Different Types of Eye-Movements alter Localization of Auditory Stimuli
Poster Presentation

Kerstin Koenigs
Neurophysik, Philipps-Universität Marburg

Frank Bremmer
Neurophysik, Philipps-Universität Marburg

     Abstract ID Number: 100
     Full text: Not available
     Last modified: March 17, 2006
     Presentation date: 06/19/2006 10:00 AM in Hamilton Building, Foyer
     (View Schedule)

Abstract
Previous studies have shown that the perceived location of visual stimuli briefly flashed during smooth pursuit, saccades or optokinetic nystagmus (OKN) is not veridical. In our current study we investigated whether these mislocalizations generalize across senses, i.e. whether they can also be observed for brief auditory stimuli presented during OKN or pursuit. Experiments were carried out in a light-proof sound attenuated chamber. Normal human subjects performed eye movements elicited by visual stimuli. An auditory target (white noise) was presented for 5 ms. The subjects had to indicate the perceived target position relative to a ruler. Our data clearly indicate that spatial mislocalization occurs during reflexive eye movements and for auditory targets. OKN induces a shift in the direction of the slow eye movement. The effect is stronger for “Schau” as compared to “Stier”-Nystagmus. Preliminary results indicate that smooth pursuit causes a centrifugal shift of perceived auditory stimulus location with respect to the fovea. The observed pattern of these mislocalizations is different from that found for visual targets. This suggests that different neural mechanisms are at play to integrate oculomotor signals and information on the spatial location of visual as compared to auditory stimuli.

Supported by DFG-Research Training Network 885 – NeuroAct