• Publications
  • Influence
Dyslexic Children Are Confronted with Unstable Binocular Fixation while Reading
Besides documented phoneme processing disorders, visual/ocular motor imperfections may exist in dyslexics that lead to fixation instability and thus, to instability of the letters or words during reading; such instability may perturb fusional processes and might – in part - complicate letter/word identification.
Measurement of refractive error and accommodation with the photorefractor PowerRef II
The infrared photorefractor PowerRef II (PR II; PlusoptiX AG, Nürnberg, Germany) used in this study did not provide a continuous stream of data and the specified sampling frequency of 25 Hz was rarely realized.
The Pupil Reflects Motor Preparation for Saccades – Even before the Eye Starts to Move
Saccade latencies across all tasks predicted the magnitude of pupil dilations post hoc: the longer the saccade latency the smaller the pupil dilation before the eye actually began to move.
Binocular Advantages in Reading
Objective vs subjective measurements of dark vergence
The nonius test is sufficient for a subjective estimation of dark vergence and found similar results with both methods in repeated tests in two sessions, indicating consistency in measures of phoria and fixation disparity.
Individual differences in binocular coordination are uncovered by directly comparing monocular and binocular reading conditions.
Evaluated systematically binocular coordination during a reading task by comparing binocular and monocular reading, and considering the potential effects of individual heterophoria and eye dominance found some vergence adjustments are driven actively by fusional processes.
Periodic letter strokes within a word affect fixation disparity during reading.
The similarity in shape between the neighboring strokes of component letters, as measured by the first peak in the horizontal auto-correlation of the images of the words, was found to be associated with a smaller minimum fixation disparity and a longer overall fixation duration.
Does Text Contrast Mediate Binocular Advantages in Reading?
It was found that word identification processes during reading were qualitatively different in monocular reading compared with effects observed when text was read with substantially reduced contrast, and a reasonable conclusion was that a reduction in contrast is not the (primary) factor that mediates less efficient lexical processing under monocularReading.
Microsaccades under monocular viewing conditions
The statistical properties of microsaccades under monocular stimulation conditions were checked and found no indication for specific interactions for monocularly detected small saccades, which might be present if they were based on a monocular physiological activation mechanism.