School of Medical Sciences, UNSW Sydney, Sydney, Australia.
Neuroscience Research Australia, Sydney, Australia.
J Neurophysiol. 2021 Feb 1;125(2):687-692. doi: 10.1152/jn.00662.2020. Epub 2021 Jan 13.
Perceived frequency of vibrotactile stimuli can be divided into two distinctive cutaneous sensations-flutter (<60 Hz) and vibratory hum (>60 Hz), mediated by two different tactile afferent types [fast adapting type I (FA1) and fast adapting type II (FA2), respectively]. We recently demonstrated a novel form of neural coding in the human tactile system, where frequency perception of stimulus pulses grouped into periodic bursts in the flutter range depended on the duration of the silent gap between bursts, rather than the periodicity or mean impulse rate. Here, we investigated whether this interburst interval could also explain the perceived frequency of electrocutaneous pulse patterns delivered at frequencies above the flutter range. At stimulus rates of 50 to 190 pulses/s, the burst gap model correctly predicted the perceived frequency. This shows that the burst gap code represents a general coding strategy that spans the range of frequencies traditionally attributed to two different tactile channels. We present evidence for a generalized frequency processing strategy on tactile afferent inputs that is shared across a broad range of frequencies extending beyond the flutter range, supporting the notion that spike timing has an important role in shaping tactile perception.
被感知的振动刺激频率可分为两种独特的皮肤感觉——颤动(<60Hz)和振动嗡嗡声(>60Hz),由两种不同的触觉传入类型介导[分别为快速适应型 I(FA1)和快速适应型 II(FA2)]。我们最近在人类触觉系统中展示了一种新的神经编码形式,其中,在颤动范围内刺激脉冲分组为周期性爆发时的频率感知取决于爆发之间的静息间隔的持续时间,而不是周期性或平均脉冲率。在这里,我们研究了这种爆发间间隔是否也可以解释在高于颤动范围的频率下传递的电触觉脉冲模式的感知频率。在 50 到 190 个脉冲/秒的刺激速率下,爆发间隙模型正确地预测了感知频率。这表明,爆发间隙编码代表了一种通用的编码策略,跨越了传统归因于两种不同触觉通道的频率范围。我们提出了一种关于触觉传入的广义频率处理策略的证据,该策略在广泛的频率范围内共享,超出了颤动范围,支持了尖峰时间在塑造触觉感知方面具有重要作用的观点。