance contingent upon responding to the incidental stimuli; whereas a second group received a random noncontingent feedback. The results indicated: (a) both groups responded to the incidental stimuli; (b) feedback contingency had no effect on frequency of responding to the incidental stimuli; (c) frequency of responding to the incidental stimuli remained constant over 32 trials.     

Restoring the associability of a pre-exposed CS by a surprising event

Three experiments are reported which use rats and the conditioned suppression technique. The first two confirmed a previous finding that prior exposure to a stimulus predicting a weak shock retards further learning when this same stimulus is subsequently used to signal a stronger shock. They further showed that this loss of stimulus associability could be attenuated by inserting trials on which the stimulus was presented alone in the absence of shock before the phase of training with the stronger shock. Experiment III demonstrated that, for animals given prior exposure to two stimuli, the insertion of nonreinforced trials with one of the stimuli will restore the associability only of that stimulus. These results are taken to show that a surprising event (the omission of an expected shock) can restore the associability of a pre-exposed conditioned stimulus.     

TRANSFER OF STIMULUS CONTROL FROM MOTOR TO VERBAL STIMULI1

A transfer of stimulus control procedure was used to teach three profoundly retarded adolescents a series of specific responses to specific verbal instructions. After imitative control of a behavior was established, a verbal instruction was presented immediately before the behavior was modelled. Each correct response was followed on the next trial by inserting a delay between the verbal instruction and the modelling of the behavior. The delays increased from trial to trial. Transfer of stimulus control was indicated when a subject responded correctly on five consecutive trials before the behavior was modelled. All three subjects responded correctly to each verbal instruction after that item was trained in a multiple-baseline order. Generalization did not occur to items that had not been trained. Probe data revealed that some variations of the verbal instructions controlled responses after training was completed.     

Correspondence training, prior verbal training, and control of nonverbal behavior via control of verbal behavior

The role of prior verbal training in correspondence training and later verbal control of nonverbal behavior was examined in two groups of Head Start children. One group received correspondence training without prior verbal training, the other with. Essentially no differences were found between the two sequences; thus it seems appropriate to consider the content phases (reinforcement contingent on target verbalization alone) of previous research as control procedures and not a necessary precursor to correspondence training.     

Feedback in behavior modification: an experimental analysis in two phobic cases

Two illustrations of single-case research are described in which an isolated therapeutic variable was sequentially introduced, withdrawn, and reintroduced while changes in a clinically relevant behavior were measured. A claustrophobic patient and a knife-phobic patient received graduated practice in facing their phobic stimuli; length of time the claustrophobic patient stayed in a small dark room per trial, and length of time the knife-phobic patient kept knife exposed per trial were measured. In both experiments, when feedback of these time scores was withdrawn, ongoing progress was retarded. Reinstatement of feedback led to renewed improvement. In Experiment 2, adding and removing contingent verbal praise against a constant background of precise feedback did not significantly alter rate of progress.     

Intermodal perception at birth: Intersensory redundancy guides newborn infants’ learning of arbitrary auditory−visual pairings

In this study the ability of newborn infants to learn arbitrary auditory–visual associations in the absence versus presence of amodal (redundant) and contingent information was investigated. In the auditory-noncontingent condition 2-day-old infants were familiarized to two alternating visual stimuli (differing in colour and orientation), each accompanied by its ‘own’ sound: when the visual stimulus was presented the sound was continuously presented, independently of whether the infant looked at the visual stimulus. In the auditory-contingent condition the auditory stimulus was presented only when the infant looked at the visual stimulus: thus, presentation of the sound was contingent upon infant looking. On the post-familiarization test trials attention recovered strongly to a novel auditory–visual combination in the auditory-contingent condition, but remained low, and indistinguishable from attention to the familiar combination, in the auditory-noncontingent condition. These findings are a clear demonstration that newborn infants’ learning of arbitrary auditory–visual associations is constrained and guided by the presence of redundant (amodal) contingent information. The findings give strong support to Bahrick’s theory of early intermodal perception.