Comparable Rates of Responding and Reinforcement Do Not Eliminate the Differential Effects of Ethanol on Response Chain Acquisition and Performance

Ethanol and other drugs commonly disrupt responding under repeated acquisition and performance baselines, with responding in the former condition being more sensitive to such disruption than the latter. The present study was conducted to determine if differential drug effects would occur when baseline rates of responding were comparable in the two baseline conditions. The acute effects of ethanol (0, 0.4, and 0.8 g/kg) were examined in healthy adult volunteers responding under a multiple schedule of repeated acquisition and performance of 10-response sequences. A 1-sec delay occurred after each response to keep rates of responding comparable in the acquisition and performance conditions. This delay also reduced differences in reinforcement rates between the two components. Nevertheless, responding in the acquisition condition was still more sensitive to the disruptive effects of ethanol than responding in the performance component. This differential sensitivity to ethanol was most evident in measures of accuracy of responding (e.g., percentage of errors). These findings suggest that differences in overall rates of responding and reinforcement in the repeated acquisition and performance conditions contribute little, if anything, to the differential drug effects observed on those baselines.

     

Self-related problems beyond the self-concept: motivational consequences of discrepant self-guides

This article considers emotional-motivational predispositions associated with self-beliefs other than the self-concept. Specifically, we examined the consequences of a chronic conflict between two valued selves. In two studies, we tested the hypothesis that people who possess conflicting standards or self-guides are vulnerable to a particular type of psychological discomfort. We found that subjects possessing discrepant self-guides experienced significantly more frequently the cluster of emotional-motivational problems predicted to be related to a chronic double approach-avoidance conflict (feeling muddled, indecisive, distractible, unsure of self or goals, rebellious, confused about identity) than did subjects without such a discrepancy. Evidence is presented that this specific relation is independent of self-concept-related beliefs and problems. However, evidence is also presented that self-guide-self-guide discrepancies influence the nature of the self-concept, which may reflect subjects' chronic difficulties with self-assessment along a dimension described by this type of discrepancy.     

Automaticity of chronically accessible constructs in person x situation effects on person perception: it's just a matter of time

Models of Person X Situation influences on social behavior and judgement have invoked two distinct mechanisms: a personality disposition and a situational press. In this study we conceptualized both influences in terms of a single underlying mechanism, construct accessibility. We pitted the characteristic ways that individuals perceive others against situational influences on accessibility (i.e., contextual priming) and tracked over time the relative power of these competing influences on the outcome of an impression-formation task. Subjects possessed either a chronically accessible (chronics) or an inaccessible (nonchronics) construct for either outgoing or inconsiderate behavior. As predicted, as the delay since the priming event lengthened (from 15 to 180 s), chronics were progressively more likely to use the chronically accessible construct instead of the primed alternative construct to categorize an ambiguous target behavior, whereas nonchronics' relative use of the primed and alternative constructs did not change as a function of postpriming delay.     

A behavioral economic analysis of concurrently available money and cigarettes.

In economic terms, consumption of a reinforcer is determined by its price and the availability and price of other reinforcers. This study examined the effects of response-requirement (i.e., price) manipulations on the self-administration of two concurrently available reinforcers. Six cigarette smokers participated in 4-hr sessions in which money and puffs on a cigarette were concurrently available according to fixed-ratio schedules of reinforcement. Once stable responding was obtained with both reinforcers available at Fixed Ratio 100, the response requirement for one reinforcer was systematically varied (Fixed Ratio 1,000 and 2,500), while the other reinforcer remained scheduled at Fixed Ratio 100. Increasing the fixed-ratio size for a reinforcer decreased its consumption, with a greater decrease occurring for monetary reinforcement. This finding was quantified in economic terms as own-price elasticity, with elasticity coefficients greater for money than cigarettes. The effects of fixed-ratio size on response output also differed across the two reinforcers. Although greater responding occurred for money at Fixed Ratio 100, increases in fixed-ratio size (for money) decreased responding for money, whereas the same increase in fixed-ratio size (for puffs) increased responding for puffs. Finally, increasing the fixed-ratio size for one reinforcer had little effect on consumption of the other concurrently available reinforcer. This finding was quantified as cross-price elasticity, with elasticity coefficients near 0.0 for most subjects, indicating little or no reinforcer interaction. The results indicate that the reinforcing effects of cigarettes and money in the setting studied here differed, and that the effects produced by changing the price of one reinforcer did not interact with the consumption of the other concurrently available reinforcer.     

Memory Errors From A Change of Standard: A Lack of Awareness or of Understanding?

Memory errors occur when the context standard that is used when judging target behaviors is different from the category norm standard that is available later when the behaviors are recalled. Is insufficient awareness the reason for this change-of-standard effect? Two kinds of awareness were maximized in each of two studies: (a) awareness of the relation between the judgment and the context - telling subjects to be sure to use the non-target persons for comparison when judging the target person (salience); and (b) awareness at recall of the earlier judgmental context - asking subjects to recall the non-target persons before recalling the target person (reinstatement). Context reinstatement reduced memory errors. But when context reinstatement and salience were combined, the memory errors reappeared. In Study 2, an attempt at debiasing failed. The change-of-standard effect is explained in terms of a "natural" tendency to use the current categorical meaning of a judgment to reconstruct the referent of its past contextualized meaning.     

Emergent equivalence relations between interoceptive (drug) and exteroceptive (visual) stimuli.

Conditional "if-then" relations between drug (interoceptive) stimuli and visual (exteroceptive) stimuli were taught to 4 normal humans. Interoceptive stimuli were the effects produced by 0.32 mg/70 kg triazolam (a prototypical benzodiazepine) and placebo (lactose-filled capsules); exteroceptive stimuli were black symbols on white flash cards. Following the training of the prerequisite conditional relations, tests of emergent relations were conducted between exteroceptive stimuli and between interoceptive and exteroceptive stimuli. Equivalence relations emerged immediately without explicit training for all 4 subjects. Accuracy of responding during the interoceptive-exteroceptive equivalence tests and subjects' self-reports showed consistent discrimination between the drug effects of triazolam and placebo. Finally, a generalization test assessed whether a novel visual stimulus presented in the context of the placebo (i.e., no drug) would generalize to visual stimuli belonging to the placebo stimulus class. All 3 subjects who completed this test reliably chose the visual stimuli belonging to the placebo class and not the visual stimuli belonging to the triazolam stimulus class. The development of equivalence relations between interoceptive and exteroceptive stimuli demonstrates that private and public stimulus events can emerge as members of the same equivalence class. Theoretical and clinical implications are discussed.     

Long-term support and personal adjustment of adolescent and older mothers.

Adolescent and older mothers reported the size and quality of social networks and perceptions of family support at 1, 6, and 12 months postpartum. Maternal behavior, general life satisfaction, and parental satisfaction were assessed at 12 months. No significant differences were found in the size of social networks and quality of interactions within those networks, though older mothers had significantly higher scores on perceived family support than did adolescent mothers. Perceived family support and quality of interactions within the social network generally were associated positively with maternal behavior, life satisfaction, and parental satisfaction. This was true in more cases for the adolescent than for older mothers.     

The effects of diazepam and triazolam on repeated acquisition and performance of response sequences with an observing response.

Drugs often disrupt the acquisition of new response sequences at doses that fail to disrupt the performance of a previously acquired response sequence. This selective drug effect may result from differences in the control exerted by the stimuli presented after each response in the acquisition and performance sequences. To examine the function of these stimuli, an observing procedure was incorporated into a multiple schedule of repeated acquisition and performance of response sequences, in which stimulus presentations were contingent upon an observing response. Three experiments were conducted with humans. Experiment 1 compared responding with and without the observing contingency. No difference was found in the overall percentage of errors across the two conditions. Within the observing condition, observing behaviour was maintained in the acquisition component as long as errors occurred, but was not maintained in the performance component. Experiment 2 examined whether a contingency that increased errors also would increase observing in both the acquisition and performance components. Specifically, reinforcer delivery in each component was contingent upon emitting 10 correct responses and one, two, or four errors. Observing responses increased in the acquisition component as the error requirement increased, whereas observing responses in the performance component increased only when the error requirement was four. Experiment 3 assessed the effects of diazepam (0, 7.5, 15, and 30 mg/70 kg, p.o.) and triazolam (0, 0.375, and 0.75 mg/70 kg, p.o.) on repeated acquisition and performance baselines with the observing contingency. Selective drug effects were obtained in this modified procedure; that is, the percentage of errors in the acquisition component increased at doses that failed to affect the percentage of errors in the performance components. Importantly, drug effects were selective, even though observing responses were not emitted in the performance component and, hence, the stimulus presentations did not occur in that component. These findings suggest that alternative explanations for these differential effects are needed; in that regard, a response-unit account of the selective drug effects is discussed.