PT  - JOURNAL ARTICLE
AU  - Christopher A. Henry
AU  - Mehrdad Jazayeri
AU  - Robert M. Shapley
AU  - Michael J. Hawken
TI  - Distinct spatiotemporal mechanisms underlie extra-classical receptive field modulation in macaque V1 microcircuits
AID  - 10.1101/802710
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 802710
4099  - http://biorxiv.org/content/early/2019/10/13/802710.short
4100  - http://biorxiv.org/content/early/2019/10/13/802710.full
AB  - Complex scene perception depends upon the interaction between signals from the classical receptive field (CRF) and the extra-classical receptive field (eCRF) in primary visual cortex (V1) neurons. While much is known about V1 eCRF properties, it remains unknown how the underlying mechanisms map onto the cortical microcircuit. We probed the spatio-temporal dynamics of eCRF modulation using a reverse correlation paradigm, and found three principal eCRF mechanisms: tuned-facilitation, untuned-suppression, and tuned-suppression. Each mechanism had a distinct timing and spatial profile. Laminar analysis showed that the timing, orientation-tuning, and strength of eCRF mechanisms had distinct signatures within magnocellular and parvocellular processing streams in the V1 microcircuit. The existence of multiple eCRF mechanisms provides new insights into how V1 responds to spatial context. Modeling revealed that the differences in timing and scale of these mechanisms predicted distinct patterns of net modulation, reconciling many previous disparate physiological and psychophysical findings.