Empirical validation of a procedure to correct position and stimulus biases in matching-to-sample

The development of position and stimulus biases often occurs during initial training on matching-to-sample tasks. Furthermore, without intervention, these biases can be maintained via intermittent reinforcement provided by matching-to-sample contingencies. The present study evaluated the effectiveness of a correction procedure designed to eliminate both position and stimulus biases. Following key-peck training, a group of 6 pigeons had extended exposure to matching-to-sample contingencies without a correction procedure, a group of 4 pigeons was briefly exposed to a simultaneous matching-to-sample procedure to assess biases prior to exposure to the correction procedure, and a group of 5 pigeons was exposed directly to the correction procedure. The correction procedure arranged that every time an incorrect match was made, the trial configuration was repeated on the subsequent trial until a correct match was made. Extended exposure to matching-to-sample contingencies without a correction procedure was associated with reduced biases eventually for most subjects, but rapid development of near-perfect accuracy and bias-free performance was observed upon the implementation of the correction procedure regardless of the type of bias. Bias-free performance was maintained following subsequent exposure to a zero-delay MTS procedure.     

Translational behavior analysis: from laboratory science in stimulus control to intervention with persons with neurodevelopmental disabilities

Throughout its history, laboratory research in the experimental analysis of behavior has been successful in elucidating and clarifying basic learning principles and processes in both humans and nonhumans. In parallel, applied behavior analysis has shown how fundamental behavior-analytic principles and procedures can be employed to promote desirable forms of behavior and to prevent or ameliorate undesirable forms in clinical, educational, and other settings. Less obviously, there has also emerged a small but identifiable bridging field that can potentially connect and inform both basic and applied behavior analysis. Although such translational behavior analysis uses laboratory methodologies, research targets are selected largely for their value in ultimate application to improve the human condition. I will discuss the distinction of translational behavior analysis from basic and applied behavior analysis and consider the potential contribution that translational research can make in the development of the science of behavior.     

Producing and Recognizing Analogical Relations

Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather than merely selection-based responses and by extending the work into additional relations, including nonsymmetrical ones. In each of the four studies participants pretrained in contextual control over nonarbitrary stimulus relations of sameness and opposition, or of sameness, smaller than, and larger than, learned arbitrary stimulus relations in the presence of these relational cues and derived analogies involving directly trained relations and derived relations of mutual and combinatorial entailment, measured using a variety of productive and selection-based measures. In Experiment 1 participants successfully recognized analogies among stimulus networks containing same and opposite relations; in Experiment 2 analogy was successfully used to extend derived relations to pairs of novel stimuli; in Experiment 3 the procedure used in Experiment 1 was extended to nonsymmetrical comparative relations; in Experiment 4 the procedure used in Experiment 2 was extended to nonsymmetrical comparative relations. Although not every participant showed the effects predicted, overall the procedures occasioned relational responses consistent with an RFT account that have not yet been demonstrated in a behavior-analytic laboratory setting, including productive responding on the basis of analogies.     

Net Amount of Food Affects Autoshaped Response Rate, Response Latency, and Gape Amplitude in Pigeons

The contribution of net amount of food to conditioned response strength and topography was assessed in four pigeons under autoshaping contingencies. In each session, under one baseline phase and three replication phases, three trial types were presented sequentially: One conditioned stimulus (keylight) signaled one small pellet, another signaled one large pellet, and a third signaled seven small pellets which were weight-matched to one large pellet. Five dependent variables were response rates and latencies based on the occurrence of both keyswitch closures and gapes (beak openings) and gape amplitudes. In result, net amount of food, not pellet diameter or number, affected all dependent variables. Notably, gape amplitudes elicited by the seven-small pellet keylights were larger than the gape amplutides elicited by the one-small pellet keylights even though the gape amplitudes elicited by both unconditioned stimuli (one or seven pellets) were equally small. This mismatch between conditioned and unconditioned responses is incompatible with stimulus substitution accounts but is compatible with an associative strength account. Furthermore, the changes in the dependent variables were most likely determined by Pavlovian and not by inadvertent operant contingencies. The findings demonstrate that an analysis of classical conditioning benefits from the inclusion of topographical measures.     

STROOP效应及其反转：无意识和意识知觉

该研究基于Stroop效应确立了意识知觉和无意识知觉间的质的差异,刺激特性(呈现时间)的改变和注意的改变引起了非常类似的行为上的质差模式,二者在决定意识时存在着补偿作用。当色词短暂呈现而被无意识知觉时,被试在对靶颜色进行命名时不能利用色词提供的预期信息,从而反应时出现典型的Stroop效应;而通过增强刺激特性或提高注意水平可以使色词被有意识知觉。从而出现了Stroop效应的反转。     

Impaired processing of rapid stimulus sequences in dyslexia

Apart from their reading difficulties, dyslexic subjects often suffer from a variety of subtle sensory and motor deficits. Whether these deficits have a causal relationship to the reading disorder, form additional risk factors, or are totally independent of the reading problem, is under vivid debate. In this article, we review the evidence and suggest that ‘sluggish attentional shifting’ (SAS) can account for the impaired processing of rapid stimulus sequences in dyslexia. Within this novel framework attention-related prolongation of input chunks is decisive for many small deficits found in dyslexic subjects.     

Evaluating the predictive validity of a single stimulus engagement preference assessment.

Most preference assessments require individuals to choose among two or more stimuli. More recently, the duration of engagement with items has been used as an index of preference. In the current study, the predictive validity of a single stimulus engagement (SSE) preference assessment was evaluated with 4 individuals. Stimuli were presented singly for a brief period while engagement with that stimulus was recorded. Although SSE preference rankings closely matched paired stimulus preference assessment rankings for only 2 of the 4 participants, relative preference rankings based on duration of engagement predicted relative reinforcer effectiveness for all participants in a subsequent concurrent‐schedule reinforcer assessment. The SSE procedure took less time to administer than the paired stimulus procedure but produced less stable preference rankings across administrations. The SSE procedure may be appropriate for individuals who have difficulty selecting one stimulus from among two or more stimuli, and it may be well suited for evaluating activities that are difficult to present in a paired stimulus format.     

Stimulus control depends on the subjective value of the outcome

Stimuli that provide information about likely future reinforcers tend to shift behavior, provided a reliable relation between the stimulus and the reinforcer can be discriminated. Stimuli that are apparently more reliable exert greater control over behavior. We asked how the subjective value (measured in terms of preference) of reinforcers associated with stimuli influences stimulus control. Five pigeons worked on a concurrent chains procedure in which half of all trials ended in a smaller reinforcer sooner, and the other half in a larger reinforcer later. In Signaled trials, the color and flash duration on the keys in the initial link signaled the outcome of the trial. In Conflicting probe trials, the color and the flash duration signaled conflicting information about the outcome of the trial. Choice in Signaled trials shifted toward the signaled outcome, but was never exclusive. In Conflicting probe trials, control was divided idiosyncratically between the 2 stimulus dimensions, but still favored the outcome with the higher subjective value. Thus, stimulus control depends not only on the perceived reliability of stimuli, but also on the subjective value of the outcome.     

Stimulus control of behavioral history.

Pigeons were exposed to two different reinforcement schedules under different stimulus conditions in each of two daily sessions separated by 6 hr (Experiments 1 and 2) or in a single session (Experiment 3). Following this, either a fixed-interval (Experiment 1) or a variable-interval schedule (Experiments 2 and 3) was effected in both stimulus conditions. In the first two experiments, exposure to fixed-ratio or differential-reinforcement-of-low-rate schedules led to response-rate, but not pattern, differences in subsequent performance on fixed- or variable-interval schedules that persisted for up to 60 sessions. The effects of reinforcement-schedule history on fixed-interval schedule performance generally were more persistent. In Experiment 3, a history of high and low response rates in different components of a multiple schedule resulted in subsequent response-rate differences under identical variable-interval schedules. Higher response rates initially occurred in the component previously correlated with high response rates. For 3 of 4 subjects, the differences persisted for 20 or more sessions. Previous demonstrations of behavioral history effects have been confined largely to between-subject comparisons. By contrast, the present results demonstrate strong behavioral effects of schedule histories under stimulus control within individual subjects.     

The nonequivalence of behavioral and mathematical equivalence.

Sidman and his colleagues derived behavioral tests for stimulus equivalence from the axiom in logic and mathematics that defines a relation of equivalence. The analogy has generated abundant research in which match-to-sample methods have been used almost exclusively to study interesting and complex stimulus control phenomena. It has also stimulated considerable discussion regarding interpretation of the analogy and speculation as to its validity and generality. This article reexamines the Sidman stimulus equivalence analogy in the context of a broader consideration of the mathematical axiom than was included in the original presentation of the analogy and some of the data that have accumulated in the interim. We propose that (a) mathematical and behavioral examples of equivalence relations differ substantially, (b) terminology is being used in ways that can lead to erroneous conclusions about the nature of the stimulus control that develops in stimulus equivalence experiments, and (c) complete analyses of equivalence and other types of stimulus-stimulus relations require more than a simple invocation of the analogy. Implications of our analysis for resolving current issues and prompting new research are discussed.