Simon Dymond

Understanding complex behavior: the transformation of stimulus functions.

The transformation of stimulus functions is said to occur when the functions of one stimulus alter or transform the functions of another stimulus in accordance with the derived relation between the two, without additional training. This effect has been demonstrated with a number of derived stimulus relations, behavioral functions, experimental preparations, and subject populations. The present paper reviews much of the existing research on the transformation of stimulus functions and outlines a number of important methodological and conceptual issues that warrant further attention. We conclude by advocating the adoption of the generic terminology of relational frame theory to describe both the derived transformation of stimulus functions and relational responding more generally.

Impaired flexible decision-making in major depressive disorder

BACKGROUND Depression is associated with dysfunctional affective states, neuropsychological impairment and altered sensitivity to reward and punishment. These impairments can influence complex decision-making in changing environments. METHODS The contingency shifting variant Iowa Gambling Task (IGT) was used to assess flexible decision-making performance in a group of medicated unipolar Major Depressive Disorder (MDD) patients (n=19) and a group of healthy control volunteers (n=20). The task comprised the standard IGT followed by a contingency-shift phase where decks progressively changed reward and punishment schedule. RESULTS Patients with MDD showed impaired performance compared to controls during both the standard and the contingency-shift phases of the IGT. Analysis of the contingency-shift phase demonstrated that individuals with depression had difficulties perceiving when a previously bad contingency became good. LIMITATIONS The present findings have several limitations including small sample size, the possible confounding role of medication and absence of other neuropsychological tests (i.e., executive function). CONCLUSION Depressed patients show impaired decision-making behaviour in static and dynamic environments. Altered sensitivity to reward and punishment is proposed as the mechanism responsible for the lack of advantageous choices and poor adjustment to a changing environment.

Fear Generalization in Humans: Systematic Review and Implications for Anxiety Disorder Research

Fear generalization, in which conditioned fear responses generalize or spread to related stimuli, is a defining feature of anxiety disorders. The behavioral consequences of maladaptive fear generalization are that aversive experiences with one stimulus or event may lead one to regard other cues or situations as potential threats that should be avoided, despite variations in physical form. Theoretical and empirical interest in the generalization of conditioned learning dates to the earliest research on classical conditioning in nonhumans. Recently, there has been renewed focus on fear generalization in humans due in part to its explanatory power in characterizing disorders of fear and anxiety. Here, we review existing behavioral and neuroimaging empirical research on the perceptual and non-perceptual (conceptual and symbolic) generalization of fear and avoidance in healthy humans and patients with anxiety disorders. The clinical implications of this research for understanding the etiology and treatment of anxiety is considered and directions for future research described.

A contemporary behavior analysis of anxiety and avoidance.

Despite the central status of avoidance in explaining the etiology and maintenance of anxiety disorders, surprisingly little behavioral research has been conducted on human avoidance. In the present paper, first we provide a brief review of the empirical literature on avoidance. Next, we describe the implications of research on derived relational responding and the transformation of functions for a contemporary behavioral account of avoidance, before providing several illustrative research examples of laboratory-based analogues of key clinical treatment processes. Finally, we suggest some challenges and opportunities that lie ahead for behavioral research on anxiety and avoidance.

Multiple Stimulus Relations and the Transformation of Stimulus Functions

The key concept in Relational Frame Theory is the concept of stimulus relation (Hayes, 1991, 1994; Barnes and Holmes, 1991; Hayes and Hayes, 1989, 1992; Hayes and Wilson, 1996). Understanding the implications of an RFT approach requires clarity about this concept and its flexibility. In this chapter we will attempt to characterize multiple stimulus relations and to distinguish this approach from a traditional class based approach. We will point to ways in which increasingly elaborate relational networks are acquired, modified, and brought under various forms of contextual control. Finally we will describe in some detail the kinds of data that are generated in RFT research, and show how methodological advances are beginning to permit more complex questions to be asked and answered.

Citation Analysis of Skinner's Verbal Behavior: 1984-2004

The present study undertook an updated citation analysis of Skinner’s (1957) Verbal Behavior. All articles that cited Verbal Behavior between 1984 and 2004 were recorded and content analyzed into one of five categories; four empirical and one nonempirical. Of the empirical categories, studies that employed a verbal operant from Skinner’s analysis were assigned to either basic, applied, or observational categories. Empirical studies that did not employ a verbal operant were categorized as other-empirical. The total number of citations remained stable across the review period and averaged just over 52 per year. Of these, 80% were from nonempirical articles, 13.7% were from other-empirical articles, 4% were from applied articles, 1.4% were from basic articles, and 0.9% were from observational articles. An “obliteration” analysis was also conducted to identify articles that employed Skinner’s verbal operant terms but did not cite Verbal Behavior. This analysis identified 44 additional articles, suggesting that a degree of obliteration had occurred in the half century since the publication of Verbal Behavior. In particular, the analysis suggests that the verbal operant of manding has sufficient presence in the applied empirical literature to render citation of Verbal Behavior redundant. Overall, Verbal Behavior continues to make an important contribution to the psychological literature.

Safe From Harm: Learned, Instructed, and Symbolic Generalization Pathways of Human Threat-Avoidance

Avoidance of threatening or unpleasant events is usually an adaptive behavioural strategy. Sometimes, however, avoidance can become chronic and lead to impaired daily functioning. Excessive threat-avoidance is a central diagnostic feature of anxiety disorders, yet little is known about whether avoidance acquired in the absence of a direct history of conditioning with a fearful event differs from directly learned avoidance. In the present study, we tested whether avoidance acquired indirectly via verbal instructions and symbolic generalization result in similar levels of avoidance behaviour and threat-beliefs to avoidance acquired after direct learning. Following fear conditioning in which one conditioned stimulus was paired with shock (CS+) and another was not (CS−), participants either learned or were instructed to make a response that cancelled impending shock. Three groups were then tested with a learned CS+ and CS− (learned group), instructed CS+ (instructed group), and generalized CS+ (derived group) presentations. Results showed similar levels of avoidance behaviour and threat-belief ratings about the likelihood of shock across each of the three pathways despite the different mechanisms by which they were acquired. Findings have implications for understanding the aetiology of clinical avoidance in anxiety.

Behavior-Analytic Approaches to Self-Awareness

The current paper provides an overview of behavior-analytic approaches to self-awareness. Skinner (1974) argued that the phenomenon of self-awareness is produced, in large part, by those social contingencies that reinforce discrimination of the organism’s own behavior. This view of self-awareness is supported by a range of empirical studies that successfully established self-discrimination performances in both nonhuman and human subjects. Recent developments in basic, applied, and conceptual analyses are currently extending Skinner’s behavior-analytic definition of self-awareness. The current paper focuses on a relational frame interpretation of human self-discrimination.

Evaluation of executive functioning in people with intellectual disabilities.

BACKGROUND Executive functioning (EF) is an important concept in cognitive psychology that has rarely been studied in people with intellectual disabilities (IDs). The aim of this study was to examine the validity of two test batteries and the structure of EF in this client group. METHODS We administered the childrens version of the Behavioural Assessment of the Dysexecutive Syndrome (BADS-C) and the Cambridge Executive Functioning Assessment (CEFA) for people with ID, to 40 participants who attended day centres for people with mild to moderate learning disabilities [mean full-scale intelligence quotient (IQ) = 59]. The BADS-C consists of six EF subtests while the CEFA contains eight EF (including two executive memory) subtests and four memory subtests. IQ and receptive language ability were also assessed. The results were subjected to principal components analysis, and regression analysis was used to examine the relationship of the ensuing factors to other cognitive variables. RESULTS Scores on both sets of EF tests were only weakly related to receptive language ability, and even more weakly related to IQ. Scores on the BADS-C were substantially lower than predicted from the published norms for people in higher IQ ranges, and many participants scored zero on three of the six subtests. This potential floor effect was less evident with scores on the CEFA. Principal components analyses produced one usable factor for the BADS-C, and two factors for the CEFA that differed in both the extent of involvement of working memory and the predominant sensory modality. A combined analysis of the subtests retained from both analyses produced three factors that related uniquely to aspects of IQ and memory. CONCLUSIONS The CEFA is suitable for use with people with mild to moderate learning disabilities, whereas the BADS-C is at the lower limit of usability with this client group. The lower-than-expected scores observed on the BADS-C may indicate that people known to learning disability services may be more impaired than people of comparable IQ not known to services. The structure of EF seen in people with IDs closely resembles a model of EF in the general population that has received a broad level of support.

The relationship between dysphoria and proneness to hallucination and delusions among young adults

Previous research suggests that measures of dysphoria relate to positive schizophrenic symptoms. These relationships have rarely been studied within the dimensionality of psychopathology framework. The present study examined the relationship between 3 distinct aspects of dysphoria (depression and state and trait anxiety) and delusion and hallucination proneness in a nonclinical sample of young adults. A total of 472 participants were assessed on measures of dysphoria and delusion and hallucination proneness. Correlation analyses revealed significant associations between both anxiety and depression and hallucination and delusion proneness, suggesting that the association between dysphoria and positive symptoms is also present at a nonclinical level. Partial correlations, and hierarchical regression models, suggest an independent contribution of depression, over anxiety, in influencing hallucination and delusional proneness. The results are discussed in the framework of the cognitive account of schizophrenia and the dimensional model of psychopathology.