Multi-sensory interaction and plasticity in the human auditory brainstem
Single Paper Presentation

Gabriella Musacchia
Communication Sciences and Disorders, NorthwesternUniversity

Mikko Sams
Laboratory of Computational Engineering, Helsinki University

Nina Kraus
Communication Sciences and Disorders, NorthwesternUniversity

     Abstract ID Number: 80
     Full text: Not available
     Last modified: March 23, 2007
     Presentation date: 07/05/2007 8:40 AM in Quad General Lecture Theatre
     (View Schedule)

Abstract
The auditory brainstem encodes acoustic stimuli with high fidelity and reliability. Animal studies tell us that brainstem activity can be altered by the addition of visual information and following auditory training. These data indicate that subcortical structures may be more dynamic than previously thought. Our aims were to investigate how human subcortical processing of acoustic stimuli can be shaped by 1) visual information and 2) extensive multi-sensory training. To this end, we recorded brainstem responses from 29 adults to speech and music stimuli in three conditions: when hearing a syllable “da” or cello note alone, viewing a person say “da” or play the note on a cello, and when seeing and hearing concordant tokens simultaneously. 16 subjects had multi-sensory training in the form of extensive musical experience. Results showed that seeing speech delays the latency of afferent brainstem response and enhances phase-locking activity to stimulus periodicity in all subjects. Musicians had larger brainstem responses than controls to both speech and music, with amplitude of response correlated to length of musical practice. Visual influence was also greater in musicians. These data indicate that the human auditory brainstem is multi-sensory, and that multi-sensory experience has pervasive effects on subcortical sensory encoding mechanisms.