Ved stickiness of your Infra-threshold stimuli was not the same as from the Sham stimulus that was produced of an acrylic material and made use of to supply the tactile condition of a non-sticky feeling. Even though the Infra-threshold stimuli failed to generate an apparently sticky feeling, the typical behavioral scores for these stimuli in the approach of continual stimuli and the magnitude-estimation tests were higher than 0 (Supplementary Tables 1, 2). Within the constant-stimuli test, the score of 0 indicates that participants had no feeling of stickiness for all trials, even though within the magnitude-estimation test, 0 was equal for the intensity of stickiness in the Sham stimulus. Taken together, we can speculate that the Infrathreshold stimuli evoked a tactile perception similar to stickiness, but the sensation was too weak to become regarded as a sticky feeling. A single drawback on the stimulations employed inside the current study is that the physical intensity of stickiness of every single silicone stimulus is unknown, so the study was unable to examine the modifications in perception of stickiness in accordance with the physical intensity of stickiness. We attempted to measure the physical intensity of stickiness of our silicone stimuli within a follow-up investigation, but no presently offered stickiness measurements, for instance the peel-strength test, could measure it properly. Hence, it really should be noted that the whole analysis in our study was primarily based on the perceived intensity of stickiness, not on the physical a single.Brain Responses in the Supra-Threshold vs. Sham and Infra-Threshold vs. Sham ContrastsContralateral S1 and ipsilateral DLPFC, the two substantially activated regions within the Supra-threshold vs. Sham contrast, could be involved inside the tactile perception of stickiness. Even thoughFrontiers in Human Neuroscience | www.frontiersin.orgJanuary 2017 | Volume 11 | 5-Hydroxy-1-tetralone site ArticleYeon et al.Neural Correlates of Tactile StickinessFIGURE 5 | Amongst the eight area of interest (ROI) regions that have been activated inside the Supra- vs. Infra-threshold, six regions showed substantial relationships amongst the mean-corrected blood-oxygen-level-dependent (BOLD) peak values and the mean-corrected magnitude estimation values (ps 0.05): left caudate (Caudate_L), right thalamus (Thalamus_R), left pallidum (Pallidum_L), left putamen (Putamen_L), ideal insula (Insula_R), correct superior temporal cortex (Temporal_Sup_R).both the Supra- and Infra-threshold stimuli have been made of your same silicone substance, only the Supra-threshold vs. Sham contrast revealed considerable activities within the two brain regions. Thus, it is plausible to attribute the activation of contralateral S1 and ipsilateral DLPFC for the perception of stickiness from the stimuli, not to the perceptual differences of the two components (i.e., the silicone plus the acryl). S1 has been reported to become involved in tactile information and facts processing in a quantity of fMRI research (Servos et al., 2001; Pleger et al., 2003, 2006; Hlushchuk and Hari, 2006; Schaeferet al., 2006; Kim et al., 2015). In distinct, S1 is well known to take part in the method of discriminative somatosensory perception (Jiang et al., 1997; Schnitzler and Ploner, 2000; Timmermann et al., 2001). As for the connection involving S1 and stickiness sensation, most preceding research documented the role of S1 within the perception of frictional forces. For example, it was reported that anesthesia of S1 led to failure of frictional sensation evoked by a grip (Brochier et al., 1999). It was also suggested.