Human cognition and a pile of sand: a discussion on serial correlations and self-organized criticality

Recently, G. C. Van Orden, J. G. Holden, and M. T. Turvey (2003) proposed to abandon the conventional framework of cognitive psychology in favor of the framework of nonlinear dynamical systems theory. Van Orden et al. presented evidence that "purposive behavior originates in self-organized criticality" (p. 333). Here, the authors show that Van Orden et al.'s analyses do not test their hypotheses. Further, the authors argue that a confirmation of Van Orden et al.'s hypotheses would not have constituted firm evidence in support of their framework. Finally, the absence of a specific model for how self-organized criticality produces the observed behavior makes it very difficult to derive testable predictions. The authors conclude that the proposed paradigm shift is presently unwarranted.     

Competition between endogenous and exogenous orienting of visual attention

The relation between reflexive and voluntary orienting of visual attention was investigated with 4 experiments: a simple detection task, a localization task, a saccade toward the target task, and a target identification task in which discrimination difficulty was manipulated. Endogenous and exogenous orienting cues were presented in each trial and their validity was manipulated orthogonally to examine whether attention mechanisms are mediated by separate systems and whether they have additive and independent effects on visual detection and discrimination. The results showed that each orienting mechanism developed its typical and independent effect in every case except for the difficult identification task. A theoretical framework for understanding the relationship between endogenous and exogenous orienting of attention is proposed, tested, and confirmed.     

Enemies and friends in the neighborhood: orthographic similarity effects in semantic categorization

Studies investigating orthographic similarity effects in semantic tasks have produced inconsistent results. The authors investigated orthographic similarity effects in animacy decision and in contrast with previous studies, they took semantic congruency into account. In Experiments 1 and 2, performance to a target (cat) was better if a previously studied neighbor (rat) was congruent (i.e., belonged to the same animate-inanimate category) than it was if it was incongruent (e.g., mat). In Experiments 3 and 4, performance was better for targets with more preexisting congruent neighbors than for targets with more preexisting incongruent neighbors. These results demonstrate that orthographic similarity effects in semantic categorization are conditional on semantic congruency. This strongly suggests that semantic information becomes available before orthographic processing has been completed.     

Atypical lateralization of memory for location: effects of deafness and sign language use

This paper examines the impact of auditory deprivation and sign language use on the enhancement of location memory and hemispheric specialization using two matching tasks. Forty-one deaf signers and non-signers and 51 hearing signers and non-signers were tested on location memory for shapes and objects (Study 1) and on categorical versus coordinate spatial relations (Study 2). Results of the two experiments converge to suggest that deafness alone supports the atypical left hemispheric preference in judging the location of a circle or a picture on a blank background and that deafness and sign language experience determine the superior ability of memory for location. The importance of including a sample of deaf non-signers was identified.     

Adults with dyslexia demonstrate space-based and object-based covert attention deficits: shifting attention to the periphery and shifting attention between objects in the left visual field

Performance on a covert visual attention task is compared between a group of adults with developmental dyslexia (specifically phonological difficulties) and a group of age and IQ matched controls. The group with dyslexia were generally slower to detect validly-cued targets. Costs of shifting attention toward the periphery when the target was invalidly cued were significantly higher for the group with dyslexia, while costs associated with shifts toward the fovea tended to be lower. Higher costs were also shown by the group with dyslexia for up-down shifts of attention in the periphery. A visual field processing difference was found, in that the group with dyslexia showed higher costs associated with shifting attention between objects in they LVF. These findings indicate that these adults with dyslexia have difficulty in both the space-based and the object-based components of covert visual attention, and more specifically to stimuli located in the periphery.     

Correlation between trait hostility and faster reading times for sentences describing angry reactions to ambiguous situations

The hypothesis that trait anger is associated with an increased tendency to interpret ambiguous situations as anger-provoking was investigated in a reading time study. A total of 48 healthy volunteers read a series of short narrative passages and were asked to adopt the perspective of the main character, identified at the start of each passage. Reading times for key sentences, which described the main characters' angry or nonangry reactions to ambiguous anger-provoking situations, were recorded. Trait anger and impulsivity were negatively correlated with reading time for sentences describing both types of reaction, but anger was also correlated with relatively faster processing of sentences describing angry reactions. This study suggests that those with angrier dispositions are more likely to anticipate angry reactions from others.     

Interval-timing deficits in individuals at high risk for schizophrenia

A duration-bisection procedure was used to study the effects of signal modality and divided attention on duration classification in participants at high genetic risk for schizophrenia (HrSz), major affective disorder (HrAff), and normal controls (NC). Participants learned short and long target durations during training and classified probe durations during test. All groups classified visual signals as shorter than equivalent duration auditory signals. However, the difference between auditory and visual signal classification was significantly larger for the HrSz group than for the NC group. We posit a model in which there is a clock rate difference between auditory and visual signals due to an attentional effect at the level of a mode switch that gates pulses into an accumulator. This attentionally mediated clock rate difference was larger for the HrSz participants than for the NC participants, resulting in a larger auditory/visual difference for the HrSz group.     

IQ decline following early unilateral brain injury: a longitudinal study

We examine whether children with early unilateral brain injury show an IQ decline over the course of development. Fifteen brain injured children were administered an IQ test once before age 7 and again several years later. Post-7 IQ scores were significantly lower than pre-7 IQ scores. In addition, pre-7 IQ scores were lower for children with larger lesions, but children with smaller lesions and higher pre-7 IQ scores showed a greater IQ decline over time. These findings suggest that the cognitive outcomes of children with early lesions, particularly those with relatively small lesions, change over the course of development.     

What policymakers need and must demand from research regarding the employment rate of persons with disabilities

Enabling persons with disabilities to prepare for and engage in gainful employment has become a priority concern in U.S. society. As a result, federal and state policymakers are adopting employment-related initiatives designed to enhance the employment rate of persons with disabilities. Policymakers need credible evidence in order to assess and reform these initiatives. This recognized need, however, begs the question of what constitutes 'credible evidence.' Of particular concern in the disability policy arena is the debate over the types of conclusion about employment rates that can and cannot be drawn from analyses of national survey data sets. This article connects standard research methodology concepts with the complexities of evaluating disability policy to help stakeholders appreciate the issues involved in this debate. This appreciation can help policymakers (1) recognize unwarranted cause-and-effect conclusions based solely on existing national survey data and (2) demand better data and stronger research designs to complement the potential over-reliance on correlational studies using problematic survey data to estimate policy impacts. To this end, the article concludes with a practical framework with a checklist for assessing the adequacy of research regarding the employment rate of persons with disabilities.     

A family-based mental health program of recovery from state terror in Kosova

Family processes of communication, mutual support, and sustenance of cultural values can play vital roles in recovery from psychological and material damage in societies afflicted by terror. This is particularly the case when a campaign of terror has specifically targeted family life and its traditions, when the culture is one whose identity has been centered in its families, and when public mental health resources have been scarce. At the end of the 1999 war in Kosova, the Kosovar Family Professional Educational Collaborative (KFPEC) was initiated to counter mental health sequelae of war in Kosova. This initiative focused upon the recovery and strengthening of Kosovar families, rather than the psychiatric treatment of individuals for post-traumatic symptoms. Findings and outcomes from this project may usefully inform the design of other international public mental health initiatives.