Fiorio Mirta, Emadi Andani Mehran, Recchia Serena, Tinazzi Michele
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Via Casorati, 43, 37131, Verona, Italy.
Multifunctional Center "Don Calabria", Verona, Italy.
Exp Brain Res. 2018 Nov;236(11):2983-2990. doi: 10.1007/s00221-018-5357-5. Epub 2018 Aug 14.
In a recent study, we showed that tactile perception can be enhanced by applying a placebo manipulation consisting of verbal suggestion and conditioning (Fiorio et al., Neuroscience 217:96-104, 2012). Whether this change in perception is related to a better tactile functioning is still unknown. Aim of this study is to investigate whether placebo-induced enhancement of tactile perception results in better somatosensory temporal discrimination threshold (STDT), as a proxy of tactile acuity. To this purpose, a group of subjects (experimental group) was verbally influenced and conditioned about the effect of an inert cream in enhancing tactile perception, while a control group was informed about the real nature of the cream. In both groups, we measured STDT before and after cream application, by means of pairs of electrical stimuli delivered on the index fingertip and separated by ascending inter-stimulus intervals. STDT was defined as the shortest time interval at which the two stimuli were perceived as separated. Results revealed an increase in subjective perception of stimulus intensity and a reduction of STDT only in the experimental group. This study proves that a placebo procedure, consisting of verbal suggestion and a short conditioning, can reduce the temporal discrimination threshold.
在最近的一项研究中，我们发现通过实施由言语暗示和条件作用组成的安慰剂操作，可以增强触觉感知（菲奥里奥等人，《神经科学》217:96 - 104，2012年）。这种感知变化是否与更好的触觉功能相关仍不清楚。本研究的目的是调查安慰剂诱导的触觉感知增强是否会导致更好的体感时间辨别阈值（STDT），以此作为触觉敏锐度的指标。为此，一组受试者（实验组）在惰性乳膏增强触觉感知的效果方面受到言语影响和条件作用，而对照组被告知乳膏的真实性质。在两组中，我们通过在食指指尖施加成对的电刺激并以递增的刺激间隔分开，来测量乳膏涂抹前后的STDT。STDT被定义为两个刺激被感知为分开的最短时间间隔。结果显示，仅在实验组中刺激强度的主观感知增加且STDT降低。这项研究证明，由言语暗示和简短条件作用组成的安慰剂程序可以降低时间辨别阈值。
