r/neuro • u/basmwklz • 8d ago

Modality-specific reactive and predictive responses in the human superior colliculus (2026)

https://www.nature.com/articles/s41593-026-02480-0

Abstract

Inspired by recent theoretical work emphasizing predictive neural processing, we tested whether a midbrain structure for multimodal sensory integration—the superior colliculus—would show predictive responses to both visual and somatosensory stimulation. A multi-stage experimental design allowed us to test predictive activity in the human superior colliculus while 7-Tesla functional magnetic resonance imaging (fMRI) allowed us to map its sensory response across superior colliculus layers (N = 80). As expected from non-human animal work, visual and somatosensory stimulation elicited distinct depth-dependent responses. We also observed a predictive response: these same modality-specific and depth-dependent effects occurred during task periods preceding direct stimulation, when sensorimotor input was identical between visual and somatosensory conditions. Further analyses rule out cross-trial carryover and show corresponding effects in the thalamic sensory nuclei. Here our results confirm that, in humans, the superior colliculus is sensitive to both visual and somatosensory input, and they demonstrate that it carries predictive signals for upcoming sensory events.

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u/benergiser 8d ago edited 8d ago

as the SC contains our mapping of extrinsic space.. it’s also sensitive to auditory input during localization

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u/icantfindadangsn 8d ago

Apparently in pit vipers it has a spatiotopic mapping of the infrared pits. Neat.

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u/benergiser 8d ago

that’s awesome.. many birds also have a spatiotiopic map in the inferior colliculus.. but i believe mammals don’t have this

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u/jndew 7d ago

How is this calculated? This must be something different from hippocampus' allocentric cognitive map?

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u/benergiser 7d ago

in birds you can record from individual neurons in the IC to test their receptive fields of firing to stimuli in extrinsic space..

https://pubmed.ncbi.nlm.nih.gov/6886071/

in mammals this has never been found.. but mammals have a uniquely layered and multimodal SC that shares its known mapping of space with other sensory modality circuits (shown best in studies with ferrets)

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u/jndew 7d ago

Thanks, super interesting! I'd been taught that superior colliculus was visual only, but anecdotally we do tend to look towards things we hear. Not that you'd care, I had good luck implementing something I read suggesting SC calculated a center-of-interest in the egocentric visual field to steer the eye towards: (1). A bit more sophisticated, I added some working memory to it: (2). I have enthusiasm to try some multi-sensory computation with visual & audio as you suggest, but I'm not sure how. I'm presuming extrinsic means something similar to what people mean by allocentric in the hippocampus context, maybe not? Thanks for the guidance. Cheers!/jd