Behavioral assessment of impulsivity: a comparison of children with and without attention deficit hyperactivity disorder

We conducted a brief computer-based assessment involving choices of concurrently presented arithmetic problems associated with competing reinforcer dimensions to assess impulsivity (choices controlled primarily by reinforcer immediacy) as well as the relative influence of other dimensions (reinforcer rate, quality, and response effort), with 58 children. Results were compared for children with attention deficit hyperactivity disorder (ADHD) who were and were not receiving medication, and with typically developing children without ADHD. Within-subject and between-groups analyses of the ordinal influence of each of the reinforcer dimensions were conducted using both time- and response-allocation measures. In general, the choices of children with ADHD were most influenced by reinforcer immediacy and quality and least by rate and effort, suggesting impulsivity. The choices of children in the non-ADHD group were most influenced by reinforcer quality, and the influence of immediacy relative to the other dimensions was not statistically significant. Results are discussed with respect to the implications for assessment and treatment of ADHD.     

Getting the Right Idea: Semantic Activation in the Right HemisphereMay Help Solve Insight Problems

Two experiments examined hemispheric differences in information processing that may contribute to solving insight problems. We propose that right-hemisphere (RH) coarse semantic coding is more likely than left-hemisphere (LH) fine semantic coding to activate distantly related information or unusual interpretations of words, and thus more likely to activate solution-relevant information for insight problems. In Experiment 1, after trying to solve insight problems, participants read aloud solution or unrelated target words presented to the left visual field (lvf) or right visual field (rvf). Participants showed greater lvf-RH than rvf-LH priming for solutions for solved problems and priming only in the lvf-RH for unsolved problems. In Experiment 2, participants showed an lvf-RH advantage for recognizing solutions to unsolved problems. These results demonstrate that in a problem-solving context, there was greater activation of solution-relevant information in the RH than in the LH. This activation is useful for recognizing, and perhaps producing, solutions to insight problems.     

Lorsque la logique rencontre l'argumentation

It is well known that classical logics are able to represent only some aspects of ordinary reasoning. In particular, by accepting the law of obversion, they remove the possibility of defining any but a propositional negation; certain natural uses of negation thus elude them. Logical theories do exist, however, that are exempt from such limitations. Among these theories are those of S. Leniewski, which differ profoundly from classical formal systems. Unlike the latter, they do not have a determined list of functors of syntactical-semantical categories. Due to formalized directives for definitions, the logics of Leniewski are constructed progressively, making new theses and consequently functors of new syntactical-semantical categories accessible. In this article we use some of these theses-definitions to define a principle of appropriateness. With this principle it is possible to represent certain logical subtleties that are used quite naturally but are neglected due to the law of obversion.

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Lorsque la logique rencontre l'argumentation

     

Observer Perceptions of Would-Be Provider and Would-Be Recipient Reactions to Rejected Social Support1

Role-playing observers predicted the reactions of hypothetical would-be recipients whose requests for social support were unmet as well as those of hypothetical would-be providers for their rejection of such requests. The extent to which the would-be recipient was depicted at fault for the problem was predicted to affect perceived reactions since support may be less likely when potential recipients are blameworthy than when they are innocent of responsibility for their predicament. Observers perceived would-be recipients of support as believing that would-be providers blamed them. Observers saw would-be providers as blaming the would-be recipients rather than themselves, especially if the victim was blameworthy. When the victim was not blameworthy, would-be providers were more likely than would-be recipients to be judged to use a mixture of rationalizations and excuses rather than blame.     

Search efficiency is not sufficient: The nature of search modulates stimulus-driven attention

It has long been debated whether or not a salient stimulus automatically attracts people’s attention in visual search. Recent findings showed that a salient stimulus is likely to capture attention especially when the search process was inefficient due to high levels of competition between the target and distractors. Expanding these studies, the present study proposes that a specific nature of visual search, as well as search efficiency, determines whether or not a salient, task-irrelevant singleton stimulus captures attention. To test this proposition, we conducted three experiments, in which participants performed two visual search tasks whose underlying mechanisms are known to be different: orientation-feature search and Landolt-C search tasks. We found that color singleton distractors captured attention when participants performed the orientation-feature search task. The magnitude of this capture effect increased as search efficiency decreased. On the contrary, the capture by singleton distractors was not observed under the Landolt-C search task. This differential pattern of capture effect was not due to differences in search efficiency across the search tasks; even when search efficiency was controlled for, stimulus-driven capture of attention by a salient distractor was found only under the feature search. Based on these results, the present study suggests that in addition to search efficiency, the nature of search strategy and the extent to which attentional control is strained play crucial roles in observing stimulus-driven attentional capture in visual search.