Visually guided catching and tracking skills in pigeons: A preliminary analysis

Research on reaching, tracking, and catching in the pigeon has been hampered by limitations of technology. A new system was developed in which the target was a small rectangle presented on a video display terminal and the pecking response was detected with touch technology. The target moved up and down vertically with sinusoidal velocity. A coincidence between the location of the pigeon's beak and the cursor produced reinforcement. The pigeon pecked ahead and behind the target, but most pecks occurred behind the target so the dominant tracking strategy was lagging. The pigeon was adept at “catching” the target at many locations throughout the trajectory. Transfer of motor learning was tested on probe trials during which the trajectory changed from vertical to horizontal. On transfer trials the pigeons' dominant pattern of pecking immediately shifted from vertical to horizontal. The motor skill displayed by the pigeons was flexible and adaptive, suggesting that the pigeons had learned to track the cursor.     

GENERALIZED LANGUAGE LEARNING BY CHILDREN WITH SEVERE MENTAL RETARDATION: EFFECTS OF PEERS' EXPRESSIVE MODELING

In this study, we investigated the conditions that contribute to observational learning of generalized language in children with severe mental retardation. Matrix-training strategies were used to teach 6 children with mental retardation to combine known words into two- or three-word utterances consistent with syntactic rules. Subsequently, the children learned two or more unknown words concurrently, inducing word-referent relations consistent with these word order rules. Generalized learning of responses not taught directly was shown to be under experimental control using a multiple baseline design across submatrices. Expressive modeling of only four or five responses was sufficient to promote recombinative generalization in the expressive and receptive modalities. Thus, 95% to 98% of subjects' learning was attributed to generalization processes. This study demonstrates how the efficiency of language training with children with mental retardation might be enhanced by coupling observational learning and matrix-training strategies.     

DISTRACTION: ITS UTILIZATION AND EFFICACY WITH CHILDREN UNDERGOING DENTAL TREATMENT

We investigated the utilization and efficacy of distraction in reducing the anxious and disruptive behavior of 4 children undergoing dental treatment. During the distraction procedure, the children were shown a poster and told a story about it during dental treatment. They earned a prize if they attended to the poster and story and could correctly answer questions about them following each intervention visit. The children's disruptive behavior was assessed via direct observation, and results were analyzed within a multiple baseline design. The children exhibited high levels of anxious and disruptive behavior across baseline visits, regardless of the length of time in treatment or number of visits. Anxious and disruptive behavior decreased upon introduction of the intervention for all children. This was accompanied by the children meeting the criterion for correct answers on the distraction quiz. However, 2 of the children demonstrated an increase in their anxious and disruptive behavior across intervention visits. Results are discussed in terms of the need to evaluate treatment strategies that promote maintenance as well as initial changes.     

Molecular maximizing characterizes choice on Vaughan's (1981) procedure

Pigeons keypecked on a two-key procedure in which their choice ratios during one time period determined the reinforcement rates assigned to each key during the next period (Vaughan, 1981). During each of four phases, which differed in the reinforcement rates they provided for different choice ratios, the duration of these periods was four minutes, duplicating one condition from Vaughan's study. During the other four phases, these periods lasted six seconds. When these periods were long, the results were similar to Vaughan's and appeared compatible with melioration theory. But when these periods were short, the data were consistent with molecular maximizing (see Silberberg & Ziriax, 1982) and were incompatible with melioration, molar maximizing, and matching. In a simulation, stat birds following a molecular-maximizing algorithm responded on the short- and long-period conditions of this experiment. When the time periods lasted four minutes, the results were similar to Vaughan's and to the results of the four-minute conditions of this study; when the time periods lasted six seconds, the choice data were similar to the data from real subjects for the six-second conditions. Thus, a molecular-maximizing response rule generated choice data comparable to those from the short- and long-period conditions of this experiment. These data show that, among extant accounts, choice on the Vaughan procedure is most compatible with molecular maximizing.     

SERIOUS DELINQUENT BEHAVIOR AS PART OF A SIGNIFICANTLY HANDICAPPING CONDITION: CURES AND SUPPORTIVE ENVIRONMENTS

The past 20 years have been productive ones for the field of applied behavior analysis. A brief review of our own efforts during this period reveals that we have accomplished several but not all of our goals for the Teaching-Family approach. In this context, we note that the setting of realistic and appropriate goals is important for the field and for society. Moreover, we suggest that the realistic goal for some persons with serious delinquent behavior may be extended supportive and socializing treatment rather than permanent cure from conventional short-term treatment programs. We base this suggestion on the accumulating evidence that serious delinquent behavior may often be part of a significantly disabling and durable condition that consists of multiple antisocial and dysfunctional behaviors, often runs in families, and robustly eludes effective short-term treatment. Like other significant disabilities such as retardation, autism, and blindness, the effects of this condition may be a function of an interaction of environmental and constitutional variables. We argue that our field has the wherewithal to construct effective and humane long-term supportive environments for seriously delinquent youths. In this regard, we explore the dimensions, rationales, logistics, and beginnings of a new treatment direction that involves long-term supportive family treatment. We contend that such supportive families may be able to provide long, perhaps even lifetime, socializing influences through models, values, and contingencies that seem essential for developing and maintaining prosocial behavior in these high-risk youths.     

CORRESPONDENCE TRAINING: AN EXAMPLE OF RULE-GOVERNED BEHAVIOR?

Two groups of six mentally retarded adults were exposed to either a “say/do” correspondence training program or a “do only” reinforcement procedure to evaluate the suggestion of Rogers-Warren and Baer (1976) that reinforcement of the nonverbal target behavior in the absence of the relevant verbal behavior may account for the behavior changes seen in correspondence training. The participants worked in an experimental setting on a variety of manipulatory responses leading to various auditory and visual consequences. Analysis of individual patterns of responding indicated no apparent differences between the groups during training; four individuals in each group appeared to develop generalized correspondence skills. We conclude that the outcome of correspondence training may not necessarily be verbal regulation of behavior as is assumed. Rather, we suggest that the notion of rule-governed behavior can best account for the type of behavior changes seen in correspondence studies.     

SOCIAL INFLUENCES ON “SELF-STIMULATORY” BEHAVIOR: ANALYSIS AND TREATMENT APPLICATION

We tested the hypothesis that the “self-stimulatory” behaviors exhibited by some individuals may be socially mediated. Four developmentally disabled children who exhibited hand flapping and body rocking participated in a series of three experiments conducted to assess the influence of social variables on stereotyped behavior and to develop a treatment based on the assessment. Experiment 1 used an assessment procedure to determine the relative influences of social attention and task demands on stereotyped behavior. For all four children, hand flapping and body rocking increased when difficult academic tasks were introduced. Experiment 2 involved the use of a procedural time-out and demonstrated that removing task demands contingent on stereotyped behavior resulted in increased rates of hand flapping and body rocking. In Experiment 3, these results were used to develop a communication treatment that consisted of teaching the children to request assistance on the difficult tasks. This treatment resulted in significant reductions in self-stimulatory behavior. These results are consistent with the hypothesis that some forms of repetitive stereotyped behavior may come to serve social functions (e.g., escape from aversive situations). Teaching a functionally equivalent communicative alternative to escape-motivated stereotyped behavior can be an effective form of intervention for this problem.     

A NEUROBIOLOGICAL ALTERNATIVE TO THE PERCEPTUAL REINFORCEMENT HYPOTHESIS OF STEREOTYPED BEHAVIOR: A COMMENTARY ON “SELF-STIMULATORY BEHAVIOR AND PERCEPTUAL REINFORCEMENT”

A perceptual reinforcement theory of stereotyped movements is advanced by Lovaas, Newsom, and Hickman (1987) in an effort to integrate a number of diverse observations about the origins and maintenance of this behavior. We, in turn, argue that the theory, as presented, is logically flawed and fails to take into account important biological findings and theory concerning pathological stereotyped acts. An alternative theory, derived primarily from neurological concepts, is briefly described.     

Saying and doing: A contingency-space analysis

Correspondences between verbal responding (saying) and nonverbal responding (doing) may be organized in terms of the classes of verbal/nonverbal relations into which particular instances of verbal/nonverbal response sequences can enter. Contingency spaces, which display relations among events in terms of the probability of one event given or not given another, have been useful in analyses of nonverbal behavior. We derive a taxonomy of verbal/nonverbal behavior relations from a contingency space that takes into account two conditional probabilities: the probability of a nonverbal response given a verbal response and that probability given the absence of the verbal response. For example, positive correspondence may be said to exist as a response class when the probability of doing is high given saying but is otherwise low. Criteria for other generalized classes, including negative correspondence, follow from this analysis.