Logical reasoning and probabilities: A comprehensive test of Oaksford and Chater (2001)

We report two experiments testing a central prediction of the probabilistic account of reasoning provided by Oaksford and Chater (2001): Acceptance of standard conditional inferences, card choices in the Wason selection task, and quantifiers chosen for conclusions from syllogisms should vary as a function of the frequency of the concepts involved. Frequency was manipulated by a probability-learning phase preceding the reasoning tasks to simulate natural sampling. The effects predicted by Oaksford and Chater (2001) were not obtained with any of the three paradigms.     

Psychopathy scores and violence among juvenile offenders: a multi-measure study

This study examined the relations between psychopathy scores and violent behavior in 113 incarcerated adolescents. We compared the results of four different instruments designed to assess psychopathy features among juveniles-the Psychopathy Checklist: Youth Version (PCL:YV), two versions of the Antisocial Processes Screening Device (APSD), and a Psychopathy Content scale on the Millon Adolescent Clinical Inventory (MACI). We found that PCLY:YV scores were significantly correlated with violent offense history, unadjudicated violence, and institutional violence, as well as measures of the severity and instrumentality of prior violence. Receiver operating characteristic analyses generated statistically significant effect sizes (AUC values) ranging from 0.64 to 0.79. The three other measures generated statistically significant correlations with one or more of the violence criteria, although correlations and effect sizes tended to be smaller in magnitude. Our results offer some support for the validity of these measures of psychopathic features, and the value of the PCL:YV in particular, with respect to short-term measures of violence outcome among juvenile offenders.     

Hemispheric, attentional, and processing speed factors in the treatment of developmental dyslexia

Aim of the study is to analyze the contributions of hemispheric, attentional, and processing speed factors to the effects of neuropsychological treatment of developmental dyslexia. Four groups of dyslexic children (M-type dyslexia) were treated over a period of four months. A first group (n = 9) underwent Bakker's Hemisphere-Specific Stimulation, with presentation of words in the right and left visual field. A second group (n = 7) received the same stimuli randomly in either visual hemifield. A third group (n = 8) received the same words presented centrally at fixation point. A fourth group (n = 6) received central stimuli with fixed presentation time (1500 ms). The children were tested before and after treatment on reading and spelling measures. All groups improved significantly after treatment on all variables. However, the group that was treated with centrally presented stimuli improved more than the other groups in spelling measures. A possible explanation is that rapid, simultaneous presentation to both hemispheres enhances interhemispheric exchange, which could produce an advantage in tasks requiring a high degree of integration between left and right hemispheric functions, such as spelling. The absence of significant differences in reading improvement may point to the role of memory functions or strategic factors characterizing all the treatment programs, possibly overweighing the effect of the other factors.     

Prognostic indicators for stuttering: the value of computer-based speech analysis

There are currently no known acoustic parameters by which stuttering children can be appraised in order to predict the further course of their speech disfluency. The present study investigates the usefulness of a computer-based speech analysis of fluent utterances. Correlations between acoustic variables, severity, and course of stuttering were sought in a prospective longitudinal study. This analyzed 57 preschool children at 6-month intervals over a period of 4.6 years. The acoustic analyses yielded no clearly distinguishing characteristics. There was, however, one subgroup consisting of children who were still disfluent at study end which showed more variable values at various measurement points for different parameters. Speech control seems to be different in children exhibiting chronic stuttering.     

Instructions to authors

Instructions for Authors

Instructions to authors     

Instructions to authors

Instructions for Authors

Instructions to authors     

Pappus in optical space

Optical space differs from physical space. The structure of optical space has generally been assumed to be metrical. In contradistinction, we do not assume any metric, but only incidence relations (i.e., we assume that optical points and lines exist and that two points define a unique line, and two lines a unique point). (The incidence relations have generally been assumed implicitly by earlier authors.) The condition that makes such an incidence structure into a projective space is the Pappus condition. The Pappus condition describes a projective relation between three collinear triples of points, whose validity can--in principle--be verified empirically. The Pappus condition is a necessary condition for optical space to be a homogeneous space (Lobatchevski hyperbolic or Riemann elliptic space) as assumed by, for example, the well-known Luneburg theory. We test the Pappus condition in a full-cue situation (open field, broad daylight, distances of up to 20 m, visual fields of up to 160 degrees diameter). We found that although optical space is definitely not veridical, even under full-cue conditions, violations of the Pappus condition are the exception. Apparently optical space is not totally different from a homogeneous space, although it is in no way close to Euclidean.     

Psychiatric Hospitalization and School and Community Adjustment of Children and Adolescents with Acquired Brain Injury

There is a high prevalence of psychiatric disorders in children and adolescents who have acquired brain injury (ABI). We examined the records of 82 students with ABI who were admitted to a community-based school for education and neurorehabilitation over a three-year period to determine how many experienced one or more psychiatric hospitalizations before admission, and whether hospitalization status was related to positive school and community adjustment. Results were that 30.4% of the students had a documented history of one or more psychiatric hospitalizations. Of this group, 60.0% were able to be maintained in the community-based school program and 40.0% were discharged to other settings. When discharged, 70.0% of students entered more restrictive treatment programs (e.g., psychiatric hospital, secure residential facility, residential school). The number of psychiatric hospitalizations did not predict discharge from the community-based school and was unrelated to the type of discharge setting. Clinical and research issues concerning psychiatric disorders in children and adolescents with ABI in relation to post-acute adjustment are discussed.     

National personality characteristics: II. Adaption-innovation in Canadian,American, and British samples

On the Kirton Adaption-Innovation Inventory 1,106 Canadians scored as more adaptive than American and British standardization samples. Means for Canadian females and males were congruent with those in national samples from six other countries.     

Exocentric pointing to opposite targets

We use an exocentric pointing task to study exocentric visual directions to targets that are opposite to a pointer relative to the observer. (The apparent distance between the target and the pointer always exceeded 90 degrees of visual angle.) All pointing takes place in the horizontal plane at eye height. Observers could not see both target and pointer at a single glance. They had to look back and forth between them, using combinations of eye movements, head turns, twists at the waist and turning on the feet. In the limit of diametrically opposite targets we find that the observers pick either one of two distinct orientations of the pointer as equally "visually correct". Which one results depends on the stance assumed by the observer. The difference between the two equally acceptable pointings is between 5 degrees and 10 degrees. Such a result is predicted from earlier measurements in the context of a model that describes the geometry of the horizon as a Riemannian space with varying intrinsic curvature. The present results thus fit--perhaps surprisingly--very well in such a picture.