Inflated perceptions of responsibility and obsessive-compulsive symptoms

In Salkovskis' [Salkovskis, P. (1985). Obsessional-compulsive problems: a cognitive-behavioural analysis. Behaviour Research and Therapy, 28, 571-588; Salkovskis P. (1989) Cognitive-behavioural factors and the persistence of intrusive thoughts in obsessional problems. Behaviour Research and Therapy, 27, 677-682] cognitive model for obsessive-compulsive disorder (OCD), inflated perception of responsibility is highlighted as the critical feature that maintains the disorder. In the current study, the relationship between responsibility and obsessive-compulsive (OC) symptoms was examined. Specifically, three measures of responsibility were evaluated for their psychometric properties. These measures were then used to test Salkovskis's model by examining the relationships among pervasive responsibility, automatic thoughts related to causing harm, and OC symptom severity. Findings provide partial support for the validity and reliability of the measures and for the model as a whole. Based on regression analyses, data support that pervasive responsibility significantly contributes to the prediction of OC symptoms. Furthermore, this relationship appears to be mediated by automatic thoughts related to causing harm in OCD contexts.     

Neuropsychological performance of emotionally disturbed students on the LNNB and LNNB-C

A number of researchers have reported an association between neuropsychological impairment and psychiatric disorders. However, there has been relatively little research on the neuropsychological functioning of emotionally disturbed students served in public schools. The purpose of this study was to determine the neuropsychological performance of 65 emotionally disturbed students 8–18 years old on the Luria-Nebraska Neuropsychological Battery: Form I (LNNB) and the Luria-Nebraska Neuropsychological Battery: Children's Revision (LNNB-C). The results indicated that approximately 42% of the younger group (99–154 months) and 38% of the older group (156– 226 months) demonstrated neuropsychological impairment as defined by criterion values for the various scales of the two batteries. On average, the emotionally disturbed students appeared to demonstrate more difficulty on more complex cognitive tasks, such as writing, arithmetic, and intellectual processes, than for less complex tasks, such as motor functions.     

Processing capacity defined by relational complexity: implications for comparative, developmental, and cognitive psychology

Working memory limits are best defined in terms of the complexity of the relations that can be processed in parallel. Complexity is defined as the number of related dimensions or sources of variation. A binary relation has one argument and one source of variation; its argument can be instantiated in only one way at a time. A binary relation has two arguments, two sources of variation, and two instantiations, and so on. Dimensionality is related to the number of chunks, because both attributes on dimensions and chunks are independent units of information of arbitrary size. Studies of working memory limits suggest that there is a soft limit corresponding to the parallel processing of one quaternary relation. More complex concepts are processed by "segmentation" or "conceptual chunking." In segmentation, tasks are broken into components that do not exceed processing capacity and can be processed serially. In conceptual chunking, representations are "collapsed" to reduce their dimensionality and hence their processing load, but at the cost of making some relational information inaccessible. Neural net models of relational representations show that relations with more arguments have a higher computational cost that coincides with experimental findings on higher processing loads in humans. Relational complexity is related to processing load in reasoning and sentence comprehension and can distinguish between the capacities of higher species. The complexity of relations processed by children increases with age. Implications for neural net models and theories of cognition and cognitive development are discussed.     

Measurement of the texture-coherence limit for bandpass arrays

Casual observation suggests that when the elements of a visual array are packed at a sufficiently high density they cohere to generate the percept of a texture. This 'texture-coherence limit' has been quantified by using arrays composed of Gabor functions, sixth Gaussian derivatives, or differences of Gaussians. In all cases the texture-coherence limit was a power-law function of the size of the elements as quantified by their space constants with an exponent averaging 0.7. Furthermore, the texture-coherence limit was independent of both element spatial frequency and contrast over a considerable range. A quantitative fit to the data is provided by a model in which the texture-coherence limit is determined by activation of complex cells, which pool a spatial range of subunit inputs, throughout the stimulus region. Possible extensions to two dimensions are considered.     

A Twin and Family Study of the Association Between Immune System Dysfunction and Dyslexia Using Blood Serum Immunoassay and Survey Data

We conducted a study of the association between developmental reading disability (DRD) and immune disorders (ID) using both survey and immunoassay data in two separate samples of families. One sample was made up of twins and their parents and was ascertained through a population-based sampling scheme. The other sample was a set of extended pedigrees selected for apparent autosomal dominant transmission of DRD. We failed to find an association between DRD and ID in either sample, regardless of the method used to assess immune system function. Even though our twin sample provided evidence that both DRD and immune conditions were significantly heritable, there was no evidence for a genetic correlation between ID and DRD nor was there any clear indication that a special subgroup of individuals may be comorbid for these conditions because of genetic reasons. How these negative findings can be reconciled with the developmental hypothesis of Geschwind, Behan, Galaburda, and colleagues, and how they may relate to the gene locus influencing DRD that has been recently located in the HLA region of the short arm of chromosome 6 is discussed.