@article {23615,
	title = {Plaid detectors in macaque V1 revealed by two-photon imaging},
	journal = {Current Biology},
	volume = {30},
	year = {2020},
	pages = {934-940},
	abstract = {Neuronal responses to one-dimensional orientations are combined to represent two-dimensional composite patterns, which plays a key role in intermediate-level vision such as texture segmentation. However, where and how the visual cortex starts to represent composite patterns, such as a plaid consisting of two superimposing gratings of different orientations, remains neurophysiologically elusive. Psychophysical and modeling evidence has suggested the existence of early neural mechanisms specialized in plaid detection\&nbsp;[1-6], but the responses of V1 neurons to an optimally orientated grating are actually suppressed by a superimposing grating of different orientation (i.e., cross-orientation inhibition)\&nbsp;[7, 8]. Would some other V1 neurons be plaid detectors? Here we used two-photon calcium imaging\&nbsp;[9]\&nbsp;to compare the responses of V1 superficial-layer neurons to gratings and plaids in awake macaques. We found that many non-orientation-tuned neurons responded weakly to gratings, but strongly to plaids, often with plaid orientation selectivity and cross-angle selectivity. In comparison, most (~94\%) orientation-tuned neurons showed more or less cross-orientation inhibition, regardless of the relative stimulus contrasts. Only a small portion (~8\%) of them showed plaid facilitation at off-peak orientations. These results suggest separate subpopulations of plaid and grating responding neurons. Because most plaid neurons (~95\%) were insensitive to motion direction, they were plaid pattern detectors, not plaid motion detectors.},
	url = {http://www.psy.pku.edu.cn/docs/20200417142952888196.pdf},
	author = {SC Guan and Zhang, SH and YC Zhang and SM Tang and C. Yu}
}
