Stimulus generalization of schedule-induced polydipsia

Five rats were exposed to an intradimensional discrimination by associating two tones of different frequency with the components of a multiple random-time 30-sec, extinction schedule of food presentation. After schedule-induced polydipsia developed and the intermittent schedule of food presentation established stable differential licking rates during the stimuli associated with the multiple schedule, a stimulus generalization test was conducted. When generalization testing was conducted by presenting stimuli that varied on the frequency dimension during the random-time 30-sec component of the multiple schedule, all five rats demonstrated moderately sloping symmetrical gradients. Thus, schedule-induced polydipsia can be brought under the control of stimuli other than the food pellet.     

Selection of verbal probabilities: A solution for some problems of verbal probability expression

A method for verbal expression of degree of uncertainty is described. It requires the subject to select a phrase from a list that spans the full range of probabilities. In a second, optional, step, the subject indicates the numerical meaning of each phrase. The method avoids two problems of verbal probabilities—the indefinitely large lexicon and the individual differences in the interpretation of words. To test whether context and ordinal position might bias subjects' selection or interpretation of the verbal expressions in the list, the list order was varied. When the verbal expressions were arranged in random order, ordinal position had a significant effect on the selection of expressions. However, these effects did not occur when the phrases were listed in ascending or descending order. Considerations of accuracy and interpersonal agreement also support the use of ordered phrase lists.     

Individual differences in patterns of developmental opportunity and constraint during COVID-19: Implications for longitudinal well-being

Individual differences in sociodemographic characteristics and trait-like perceptions of opportunities and constraints may shape how people respond to adversities such as the COVID-19 pandemic. However, little is known about how these factors combine to form multifaceted profiles of developmental opportunity and constraint or the implications of such profiles for longitudinal well-being following major life stressors. Using 1-year data from a national sample of U.S. adults (n = 293), we identified profiles based on relevant sociodemographic characteristics (age, socioeconomic status, chronic conditions, functional status) and trait-like perceptions of opportunity and constraints (perceived mastery, perceived constraints). Results of latent profile analyses showed that three common profiles emerged at pandemic onset (veridical opportunity, perceived constraints, perceived opportunity). Subsequent latent growth models showed that, despite reporting more sociodemographic constraints, the perceived opportunity profile exhibited better 1-year emotional well-being (positive and negative affect) during the pandemic than the perceived constraints profile. Findings advance the literature by identifying multifaceted individual differences in profiles of developmental opportunity and constraint and by showing these profiles have consequences for longitudinal well-being following the pandemic onset.     

Sensitization and aversive conditioning: Effects on the startle reflex and electrodermal responding

Animal data suggest that shock sensitization as well as aversive learning potentiates the acoustic startle reflex. The present experiment tested, whether this shock sensitization also occurs in human subjects and whether it precedes aversive conditioning. Sixty subjects viewed—prior to conditioning—a series of slides of different emotional contents including the to be conditioned stimuli (CSs). Afterwards, the experimenter attached the shock electrodes and initiated shock exposure. Then, subjects were randomly assigned to view a series of two slides, each for eight acquisition trials in which one slide was followed by a shock. Subsequently, extinction trials (12 for each slide) were administered. During preconditioning, acquisition, and extinction, startle probes occurred unpredictably during and between slide viewing. Preconditioning data replicated previous results by Lang and his associates, showing that the startle response magnitude is directly related to the affective valence induced by the slides. Shock exposure strongly facilitated the startle reflex magnitude. This shock sensitization was absent for the skin conductance response. Course of learning also varied for both response systems. The data suggest that startle reflex potentiation indexes the acquisition of an avoidance disposition, which is preceded by a general sensitization of the protective reflexes. Skin conductance learning follows arousal changes and is modulated by cognitive processes.