Invariance of the psychometric function for character recognition across the visual field

The psychometric function for recognition of singly presented digits as a function of digit contrast was measured at 2° steps across the horizontal meridian of the visual field, under monocular and binocular viewing conditions. A maximum-likelihood staircase procedure was used in a 10-alternative forcedchoice recognition paradigm to gather the data. Both the Weibull and the logistic psychometric functions provide excellent fits to the observed data. The slopes of these functions at their point of inflection ranged from 4.0 to 5.0 proportion-correct/log₁₀-unit contrast, for both monocular and binocular viewing and for all loci in the visual field. These slope values correspond to short-term measurements (around 30 trials, or 1 min) and do not include performance variations of longer duration; the latter are estimated to increase slope by a factor of about 1.5. A single psychometric function shape, centered around a threshold value, therefore describes recognition performance at all retinal loci and binocularity. An empirical comparison of slope results across the literature shows that the function’s slope is about twice that reported for a number of detection tasks. The comparison of recognition contrast thresholds, percentage correct values, and other performance measures across studies requires the knowledge of the psychometric function’s slope, and our results thus provide a firm basis for the study of low-contrast character recognition     

Dissociative Experiences and Trauma Exposure Among Newly Arrived and Settled Young War Refugees

War-traumatized refugee adolescents are a vulnerable and understudied group. This study of two different groups of war-traumatized youth (N = 77) resettled in Sweden (newly arrived refugee adolescents, n = 42, 13–19 years, and settled students with childhood war experiences, n = 35, 11–18 years) evaluated their war experiences, refugee journey, general trauma exposure, posttraumatic stress symptoms, and dissociative experiences. Both groups had experienced many traumas and a substantial proportion reported levels consistent with posttraumatic stress (71% in the newly arrived group and 34% among the settled students) and dissociation (36% and 23%, respectively). The study also provides information about the type of adverse events experienced by war-refugee adolescents, including their own subjective appraisals of the worst events. The results show that the extent of trauma exposure and posttraumatic and dissociative symptomatology among refugee adolescents are considerable even after a period of resettlement, a finding that has educational, clinical, and social implications.     

Metacognitive Therapy in Major Depression: An Open Trial of Comorbid Cases

This open trial investigated the transdiagnostic effects of metacognitive therapy (MCT) in patients with severe major depressive disorder and comorbid psychiatric disorder. Ten patients were treated with MCT over 10 sessions and were assessed with measures of depression, anxiety, rumination, and metacognitions at pre- and posttreatment and at 6 months follow-up. None of the patients were diagnosed as depressed at posttreatment, and of the initial 21 total diagnoses at pretreatment only 3 diagnoses remained at postintervention. The effect sizes were large for symptoms of depression, rumination, and worry. At 6 months follow-up standardized recovery criteria on the BDI showed that 70% were recovered, 20% improved, and 10% unchanged. The results indicate that MCT was associated with high rates of transdiagnostic improvement.     

Aus dem briefwechsel wilhelm ackermanns

A selection from the correspondence of the logician Wilhelm Ackermann (1896–1962) is presented in this article. The most significant letters were exchanged with Bernays, Scholz and Lorenzen, from which extensive passages are transcribed. Some remarks from other letters, with quotations, are also included.     

Contributions of longitudinal research to a cognitive theory of adjustment to aging

In agreement with Costa and McCrae (1992), the principle of ‘multiple uses’ of longitudinal studies is stressed based on a comparative review of the history of the Berkeley longitudinal studies and their different uses, and of those of the Bonn Longitudinal Study on Aging (BOLSA). Of the many uses of BOLSA, its contribution to the testing of a cognitive theory of aging is discussed. A selection of the findings of BOLSA and other studies of the Bonn Department of Psychology and the Institute of Gerontology, University of Heidelberg, is reported. These findings support three postulates of this theory: ( 1 ) the perceived rather than the objective situation directs behaviour; (2) perceptions of situations are related to dominant concerns of the person; and (3) adjustment to aging is achieved when a balance between the cognitive and motivational systems of the person has been attained.