Sequence of visual cortex stimulation affects phosphene brightness in blind subjects.
Sequence of visual cortex stimulation affects phosphene brightness in blind subjects.
复制标题
视觉皮层刺激的顺序会影响盲人受试者的光幻视亮度。
DOI：
10.1016/j.brs.2022.03.008
复制
发表时间：
2022
影响因子：
7.7
通讯作者：
Pouratian,Nader
中科院分区：
文献类型：
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作者：
ArmentaSalas,Michelle;Bell,Joseph;Niketeghad,Soroush;Oswalt,Denise;Bosking,William;Patel,Uday;Dorn,JessyD;Yoshor,Daniel;Greenberg,Robert;Bari,Ausaf;Pouratian,Nader
背景视觉皮质假体(VCP)可能使大多数盲人受益。这些VCP的可行性测试为表征盲人视皮层的刺激开辟了新的途径。目的/假设为了确定顺序刺激视皮层是否会在荧光素亮度上产生知觉偏差。方法我们用两个和三个电极的序列刺激了三个盲人受试者，并要求他们使用间隔强迫选择范式来确定较亮的荧光素。我们选择了一组参考电极作为序列中的恒定刺激，并在保持电极上所有其他刺激参数不变的情况下，对三个不同的幅度水平进行了比较。结果对于两个受试者，我们测量了在序列后面刺激时，感知到低水平幅度与高水平幅度一样亮或比高水平幅度亮的概率显著增加(p<0.001，Wilcoxon秩和检验)。在第二阶段，在大多数幅度比较中，参考电极被选为更亮的概率也更高。对于第三个受试者，有可测量但不显著的变化，其中第一个刺激被认为更明亮。在三电极序列中，这些效应在受试者中是一致的，其中被选为更亮的参考电极的概率与它在序列中呈现的时间相关。结论我们在非重叠的电极序列中显示了时间相互作用的证据，其中效应的方向是受试者特定的，但在不同的电极位置和电流幅度水平上是一致的。
BackgroundVisual cortical prostheses (VCP) could potentially benefit a majority of the blind population. Feasibility testing of these VCP opens new avenues to characterize stimulation of visual cortex in blind subjects.Objective/hypothesisTo determine if sequential stimulation of visual cortex produces a perception bias in phosphene brightness.MethodsWe stimulated three blind subjects implanted with the Orion array with sequences of two and three electrodes and asked them to determine the brighter phosphene, using interval forced-choice paradigms. We selected a set of reference electrodes as the constant stimuli across sequences and compared across three different amplitude levels keeping all other stimulation parameters fixed across electrodes.ResultsFor two subjects, we measured a significant increase in the probability of perceiving a lower-level amplitude just as bright or brighter than a higher-level amplitude when stimulated later in the sequence (p < 0.001, Wilcoxon rank sum test). The probability of reference electrodes selected as brighter was also higher during the second phase, across most amplitude comparisons. For the third subject, there were measurable but not significant changes, where the first stimuli were perceived as brighter. The effects were consistent within subjects in the three-electrode sequences, where the probability of the reference electrode selected as brighter was correlated to when it was presented in the sequence.ConclusionsWe showed evidence of temporal interactions in non-overlapping sequences of electrodes, where the direction of the effect was subject specific but consistent across a variety of electrode locations and current amplitude levels.