Sound Found to Be Linked with Sight

Researchers at the UCSD School of Medicine have completed a study supporting the theory that drawing attention to a sound enhances the ability to see objects that appear at the same location.

John McDonald, post-doctoral researcher, collaborated with UCSD professor of neurosciences Steven Hillyard and UCSD assistant project scientist Wolfgang A. Teder-Salejarvi. Together they examined two senses rather than just one, as previous studies had done, to discover that the sense of sound influences that of sight.

“”We used new techniques in relating cross modal interactions with attention processing,”” McDonald said. “”We’re basically trying to figure out how the brain works and how sensory information in one modality affects information of other modalities.””

The study consisted of two separate experiments using 33 volunteers who were asked to indicate whether a dim light in their peripheral vision appeared following a sound. The light and sound either appeared on the same side or on opposite sides.

“”These studies show a stronger linkage between sight and hearing than previously demonstrated,”” Hillyard said. “”Our results suggest that you will see an object or event more clearly if it makes a sound before you see it.””

Hillyard said he considers the findings a first step to helping researchers better understand mental disorders, such as attention deficit disorder and schizophrenia. Industrially, the study opens possibilities of safer warning systems and man-machine interfaces where attention is crucial, such as air-traffic control systems.

“”Audio/visual and brain electricity studies such as this give us a clearer picture of how the brain works and can greatly contribute to the world of neuroscience in the field of human selective attention as well as having real world applications,”” McDonald said. “”My interest is in looking at interactions between sensory modalities and ultimately see how people perceive objects in the real world.””

Not only did the researchers observe behavioral reactions to sound and sight, but they also recorded brain waves and electrical patterns that are associated with people’s sensory experience as an attempt to see where the brain analyzes sensory information.

“”No one study can show how the brain puts together both auditory and visual inputs,”” Hillyard said. “”But this study is a first step to understanding this.””

The next phase for research includes more studies of normal brain function involving different senses and comparisons to individuals with abnormal brain function.

UCSD is a leader in cognitive neuroscience and is one of the world’s most advanced centers for this type of research, according to Hillyard.