Intracortical recordings in human lateral occipital complex support the biased-competition model of spatial attention

Spatial attention is fundamental for prioritizing relevant information in complex visual environments. Yet, the neural mechanisms underlying this process in humans remain elusive, given the spatiotemporal constraints of noninvasive functional imaging. Here we present multi-unit spiking activity from the human lateral occipital complex (LO) during a covert spatial visual attention task.

Spatial attention strongly modulates neural activity when two competing stimuli fall within the receptive field, but not when only one of them does, supporting the biased-competition model of attention. This model suggests that spatial attention reduces interference between stimuli by favoring the attended one. We further found that, under competition, attended, task-relevant objects are selectively maintained.

This is, to our knowledge, the first demonstration of the neural effects of spatial attention in human visual cortex at the level of multi-unit spiking activity, offering a more naturalistic view of human visual attention, as participants received no prior training, unlike electrophysiological studies in trained macaques. Our study bridges human neuroimaging and primate electrophysiology, providing insights into the neural basis of attention. We are grateful to both patients for their participation.

We thank Stijn Verstraeten and Wouter Depuydt for technical assistance with the recording setup, Anaïs Van Hoylandt for assisting with data recording and data monitoring and Thomas Decramer for fine-tuning the implantation and recording technique from Utah-arrays in humans. This work was supported by Fonds Wetenschappelijk Onderzoek (FWO) grant G0B6422N and KU Leuven grant C14/22/134. T.T. is Senior Clinical Investigator of FWO Flanders (FWO 1830722 N).

T.T. holds a Medtronic learning chair. M.V. holds an FWO fellowship for fundamental research (1169321 N) and is funded by the Helaers Foundation. Michaël Vanhoyland, Jesus Garcia Ramirez: These authors contributed equally to this work.

Research group Experimental Neurosurgery and Neuroanatomy, KU Leuven, Leuven, Belgium Michaël Vanhoyland, Jesus Garcia Ramirez & Tom Theys Laboratory for Neuro- and Psychophysiology, Department of Neurosciences, KU Leuven and the Leuven Brain Institute, Leuven, Belgium Michaël Vanhoyland, Jesus Garcia Ramirez, Peter Janssen & Tom Theys Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium The authors declare no competing interests. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Below is the link to the electronic supplementary material.