Estimation of premorbid cognitive function based on word knowledge: the Swedish Lexical Decision Test (SLDT)

In clinical neuropsychology, the present status of a patient is evaluated in relation to the assumed premorbid status. However, in Sweden, existing methods to assess premorbid status are far from optimal. In the present study, the design and evaluation of a Swedish Lexical Decision Test (SLDT) for premorbid global cognitive function (i.e., premorbid intelligence) is described. The design was based on the empirical finding that, in general adult population, word knowledge is strongly associated with measures of global cognitive functioning. Linear stepwise regression analysis demonstrated that SLDT findings accounted for 48% of the variance of global cognitive function as assessed by the Full Scale Intelligence Quotient (FSIQ) from the Wechsler Adult Intelligence Scale Revised (WAIS-R). Demographic variables alone accounted for 31% and a combination of SLDT results and demographics accounted for 60%. Psychometric properties are presented using data from 109 healthy individuals stratified according to age, gender, and level of education. In addition, a case of Alzheimer's disease is presented to illustrate the relationship between SLDT performance and cognitive function. Finally, the theoretical foundation for the relationship between word knowledge and global cognitive function is discussed.     

Aspects of Fluency in Writing

The notion of ‘fluency’ is most often associated with spoken-language phenomena such as stuttering. The present article investigates the relevance of considering fluency in writing. The basic argument for raising this question is empirical—it follows from a focus on difficulties in written and spoken language as manifestations of different problems which should be investigated separately on the basis of their symptoms. Key-logging instruments provide new possibilities for the study of writing. The obvious use of this new technology is to study writing as it unfolds in real time, instead of focusing only on aspects of the end product. A more sophisticated application is to exploit the key-logging instrument in order to test basic assumptions of contemporary theories of spelling. The present study is a dictation task involving words and ‘non-words’, intended to investigate spelling in nine-year-old pupils with regard to their mastery of the doubling of consonants in Norwegian. In this study, we report on differences with regard to temporal measures between a group of strong writers and a group of poor ones. On the basis of these pupils’ writing behavior, the relevance of the concept of ‘fluency’ in writing is highlighted. The interpretation of the results questions basic assumptions of the cognitive hypothesis about spelling; the article concludes by hypothesizing a different conception of spelling.     

Executable specifications for hypothesis-based reasoning with Prolog and Constraint Handling Rules

Constraint Handling Rules (CHR) is an extension to Prolog which opens up a spectrum of hypothesis-based reasoning in logic programs without additional interpretation overhead. Abduction with integrity constraints is one example of hypothesis-based reasoning which can be implemented directly in Prolog and CHR with a straightforward use of available and efficiently implemented facilities.The present paper clarifies the semantic foundations for this way of doing abduction in CHR and Prolog as well as other examples of hypothesis-based reasoning that is possible, including assumptive logic programming, hypotheses with priority and scope, and nonmonotonic reasoning.Examples are presented as executable code so the paper may also serve the additional purpose of a practical guide for developing such programs, and it is demonstrated that the approach provides a seamless integration with existing constraint solvers.     

The influence of practice on the development of motor skills in pianists: a longitudinal study in a selected motor task

A longitudinal study was conducted to investigate the influence of practice on the long-term development of expert pianists' motor skills in a relevant musical context. Temporal evenness in standardized scale playing was assessed twice in 19 pianists within an average time interval of 27 months. Questionnaires were used for retrospective assessment of practice quantity and several qualitative parameters related to practicing of scales. The development of temporal evenness in scale playing over the follow-up period correlated with the practice time accumulated during that period and with the average daily practice time. Expert pianists with an average daily practice time of 3.75h or more showed an improvement of performance in this selected motor skill. No significant association was observed between motor skill development during the follow-up period and the content of practice. Stepwise linear regression revealed a model predicting 43% of the variance of motor skill development, with practice time accumulated during the follow-up period as the only predictor. It was concluded that, in expert pianists, maintenance of motor skills in the selected motor task was strongly influenced by practice quantity.     

Risk‐taking and the adolescent brain: who is at risk?

Relative to other ages, adolescence is described as a period of increased impulsive and risk-taking behavior that can lead to fatal outcomes (suicide, substance abuse, HIV, accidents, etc.). This study was designed to examine neural correlates of risk-taking behavior in adolescents, relative to children and adults, in order to predict who may be at greatest risk. Activity in reward-related neural circuitry in anticipation of a large monetary reward was measured with functional magnetic resonance imaging, and anonymous self-report ratings of risky behavior, anticipation of risk and impulsivity were acquired in individuals between the ages of 7 and 29 years. There was a positive association between accumbens activity and the likelihood of engaging in risky behavior across development. This activity also varied as a function of individuals' ratings of anticipated positive or negative consequences of such behavior. Impulsivity ratings were not associated with accumbens activity, but rather with age. These findings suggest that during adolescence, some individuals may be especially prone to engage in risky behaviors due to developmental changes in concert with variability in a given individual's predisposition to engage in risky behavior, rather than to simple changes in impulsivity.     

Judging the cross on rings: a matter of achieving shape constancy

The present study examines the influence of viewing position, experience, processing time, and attention on shape constancy in gymnastics judging. In an experiment, 40 gymnastics judges and as many laypeople were presented with a series of photographs that show athletes holding a ‘cross on rings’. They were simultaneously taken from different viewpoints. Participants had to judge how many degrees the arms deviated from horizontal for each picture. One half of the participants had a secondary task, to judge the duration of the picture presentation, which varied also. The overall performances of the gymnastics judges were much better than those of the laypeople, and in contrast to the lay‐judgments, they were not influenced by the secondary task. However, gymnastics judges were still significantly influenced by viewpoint, that is, their error rate increased with an increase in deviation from a frontal view. Copyright © 2005 John Wiley & Sons, Ltd.     

Group size,group status and trait valence as determinants of intergroup bias: Stereotyping in Finland and Sweden

The effects of group size, group status and trait valence (positive or negative stereotypes of in‐ and outgroup) on intergroup bias was studied in nation‐wide probability samples of majority and minority groups in Finland and Sweden, (N = 2479). Ethnolinguistic vitality was used as a proxy for status. It is argued that the specific history of real‐life intergroup relations has to be duly acknowledged when predicting main and interactive effects on intergroup bias in natural contexts. Supporting the predictions made, numerical group size showed a stable main effect; members of numerical minorities showed more bias than members of numerical majorities, regardless of trait valence. While status had no main effect, there was a significant interaction between status and size as well as between status and trait valence: intergroup bias was highest in the high status minority, and low status groups showed less bias than high status groups on negatively valenced traits. In fact, minority members showed the reverse of PNAE. In addition, majority members favoured the outgroup on negatively valenced traits, but favoured their ingroup on positively valenced traits. Different explanations for these results are discussed. Copyright © 2008 John Wiley & Sons, Ltd.