A Neural Circuit for Auditory Dominance over Visual Perception

Abstract

When conflicts occur during integration of visual and auditory information, one modality often dominates the other, but the underlying neural circuit mechanism remains unclear. Using auditory-visual discrimination tasks for head-fixed mice, we found that audition dominates vision in a process mediated by interaction between inputs from the primary visual (VC) and auditory (AC) cortices in the posterior parietal cortex (PTLp). Co-activation of the VC and AC suppresses VC-induced PTLp responses, leaving AC-induced responses. Furthermore, parvalbumin-positive (PV+) interneurons in the PTLp mainly receive AC inputs, and muscimol inactivation of the PTLp or optogenetic inhibition of its PV+ neurons abolishes auditory dominance in the resolution of cross-modal sensory conflicts without affecting either sensory perception. Conversely, optogenetic activation of PV+ neurons in the PTLp enhances the auditory dominance. Thus, our results demonstrate that AC input-specific feedforward inhibition of VC inputs in the PTLp is responsible for the auditory dominance during cross-modal integration.

Multisensory Control of Orientation in Tethered Flying Drosophila

“…“Winner-take-all” effects have been observed in multisensory decision-making [8,9], while our summation model predicts that the influence of each modality should grow smoothly with intensity. To examine the effects of intensity, we presented real flies with single and multimodal stimuli at higher and lower wind speeds ( N = 11, 11, and 12 for wind at 10, 25, and 45 cm/s, respectively), while holding visual stimulus intensity constant.…”

“…However, conflicting cues must also be integrated by the brain [2,3]. The algorithms used by the nervous system to integrate synergistic and conflicting stimuli across modalities are an active area of investigation [4–9]. …”

Multisensory Conflict Resolution: Should I Stay or Should I Go?

“…Swift action is often required in the face of indeterminate sensory evidence. In this issue of Neuron, Song et al (2017) describe an inhibitory circuit in the posterior parietal cortex that evaluates conflicting auditory and visual cues and supports resolute perceptual decision making.…”

“…The American novelist F. Scott Fitzgerald famously remarked, ''The test of a firstrate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function'' (The Crack-Up). In this issue of Neuron, Song et al (2017) put this idea to the test by describing a neural circuit in the mouse cerebral cortex that weighs conflicting sensory evidence and provides a singular output in support of purposeful behavior. Many regions of the cerebral cortex are modulated-if not explicitly driven-by inputs from more than one sensory modality.…”

“…Here, Song et al (2017) perform an ingenious set of experiments to identify a neural circuit in the mouse parietal cortex that performs just such an operation. Head-fixed mice were trained in a Go-Nogo task arranged in two different configurations.…”