Scalable choice models

Two representational criteria for probabilistic choice models are studied. These criteria, called scalability and weak scalability, are shown to be characterized by behavioral axioms designated, respectively, as pairwise dependence and weak pairwise dependence. The former is shown to be equivalent to the order independence axiom of Tversky. In addition, structural conditions on the choice alternatives are established under which all axioms are equivalent.     

Inhibition, Contextual Segregation, and Subject Strategies in List Method Directed Forgetting

This experiment tested alternative explanations of list method directed forgetting effects. Two word lists were studied by 135 subjects. Between lists, subjects were instructed to remember both lists (remember group), remember both lists as well as in which list words were studied (segregate group), or to forget the first list and remember the second (forget group). All subjects took both recall and recognition tests with test order varied between subjects. Among subjects who took the recall test first, the forget group showed a directed forgetting effect (poorer performance on List 1 than List 2) with both recall accuracy, recall typing time, and recognition reaction time measures. Contextual segregation of List 1 words by forget subjects was ruled out as a sufficient cause of the effect. Limited support was obtained for a differential rehearsal explanation of the effect. Within-group comparisons and findings of release from directed forgetting support inhibitory processes as the major cause of the directed forgetting effect.     

Response Channel Activation and the Temporoparietal Junction

When we learn to make one motor response to one visual stimulus and a different motor response to another, representations of these stimulus–response associations must be maintained to efficiently transduce perception into action. When an irrelevant distractor is presented adjacent to a target stimulus, interference is observed when the two stimuli are associated with conflicting responses, presumably due to response channel activation by the incompatible information. We have explored the neural bases of these interference effects. In a previous study, patients with hemispatial neglect showed normal interference from contralesional flankers. In another study, patients with lesions of the lateral prefrontal cortex were found not to show interference from distractors presented in the contralesional hemifield. The current study provided a more anatomically detailed investigation of the effects of posterior association cortex lesions on flanker interference. Patients with chronic, unilateral lesions involving the temporoparietal junction (TPJ), two of whom had hemispatial neglect, were compared with patients with lesions of the posterior association cortex not involving the TPJ. All patients performed a color discrimination task at fixation while a congruent or incongruent colored flanker was briefly presented (16.7 ms) in the adjacent contralesional or ipsilesional hemifield. Patients with TPJ lesions showed no interference effects from the contralesional flankers. These results suggest that the TPJ, in combination with the dorsolateral prefrontal cortex, is involved in transducing perception into action.     

The Representation of Arithmetic Facts in Memory: Results from Retraining a Brain-Damaged Patient

This single case study was designed to gather evidence regarding whether the mental representations mediating multiplication fact retrieval make use of single or multiple codes. MC is a brain-damaged volunteer whose numerical processing impairments were limited to multiplication fact retrieval. He relearned three sets of multiplication facts. Each set was relearned in one of three input formats: Arabic, written verbal, or spoken verbal. Following training all facts were tested in all input formats. MC's posttraining performance was virtually error free and showed no effects of input format. However, reaction-time data showed fact retrieval was fastest when the training format matched the test format. Results are discussed in relation to single- and multiple-code models of multiplication fact retrieval.     

What are television advertisements really trying to tell us? A postmodern perspective

This paper differentiates between the modern and the postmodern approach to advertising. It provides indicators of the nature of postmodern advertisements and proposes a methodology based on critical discourse analysis for interpreting the meaning and understanding the structure of such advertisements. The paper discusses the purpose of the postmodern approach to advertising and argues that its very imagery may further confuse an already confused postmodern consumer. The credibility of the imagery may also be questioned where it is perceived to be an illusion that is incapable of being substantiated. Copyright © 2002 Henry Stewart Publications.     

Domain specific attentional impairments in children with chromosome 22q11.2 deletion syndrome

One of the defining cognitive characteristics of the chromosome 22q deletion syndrome (DS22q11.2) is visuospatial processing impairments. The purpose of this study was to investigate and extend the specific attentional profile of children with this disorder using both an object-based attention task and an inhibition of return task. A group of children with the disorder was compared in these tasks with a group of age-matched typically developing children. The children with DS22q11.2 demonstrated impaired spatially based orienting which is consistent with previous findings in this group. Strikingly, the children with DS22q11.2 also demonstrated an improved ability to use object-based cues, relative to the typically developing group. Finally, the children with DS22q11.2 demonstrated an intact inhibition of return system, however, it appears to be delayed developmentally.     

Bullying and victimisation in school children: the role of social identity, problem-solving style, and family and school context

The relationship between social identity, family and school context, problem-solving style, self-esteem, health behaviour, psychological distress, and victimisation, was explored in a quasi-experimental survey of 461 children aged between 11 and 15 years old. There was a high prevalence of victimisation (29%) in the group and 44% of those victimised scored above the clinical cut-off on the GHQ. Victims exhibited higher levels of psychological distress, lower self-esteem, more unhealthy behaviours, less support from parents and teachers, poorer problem-solving styles, and lower perceived social identity. Girls had a higher prevalence of victimisation than boys. The best predictors of victimisation were sex, family situation, social identity and problem-solving style. Some implications for interventions are discussed.

Musical expertise modulates the effects of visual perceptual load

Several studies have demonstrated that faces are processed differently from other types of objects, implicating a special role that faces have within the human visual system. However, other studies have suggested that faces may be special only in that they constitute a highly familiar category of visual objects with which most humans have expertise. In this study, we tested a group of expert musicians with a musical instrument classification task during which irrelevant images of musical instruments were presented as visual distractors under varying conditions of perceptual load. Unlike nonmusicians (who had been tested in Lavie, Ro, & Russell, 2003, using the same paradigm as in the present study), the musicians processed these irrelevant images of musical instruments even under conditions of high perceptual load. These results suggest that musical instruments are processed automatically and without capacity limits in subjects with musical expertise and implicate a specialized processing mechanism for objects of high familiarity.