Electrophysiological indices of surround suppression in humans.
Electrophysiological indices of surround suppression in humans.
复制标题
人类周围抑制的电生理指标。
DOI：
10.1152/jn.00774.2014
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发表时间：
2015
影响因子：
2.5
通讯作者：
Kelly,SimonP
中科院分区：
文献类型：
--
作者：
Vanegas,MIsabel;Blangero,Annabelle;Kelly,SimonP
周围抑制是视觉皮质神经生理学中的一个著名的语境交互作用的例子，在这种情况下，神经对神经元经典感受野内出现的刺激的反应被周围刺激抑制。人类心理物理学报告提出了一个明显类似于在单个神经元水平上看到的效果：当刺激嵌入到周围环境中时，被认为是低对比度。在这里，我们报告了一种视觉范式，它提供了人类电生理学中相对直接、直接的环绕抑制指数，使我们能够再现几种众所周知的神经生理和心理物理效应，并对时间趋势和视网膜位置效应进行新的分析。在不同静态环境模式下，对闪烁“前景”刺激诱发的稳态视觉诱发电位(SSVEP)进行了测量。利用早期视觉皮质几何结构和视网膜组织来增强SSVEP波幅。前景反应作为环境对比度的单调函数被强烈抑制。此外，匹配方向周围的抑制比垂直方向的抑制更强，周围位置的抑制比中心凹位置更强。这些模式在感知对比度的心理物理报告中重现，外周电生理抑制效应与受试者的心理物理效应相关。对SSVEP幅度的时间分析表明，短期的对比度适应效应导致前景信号随着时间的推移而减弱或增大，这取决于周围环境的相对对比度，与抑制驱动的更强适应一致。这种电生理学范式不仅在索引视觉缺陷方面具有临床潜力，而且可能在更广泛地表达在无序大脑中的获得控制缺陷方面具有临床潜力。
Surround suppression is a well-known example of contextual interaction in visual cortical neurophysiology, whereby the neural response to a stimulus presented within a neuron's classical receptive field is suppressed by surrounding stimuli. Human psychophysical reports present an obvious analog to the effects seen at the single-neuron level: stimuli are perceived as lower-contrast when embedded in a surround. Here we report on a visual paradigm that provides relatively direct, straightforward indices of surround suppression in human electrophysiology, enabling us to reproduce several well-known neurophysiological and psychophysical effects, and to conduct new analyses of temporal trends and retinal location effects. Steady-state visual evoked potentials (SSVEP) elicited by flickering “foreground” stimuli were measured in the context of various static surround patterns. Early visual cortex geometry and retinotopic organization were exploited to enhance SSVEP amplitude. The foreground response was strongly suppressed as a monotonic function of surround contrast. Furthermore, suppression was stronger for surrounds of matching orientation than orthogonally-oriented ones, and stronger at peripheral than foveal locations. These patterns were reproduced in psychophysical reports of perceived contrast, and peripheral electrophysiological suppression effects correlated with psychophysical effects across subjects. Temporal analysis of SSVEP amplitude revealed short-term contrast adaptation effects that caused the foreground signal to either fall or grow over time, depending on the relative contrast of the surround, consistent with stronger adaptation of the suppressive drive. This electrophysiology paradigm has clinical potential in indexing not just visual deficits but possibly gain control deficits expressed more widely in the disordered brain.