Memory-based and surround-based pattern completion show distinct laminar profiles in human V1
- 1University of Glasgow
Abstract
Visual input is often incomplete, requiring the brain to infer missing information from prior experience or contextual cues. Establishing whether memory-derived and context-derived information shape pattern completion through shared or distinct top-down pathways is central to understanding how perception emerges from the integration of sensory input and prior knowledge. Across two experiments, we used 7T layer fMRI to measure activity in an occluded region of human V1 while participants viewed natural scenes. Memory-based completion was enabled by varying the level of exposure to full scene images before scanning, while surround-based completion was implemented via two scenes that were repeatedly presented in partially occluded form but never seen intact. In both fMRI experiments, category decoding in the occluded V1 region only emerged after multiple prior exposures, whereas novel scenes did not show reliable decoding. Repeated partially occluded scenes also supported decoding, despite the hidden region never being shown, consistent with surround-based pattern completion. Critically, mnemonic and surround-based pattern completion showed opposite laminar decoding profiles across V1 depths, with mnemonic feedback dominating deep layers, and surround-based feedback dominating superficial layers. Together, these findings suggest that completion in the early visual cortex depends on the sources of inferred information, revealing dissociable feedback pathways for memory- and context-driven inference.
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BibTeX
@misc{zhang2026memorybased,
title = {{Memory-based and surround-based pattern completion show distinct laminar profiles in human V1}},
author = {Z. Zhang and C. Abbatecola and Y. Huang and Y. Y. Lazarova and A. Paton and M. Wimber and C. N. Levelt and M. E. Larkum and L. F. Muckli and L. S. Petro},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.24.753595},
url = {https://www.biorxiv.org/content/10.64898/2026.09.24.753595v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Memory-based and surround-based pattern completion show distinct laminar profiles in human V1
AU - Z. Zhang
AU - C. Abbatecola
AU - Y. Huang
AU - Y. Y. Lazarova
AU - A. Paton
AU - M. Wimber
AU - C. N. Levelt
AU - M. E. Larkum
AU - L. F. Muckli
AU - L. S. Petro
PY - 2026
DA - 2026/09/24
PB - bioRxiv
DO - 10.64898/2026.09.24.753595
UR - https://www.biorxiv.org/content/10.64898/2026.09.24.753595v1
AB - Visual input is often incomplete, requiring the brain to infer missing information from prior experience or contextual cues. Establishing whether memory-derived and context-derived information shape pattern completion through shared or distinct top-down pathways is central to understanding how perception emerges from the integration of sensory input and prior knowledge. Across two experiments, we used 7T layer fMRI to measure activity in an occluded region of human V1 while participants viewed natural scenes. Memory-based completion was enabled by varying the level of exposure to full scene images before scanning, while surround-based completion was implemented via two scenes that were repeatedly presented in partially occluded form but never seen intact. In both fMRI experiments, category decoding in the occluded V1 region only emerged after multiple prior exposures, whereas novel scenes did not show reliable decoding. Repeated partially occluded scenes also supported decoding, despite the hidden region never being shown, consistent with surround-based pattern completion. Critically, mnemonic and surround-based pattern completion showed opposite laminar decoding profiles across V1 depths, with mnemonic feedback dominating deep layers, and surround-based feedback dominating superficial layers. Together, these findings suggest that completion in the early visual cortex depends on the sources of inferred information, revealing dissociable feedback pathways for memory- and context-driven inference.
ER -