Conflict adaptation in time: Foreperiods as contextual cues for attentional adjustment

Interference evoked by distractor stimulus information, such as flankers in the Eriksen task, is reduced when the proportion of conflicting stimuli is increased. This modulation is sensitive to contextual cues such as stimulus location or color, suggesting attentional adjustment to conflict contingencies on the basis of context information. In the present study, we explored whether conflict adjustment is modulated by temporal variation of conflict likelihood. To this end, we associated low and high proportions of conflict stimuli with foreperiods of different lengths. Flanker interference was higher with foreperiods associated with low conflict proportions, suggesting that participants use the foreperiod as a contextual cue for attentional adjustment. We conjecture that participants initially adopt the strategy useful for conflict contingencies associated with short foreperiods, and then readjust during the trial, in the absence of any additional exogenous cue, when the imperative stimulus has not occurred during a certain time interval.     

Decision-making under uncertainty: biases and Bayesians

Animals (including humans) often face circumstances in which the best choice of action is not certain. Environmental cues may be ambiguous, and choices may be risky. This paper reviews the theoretical side of decision-making under uncertainty, particularly with regard to unknown risk (ambiguity). We use simple models to show that, irrespective of pay-offs, whether it is optimal to bias probability estimates depends upon how those estimates have been generated. In particular, if estimates have been calculated in a Bayesian framework with a sensible prior, it is best to use unbiased estimates. We review the extent of evidence for and against viewing animals (including humans) as Bayesian decision-makers. We pay particular attention to the Ellsberg Paradox, a classic result from experimental economics, in which human subjects appear to deviate from optimal decision-making by demonstrating an apparent aversion to ambiguity in a choice between two options with equal expected rewards. The paradox initially seems to be an example where decision-making estimates are biased relative to the Bayesian optimum. We discuss the extent to which the Bayesian paradigm might be applied to the evolution of decision-makers and how the Ellsberg Paradox may, with a deeper understanding, be resolved.     

His biceps become him: a test of objectification theory's application to drive for muscularity and propensity for steroid use in college men

Men's body image problems may manifest as an unhealthy drive for muscularity and propensity to use anabolic-androgenic steroids (AAS). Aspects of objectification theory were integrated with literature on men's drive for muscularity and AAS use to identify correlates of these problems. The resultant model was tested with path analyses of data from 270 college men. First, consistent with prior research on objectification theory, results indicated that body surveillance partially mediated the link of internalization of cultural standards of attractiveness with body shame. Second, positive outcome expectation for AAS use partially mediated the link of drive for muscularity with intention to use AAS. Third, drive for muscularity partially mediated the links of internalization with outcome expectation for AAS use and intention to use AAS. Finally, outcome expectation for AAS use was an additional partial mediator of the link of internalization with intention to use AAS. Body surveillance and body shame did not have unique direct or mediated relations with drive for muscularity or AAS variables. These findings point to internalization of cultural standards of attractiveness as the nexus of overlap between the objectification theory variables and men's drive for muscularity and propensity to use AAS.     

The impact of cognitive predispositions on exploration decisions in the minerals industry

Minerals exploration is conducted within an environment of ambiguity in the information and a high degree of uncertainty concerning success. In an extension and application of Tetlock (2005) the present research examined the impact of cognitive predispositions on the quality of minerals exploration decision‐making. Utilising instruments specifically designed to assess thinking and judgement predispositions results indicate that for this sample (n = 94) an enjoyment of rational thinking and the need for cognitive closure were predictive of lower estimated percentages of the likelihood of finding an exploitable deposit keeping geophysical data constant. Several counter‐intuitive findings related to the relationship between likelihood and amount of expenditure were also found. The findings add further support to Tetlock's (2005) call to hold experts in all fields to account for the recommendations they make and to examine not just what they think but how they think. Copyright © 2010 John Wiley & Sons, Ltd.     

Order or disorder? Impaired Hebb learning in dyslexia

The present study offers an integrative account proposing that dyslexia and its various associated cognitive impairments reflect an underlying deficit in the long-term learning of serial-order information, here operationalized as Hebb repetition learning. In nondyslexic individuals, improved immediate serial recall is typically observed when one particular sequence of items is repeated across an experimental session, a phenomenon known as the Hebb repetition effect. Starting from the critical observation that individuals with dyslexia seem to be selectively impaired in cognitive tasks that involve processing of serial order, the present study is the first to test and confirm the hypothesis that the Hebb repetition effect is affected in dyslexia, even for nonverbal modalities. We present a theoretical framework in which the Hebb repetition effect is assumed to be a laboratory analogue of naturalistic word learning, on the basis of which we argue that dyslexia is characterized by an impairment of serial-order learning that affects language learning and processing.     

Superstition predicts perception of illusory control

Superstitions are common, yet we have little understanding of the cognitive mechanisms that bring them about. This study used a laboratory‐based analogue for superstitious beliefs that involved people monitoring the relationship between undertaking an action (pressing a button) and an outcome occurring (a light illuminating). The task was arranged such that there was no objective contingency between pressing the button and the light illuminating – the light was just as likely to illuminate whether the button was pressed or not. Nevertheless, most people rated the causal relationship between the button press and the light illuminating to be moderately positive, demonstrating an illusion of causality. This study found that the magnitude of this illusion was predicted by people's level of endorsement of common superstitious beliefs (measured using a novel Superstitious Beliefs Questionnaire), but was not associated with mood variables or their self‐rated locus of control. This observation is consistent with a more general individual difference or bias to overweight conjunctive events over disjunctive events during causal reasoning in those with a propensity for superstitious beliefs.     

Simplified Estimation and Testing in Unbalanced Repeated Measures Designs

In this paper we propose a simple estimator for unbalanced repeated measures design models where each unit is observed at least once in each cell of the experimental design. The estimator does not require a model of the error covariance structure. Thus, circularity of the error covariance matrix and estimation of correlation parameters and variances are not necessary. Together with a weak assumption about the reason for the varying number of observations, the proposed estimator and its variance estimator are unbiased. As an alternative to confidence intervals based on the normality assumption, a bias-corrected and accelerated bootstrap technique is considered. We also propose the naive percentile bootstrap for Wald-type tests where the standard Wald test may break down when the number of observations is small relative to the number of parameters to be estimated. In a simulation study we illustrate the properties of the estimator and the bootstrap techniques to calculate confidence intervals and conduct hypothesis tests in small and large samples under normality and non-normality of the errors. The results imply that the simple estimator is only slightly less efficient than an estimator that correctly assumes a block structure of the error correlation matrix, a special case of which is an equi-correlation matrix. Application of the estimator and the bootstrap technique is illustrated using data from a task switch experiment based on an experimental within design with 32 cells and 33 participants.

     

Meeting Scotus: On Scholasticism and Its Ghosts

Recalling the story of the ghost of Duns Scotus that haunts Merton Library, we investigate in this article whether Christian theology contains room for belief in ghosts. We conclude that there is no good reason why ghosts should not exist within a proper dogmatic account of death and resurrection, but that there is no theological need to affirm that ghosts do exist either. Thus we suggest that this matter is dogmatically indifferent. That same dogmatic account, however, demands that we take seriously the continuing lively voices of those, like Scotus, who have gone before as we pursue our own theological vocations.     

Relative informativeness of quantifiers used in syllogistic reasoning

Three experiments tested a possible resolution of the probability heuristics model (PHM) of syllogistic reasoning proposed by Chater and Oaksford (1999), with their experimental results apparently showing that the generalized quantifier few was not as informative as suggested theoretically. Modifying the interpretation of few to take into account the distinction between positive and negative quantifiers (Moxey & Sanford, 1993) indicated two orderings over the quantifiers all, most, few, some, none, and some...not that are more consistent with the results. Experiments 1-3 tested these orderings empirically by having participants rank whether a quantifier applied to a particular probabilistic state of affairs. Experiments 1 and 2 showed that participants agreed on when a quantifier applied and that the empirically derived informativeness orderings were consistent with the proposed modifications of the order. Experiment 3 showed that this finding was robust even when response competition was eliminated.