Overestimation of base-rate differences in complex perceptual categories

The optimality of multidimensional perceptual categorization performance was examined for several base-rate ratios, for both integral and separable dimension stimuli, and for complex category structures. In all cases, the optimal decision bound was highly nonlinear. Observers completed several experimental sessions, and all analyses were performed at the single-observer level using a series of nested models derived from decision-bound theory (Maddox, 1995; Maddox & Ashby, 1993). In every condition, all observers were found to be sensitive to the base-rate manipulations, but the majority of observers appeared to overestimate the base-rate difference. These findings converge with those for cases in which the optimal decision bound was linear (Maddox, 1995) and suggest that base-rates are learned in a similar fashion regardless of the complexity of the optimal decision bound. Possible explanations for the consistent overestimate of the base-rate difference are discussed. Several continuous-valued analogues of Kruschke’s (1996) theory of base-rate learning with discrete-valued stimuli were tested. These models found some support, but in all cases were outperformed by a version of decision-bound theory that assumed accurate knowledge of the category structure and an overestimate of the base-rate difference.     

Subjective Change and Its Consequences for Emotional Well-Being

This study investigates the impact of subjective changes in the execution of the roles of spouse, worker, and parent on the level and structure of positive and negative affect. According to the self-theory of subjective change, perceived improvement and decline are unsettling because each violate standards of self-conception, but perceived stability satisfies the organismic desire for homeostasis. Therefore individuals who perceive more changes in themselves should report more negative and less positive affect, compared with individuals who feel they have remained the same. The context-dependence theory of affects also argues that the correlation of negative and positive affect is strong when individuals are distressed and modest when they are in homeostasis. Thus, the correlation of positive and negative should approach unity as individuals perceive more change in themselves. Data are from the MIDUS study and sample (N = 3,032) of adults between the ages of 25 and 74. Respondents completed scales of positive and negative affect, and evaluated their current and past (10 years ago) functioning as spouses (or close relationship), in work, and as parents (relationship with their children). The correlation of positive and negative affect approached unity at the highest levels of perceived improvement, r = –.93, and at the highest levels of perceived decline, r = –.90, but was modestly correlated at no change, r = –.52. Moreover, the level of positive affect was lower, and negative affect was higher, among adults who perceived more improvement as well as declines, compared with adults who remained the same. Implications for the study of objective life events as well as health interventions are discussed.an affiliated program of Emory University     

Probability matching, accuracy maximization, and a test of the optimal classifier’s independence assumption in perceptual categorization

Observers completed perceptual categorization tasks that included 25 base-rate/payoff conditions constructed from the factorial combination of five base-rate ratios (1:3, 1:2, 1:1, 2:1, and 3:1) with five payoff ratios (1:3, 1:2, 1:1, 2:1, and 3:1). This large database allowed an initial comparison of the competition between reward and accuracy maximization (COBRA) hypothesis with a competition between reward maximization and probability matching (COBRM) hypothesis, and an extensive and critical comparison of the flat-maxima hypothesis with the independence assumption of the optimal classifier. Model-based instantiations of the COBRA and COBRM hypotheses provided good accounts of the data, but there was a consistent advantage for the COBRM instantiation early in learning and for the COBRA instantiation later in learning. This pattern held in the present study and in a reanalysis of Bohil and Maddox (2003). Strong support was obtained for the flat-maxima hypothesis over the independence assumption, especially as the observers gained experience with the task. Model parameters indicated that observers’ reward-maximizing decision criterion rapidly approaches the optimal value and that more weight is placed on accuracy maximization in separate base-rate/payoff conditions than in simultaneous base-rate/payoff conditions. The superiority of the flat-maxima hypothesis suggests that violations of the independence assumption are to be expected, and are well captured by the flat-maxima hypothesis, with no need for any additional assumptions.     

Correction to: Closed but Not Protected: Excess Deaths Among the Amish and Mennonites During the COVID‑19 Pandemic

Journal of Religion and Health -     

Psychological momentum: intuitive physics and naive beliefs

The present research examines psychological momentum (PM), a perceived force that lay intuition suggests influences performance. PM theory is proposed to account for how momentum perceptions arise, and four studies demonstrate the influence of lay intuitions about PM on expectations regarding performance outcomes. Study 1 establishes that individuals share intuitions about the types of events that precipitate PM, and Study 2 finds that defeating a rival increases momentum perceptions. Study 3 provides evidence for the lay belief that as more PM accumulates during a prior task, there should be more residual momentum left to carry over to a subsequent task, and Study 4 finds that an individual whose PM is interrupted is expected to have greater difficulty completing a task than is an individual whose steady progress is interrupted. Discussion focuses on linkages between PM and related constructs.     

Ethical and legal issues in group counseling

Legal and ethical issues involved in group work are reviewed and discussed. Variations in different professional ethics codes are discussed. Recommendations for consideration by group leaders are made.     

WOMEN'S PSYCHOLOGICAL ADJUSTMENT FOLLOWING EMERGENCY CESAREAN VERSUS VAGINAL DELIVERY

The present study was designed to investigate possible differences in psychological adjustment and satisfaction between women delivering vaginally and those delivering by emergency cesarean section. Women's satisfaction with the birth experience was distinguished from postpartum psychological adjustment, as measured by depression, anxiety, and confidence in mothering ability. Twenty-two women who delivered vaginally and twenty-two women who delivered by emergency cesarean section were selected according to stringent criteria, to control for factors known to be associated with positive cesarean outcomes. Significant differences were found in level of satisfaction, with cesarean mothers reporting less satisfaction with the delivery than vaginal mothers. However, no differences were found between the groups on the three measures of psychological adjustment. Under optimal conditions, cesarean deliveries are not associated with adverse early postpartum psychological adjustment.