Sy Jocelyn L, Tomarken Andrew J, Patel Vaama, Blake Randolph
Department of Psychology, Vanderbilt University, Nashville, TN,
J Vis. 2016 Dec 1;16(15):22. doi: 10.1167/16.15.22.
Binocular rivalry occurs when markedly different inputs to the two eyes initiate alternations in perceptual dominance between the two eyes' views. A link between individual differences in perceptual dynamics of rivalry and concentrations of GABA, a prominent inhibitory neurotransmitter in the brain, has highlighted binocular rivalry as a potential tool to investigate inhibitory processes in the brain. The present experiment investigated whether previously reported fluctuations of GABA concentrations in a healthy menstrual cycle (Epperson et al., 2002) also are associated with measurable changes in rivalry dynamics within individuals. We obtained longitudinal measures of alternation rate, dominance, and mixture durations in 300 rivalry tracking blocks measured over 5 weeks from healthy female participants who monitored the start of the follicular and luteal phases of their cycle. Although we demonstrate robust and stable individual differences in rivalry dynamics, across analytic approaches and dependent measures, we found no significant change or even trends across menstrual phases in the temporal dynamics of dominance percepts. We found only sparse between-phase differences in skew and kurtosis on mixture percepts when data were pooled across sessions and blocks. These results suggest a complex dynamic between hormonal steroids, binocular rivalry, and GABAeric signaling in the brain and thus implicate the need to consider a systemic perspective when linking GABA with perceptual alternations in binocular rivalry.
当两只眼睛接收到明显不同的输入时，就会出现双眼竞争，即两眼的视觉在感知优势上出现交替。竞争的感知动态中的个体差异与大脑中一种重要的抑制性神经递质γ-氨基丁酸（GABA）的浓度之间存在联系，这使得双眼竞争成为研究大脑抑制过程的一种潜在工具。本实验研究了先前报道的健康月经周期中GABA浓度的波动（Epperson等人，2002年）是否也与个体内竞争动态的可测量变化相关。我们从监测其月经周期卵泡期和黄体期开始的健康女性参与者那里，在5周内获得了300个竞争跟踪块的交替率、优势度和混合持续时间的纵向测量数据。尽管我们在竞争动态中证明了强大且稳定的个体差异，涵盖各种分析方法和相关测量，但我们发现在月经周期各阶段，优势感知的时间动态没有显著变化，甚至没有明显趋势。当跨会话和块汇总数据时，我们仅在混合感知的偏度和峰度上发现了稀疏的阶段间差异。这些结果表明大脑中激素类固醇、双眼竞争和GABA能信号之间存在复杂的动态关系，因此意味着在将GABA与双眼竞争中的感知交替联系起来时，需要考虑系统的观点。
