Bayesian generic priors for causal learning

The article presents a Bayesian model of causal learning that incorporates generic priors--systematic assumptions about abstract properties of a system of cause-effect relations. The proposed generic priors for causal learning favor sparse and strong (SS) causes--causes that are few in number and high in their individual powers to produce or prevent effects. The SS power model couples these generic priors with a causal generating function based on the assumption that unobservable causal influences on an effect operate independently (P. W. Cheng, 1997). The authors tested this and other Bayesian models, as well as leading nonnormative models, by fitting multiple data sets in which several parameters were varied parametrically across multiple types of judgments. The SS power model accounted for data concerning judgments of both causal strength and causal structure (whether a causal link exists). The model explains why human judgments of causal structure (relative to a Bayesian model lacking these generic priors) are influenced more by causal power and the base rate of the effect and less by sample size. Broader implications of the Bayesian framework for human learning are discussed.     

Perceived freedom-responsibility covariation among Cypriot adolescents

Participants were 67 Cypriot adolescents who responded to propositions regarding positive, negative, and noncontingent relations between freedom and responsibility. The authors framed items so that half dealt with freedom given responsibility, and the other half dealt with responsibility given freedom. Results indicated participants were more likely to endorse positive-contingency items than they were negative and noncontingency items when items were framed around freedom given responsibility. However, when items were framed around responsibility given freedom, no such differences emerged. The authors discuss results relative to cultural and sociopolitical differences and similarities between children in Cypress and participants in the United States and implications concerning the present study and previous studies regarding these constructs.     

Factors affecting infants' manual search for occluded objects and the genesis of object permanence

Two experiments systematically examined factors that influence infants’ manual search for hidden objects (N = 96). Experiment 1 used a new procedure to assess infants’ search for partially versus totally occluded objects. Results showed that 8.75-month-old infants solved partial occlusions by removing the occluder and uncovering the object, but these same infants failed to use this skill on total occlusions. Experiment 2 used sound-producing objects to provide a perceptual clue to the objects’ hidden location. Sound clues significantly increased the success rate on total occlusions for 10-month-olds, but not for 8.75-month-olds. An identity development account is offered for why infants succeed on partial occlusions earlier than total occlusions and why sound helps only the older infants. We propose a mechanism for how infants use object identity as a basis for developing a notion of permanence. Implications are drawn for understanding the dissociation between looking time and search assessments of object permanence.     

The transience of constructed preferences

A large body of research suggests that preferences are constructed rather than merely accessed in the course of making decisions. The current research examines the stability of constructed preferences over time. Preferences for various factors relevant to a job choice were measured prior to presentation of the job‐choice task, at the point of decision, and again following a delay. It was found that relative to baseline pre‐decision levels, preferences shifted to provide stronger support for the emerging decision. Preference changes proved to be transient, receding to baseline after 1 week (Experiment 1), and even within 15 minutes (Experiment 2). These findings, which can be interpreted in terms of decision‐making by constraint satisfaction, suggest that preferences are constructed to serve the decision at hand, without constraining the decision maker in future decisions. Copyright © 2007 John Wiley & Sons, Ltd.     

Who says grandparents matter?

Data from the Church Life Profile of 2001 confirm a high proportion of grandparents among churchgoers and demonstrate a link between the religiosity of grandparents and that of their grandchildren. This article presents empirical evidence to show that the importance of this link is acknowledged by rural clergy and taken into account when determining whether to baptise the children of parents who cannot themselves profess the Christian faith.     

Diagnostic test evaluation of a nasal flow monitor for obstructive sleep apnea detection in sleep apnea research

In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea (OSA), 34 patients referred for polysomnography were studied at home for three consecutive nights with the monitor. The mean age of subjects (+/-SD) was 41.9+/-10.3 years, and their mean apnea-hypopnea index (AHI) was 31.5+/-27.2. The difference between the average AHI from three nights at home on the monitor and the polysomnogram (PSG) result was 1.8+/-17.1. The area under the receiver operating characteristic curve (AUC) for PSG AHI > or = 10 was .96. With a threshold AHI of 18 on the flow monitor, sensitivity was .92, specificity .86, positive predictive value .96, and negative predictive value .75. For detecting severe OSA (AHI > or = 30), the AUC was .85. With knowledge of appropriate thresholds and the pretest risk of OSA, the flow monitor can be used to detect or exclude OSA for sleep-related research, as well as to identify severe cases needing priority for further evaluation.     

Differential Mastication Kinematics of the Rabbit in Response to Food and Water: Implications for Conditioned Movement

Analysis of naturalistic chewing patterns may provide insight into mapping the neural substrates of jaw movement control systems, including their adaptive modification during the classically conditioned jaw movement (CJM) paradigm. Here, New Zealand White rabbits were administered food and water stimuli orally to evaluate the influence of stimulus consistency on masticatory pattern. Chewing patterns were recorded via video camera and movements were analyzed by computerized image analysis. The mandibular kinematics, specifically the extent of dorsal/ventral, medial/lateral, and rostral/caudal movement, were significantly larger in food-evoked than water-evoked chewing. Water-evoked chewing frequency, however, was significantly higher than that of food-evoked movements. In light of known cortical mastication modulatory centers, our findings implicate different neural substrates for the responses to food and water stimuli in the rabbit. A detailed delineation of jaw movement patterns and circuitry is essential to characterize the neural substrates of CJM.     

Memory monitoring and the control of stereotype distortion

We propose a framework for investigating the role of conscious experience in regulating stereotype-based memory distortions. Memory biases are mediated by multiple memory processes, including forms of discriminability and response biases. Different psychological interpretations of these processes depend on how they relate to subjective experiences (e.g., conscious recollection vs. implicit accessibility processes). The ability to control memory distortions, in turn, depends on the psychological meaning attached to these parameters. In Experiment 1 we found that confidence was positively related to discriminability but uncorrelated with stereotype-consistent bias. In Experiment 2 participants were allowed to selectively control when they responded. Because of the asymmetry in monitoring ability, participants were able to increase overall accuracy, but were not able to reduce the stereotype bias. Discussion focuses on the conditions in which subjective experience may provide a valid basis for controlling biases, and when subjective experience may prove deceptive, exacerbating biases.     

Manipulating subcategory salience: exploring the link between skin tone and social perception of Blacks

Guided by the model of social category salience proposed by M. Blanz ( 1999 ), the present paper explores factors affecting the salience of skin tone‐based subcategories among Blacks in the United States. Adapting the group discussion paradigm developed by S.E. Taylor and colleagues ( 1978 ), Experiment 1 demonstrated that a manipulation of issue relevance enhanced the category salience of skin tone. Participants made more within‐ than between‐category errors when the topic of conversation was related to perceiver's skin tone‐based beliefs. Experiment 2 demonstrated that the influence of the issue relevance manipulation was independent of the presence of structural and/or normative fit. Merely discussing the topic of race relations was sufficient to increase encoding and use of skin tone. These studies provide evidence linking skin tone and social beliefs in memory. In addition, they demonstrate support for a category‐based perspective in the study of skin tone bias. Additional factors affecting the salience of skin tone are discussed. Copyright © 2004 John Wiley & Sons, Ltd.