Online research in philosophy

This study investigated the roles of the executive functions of inhibition and switching, and of verbal and visuo-spatial working memory capacities, in insight and non-insight tasks. A total of 18 insight tasks, 10 non-insight tasks, and measures of individual differences in working memory capacities, switching, and inhibition were administered to 120 participants. Performance on insight problems was not linked with executive functions of inhibition or switching but was linked positively to measures of verbal and visuo-spatial working memory capacities. Non-insight task performance was positively linked to the executive function of switching (but not to inhibition) and to verbal and visuo-spatial working memory capacities. These patterns regarding executive functions were maintained when the insight and non-insight composites were split into verbal and spatial insight and non-insight composite scores. The results are discussed in relation to dual processing accounts of thinking.

This study investigated the roles of the executive functions of inhibition and switching, and of verbal and visuo-spatial working memory capacities, in insight and non-insight tasks. A total of 18 insight tasks, 10 non-insight tasks, and measures of individual differences in working memory capacities, switching, and inhibition were administered to 120 participants. Performance on insight problems was not linked with executive functions of inhibition or switching but was linked positively to measures of verbal and visuo-spatial working memory capacities. Non-insight task performance was positively linked to the executive function of switching (but not to inhibition) and to verbal and visuo-spatial working memory capacities. These patterns regarding executive functions were maintained when the insight and non-insight composites were split into verbal and spatial insight and non-insight composite scores. The results are discussed in relation to dual processing accounts of thinking.

The mental model theory predicts variations in the percentage of errors in meta-propositional reasoning tasks but does not specify the nature of these errors (Johnson-Laird & Byrne, 1990). In the present study, we drew predictions concerning the nature of errors in a meta-propositional reasoning task by importing and elaborating the distinction between implicit and explicit models previously applied by the mental model theory to the domain of propositional reasoning (Johnson-Laird, Byrne, & Schaeken, 1992). An experiment was conducted in which participants were asked to solve problems concerning the truth or falsity of propositional assertions. The task was to determine the truth-status (liar or truth-teller) of two persons making a propositional assertion about their own truth-status and/or the truth-status of the other person. The results were consistent with the hypothesis that people may reason in ways that differ in the extent to which initially implicit models are made explicit. As such, the results corroborate a basic principle of the mental model theory: the errors that reasoners make are consistent with at least one of the mental models they construct during the process of reasoning.

This study examined the hypothesis that conditional reasoning involves visual short-term memory resources (Johnson-Laird, 1985). A total of 147 university students were given measures of verbal and visual short-term memory capacity and a series of concrete and abstract conditional reasoning problems. Results indicate that there is a positive correlation between verbal working memory capacity and reasoning with both concrete and abstract premises. A positive correlation was also obtained between visual working memory capacity and reasoning with concrete premises.

Johnson-Laird (1983) has argued that spatial reasoning is based on the construction and manipulation of mental models in memory. The present article addresses the question of whether reasoning about time relations is constrained by the same factors as reasoning about spatial relations. An experiment is reported that explored the similarities and the differences in the performance of subjects in comparable spatial and temporal reasoning tasks. The results indicated that, in both the temporal and the spatial content domains, the data were in agreement with the view that subjects solved problems by constructing models in memory rather than with a logical rule conceptualisation of reasoning. An analysis of the premise-reading times on the basis of premise-linking order provided support for an on-line process of mental models construction, and offered an explanation for the finding that spatial problems that did require an inference of transitivity were easier than problems that did not. No essential differences in processing and performance were observed across the two content domains, although in the time domain the correctness data were in agreement with both the mental models theory and the logical rules view. The results are discussed with respect to the mental models theory and the structural characteristics of the problems.

The ability to reason independently from one's own goals or beliefs has long been recognised as a key characteristic of the development of formal operational thought. In this article we present the results of a study that examined the correlates of this ability in a group of 10-year-old children ( N  = 61). Participants were presented with conditional and relational reasoning items, where the content was manipulated such that the conclusion to the arguments were either congruent, neutral, or incongruent with beliefs, and either logically valid or logically invalid. Participants also received a measure of working memory capacity (the counting span task) and a measure of inhibitory control (the stop signal task). Indices of belief bias and logical reasoning on belief-based problems were predicted independently by both measures. In contrast logical reasoning on belief neutral problems was predicted by working memory alone. The findings suggest that executive functions play a key role in the development of children's ability to decontextualise their thinking.

This article reports three experiments that investigated the relationship between working memory capacity and syllogistic and five-term series spatial inference. A series of complex and simple verbal and spatial working memory measures were employed. Correlational analyses showed that verbal and spatial working memory span tasks consistently predicted syllogistic and spatial reasoning performance. A confirmatory factor analysis showed that three factors best accounted for the data--a verbal, a spatial, and a general factor. Syllogistic reasoning performance loaded all three factors, whilst spatial reasoning loaded only the general factor. The implications of these findings are discussed in the context of reasoning theories and contemporary accounts of the structure of working memory.

Johnson-Laird's mental models theory claims that reasoning is a semantic process of construction and manipulation of models in working memory of limited capacity. Accordingly, both a deduction and a given interpretation of a premise would be all the harder the higher the number of models they require. The purpose of the present experiment was twofold. First, it aimed to demonstrate that the interpretation of if...then conditional sentences in children (third, sixth, and ninth graders) evolves as a function of the number of models the children can produce. We proposed a theory of conditional reasoning development that hypothesises a developmental trend of three successive levels of interpretations underlain by one, two, and then three models, i.e. conjunctive, biconditional, and conditional respectively. Second, we aimed to show that these different levels correlate with working memory capacities: the higher the working memory span, the higher the number of models underlying the conditional interpretation. These two hypotheses were verified, supporting the mental models theory. The results are compared with the rival theory of mental logic.

Four experiments assessed the relative involvement of different working memory components in two types of reasoning tasks: propositional and spatial reasoning. Using the secondary-task methodology, visual, central-executive, and phonological loads were realised. Although the involvement of visuospatial resources in propositional reasoning has traditionally been considered to be small, an overall analysis of the present data suggests an alternative account. A theoretical analysis of the pattern of results in terms of Evans' (1984, 1989) twostage theory of reasoning is proposed and tested in Experiments 3 and 4, in which direct evidence for the alternative account was obtained: significant disruption of propositional reasoning by a concurrent spatial load.