Visual Enhancement of the Information Representation in Auditory Cortex

• DOI: 10.1016/j.cub.2009.10.068
• Publication Date: 2010-01-06T10:54:43Z
• Authors: Christoph Kayser; Nikos K. Logothetis; Stefano Panzeri
• Keywords: Auditory Cortex; Neurons; Acoustic Stimulation Animals Auditory Cortex/ physiology Auditory Perception/ physiology Evoked Potentials; Agricultural and Biological Sciences(all); Biochemistry, Genetics and Molecular Biology(all); Models, Neurological; Auditory Evoked Potentials; Neurological Neurons/physiology Photic Stimulation Visual Perception/ physiology; Macaca mulatta; Visual Macaca mulatta/physiology Models; 03 medical and health sciences; 0302 clinical medicine; Acoustic Stimulation; Auditory Perception; Evoked Potentials, Auditory; Visual Perception; Animals; Evoked Potentials, Visual; SYSNEURO; Photic Stimulation

Combining information across different sensory modalities can greatly facilitate our ability to detect, discriminate, or recognize sensory stimuli. Although this process of sensory integration has usually been attributed to classical association cortices, recent work has demonstrated that neuronal activity in early sensory cortices can also be influenced by cross-modal inputs. Here we demonstrate that such "early" multisensory influences enhance the information carried by neurons about multisensory stimuli. By recording in auditory cortex of alert monkeys watching naturalistic audiovisual stimuli, we quantified the effect of visual influences on the trial-to-trial response variability and on the amount of information carried by neural responses. We found that firing rates and precisely timed spike patterns of individual units became more reliable across trials and time when multisensory stimuli were presented, leading to greater encoded stimulus information. Importantly, this multisensory information enhancement was much reduced when the visual stimulus did not match the sound. These results demonstrate that multisensory influences enhance information processing already at early stages in cortex, suggesting that sensory integration is a distributed process, commencing in lower sensory areas and continuing in higher association cortices.