The association of macro- and microstructure of the corpus callosum and language lateralisation

The present study aimed to examine how differences in functional lateralisation of language are related to interindividual variations in interhemispheric connectivity. Utilising an fMRI silent word-generation paradigm, 89 left- and right-handed subjects were subdivided into four lateralisation subgroups. Applying morphological and diffusion-tensor MRI, midsagittal cross-sectional area as well as quantitative measures of molecular diffusion (anisotropy, mean diffusion) of the corpus callosum were determined to assess interhemispheric connectivity. Statistical analyses revealed group differences in molecular diffusion but not in callosal size, which may be interpreted to reflect a stronger and/or faster interhemispheric connection in strongly left-lateralised subjects as compared to moderately left-lateralised, bilateral, or moderately right-lateralised subjects.     

Magic,Religion, and Science: Secularization Trends and Continued Coexistence

While multiple studies have applied cultural evolutionary perspectives to the study of religion, few studies have examined the cultural evolutionary dynamics of a more secretive but equally ubiquitous form of supernatural belief: magic. We conducted two studies, an American nationally representative survey and a comparative phylogenetic analysis of religious traditions, to test three hypothesized cultural evolutionary drivers for beliefs in magic. We find the greatest support for the hypothesis that magic is employed when it provides its users benefits that are distinct from those provided by either science or religion, some support for secularization (broadly conceived) trends applying to magic, and no evidence that innate and unavoidable features of human cognition are primary drivers of the cultural evolution of magical beliefs. We conclude by suggesting specific hypothesized benefits for magic that may account for the evolution of humanity's facultative (i.e., context-dependent) use of magical beliefs.     

Effects of color on perceptual and conceptual tests of implicit memory

Two experiments are reported that explore why recent investigations of implicit memory failed to find any effects of color information on test performance. In the first experiment, participants studied colored pictures as well as words printed in colored ink without any memory instructions. During the test phase, a verbal and a pictorial version of a color-choice task (a conceptual priming test) were compared to two perceptual tests (word-stem completion and picture-fragment identification). Similar and significant amounts of priming to color occurred in both color-choice tasks. The perceptual tests were found to be sensitive to changes in the stimulus-presentation mode from study to test, but stimuli remaining the same color and those changed to black-and-white did not differ in the priming scores. In the second experiment, a mild division of attention was introduced in the study phase. Once again, priming to color was observed only in the verbal version of a color-choice test and not in the word-stem completion test. Dividing attention did not decrease performance on both implicit tests, whereas an explicit test of color recall for studied pictures suffered from dividing attention at encoding. It is concluded that a perceptual attribute such as color may be represented and coded by conceptual processing. Furthermore, automatic (or not attention-demanding) encoding processes may suffice for later conceptual tests of implicit memory. Previous failures to find any effects of color information on implicit performance are attributed to the use of perceptual priming tests. Received: 30 June 1997 / Accepted: 20 April 1998     

Sampling frequency and the study of eye-hand coordination in aiming

This study synchronized sampling of point of gaze (PG) and hand movements in a fast aiming task, using a 60- and a 120-Hz sampling frequency. The subjects moved eyes, head, hand, and trunk freely. For limb kinematics, a significant difference between sampling conditions was only found for the number of accelerations in the profile following peak velocity of the hand. For PG movements, no differences were found for initiation time, saccade angle, fixation duration, and overall number of saccades. However, significant differences were observed for saccade duration. Previously, an invariant feature was found for the ratio of PG and hand response times (50%). For both sampling frequencies, a significant correlation and, thus, temporal coupling was found between PG response time and time to peak acceleration for the hand. Depending on the measures required, a 60-Hz sampling of PG and hand movements may provide as meaningful results as a 120-Hz sampling.     

Leukocyte migration inhibition test in multiple sclerosis - results of a migration technic according to Clausen using brain specific antigens

The leukocyte migration inhibitory factor (LIF) was examined in 57 test persons--27 patients with multiple sclerosis (MS) and 30 normals--with the indirect and the direct leucocyte migration inhibition test in agarose (LMIAT). The stimulation of lymphocytes was carried out by the application of myelin basic protein (BP) and a membrane-associated antigen of normal brain (NTA). The mean value of controls +/- 2 s and the migration index less than or equal to 0,80 were used for limiting. In the indirect technique could be established significant group effects (NTA- and BP-values of MS cases compared to the controls) after 10 hours of incubation. The direct method showed in MS patients a significant lowered migration-index on an average after stimulation with the NTA; controls gave negative findings (except two cases). The valence of the test system and prospective modifications for further results were indicated.     

Loss of vision during the retinal stabilization of letters

Upper- and lower-case letters of the alphabet were stabilized until loss of vision occurred. Loss of straight-line visibility was the most frequently reported perceptual event. Occasionally, features of letters separated spatially before their loss of visibility. In both instances, loss of visibility often resulted in the perception of a less complex letter. Confidence ratings for each loss of letter visibility indicated that participants were quite certain about perceived fragmentations. In a control experiment, participants were asked to guess how letters would fragment during stabilization. Again, loss of line visibility was the most frequently reported event. However, spatial separation of features was rarely predicted and complex letters were not predicted to fragment into simpler letter forms. Furthermore, the confidence in predicted fragmentation was quite low. These results are consistent with the view that losses of visibility during retinal stabilization constitute a distinct perceptual experience. Fragmentations appear to be determined by the availability of less complex letter forms and by the loss of subletter information, consisting of letter features and information specifying spatial configurations.     

Measuring activism regarding the nuclear arms race

A 14-item questionnaire measure of activism regarding the nuclear arms race is described. Scale development analyses were conducted on 227 subjects, and internal consistency reliabilities ranged from .56 to .91 for scales assessing four aspects of activism on this issue. High correlations were obtained between these brief scales and corresponding measures derived from a 50-item long form. Responses of five subject groups were also compared: workers in defense industries, participants in a Republican party meeting, graduate students in psychology, religious teachers, and peace activists. Applications of this measure for study of the behavioral component of responses to the nuclear arms race are discussed.