Auditory Spatial Perception Dynamically Realigns with Changing Eye Position

• Published in: The Journal of neuroscience Vol. 27; no. 38; pp. 10249 - 10258
• Main Authors: Razavi, Babak, O'Neill, William E, Paige, Gary D
• Format: Journal Article
• Language: English
• Published: United States Soc Neuroscience 19.09.2007; Society for Neuroscience
• Subjects: Acoustic Stimulation - methods; Adaptation, Physiological - physiology; Adult; Auditory Perception - physiology; Eye Movements - physiology; Female; Humans; Male; Middle Aged; Psychomotor Performance - physiology; Reaction Time - physiology; Sound Localization - physiology
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/JNEUROSCI.0938-07.2007

Audition and vision both form spatial maps of the environment in the brain, and their congruency requires alignment and calibration. Because audition is referenced to the head and vision is referenced to movable eyes, the brain must accurately account for eye position to maintain alignment between the two modalities as well as perceptual space constancy. Changes in eye position are known to variably, but inconsistently, shift sound localization, suggesting subtle shortcomings in the accuracy or use of eye position signals. We systematically and directly quantified sound localization across a broad spatial range and over time after changes in eye position. A sustained fixation task addressed the spatial (steady-state) attributes of eye position-dependent effects on sound localization. Subjects continuously fixated visual reference spots straight ahead (center), to the left (20 degrees), or to the right (20 degrees) of the midline in separate sessions while localizing auditory targets using a laser pointer guided by peripheral vision. An alternating fixation task focused on the temporal (dynamic) aspects of auditory spatial shifts after changes in eye position. Localization proceeded as in sustained fixation, except that eye position alternated between the three fixation references over multiple epochs, each lasting minutes. Auditory space shifted by approximately 40% toward the new eye position and dynamically over several minutes. We propose that this spatial shift reflects an adaptation mechanism for aligning the "straight-ahead" of perceived sensory-motor maps, particularly during early childhood when normal ocular alignment is achieved, but also resolving challenges to normal spatial perception throughout life.