Murray Sidman: A life of giving

Murray Sidman's contributions to the science of behavior span many areas including avoidance behavior, coercion and its effects, stimulus control, errorless learning, programmed learning, stimulus equivalence, and single-subject methodology. He was also a great mentor to many and helped shape the discipline we now call behavior analysis. In this memoriam, we briefly highlight his scholarly legacy and share some personal anecdotes.     

Predictors of Client Attrition in a University-Based Community Counseling Clinic

The purpose of this study was to investigate how symptom distress, social role, interpersonal relationships, gender, age, number of supports, and education level predict client attrition in a community sample. Using binary logistic regression and cross-sectional data, the authors examined the predictive impact of 8 variables on adult client attrition in a university-based community counseling clinic. Results indicated that education level, interpersonal relationships, and number of supports significantly predicted attrition. In this sample, gender, age, symptom distress, social role, and race did not significantly predict attrition. Implications for clinical assessment and counseling practice are discussed.     

留守初中生同伴侵害与攻击性的关系:链式多重中介模型

为探究留守初中生同伴侵害与攻击性的关系机制,通过构建链式多重中介模型,考察歧视知觉、孤独感和心理韧性在二者关系中的多重中介效应。采用问卷调查法对519名留守初中生进行调查,结果显示：（1）留守初中生同伴侵害的发生率为96.3%,具有普遍性;（2）留守初中生同伴侵害、歧视知觉、孤独感、心理韧性与攻击性之间均呈显著相关;（3）留守初中生的歧视知觉、孤独感和心理韧性在其同伴侵害与攻击性的关系中具有链式多重中介作用;（4）同伴侵害与攻击性关系模型具有一定稳定性,同时在是否留守及单亲与双亲外出留守初中生群体中存在显著差异。研究结果揭示了同伴侵害与攻击性的关系机制,可为探索留守初中生不良同伴关系的教育策略提供参考。     

A comparison of teaching tacts with and without background stimuli on acquisition and generality

We evaluated whether teaching tacts of images with or without backgrounds would affect acquisition during teaching and generality across untaught targets with four children diagnosed with autism spectrum disorder. Including backgrounds could slow acquisition but bolster generality across other media containing backgrounds, whereas removing backgrounds may improve acquisition but result in poorer generality. Overall, acquisition rates were similar across conditions for three children, although one child displayed consistently slower acquisition during the background condition. We rarely observed generality to untaught targets when programming extinction, but embedding differential reinforcement or teaching additional images with backgrounds led to equally successful outcomes irrespective of initial teaching conditions. Teaching with or without backgrounds may result in marginal differences in acquisition of teaching and untaught targets, especially when arranging supplemental procedures during tests for generality. We discuss the importance of intrasubject replication, considerations when testing for generality, and implications for practice.     

Assessment and treatment of elopement maintained by chase

Elopement can have serious or fatal consequences associated with leaving the presence of an adult or getting lost (e.g., traffic injury and drowning). Given the dangers associated with elopement, caregivers are likely to chase after their child when elopement occurs. Like other forms of attention that follow problem behavior, chasing and retrieving the child may serve as a reinforcer and therefore maintain elopement. However, no study to date has evaluated whether elopement is sensitive to positive reinforcement in the form of chase. We evaluated the effects of chase on elopement with an 8‐year old boy diagnosed with autism. Elopement was maintained, at least in part, by chase. We then conducted a treatment evaluation in which we tested the effects of various antecedent‐ and consequence‐based treatment components within a multiple schedule.     

Statistical learning of multiple speech streams: A challenge for monolingual infants

Language acquisition depends on the ability to detect and track the distributional properties of speech. Successful acquisition also necessitates detecting changes in those properties, which can occur when the learner encounters different speakers, topics, dialects, or languages. When encountering multiple speech streams with different underlying statistics but overlapping features, how do infants keep track of the properties of each speech stream separately? In four experiments, we tested whether 8‐month‐old monolingual infants (N = 144) can track the underlying statistics of two artificial speech streams that share a portion of their syllables. We first presented each stream individually. We then presented the two speech streams in sequence, without contextual cues signaling the different speech streams, and subsequently added pitch and accent cues to help learners track each stream separately. The results reveal that monolingual infants experience difficulty tracking the statistical regularities in two speech streams presented sequentially, even when provided with contextual cues intended to facilitate separation of the speech streams. We discuss the implications of our findings for understanding how infants learn and separate the input when confronted with multiple statistical structures.     

社会性发展迟滞大学生对社交信息的内隐态度

本研究目的在于探索社会性发展迟滞大学生对社交信息的内隐认知特点,三个实验分别通过GNAT、IRAP、IAT范式探讨社会性发展迟滞大学生对社交活动、社交关系的内隐态度和内隐社交自我评价的内隐加工特点。结果发现:①社会性发展迟滞组对群体活动的反应时更短;②社会性发展迟滞组对师生关系持消极的内隐态度,对同学关系持积极的内隐态度;③社会性发展迟滞组存在社交自我评价积极偏向,但对积极评价他人/消极评价自我的反应时更短,对评价的整体反应时更短。结论:迟滞个体对社交活动较敏感,对师生关系持消极态度和对同学关系持积极态度,对社交自我评价存在积极偏向。     

Contextual control of equivalence-based transformation of functions

The transformation of functions refers to the untrained acquisition of stimulus functions among members of stimulus equivalence classes or relational frames. Although it is widely assumed that contextual control over the transformation of fuctions must exist, this has not yet been conclusively demonstrated in laboratory studies. Four experiments are reported in which (a) stimulus equivalence classes were established, (b) a conditional stimulus function was trained for one member of each of the classes, and (c) multiple-exemplar procedures were used to train and test for contextual control over the transformation of the stimulus function within the classes and to assess whether it generalized to new equivalence classes. Although a significant amount of training was required, the procedures ultimately resulted in the contextual control of function transformation for 9 of 10 participants and generalized contextual control for 4 of 5 participants.     

A tuned-trace theory of interval-timing dynamics

Animals on interval schedules of reinforcement can rapidly adjust a temporal dependent variable, such as wait time, to changes in the prevailing interreinforcement interval. We describe data on the effects of impulse, step, sine-cyclic, and variable-interval schedules and show that they can be explained by a tuned-trace timing model with a one-back threshold-setting rule. The model can also explain steady-state timing properties such as proportional and Weber law timing and the effects of reinforcement magnitude. The model assumes that food reinforcers and other time markers have a decaying effect (trace) with properties that can be derived from the rate-sensitive property of habituation (the multiple-time-scale model). In timing experiments, response threshold is determined by the trace value at the time of the most recent reinforcement. The model provides a partial account for the learning of multiple intervals, but does not account for scalloping and other postpause features of responding on interval schedules and has some problems with square-wave schedules.     

A new approach to the formation of equivalence classes in pigeons

Four pigeons were given simultaneous discrimination training with visual patterns arbitrarily divided into two sets, with the stimuli in one set designated A1, B1, C1, and D1 and those in the other set designated A2, B2, C2, and D2. In sequentially introduced training phases, the pigeons were exposed to a series of reversals to establish AB and then CD equivalences. In subsequent testing sessions, a subset of stimuli from one set served as positive stimuli and those from the other set as negative stimuli on training trials, and transfer of the reinforced relation to other members of the sets was tested with nonreinforced probe trials. The pigeons were trained further on AC and BD equivalences and then were tested for the emergence of untrained AD and BC equivalences. Two of the 4 pigeons exhibited the emergence of one of these untrained equivalences, evidence for the emergence of transitive relations. This finding suggests that the pigeons established three-member functional equivalence classes by incorporating separately trained multiple equivalence relations. Repeated reversal training and probe testing enabled us to explore the formation and expansion of functional equivalence classes in pigeons.