Spaak Eelke, Bouwkamp Floortje G, de Lange Floris P
Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, The Netherlands.
Imaging Neurosci (Camb). 2024 Jul 26;2. doi: 10.1162/imag_a_00242. eCollection 2024.
Recent years have seen the emergence of a visual stimulation protocol called Rapid Invisible Frequency Tagging (RIFT) in cognitive neuroscience. In RIFT experiments, visual stimuli are presented at a rapidly and sinusoidally oscillating luminance, using high refresh rate projection equipment. Such stimuli result in strong steady-state responses in visual cortex, measurable extracranially using EEG or MEG. The high signal-to-noise ratio of these neural signals, combined with the alleged invisibility of the manipulation, make RIFT a potentially promising technique to study the neural basis of visual processing. In this study, we set out to resolve two fundamental, yet still outstanding, issues regarding RIFT; as well as to open up a new avenue for taking RIFT beyond frequency tagging per se. First, we provide robust evidence that RIFT is indeed subjectively undetectable, going beyond previous anecdotal reports. Second, we demonstrate that full-amplitude luminance or contrast manipulation offer the best tagging results. Third and finally, we demonstrate that, in addition to frequency tagging, phase tagging can reliably be used in RIFT studies, opening up new avenues for constructing RIFT experiments. Together, this provides a solid foundation for using RIFT in visual cognitive neuroscience.
近年来，认知神经科学领域出现了一种名为快速不可见频率标记（RIFT）的视觉刺激方案。在RIFT实验中，使用高刷新率投影设备以快速且呈正弦振荡的亮度呈现视觉刺激。此类刺激会在视觉皮层中产生强烈的稳态反应，可通过脑电图（EEG）或脑磁图（MEG）在颅外进行测量。这些神经信号的高信噪比，再加上该操作据称具有不可见性，使得RIFT成为一种研究视觉处理神经基础的潜在有前景的技术。在本研究中，我们着手解决关于RIFT的两个基本但仍未解决的问题；同时为将RIFT拓展到频率标记本身之外开辟一条新途径。首先，我们提供了有力证据，表明RIFT确实在主观上无法被检测到，超越了以往的传闻报道。其次，我们证明全幅度亮度或对比度操作能提供最佳的标记结果。第三也是最后一点，我们证明，除了频率标记外，相位标记也可可靠地用于RIFT研究，为构建RIFT实验开辟了新途径。总之，这为在视觉认知神经科学中使用RIFT奠定了坚实基础。
