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Biomedical subjects

D Leutner

Publications and source records attributed to D Leutner.

6 recordsLinked to original sources
PubMed1996

Temporal discrimination as a function of marker duration.

In a series of three experiments, the effect of marker duration on temporal discrimination was evaluated with empty auditory intervals bounded by markers ranging from 3 to 300 msec or presented as a gap within a continuous tone. As a measure of performance, difference thresholds in relation to a base duration of 50 msec were computed. Performance on temporal discrimination was significantly better with markers ranging from 3 to 150 msec than with markers ranging from 225 to 300 msec or under the gap condition. However, within each range of marker duration (3-150 msec; 225-300 msec or gap) performance did not differ significantly. A fourth experiment provided evidence that the effect of marker duration cannot be explained in terms of marker-induced masking. A good approximation of the relationship between marker duration and temporal discrimination performance in the present experiments is a smooth step function, which can account for 99.3% of the variance of mean discrimination performance. Thus, the findings of the present study point to the conclusion that two different mechanisms are used in the processing of temporal information, depending on the duration of the auditory markers. The tradeoff point for the hypothetical shift from one timing mechanism to the other may be found at a marker duration of approximately 200 msec.

Adult↗
PubMed1995

[RADIOLIS. A radiologic instruction and training system for systematic evaluation of roentgen images exemplified by focal bone lesions].

RADIOLIS is an instructional software system for radiological training that guides the user through a systematic analysis of an image. The backbone of the analysis is a detailed and structured questionnaire which, as applied to our example, includes all relevant differential-diagnostic criteria for focal bone lesions. The variation range of the radiomorphologic characteristics in the questionnaire is introduced to the user with digitized X-ray images, making the simulation of an image analysis possible. In preparation, diverse teaching/learning methods reinforced by instructional psychology were incorporated during the system's development. At the core of the training system are an expandable image database and a database containing descriptions of image material formulated by radiology experts. The field of focal bone lesions, for instance, has already been integrated into RADIOLIS. A graphic user interface and an interactive dialogue enable both comfortable and simple use of the system and the user-specific structuring of the learning process.

Bone Neoplasms↗
PubMed1993

Seasonal allergic rhinitis and antihistamine effects on children's learning.

Children suffering from seasonal allergic rhinitis and matched normals were instructed on the use of a didactic computer simulation in a realistic classroom situation. Groups of atopic children received different treatments before instruction; ie, sedating (diphenylhydramine HCl) or nonsedating (loratadine) antihistamines or placebo. All returned after 2 weeks for an examination measuring factual and conceptual knowledge and the application of a learned strategy. Examination results showed large and consistent impairing effects of the allergic reaction on prior learning. Both the placebo and diphenhydramine groups learned significantly less than normal controls. The loratadine group's learning performance was superior to either of the other atopic groups' but still inferior to the normals'. Our conclusions are that the allergic reaction reduces learning ability in children and that this effect is partially counteracted by treatment with loratadine and aggravated by diphenhydramine.

Child↗