Effects of atropine on the repeated acquisition and performance of response sequences in humans.

The present study assessed a 24-hr time course for the acute effects of intramuscular injections of atropine sulfate (0, 1.5, 3.0, and 6.0 mg/70 kg) in healthy adult humans responding under a two-component multiple schedule of repeated acquisition and performance of response sequences. Subjects resided in an inpatient research ward for the duration of the study. In each component of the multiple schedule, subjects completed a different sequence of 10 responses in a predetermined order using three keys of a numeric keypad. In the acquisition component, the subjects' task was to acquire a new sequence each session. Eight sessions were conducted daily: one immediately before administration of the drug and then 0.5, 1.5, 3.0, 5.0, 7.0, 9.0, and 24.0 hr after administration. In the performance component, the response sequence always remained the same. Overall percentage of errors increased and overall response rates decreased in the acquisition and performance components as an orderly function of drug dose. However, these effects were selective in that behavior in the acquisition component generally was affected at lower doses than in the performance component. When behavior was affected in both the acquisition and performance components, the time courses of effects were similar. Drug effects began at 0.5 or 1.5 hr, reached peak effects between 3.0 and 5.0 hr, and returned to placebo levels between 7.0 and 9.0 hr postdrug in both schedule components. None of the drug doses produced reliable effects the day after drug administration (24-hr postdrug) in either schedule component. The present study provides the first within-subject assessment of the magnitude and duration of the effects of an anticholinergic on repeated acquisition and performance baselines and extends to atropine the selective effects on these two baselines demonstrated previously with other compounds in humans and nonhumans.     

INTERACTION EFFECTS IN MULTIELEMENT DESIGNS: INEVITABLE,DESIRABLE, AND IGNORABLE

A single-subject design often used to compare the effectiveness of two or more independent variables (like treatment programs) is the multielement (alternating treatments or simultaneous treatments) design. Variants of this design approximate the concurrent comparison of the effects of two or more variables (or levels of variables) by programming the variables (or levels) in rapid alternation, typically across or within daily sessions. Properly combined with conventional reversal designs, these designs can also display a variety of interaction effects, some of them worrisome, others highly desirable for the future development of the field. A worrisome model is the possibility that when Treatment B alternates rapidly with Treatment C, the effects of each will not be the same as when each is the only treatment used. A desirable model is the use of the multielement design as a fast-paced component of an otherwise conventional reversal design examining contextual control of some relationship: the possibility that some behavior responds differently to Controlling Variables A and B in Context X than in Context Y. This second possibility opens single-subject designs to the more efficient examination of all interactive effects and is highly desirable, considering the prevalence and importance of interactions in determining the limits and the generality of currently understood behavioral phenomena.     

Persistence in a Putting Task During Perceived Failure: Influence of State-attributions and Attributional Style

Dans cette étude, on a examiné l’influence de l’état des attributions et le style attributionnel (AS) sur la persistance à court‐terme d’un échec perçu à une tâche de putting. 101 élèves débutants en golf ont participéà cette recherche. Deux épreuves de 8 putts ont été interrompues chacune pendant trois minutes. Durant cette période, on a mesuré la persistance individuelle en comptant le nombre de fois que le sujet essayait de putter. L’analyse des résultats montre que le style attributionnel influence la persistance à court‐terme contrairement à l’état des attributions. Les sujets ayant un AS “fort contrôle personnel” font montre de plus de persistance que ceux ayant un AS “faible contrôle personnel”. Ces résultats confirment ceux obtenus lors de recherches antérieures sur les bénéfices motivationnels d’un style attributionnel “optimiste” dans des situations d’échec lors de la réalisation d’une tâche. Des attributions instables sont particulièrement bénéfiques aux sujets ayant un AS externe/incontrôlable. Ces derniers ont un niveau significativement plus élevé de persistance que les sujets ayant un AS externe/incontrôlable mais qui ont fait des attributions causales stables. This study investigated the influence of state‐attributions and attributional style (AS) on short‐term persistence in a putting task during perceived failure. Participants were 101 novice golf students. Two trials of eight putts each were interrupted by a 3‐minute free period during which individual persistence was measured by calculating the number of putts attempted in the free period. Analyses revealed that attributional style influenced short‐term putting persistence but state‐attributions did not. Participants with a “high personal control” AS showed greater persistence than those with a “low personal control” AS, which supports past research on the positive motivational benefits of a more “optimistic” attributional style in task failure situations. Moreover, unstable attributions were particularly protective for individuals with an external/uncontrollable AS, in that they promoted significantly higher levels of persistence than was shown by external/uncontrollable AS individuals who made stable causal attributions.