Asymmetries of Dark and Bright Negative Afterimages Are Paralleled by Subcortical ON and OFF Poststimulus Responses
Asymmetries of Dark and Bright Negative Afterimages Are Paralleled by Subcortical ON and OFF Poststimulus Responses
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暗和亮负残像的不对称性与皮层下的开和关后刺激反应平行。
DOI：
10.1523/jneurosci.2021-16.2017
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发表时间：
2017-02-22
影响因子：
5.3
通讯作者：
Wang, Wei
中科院分区：
文献类型：
--
作者：
Li, Hui;Liu, Xu;Wang, Wei
人类对亮度的降低比亮度的增加更敏感，这从较低的阈值和较短的暗刺激潜伏期得到了证明。这种不对称性与猫和猴的膝状体背外侧核(DLGN)和初级视皮层(V1)的神经生理记录结果一致。具体地说，V1群体反应表明，暗反应比亮反应引起更高水平的激活，而dLGN和V1的OFF反应的潜伏期比ON反应的短。去除暗盘或亮盘通常会产生负后像的感觉，这里我们要问的是，暗盘和亮盘引起的负后像是否也存在不对称性。如果是这样的话，皮层下ON和OFF细胞的刺激后反应是否平行于这种后像不对称性？为了验证这些假设，我们在人类身上进行了心理物理实验，并在CAT dLGN上进行了单细胞/S电位记录。在心理生理上，我们发现亮度递减产生的明亮余像比同等大小的亮度增量产生的暗余像更强且持续时间更长。神经生理学上，我们发现ON细胞对摘除暗盘的反应具有更高的放电率，而ON细胞对摘除亮盘的反应时间比OFF细胞长。在dLGN，长时间刺激时，开、关细胞的不对称性最为明显。我们的结论是，开通道和关通道之间的皮层下反应强度差异平行于亮和暗负残像之间的不对称性，进一步支持了亮和暗残像知觉的皮层下起源。
Humans are more sensitive to luminance decrements than increments, as evidenced by lower thresholds and shorter latencies for dark stimuli. This asymmetry is consistent with results of neurophysiological recordings in dorsal lateral geniculate nucleus (dLGN) and primary visual cortex (V1) of cat and monkey. Specifically, V1 population responses demonstrate that darks elicit higher levels of activation than brights, and the latency of OFF responses in dLGN and V1 is shorter than that of ON responses. The removal of a dark or bright disc often generates the perception of a negative afterimage, and here we ask whether there also exist asymmetries for negative afterimages elicited by dark and bright discs. If so, do the poststimulus responses of subcortical ON and OFF cells parallel such afterimage asymmetries? To test these hypotheses, we performed psychophysical experiments in humans and single-cell/S-potential recordings in cat dLGN. Psychophysically, we found that bright afterimages elicited by luminance decrements are stronger and last longer than dark afterimages elicited by luminance increments of equal sizes. Neurophysiologically, we found that ON cells responded to the removal of a dark disc with higher firing rates that were maintained for longer than OFF cells to the removal of a bright disc. The ON and OFF cell asymmetry was most pronounced at long stimulus durations in the dLGN. We conclude that subcortical response strength differences between ON and OFF channels parallel the asymmetries between bright and dark negative afterimages, further supporting a subcortical origin of bright and dark afterimage perception.