Coherent mapping of position and head direction across auditory and visual cortex

Abstract

Neurons in primary visual cortex (V1) may not only signal current visual input but also relevant contextual information such as reward expectancy and the subject's spatial position. Such location-specific representations need not be restricted to V1 but could participate in a coherent mapping throughout sensory cortices. Here we show that spiking activity in primary auditory cortex (A1) and lateral, secondary visual cortex (V2L) of freely moving rats coherently represents a location-specific mapping in a sensory detection task performed on a figure-8 maze. Single-unit activity of both areas showed extensive similarities in terms of spatial distribution, reliability and position coding. Importantly, reconstructions of subject position on the basis of spiking activity displayed decoding errors that were correlated between areas in magnitude and direction. In addition to position, we found that head direction, but not locomotor speed or head angular velocity, was an important determinant of activity in A1 and V2L. Finally, pairs of units within and across areas showed significant correlations in instantaneous variability of firing rates (noise correlations). These were dependent on the spatial tuning of cells as well as the spatial position of the animal. We conclude that sensory cortices participate in coherent, multimodal representations of the subject's sensory-specific location. These may provide a common reference frame for distributed cortical sensory and motor processes and may support crossmodal predictive processing.

How ‘visual’ is the visual cortex? The interactions between the visual cortex and other sensory, motivational and motor systems as enabling factors for visual perception

“…Across the dorsal surface of mouse neocortex, areas are shown to project to the visual cortical system, in this figure to V1 in particular. Motor areas (MOT) project predictive information to V1, conveying information about expected consequences of eye, head and body movements for vision [50,92,94]. Somatosensory areas (SOM) carry information to V1 on how tactile and proprioceptive information predictably affects visual representations [37,52,53].…”

“…However, it cannot yet be excluded that navigational representations in V1 reflect behavioural, cognitive or sensorimotor covariates (e.g. posture, stereotyped movements, reward expectancy or local sensory cues [92]) rather than actual location information, similar to what has been reported for auditory-related activity [45,46].…”

Cell type-specific representation of spatial context in the rat prefrontal cortex

“…Foraging decisions incorporate the own localization and place-associated objects, rewards, and threats. The importance of the hippocampal formation in spatial processing has been firmly established, but spatial activation patterns are also widespread in cortical regions [1][2][3][4][5] . This suggests that spatial variables are diversely utilized in brain functioning, although the specificities remain to be established.…”