Brief report: An extension of the sequential alternating treatment design using reversals with subjects not available concurrently

This brief report proposes an extension of the traditional Alternating Treatments Design that would be acceptable to use in hospital and residential settings where subjects are often not concurrently available. Concerns about the inability of traditional designs to work in these special situations and the emergence of a “scientist–practitioner split” are discussed. An example of how the Extended Alternating Treatments Design might be used is provided.     

MULTIPLE TREATMENT INTERFERENCE IN THE ALTERNATING TREATMENTS DESIGN AS A FUNCTION OF THE INTERCOMPONENT INTERVAL LENGTH

In experimental designs requiring the administration of more than one treatment to the same subject(s), the effect of one treatment may be influenced by the effect of another treatment (Campbell & Stanley, 1963), a phenomenon known as multiple treatment interference. We conducted two studies in which multiple treatment interference in an alternating treatments design was shown to be a function of the length of the intercomponent interval (ICI) separating treatment conditions. In the first study, we evaluated the effects of four different treatments on the mouthing of a severely retarded boy. Under a 1-min ICI no consistent differential responding to treatment was obtained. Differential responding emerged when the ICI was increased from 1 min to 120 min, thus suggesting multiple treatment interference in the lack of differential responding under a 1-min changeover interval. Functional control of the nondifferential and differential responding as a function of the ICI length was replicated in a reversal phase. In the second study, we compared two treatment procedures for the disruptive noncompliant behavior of a moderately retarded boy. Multiple treatment interference (i.e., the lack of differential responding) occurred with the 1-min intercomponent interval. An increase to a 120-min ICI again resulted in differential responding. A replication of multiple treatment interference by a reversal to a short interval phase was not achieved in the second subject. Results of this study support much of the basic literature on discrimination and multiple treatment interference. Major findings of this study are twofold: Multiple treatment interference can depend on the length of the changeover interval between treatments and multiple treatment interference can take the form of a lack of differential responding to various treatments. Implications for future research are discussed.     

APPLICATIONS OF A SEQUENTIAL ALTERNATING TREATMENTS DESIGN

We propose the use of a combined version of the alternating treatments and multiple baseline designs in situations in which a traditional baseline (no treatment) condition either does not provide an adequate contrast condition or is not feasible or practical due to clinical constraints. We refer to this design as a sequential alternating treatments design because two treatments are initially implemented in a random or counterbalanced fashion and are followed by a sequential change in one or both treatments across settings, subjects, or tasks. The effects of the independent variables are assessed first by analyzing the two series of data points representing the different treatments (relative effects) and then by assessing changes in one or both series, as application of the alternative treatment is introduced sequentially. The sequential application of treatment provides an analysis of control in the same manner as the multiple baseline design; the initial alternating treatments phase provides a contrast condition in much the same manner as a baseline condition. Applications of this design to the assessment of peer training and self-injurious behavior are described.     

AN ALTERNATING TREATMENTS COMPARISON OF ORAL AND TOTAL COMMUNICATION TRAINING WITH MINIMALLY VERBAL RETARDED CHILDREN

This study was a comparison of the effects of oral speech with total communication (speech plus sign language) training on the ability of mentally retarded children to repeat 4-word sentences. Three children were chosen who used single words to communicate but who did not combine words into complete sentences. Three sentence pairs were trained, with each pair having one sentence trained using oral methods and an equivalent one trained using the total communication approach. Both training procedures involved chaining sentence parts, reinforcement, and prompting. Oral methods involved presenting vocal stimuli and requiring vocal responses whereas total communication methods involved presenting vocal and signed stimuli and requiring vocal and signed responses. For the initial sentence pair with each child, an alternating treatments design was used to determine the relative efficacy of the two language training approaches. This was repeated with a second and third sentence pair using a multiprobe technique within a multiple baseline design. Results pointed to the superiority of the total communication approach in facilitating sentence repetition. Possible explanations of these results are offered and the utility of the alternating treatments experimental design is discussed.     

Virtually no evidence for virtually perfect time-sharing

An examination of previous claims for virtually perfect time-sharing in dual-task situations reveals confounding effects that may have obscured dual-task interference. Two experiments are conducted in which these confounding effects are minimized, revealing statistically significant dual-task interference. These results support the hypothesis that human information processing is dominated by a structural central capacity limitation and call into question the hypothesis that dual-task interference can be eliminated by meeting the 5 conditions outlined by D. Meyer and D. Kieras (1999).     

A COMPARISON OF NONCONTINGENT REINFORCEMENT AND SENSORY EXTINCTION AS TREATMENTS FOR SELF-INJURIOUS BEHAVIOR

We compared the effects of two treatments, noncontingent reinforcement (NCR) and sensory extinction (EXT), on the self-injurious behavior (SIB) exhibited by 3 individuals with developmental disabilities. Results of a functional analysis indicated that their SIB was not maintained by social reinforcement, as indicated by undifferentiated responding across assessment conditions or higher rates of responding in the alone condition. Prior to treatment, leisure probes were conducted to identify highly preferred items for use in the NCR condition, and equipment probes were conducted to identify devices that produced the greatest behavioral suppression for use in the EXT condition. Following baseline, treatment was implemented in a multiple baseline across subjects design, and the effects of NCR and EXT were compared in a multielement format. During NCR sessions, participants had continuous access to a highly preferred item. During EXT sessions, participants wore equipment (gloves or protective sleeves) that seemed to attenuate stimulation directly produced by their SIB, while still allowing the behavior to occur. Results indicated that both procedures were effective in reducing SIB, although NCR was associated with either more rapid or greater overall response suppression.     

Design considerations for an on-line computer system for automated psychiatric assessment

The computer-assisted multidisciplinary Psychiatric Assessment Unit at the Salt Lake City VA Hospital required a unique computer system. Design considerations and procedures for development of a Psychiatric Real-Time Information System for Management (PRISM) are outlined. This design is presented as an example for others considering implementing on-line systems. Advantages of the approach are discussed.     

THE USE OF BEHAVIORAL ASSESSMENT TO PRESCRIBE AND EVALUATE TREATMENTS FOR SEVERELY HANDICAPPED CHILDREN

Behavioral assessment procedures were used to prescribe and evaluate treatments of maladaptive behavior for 2 children with severe multiple handicaps. In Experiment 1, the results of an assessment of reinforcer preference were used in conjunction with a functional analysis of the conditions maintaining self-injurious behavior to prescribe a treatment for a child with severe disabilities. The treatment procedure involved the use of a pressure-sensitive microswitch to activate reinforcing stimuli during two solitary conditions, during which self-injurious behavior had occurred at high rates. The results were evaluated with a multiple baseline across settings design and indicated that self-injury decreased with concomitant increases in microswitch activation. Results were maintained at 6 weeks, 8 weeks, and 6 months. In Experiment 2, the results of behavioral assessments of reinforcer preference and self-injurious behavior were combined to develop a treatment for a second severely handicapped child, who exhibited high rates of self-injury in demand situations. This treatment was evaluated with a multiple baseline across tasks design and resulted in the elimination of self-injury for up to 15 months.     

Exploring unique roles for psychologists

Presents a comment on "Psychological Treatments" by D. H. Barlow. Barlow highlighted unique roles that psychologists can play in mental health service delivery by providing psychological treatments--treatments that psychologists would be uniquely qualified to design and deliver. In support of Barlow's position, the authors draw from their own clinical practice with special psychiatric populations, such as adults with severe and persistent mental illness and behaviorally disordered youths, to illustrate some potential unique roles for psychologists. The authors believe psychologists are uniquely trained to design such individualized functional behavioral analysis protocols because of their training in research design, behavior analysis, learning theory, and behavior change. Psychologists may also be uniquely qualified to design, implement, and evaluate many specialized therapy techniques, as Barlow has outlined and suggested.     

Response interference under near-concurrent presentation of safety and non-safety information

The growing advent of Connected Vehicle Systems (CVS) is changing the information environment within the vehicle cab. As vehicles add the capability to receive data from the road infrastructure or share data with other vehicles, there is an expanding amount of safety and non-safety information from these systems with which the driver must contend. The information processing demands for the driver may become more complex, especially under conditions that present multiple information signals to the driver at the same time. To manage this complexity, the design of CVS will need to incorporate information management functions to prioritize information so as to be compatible with the processing capacity of the driver. The objective of this research was to examine the potential interference effect of non-safety critical information on driver responses to near concurrent, critical safety warnings. The study design was based on theory and evidence that there is a “bottle neck” in a human’s central processing of information, such that the processing of early signals (S1) in the environment may delay the response to a later signal (S2) until such time as the response to the first stimulus has been initiated. The results of the study suggest that there is the possibility that near concurrent presentation of safety and non-safety critical information may generate interference effects, but the combination of signal parameters (modality, timing) that are most likely to create this interference may be infrequent in most real world conditions. Future research should focus on the specific parameters that increase the probability of such interference. Such research would then provide a better estimate of the potential frequency of this interference and also guide the formulation of design guidelines to minimize this potential.     

Assessing a retrieval account of the generation and perceptual-interference effects

A number of memory phenomena are modulated by experimental design, with the effect (e.g., of bizarreness, generation, or perceptual interference) occurring in recall for mixed-list, but not pure-list designs. These effects have other similarities and have been treated in common theoretical frameworks, some focusing on encoding and others on retrieval. The typical paradigm for examining design effects confounds encoding and retrieval contexts, making it difficult to compare these accounts. Using a new paradigm, McDaniel, Dornburg, and Guynn (2005) concluded that retrieval processes contribute to the bizarreness effect. We applied this paradigm to the related perceptual-interference and generation effects. Participants were presented with two pure study lists and later recalled the lists separately (inducing pure retrieval sets) or together (inducing a combined or mixed retrieval set) in a single test. In four experiments, the combined recall condition consistently failed to enhance the size of the generation or perceptual-interference effect. Two additional experiments verified that perceptual interference and generation enhanced recognition memory, as predicted by the standard encoding accounts. The results provide no support for the retrieval account of these two variables but generally are consistent with an encoding locus.     

ACCEPTABILITY OF ALTERNATIVE TREATMENTS FOR DEVIANT CHILD BEHAVIOR

The acceptability of alternative treatments for deviant child behavior was evaluated in two experiments. In each experiment, clinical cases were described to undergraduate students along with four different treatments in a Replicated Latin Square Design. The treatments included reinforcement of incompatible behavior, time out from reinforcement, drug therapy, and electric shock and the treatments were described as they were applied to children with problem behaviors. Experiment 1 developed an assessment device to evaluate treatment acceptability and examined whether treatments were rated as differentially acceptable. Experiment 2 replicated the first experiment and examined whether the severity of the presenting clinical problem influenced ratings of acceptability. The results indicated that treatments were sharply distinguished in overall acceptability. Reinforcement of incompatible behavior was more acceptable than other treatments which followed, in order, time out from reinforcement, drug therapy, and electric shock. Case severity influenced acceptability of alternative treatments with all treatments being rated as more acceptable with more severe cases. However, the strength of case severity was relatively small in relation to the different treatment conditions themselves which accounted for large portions of variance.     

A Latent Variable Framework for Power Estimation Within Intervention Contexts

This paper presents a latent growth SEM approach for the estimation of treatment effects, and power to detect such effects, within a true experimental design setting in which subjects are randomly assigned to treatment and control conditions. Power estimation is a critical component of intervention experiment design and the testing of their results. Although researchers have become increasingly sophisticated in applying tests for statistical significance in intervention contexts, few are aware of the power of these tests. The issues raised in this paper are not new; however, reminding researchers to consider these points is important. Exactly how the researcher handles these issues will depend on the questions asked and the resources available, as well as other considerations. Discussion underscores the relationship between the reliability of a study's measures and concomitant increases in power obtained within the SEM framework.     

AN ALTERNATING TREATMENTS COMPARISON OF TWO INTENSIVE INTERVENTIONS FOR FOOD REFUSAL

We compared two treatment packages involving negative reinforcement contingencies for 3 children with chronic food refusal. One involved physically guiding the child to accept food contingent on noncompliance, whereas the other involved nonremoval of the spoon until the child accepted the presented food. Subsequent to baseline, an alternating treatments comparison was implemented in a multiple baseline design across subjects. After each child had been exposed to at least nine sessions of each treatment condition and percentage of bites accepted had increased to at least 80%, the child's caregivers selected the preferred treatment package. The results indicated that both treatments were effective in establishing food acceptance. However, physical guidance was associated with fewer corollary behaviors, shorter meal durations, and parental preference.     

Semantic interference in language production is due to graded similarity,not response relevance

There is an ongoing debate on the question whether semantic interference effects in language production reflect competitive processes at the level of lexical selection or whether they reflect a post-lexical bottleneck, occupied in particular by response-relevant distractor words. To disentangle item-inherent categorical relatedness and task-related response relevance effects, we combined the picture–word interference task with the conditional naming paradigm in an orthogonal design, varying categorical relatedness and task-related response relevance independent of each other. Participants were instructed to name only objects that are typically seen in or on the water (e.g. canoe) and refrain from naming objects that are typically located outside the water (e.g. bike), and vice versa. Semantic relatedness and the response relevance of superimposed distractor words were manipulated orthogonally. The pattern of results revealed no evidence for response relevance as a major source of semantic interference effects in the PWI paradigm. In contrast, our data demonstrate that semantic similarity beyond categorical relations is critical for interference effects to be observed. Together, these findings provide support for the assumption that lexical selection is competitive and that semantic interference effects in the PWI paradigm reflect this competition.     

The effect of repeated presentation of items on paired associate learning

An experimental design is outlined which allows the probability of an item being learned to be related to the number of presentations of that item. The results of an experiment of this design are considered in relation to the hypothesis that learning is a single trial occurrence. The results are found to support neither the single trial hypothesis nor the incremental hypothesis. A “dual factor” hypothesis is put forward and considered in relation to these and other experimental findings. The scoring procedures employed allow consideration of the response learning and the associative phases of paired associate learning. It is suggested that the response learning phase may be explained by the single trial hypothesis and the associative phase by the dual factor hypothesis.     

A comparison of a modified sequential oral sensory approach to an applied behavior‐analytic approach in the treatment of food selectivity in children with autism spectrum disorder

Treatments of pediatric feeding disorders based on applied behavior analysis (ABA) have the most empirical support in the research literature (Volkert & Piazza, 2012); however, professionals often recommend, and caregivers often use, treatments that have limited empirical support. In the current investigation, we compared a modified sequential oral sensory approach (M‐SOS; Benson, Parke, Gannon, & Muñoz, 2013) to an ABA approach for the treatment of the food selectivity of 6 children with autism. We randomly assigned 3 children to ABA and 3 children to M‐SOS and compared the effects of treatment in a multiple baseline design across novel, healthy target foods. We used a multielement design to assess treatment generalization. Consumption of target foods increased for children who received ABA, but not for children who received M‐SOS. We subsequently implemented ABA with the children for whom M‐SOS was not effective and observed a potential treatment generalization effect during ABA when M‐SOS preceded ABA.     

Fractional Design Wizard: A computer program for cost-effective experimental research design

The computer program Fractional Design Wizard creates fractional factorial designs that are cost-effective and especially useful for discarding irrelevant factors from a large number of possible candidates. The program is intended for researchers who are relativelynew to the field of fractional design and who want to acquaint themselves with the use of fractions for the reduction of large experimental designs. Fractional designs allow estimation of main effects, and sometimes two-way interactions, without one’s having to examine all treatment conditions. The program needs Microsoft Windows 95 or better and 32 MB of memory. In a step-by-step fashion, the user can specify the required properties of the fractional design. When there are more valid designs, the user can generate these successively If necessary the user can go back to diminish the requirements. The output can be copied, printed, and saved. The program generates all the information that is needed for the use and interpretation of fractional designs. A help file explains the use of the program and also the purpose, the analysis, and the interpretation of fractional designs. The program, which is written in Object Pascal, is available as freeware on www.fss.uu.nl/ms/hl/fracdes.htm.     

Behavioral neuropsychology: Past,present, and future direction with organically based affect/mood disorders

Affective/mood disturbances have been widely described in association with central nervous system dysfunction. There have been multiple divergent viewpoints regarding the origin of these disorders, however. This is not surprising, as theories evolve in relation to our degree of technological advancement. This review describes the evolution of some of these views, and discusses the advantages of behavioral neuropsychology as an effective approach to assessment/treatment in this context. Although there have been few articles published describing the use of behaviorally based approaches to treat these disorders, it is thought that this approach shows promise, particularly when combined with information based on neuropsychological assessment data. Future directions for the continued evolution of this field are outlined.