Opposite brain laterality in analogous auditory and visual tests

ABSTRACT

Laterality for language processing can be assessed by auditory and visual tasks. Typically, a right ear/right visual half-field (VHF) advantage is observed, reflecting left-hemispheric lateralization for language. Historically, auditory tasks have shown more consistent and reliable results when compared to VHF tasks. While few studies have compared analogous tasks applied to both sensory modalities for the same participants, one such study by Voyer and Boudreau [(2003). Cross-modal correlation of auditory and visual language laterality tasks: a serendipitous finding. Brain Cogn, 53(2), 393–397] found opposite laterality for visual and auditory language tasks. We adapted an experimental paradigm based on a dichotic listening and VHF approach, and applied the combined language paradigm in two separate experiments, including fMRI in the second experiment to measure brain activation in addition to behavioural data. The first experiment showed a right-ear advantage for the auditory task, but a left half-field advantage for the visual task. The second experiment, confirmed the findings, with opposite laterality effects for the visual and auditory tasks. In conclusion, we replicate the finding by Voyer and Boudreau (2003) and support their interpretation that these visual and auditory language tasks measure different cognitive processes.

KEYWORDS:

• Hemispheric asymmetry
• laterality
• dichotic listening
• visual half-field
• fMRI

Acknowledgements

The authors want to express their thanks to Roger Barndon, Christel Jansen, Turid Randa, Eva Øksnes and Trond Martin Øvreaas for assistance in acquiring the MR data. We are grateful to Rene Westerhausen for valuable discussions and help with study design and analysis.

Disclosure statement

Kenneth Hugdahl has stocks in the company NordicNeurolab Inc. which produced the goggles and headphones for the stimulus presentations in the fMRI experiment, he reports no conflicts of interest.