One-Sided Arguments

When is an argument to be called one-sided? When is putting forward such an argument fallacious? How can we develop a model for critical discussion, such that a fallaciously one-sided argument corresponds to a violation of a discussion rule? These issues are dealt with within ‘the limits of the dialogue model of argument’ by specifying a type of persuasion dialogue in which an arguer can offer complex arguments to anticipate particular responses by a critic.     

The effects of prior knowledge and text structure on comprehension processes during reading of scientific texts

The aim of the present study was to investigate the effects of prior knowledge and text structure on cognitive processes during comprehension of scientific texts. To investigate the processes online, we used a think-aloud methodology in Experiment 1 and a reading time methodology in Experiment 2. In both experiments, we obtained offline comprehension measures and measures of individual differences in working memory and need for cognition. Across the two experiments, the results indicated that readers adjust their processing as a function of the interaction between prior knowledge and text structure. In particular, adjustments in theactual processes that take place during reading were observed for readers who had erroneous prior knowledge,but only when they read a text that was structured to explicitly refute this prior knowledge. Furthermore, the results showed that readers' memory for the text was affected by differences in their prior knowledge, independently of text structure. These findings contribute to our understanding of the relation between different factorsthat are associated with comprehension of scientific texts and have implications for theories of comprehension and conceptual change.     

Memory for Angry Faces,Impulsivity, and Problematic Behavior in Adolescence

Research has shown that cognitive processes like the attribution of hostile intention or angry emotion to others contribute to the development and maintenance of conduct problems. However, the role of memory has been understudied in comparison with attribution biases. The aim of this study was thus to test if a memory bias for angry faces was related to conduct problems in youth. Adolescents from a junior secondary school were presented with angry and happy faces and were later asked to recognize the same faces with a neutral expression. They also completed an impulsivity questionnaire. A teacher assessed their behavior. The results showed that a better recognition of angry faces than happy faces predicted conduct problems and hyperactivity/inattention as reported by the teacher. The memory bias effect was more pronounced for impulsive adolescents. It is suggested that a memory bias for angry faces favors disruptive behavior but that a good ability to control impulses may moderate the negative impact of this bias.     

Psychopathy and behavioral correlates of victim injury in serious juvenile offenders

The study examines delinquent behavior and psychopathy and assesses their relationship to victim injury in a population of 168 incarcerated juvenile delinquent males with lengthy histories of criminal and violent behavior. A series of multiple regressions found that 17% of the variance associated with level of victim injury was accounted for by a model that included the three-factor model of the Psychopathy Checklist: Youth Version [Forth, Kosson, and Hare, 2003], criminal versatility, and age of onset of criminal offending. Notably, anger and DSM-IV symptoms of conduct disorder were not related to level of victim injury. The results of this study support an escalation hypothesis where individuals with earlier onset to criminal behavior and greater criminal versatility escalate to more severe violence. The current results demonstrate the importance of integrating established theories of juvenile delinquency when explaining severe violence in youth.     

The emergent coordination of cognitive function

1/f scaling has been observed throughout human physiology and behavior, but its origins and meaning remain a matter of debate. Some argue that it is a byproduct of ongoing processes in the brain or body and therefore of limited relevance to psychological theory. Others argue that 1/f scaling reflects a fundamental aspect of all physiological and cognitive functions, namely, that they emerge in the balance of independent versus interdependent component activities. In 4 experiments, series of key-press responses were used to test between these 2 alternative explanations. The critical design feature was to take 2 measures of each key-press response: reaction time and key-contact duration. These measures resulted in 2 parallel series of intrinsic fluctuations for each series of key-press responses. Intrinsic fluctuations exhibited 1/f scaling in both reaction times and key-contact durations, yet the 2 measures were uncorrelated with each other and separately perturbable. These and other findings indicate that 1/f scaling is too pervasive to be idiosyncratic and of limited relevance. It is instead argued that 1/f scaling reflects the coordinative, metastable basis of cognitive function.     

Low target prevalence is a stubborn source of errors in visual search tasks

In visual search tasks, observers look for targets in displays containing distractors. Likelihood that targets will be missed varies with target prevalence, the frequency with which targets are presented across trials. Miss error rates are much higher at low target prevalence (1%-2%) than at high prevalence (50%). Unfortunately, low prevalence is characteristic of important search tasks such as airport security and medical screening where miss errors are dangerous. A series of experiments show this prevalence effect is very robust. In signal detection terms, the prevalence effect can be explained as a criterion shift and not a change in sensitivity. Several efforts to induce observers to adopt a better criterion fail. However, a regime of brief retraining periods with high prevalence and full feedback allows observers to hold a good criterion during periods of low prevalence with no feedback.     

The role of spatial and nonspatial information in visual selection

Even though it is undisputed that prior information regarding the location of a target affects visual selection, the issue of whether information regarding nonspatial features, such as color and shape, has similar effects has been a matter of debate since the early 1980s. In the study described in this article, measures derived from signal detection theory were used to show that perceptual sensitivity is affected by a top-down set for spatial information but not by a top-down set for nonspatial information. This indicates that knowing where the target singleton is affects perceptual selectivity but that knowing what it is does not help selectivity. Furthermore, perceptual sensitivity can be enhanced by nonspatial features, but only through a process related to bottom-up priming. These findings have important implications for models of visual selection.     

In sight, out of mind: the role of eye movements in the rapid resumption of visual search

Three experiments investigated the role of eye movements in the rapid resumption of an interrupted search. Passive monitoring of eye position in Experiment 1 showed that rapid resumption was associated with a short distance between the eye and the target on the next-to-last look before target detection. Experiments 2 and 3 used two different methods for presenting the target to the point of eye fixation on some trials. If eye position alone is predictive, rapid resumption should increase when the target is near fixation. The results showed that gaze-contingent targets increased overall search success, but that the proportion of rapid responses decreased dramatically. We conclude that rather than depending on a high-quality single look at a search target, rapid resumption of search depends on two glances; a first glance in which a hypothesis is formed, and a second glance in which the hypothesis is confirmed.     

Extending the spectrum idea: child personality,parenting and psychopathology

The spectrum hypothesis, postulating that differences between referred and non‐referred samples are confined to mean level differences, is elaborated by exploring whether the covariation between child problem behaviour and its predictors—child personality and parenting, rated by mothers—is similar in referred (N = 205) and non‐referred (N = 596) children and whether personality by parenting interactions can be generalized across samples. Results showed significant mean level differences for all the variables. Both personality and parenting explained problem behaviour, with some differences in strength of the effects across samples. Parenting by personality interactions mainly predicted externalizing behaviour, with benevolence and conscientiousness as the most prominent moderators. Results confirmed that moderators of problem behaviour operate similarly in the two samples, thus corroborating the spectrum hypothesis. Copyright © 2006 John Wiley & Sons, Ltd.     

Neural substrates of word generation during stroke recovery: the influence of cortical hypoperfusion

Several studies have demonstrated reorganization of cognitive and motor function caused by stroke. This study examined the influence of hypoperfused brain regions, in addition to the area of the infarct itself, on reorganization of the cognitive processes underlying word generation in stroke patients. In addition, we also sought to determine the influence of hypoperfusion on the blood oxygen level dependent/(BOLD) effect. Subjects with left and right subacute or chronic subcortical strokes, along with normal controls, were imaged while performing a verbal fluency task (word generation). The study population included six normal subject and six stroke patients with subcortical infarcts and cortical hypoperfusion in the middle cerebral artery territory who had recovered or improved markedly in word fluency. While normal subjects displayed a left-lateralized fronto-temporo-parietal and bilateral cingulo-striatal-thalamic-cerebellar network, the activation pattern of stroke patients was determined both by the hypoperfused regions and infarcted areas of the brain. Specifically, patients showed diminished BOLD effect in the cortical regions that were hypoperfused, even though their infarcts were subcortical, and showed increased BOLD effect in the homologous regions of the normal hemisphere. This finding raises the possibility that cortical hypoperfusion in the absence of infarct can cause shift of language functions to the opposite, intact hemisphere. However, reduced BOLD effect in the task relative to rest was found in hypoperfused regions in two patients, raising the possibility that regional function persisted, even though vascular reactivity was impaired. Results illustrate the complexities of functional imaging studies of recovery in patients with vascular lesions.