Auditorily elicited EEG desynchronization and synchronization: A review of Christina M. Krause's doctoral thesis

The present paper reviews the doctoral dissertation of Christina M. Krause, in which auditorily elicited EEG desynchronization (ERD) and synchronization (ERS) was studied in five experiments. These experiments which were conducted by Krause and co-workers are the first in which the ERD-method was systematically applied to the analysis of the perception and processing of complex auditory stimuli. The main conclusion is that listening to sounds elicits ERS, whereas cognitive and/or memory processes elicit ERD.     

Die Entwicklung wissenschaftlich begründeter Leitlinien

Ohne Zusammenfassung     

On the “absoluteness” of category and magnitude scales of pain

The concept of “absolute scaling” (Zwislocki & Goodman, 1980) implies that direct judgments of sensory magnitude not only reflect the relative positions of the stimuli being judged, but also permit us to assess level differences in sensation. In order to explore this notion for different scaling methods, in the present investigation we compared magnitude estimation with category partitioning, a verbally anchored categorization procedure, in scaling painful pressure stimuli covering different intensity ranges. The results indicate that when the same stimulus range was presented after 1 week, both methods appeared to be highly reliable, with category partitioning faring somewhat better than magnitude estimation. When the stimulus range was unobtrusively changed between sessions, both methods reflected the within-subjects shift in absolute level. When two different sets of subjects judged the slightly different stimulus ranges, both methods resulted in scale values consistent with absolute scaling, though only category partitioning was sensitive enough to differentiate the two stimulus ranges. The results are discussed in the context of different possibilities of anchoring direct scaling methods in order to obtain “absolute” level information.     

The effect of judges' attitudes on ratings of attitude statements. A theoretical analysis

Judgments of attitude statements with the method of equal-appearing intervals have been found to vary as a function of the judges' attitudes. In this paper explanations of the relationship between judges' attitudes and judgments of attitude statements in terms of models of psychophysical judgment are discussed. It is argued that psychophysical models such as adaptation-level theory, the range-frequency model, and the ‘rubber-band’ model and its derivations, cannot account satisfactorily for judges' performance of the attitude rating task in a great number of studies. The reason for this failure, it is argued, is that the stimulus series employed in the psychophysical judgment research on which these models are based typically varied only on the dimension being judged. The sets of statements judged in attitude rating studies, however, vary not only on the dimension of interest (favourability—Unfavourability) but also on a number of other dimensions. It is suggested that this incidental stimulus variation of attitude statements may account for the failure of psychophysical models to predict accurately the performance of judges in the attitude rating task. It is argued that if principles which could account for the effects of this incidental stimulus variation on attitude ratings could be incorporated into psychophysical models, the predictive qualities of these models could be improved considerably. One such model is discussed.     

Integration of information in visual search

Two experiments studied how information about the nontarget items in a visual search task is used for the control of the search. The first experiment used the detection of “hurdle” stimuli to demonstrate that efficient memory representations of the context items can be established within each particular trial. This finding is explained by a model for the short-term integration of context information. The second experiment which varied the complexity of the local but not the global context provided some information about the nature of the integration operations involved. In its final version the model postulates two stages of processing with independent mechanisms of integration. Spatial integration at the first stage deletes repetitions within small samples. Temporal integration at the second stage stores and primes the memory representations of the context items over larger intervals. It is assumed that transient temporal integration within trials is mediated by the same mechanism that underlies permanent temporal integration between trials.     

Cellular spaces

This paper is an introduction into the theory of cellular spaces. From the more general model of nets of abstract cells which are interpreted by finite automata, it is shown how the model of cellular spaces is achieved by specialization. Cellular spaces are extremely homogeneous in function and in geometry. The relation between local and global behavior is regarded as the main topic of the theory. After a formal definition of cellular spaces, it is shown that not all functions of the configuration space are induced by cellular spaces. In addition, the Garden-of-Eden problem is discussed, and a simple self-reproduction property is explained.     

Simple predictions fueled by capacity limitations: when are they successful?

Counterintuitively, Y. Kareev, I. Lieberman, and M. Lev (1997) found that a lower short-term memory capacity benefits performance on a correlation detection task. They assumed that people with low short-term memory capacity (low spans) perceived the correlations as more extreme because they relied on smaller samples, which are known to exaggerate correlations. The authors consider, as an alternative hypothesis, that low spans do not perceive exaggerated correlations but make simpler predictions. Modeling both hypotheses in ACT-R demonstrates that simpler predictions impair performance if the environment changes, whereas a more exaggerated perception of correlation is advantageous to detect a change. Congruent with differences in the way participants make predictions, 2 experiments revealed a low capacity advantage before the environment changes but a high capacity advantage afterward, although this pattern of results surprisingly only existed for men.     

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.