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Ralf Engbert

Publications and source records attributed to Ralf Engbert.

20 records · Page 2Linked to original sources

The effects of expertise and age on rhythm production: adaptations to timing and sequencing constraints.

We investigate age- and expertise-related individual differences in component processes of rhythmic timing. To this end we apply analysis of covariance structure and symbolic dynamics to time series obtained from performances of two bimanual rhythm tasks at different tempos. Results show similar effects for peripheral motor implementation and timekeeper execution in young and older amateur pianists. Older participants show specific problems with temporal sequencing processes (specification of different target intervals). Expert pianists show lower variability in both motor implementation and timekeeper execution and they accommodate to the sequencing demands of different tempos by selectively relying on integrated or parallel timing. We argue that the observed timing control characteristics reflect individuals' adaptations to internal processing limitations and performance constraints.

Adaptation, Psychological↗

A dynamical model of saccade generation in reading based on spatially distributed lexical processing.

The understanding of the control of eye movements has greatly benefited from the analysis of mathematical models. Currently most comprehensive models include sequential shifts of visual attention. Here we propose an alternative model of eye movement control, which includes three new principles: spatially distributed lexical processing, a separation of saccade timing from saccade target selection, and autonomous (random) generation of saccades with foveal inhibition. These three features provide a common control mechanism for fixations, refixations, and regressions. Consequently, the model is called SWIFT (Saccade-generation with inhibition by foveal targets). Results from numerical simulations are in good agreement with effects of word frequency on single-fixation, first-fixation, and gaze durations as well as fixation and word skipping probabilities in first-pass analysis. The model inherently produces complex eye movement patterns including refixations and regressions due to its underlying dynamical principles.

Computer Simulation↗