Spatial audio-visual integration without localizing the auditory stimulus?
Rike Steenken, Hans Colonius, Adele Diederich
Poster
Last modified: 2008-05-13
Abstract
It is well known that in a focused attention task saccadic reaction time (SRT) to a visual target is modulated by the position and time of occurrence of an auditory non-target (Diederich & Colonius, 2004, Hdbk Multisensory Processes, Frens et al., 1995, P&P). The question addressed here is how the localizability of an auditory stimulus affects the response to a visual target stimulus. Two experiments were conducted to approach this issue. In the first, awareness of the acoustical stimulus location was manipulated by varying the amplitude of an additional auditory masker; in the second, a temporal masking paradigm was used. The performance levels in the localization tasks were correlated with the mean SRTs obtained from presenting identical stimulus configurations in separate blocks (Schmidt & Vorberg, 2006, P&P). The data indicate that there is no direct relation between the spatial SRT effect and the localizability of the auditory non-target, as has been previously suggested (Steenken et. al. 2007, Brain Res.). More specifically, it is suggested that localizability is not the dominant factor in determining the SRT and that localizing an auditory stimulus occurs on a higher level of processing generally not influencing the initiation of a saccade, respectively.