Using forced choice to test belief bias in syllogistic reasoning.

In deductive reasoning, believable conclusions are more likely to be accepted regardless of their validity. Although many theories argue that this belief bias reflects a change in the quality of reasoning, distinguishing qualitative changes from simple response biases can be difficult (Dube, Rotello, & Heit, 2010). We introduced a novel procedure that controls for response bias. In Experiments 1 and 2, the task required judging which of two simultaneously presented syllogisms was valid. Surprisingly, there was no evidence for belief bias with this forced choice procedure. In Experiment 3, the procedure was modified so that only one set of premises was viewable at a time. An effect of beliefs emerged: unbelievable conclusions were judged more accurately, supporting the claim that beliefs affect the quality of reasoning. Experiments 4 and 5 replicated and extended this finding, showing that the effect was mediated by individual differences in cognitive ability and analytic cognitive style. Although the positive findings of Experiments 3-5 are most relevant to the debate about the mechanisms underlying belief bias, the null findings of Experiments 1 and 2 offer insight into how the presentation of an argument influences the manner in which people reason

Logic brightens my day: Evidence for implicit sensitivity to logical validity.

A key assumption of dual process theory is that reasoning is an explicit, effortful, deliberative process. The present study offers evidence for an implicit, possibly intuitive component of reasoning. Participants were shown sentences embedded in logically valid or invalid arguments. Participants were not asked to reason but instead rated the sentences for liking (Experiment 1) and physical brightness (Experiments 2-3). Sentences that followed logically from preceding sentences were judged to be more likable and brighter. Two other factors thought to be linked to implicit processing-sentence believability and facial expression-had similar effects on liking and brightness ratings. The authors conclude that sensitivity to logical structure was implicit, occurring potentially automatically and outside of awareness. They discuss the results within a fluency misattribution framework and make reference to the literature on discourse comprehension.10 page(s

Better but still biased: Analytic cognitive style and belief bias

Belief bias is the tendency for prior beliefs to influence people's deductive reasoning in two ways: through the application of a simple belief-heuristic (response bias) and through the application of more effortful reasoning for unbelievable conclusions (accuracy effect or motivated reasoning). Previous research indicates that cognitive ability is the primary determinant of the effect of beliefs on accuracy. In the current study, we show that the mere tendency to engage analytic reasoning (analytic cognitive style) is responsible for the effect of cognitive ability on motivated reasoning. The implications of this finding for our understanding of the impact of individual differences on belief bias are discussed

Investigating reasoning with multiple integrated neuroscientific methods.

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The logic-bias effect: The role of effortful processing in the resolution of belief-logic conflict.

According to the default interventionist dual-process account of reasoning, belief-based responses to reasoning tasks are based on Type 1 processes generated by default, which must be inhibited in order to produce an effortful, Type 2 output based on the validity of an argument. However, recent research has indicated that reasoning on the basis of beliefs may not be as fast and automatic as this account claims. In three experiments, we presented participants with a reasoning task that was to be completed while they were generating random numbers (RNG). We used the novel methodology introduced by Handley, Newstead & Trippas (Journal of Experimental Psychology: Learning, Memory, and Cognition, 37, 28-43, 2011), which required participants to make judgments based upon either the validity of a conditional argument or the believability of its conclusion. The results showed that belief-based judgments produced lower rates of accuracy overall and were influenced to a greater extent than validity judgments by the presence of a conflict between belief and logic for both simple and complex arguments. These findings were replicated in Experiment 3, in which we controlled for switching demands in a blocked design. Across all three experiments, we found a main effect of RNG, implying that both instructional sets require some effortful processing. However, in the blocked design RNG had its greatest impact on logic judgments, suggesting that distinct executive resources may be required for each type of judgment. We discuss the implications of our findings for the default interventionist account and offer a parallel competitive model as an alternative interpretation for our findings

The relationships between perfectionism, pathological worry and generalised anxiety disorder

Background: The relationships between perfectionism, pathological worry and generalised anxiety disorder (GAD) were investigated in a clinical sample presenting for treatment of perfectionism. Method: This study explored the utility of perfectionism in predicting pathological worry in a sample of individuals with elevated perfectionism and GAD (n = 36). Following this, the study examined whether perfectionism could predict a principal GAD diagnosis in the full sample (n = 42).Results: Scores on the perfectionism dimensions Concern over Mistakes, Personal Standards, and Clinical Perfectionism significantly predicted pathological worry among participants with GAD after controlling for gender and depression. The perfectionism dimension Doubts about Actions significantly predicted whether individuals from the full sample received a principal diagnosis of GAD. Conclusions: These findings support certain dimensions of perfectionism having significant associations with pathological worry and GAD

When fast logic meets slow belief: Evidence for a parallel-processing model of belief bias.

Two experiments pitted the default-interventionist account of belief bias against a parallel-processing model. According to the former, belief bias occurs because a fast, belief-based evaluation of the conclusion pre-empts a working-memory demanding logical analysis. In contrast, according to the latter both belief-based and logic-based responding occur in parallel. Participants were given deductive reasoning problems of variable complexity and instructed to decide whether the conclusion was valid on half the trials or to decide whether the conclusion was believable on the other half. When belief and logic conflict, the default-interventionist view predicts that it should take less time to respond on the basis of belief than logic, and that the believability of a conclusion should interfere with judgments of validity, but not the reverse. The parallel-processing view predicts that beliefs should interfere with logic judgments only if the processing required to evaluate the logical structure exceeds that required to evaluate the knowledge necessary to make a belief-based judgment, and vice versa otherwise. Consistent with this latter view, for the simplest reasoning problems (modus ponens), judgments of belief resulted in lower accuracy than judgments of validity, and believability interfered more with judgments of validity than the converse. For problems of moderate complexity (modus tollens and single-model syllogisms), the interference was symmetrical, in that validity interfered with belief judgments to the same degree that believability interfered with validity judgments. For the most complex (three-term multiple-model syllogisms), conclusion believability interfered more with judgments of validity than vice versa, in spite of the significant interference from conclusion validity on judgments of belief

Alzheimer's disease markers in the aged sheep (Ovis aries)

This study reports the identification and characterization of markers of Alzheimer's disease (AD) in aged sheep (Ovis aries) as a preliminary step toward making a genetically modified large animal model of AD. Importantly, the sequences of key proteins involved in AD pathogenesis are highly conserved between sheep and human. The processing of the amyloid-β (Aβ) protein is conserved between sheep and human, and sheep Aβ1–42/Aβ1–40 ratios in cerebrospinal fluid (CSF) are also very similar to human. In addition, total tau and neurofilament light levels in CSF are comparable with those found in human. The presence of neurofibrillary tangles in aged sheep brain has previously been established; here, we report for the first time that plaques, the other pathologic hallmark of AD, are also present in the aged sheep brain. In summary, the biological machinery to generate the key neuropathologic features of AD is conserved between the human and sheep, making the sheep a good candidate for future genetic manipulation to accelerate the condition for use in pathophysiological discovery and therapeutic testing

Potential molecular consequences of transgene integration: The R6/2 mouse example

Integration of exogenous DNA into a host genome represents an important route to generate animal and cellular models for exploration into human disease and therapeutic development. In most models, little is known concerning structural integrity of the transgene, precise site of integration, or its impact on the host genome. We previously used whole-genome and targeted sequencing approaches to reconstruct transgene structure and integration sites in models of Huntington's disease, revealing complex structural rearrangements that can result from transgenesis. Here, we demonstrate in the R6/2 mouse, a widely used Huntington's disease model, that integration of a rearranged transgene with coincident deletion of 5,444 bp of host genome within the gene G$\textit{m}$12695 has striking molecular consequences. G$\textit{m}$12695, the function of which is unknown, is normally expressed at negligible levels in mouse brain, but transgene integration has resulted in cortical expression of a partial fragment (exons 8-11) 3' to the transgene integration site in R6/2. This transcript shows significant expression among the extensive network of differentially expressed genes associated with this model, including synaptic transmission, cell signalling and transcription. These data illustrate the value of sequence-level resolution of transgene insertions and transcription analysis to inform phenotypic characterization of transgenic models utilized in therapeutic research.This work was supported by the National Institutes of Health HD065286 (JFG), MH095867 (MET), GM061354 (MET, JFG), CHDI Inc. (JFG, AJM), NARSAD (MET), the Canada Research Chairs program and a grant from the Natural Science and Engineering Research Council of Canada (CE), and the Neurological Foundation of New Zealand (JJ)