0000000000056260
AUTHOR
Jean-françois Lecas
showing 5 related works from this author
Using visual strategies to support verbal comprehension in an adolescent with Down syndrome
2011
International audience; It has been frequently reported that children with Down syndrome have deficits in verbal short-term memory while having relatively good performance in visual short-term memory tasks. Such verbal deficits have a detrimental effect on various high-level cognitive processes, most notably language comprehension. In this study, we report the case of an adolescent with Down syndrome whose verbal short-term memory and comprehension capacities are impaired. Noting that his visual memory remained relatively well preserved, we developed a remediation strategy based on his visual abilities to support his verbal memory deficit. This remediation led to significant improvements in…
Conditional reasoning by mental models: chronometric and developmental evidence
2000
The aim of this article is to verify two predictions resulting from the mental models theory of conditional reasoning. First, the denial of antecedent (DA) and modus tollens (MT) inferences should take longer to verify than modus ponens (MP) and affirmation of consequent (AC) because the former require subjects to flesh out the initial model whereas the latter do not. This prediction was confirmed in two reaction time experiments in adults. In line with Evans' proposal (Evans, J. St. B. T. (1993). The mental model theory of conditional reasoning: critical appraisal and revision. Cognition, 48, 1-20), there was a strong directionality effect: inferences from antecedent to consequent (MP and …
Content and context effects in children's and adults' conditional reasoning
2002
We have recently shown that children interpret conditional sentences with binary terms (e.g., male/female) in both the antecedent and the consequent as biconditionals (Barrouillet & Lecas, 1998). We hypothesized that the same effect can be obtained with conditionals that do not contain binary terms provided that they are embedded in a context that restricts to only two the possible values on both the antecedent and the consequent. In the present experiment, we asked 12-year-old children, 15-year-old children, and adults to draw conclusions from conditional syllogisms that involved three types of conditional sentence: (1) conditionals with binary terms (BB), (2) conditionals with non-bi…
How can mental models theory account for content effects in conditional reasoning? A developmental perspective
1998
Abstract This article proposes a modification to Johnson-Laird's mental models theory applied to the interpretation of conditional statement of the form `if...then'. The model suggests that this interpretation is based on the construction of mental models supplied by establishing a correspondence between the semantic spaces associated with the antecedent and consequent of the statements. The construction of the models and the interpretation of the statements would depend on the nature of the semantic spaces involved, the interpretative context and the subject's knowledge and processing capacity. Three experiments show that the interpretation of conditional rules depends, for example, on whe…
Illusory inferences from a disjunction of conditionals: a new mental models account
2000
(Johnson-Laird, P.N., & Savary, F. (1999, Illusory inferences: a novel class of erroneous deductions. Cognition, 71, 191-229.) have recently presented a mental models account, based on the so-called principle of truth, for the occurrence of inferences that are compelling but invalid. This article presents an alternative account of the illusory inferences resulting from a disjunction of conditionals. In accordance with our modified theory of mental models of the conditional, we show that the way individuals represent conditionals leads them to misinterpret the locus of the disjunction and prevents them from drawing conclusions from a false conditional, thus accounting for the compelling char…