Semantic Potential of Tactile Metaphors (Based on Words Naming the Property of Softness)

This article describes the results of the study on the psychophysiological phenomenon of synaesthesia projected onto language and speech. Synaesthesia is considered on the basis of words with the root myagk- (myagky, myagko, myagkost’, smyagchit’), which in their original meaning name the tactile sensation of softness. The paper aimed to identify the potential of this vocabulary and the sensory impression behind it as a means of conceptualizing knowledge about the world as well as to study the mechanism for the development of metaphorical, primarily synaesthetic, semantics. It is important to assess the sequence of expression of synaesthetic semantics and meanings that go beyond synaesthetic meanings, as well as to study whether vocabulary with the original semantics of softness can figuratively conceptualize knowledge. The research revealed a universal ability of this kind of vocabulary to conceptualize all types of sensory impressions (visual, auditory, olfactory and gustatory) when used metaphorically. In addition to conveying a multimodal perception of the world, these words can express new sensory sensations, unusual for the speaker, for which there are no special names in the language. Along with the synaesthetic semantics itself, vocabulary with the meaning of softness is able to reflect the psychological impressions of comfort, pleasure and enjoyment, as well as the psychological characteristics of a person and the psychological aspect of interpersonal interaction, including speech. The next stage of abstraction of the tactile impression is the development on its basis of quantitative semantics, i.e. the meaning of low intensity of the manifestation of an attribute or an action in their psychological perception. The results obtained can be used to identify the mechanism for conceptualizing sensory impressions and forming synaesthetic metaphors, as well as applied in the practice of lexicographic description of cognitive metaphors.

In-vitro Assessment of Silver Diamine Fluoride Effect on Natural Carious Dentin Microhardness

This study aimed to assess the effect of silver diamine fluoride (SDF) on natural carious dentin microhardness and the correlation between tactile sensation, fluorescence, and microhardness on carious dentin. Permanent carious teeth scored ICDAS 4–6 were longitudinally sectioned into tooth slabs exposing carious dentin on one side and sound dentin on the other. Both sides were assessed for tactile sensation (soft/leathery/firm), fluorescence (red/pink/no fluorescence) with FACE technology (SiroInspect®, Dentsply Sirona, USA), and Vickers's microhardness (VMH). Samples were randomized into 3 groups based on SDF protocol (n = 30): Control/Group A- No SDF treatment; Group B- 38% SDF (Advantage Arrest™, Elevate Oral Care®, USA); Group C- SDF with potassium iodide/KI (Riva Star, SDI, Australia). After SDF application, all samples were stored for 1 week under 100% humidity at 37°C and re-assessed for tactile sensation, fluorescence, and microhardness. Change in microhardness (ΔVMH; mean ± SD), tactile sensation (ΔT), and fluorescence (ΔF) were calculated using the difference between pre-SDF and post-SDF values. Mixed ANOVA analysis showed that ΔVMH of carious and sound surfaces were statistically significantly higher for each of the experimental groups (Group B-sound: 20.22 ± 11.98 HV, carious: 19.76 ± 9.35 HV; Group C-sound: 14.26 ± 10.11 HV, carious: 22.51 ± 7.67 HV) than the control group (Group A–sound: 7.34 ± 8.28 HV, carious: 0.69 ± 3.53 HV) (p < 0.0001). There was no statistically significant difference between the experimental groups themselves for carious surfaces (p = 0.146). On sound surfaces, Group B showed a statistically significantly higher ΔVMH than Group C (p = 0.026). There was no statistically significant interaction between type of surface and ΔVMH in Group B (p = 0.809). In Group C, sound surfaces showed a statistically significantly lower ΔVMH than carious surfaces (p < 0.0001). Spearman rank-order correlation showed a statistically significant negative correlation between ΔVMH and ΔT (rs = −0.588, p < 0.0001) and between ΔVMH and ΔF (rs = −0.269, p = 0.01). There was a statistically significant positive correlation between ΔT and ΔF (rs = 0.226, p = 0.032). In conclusion, the microhardness of SDF-treated dentin surfaces increased as compared to non-SDF-treated surfaces. SDF (Advantage Arrest™) increased microhardness of carious and sound dentin to a similar extent whereas, SDF/KI (Riva Star) increased microhardness of carious dentin more than sound dentin. An increase in microhardness was correlated with a firmer tactile sensation.

Teaching cadaveric laparoscopic anatomy in medical curriculum – An essential learning option

Teaching anatomy to the medical students is shifting from learning the traditional gross anatomy with didactic lectures to learning anatomy by laparoscopic dissection on the cadavers. The open dissection hall teaching is loosing relevance to learning clinical anatomy with laparoscopic dissection live by the medical students. Laparoscopic demonstrations can generate interest in surgery in the students that would otherwise not be possible in the preclinical years. Additional advantages of laparoscopic anatomy learning are improved three-dimensional orientation, increased dexterity and development of team working skills among students. The magnified laparoscopic views and the ability to deeply explore anatomical features to demonstrate the basic anatomy better with full clarity does makes an impression on the young medical students. The major disadvantage is student may feel the lack of pleasure of tactile sensation, of touching the anatomical organs during laparoscopic demonstration.

Alimentary tract obstruction attributed to use of barbed suture for double tract reconstruction after robot-assisted proximal gastrectomy: a case report

Background Anastomotic stenosis following esophagojejunostomy reconstruction by the overlap method with absorbable barbed sutures occurs only rarely in patients who have undergone laparoscopic surgery. We report anastomotic stenosis by the overlap method that we attributed to the lack of tactile sensation during robot-assisted surgery. Case presentation An 83-year-old man underwent robot-assisted laparoscopic proximal gastrectomy and lymph node dissection at our hospital for treatment of gastric cancer. Double tract reconstruction followed with side-to-side esophagojejunostomy (overlap method) performed with an endoscopic linear stapler. On completion of the anastomosis, the enterotomy was closed under robotic assistance with absorbable barbed suture. Once solid foods were introduced, the patient had difficulty swallowing and felt as though his digestive tract was stopped up. When upper gastrointestinal endoscopy was performed, we found the anastomotic lumen to be coated with food residue. After rinsing off the residue with water, we could see barbed suture protruding into the anastomotic lumen that had become entangled upon itself, which explained how the food residue had accumulated. We cut the entangled suture under endoscopic visualization using a loop cutter. Conclusion This case highlights a stricture caused by insufficiently tensioning barbed suture, which subsequently protruded into the anastomotic lumen and became entangled upon itself. We believe this occurrence was associated with the lack of tactile sensation in robot-assisted surgery.

A Model for Estimating Tactile Sensation by Machine Learning Based on Vibration Information Obtained while Touching an Object

The tactile sensation is an important indicator of the added value of a product, and it is thus important to be able to evaluate this sensation quantitatively. Sensory evaluation is generally used to quantitatively evaluate the tactile sensation of an object. However, statistical evaluation of the tactile sensation requires many participants and is, thus, time-consuming and costly. Therefore, tactile sensing technology, as opposed to sensory evaluation, is attracting attention. In establishing tactile sensing technology, it is necessary to estimate the tactile sensation of an object from information obtained by a tactile sensor. In this research, we developed a tactile sensor made of two-layer silicone rubber with two strain gauges in each layer and obtained vibration information as the sensor traced an object. We then extracted features from the vibration information using deep autoencoders, following the nature of feature extraction by neural firing due to vibrations perceived within human fingers. We also conducted sensory evaluation to obtain tactile scores for different words from participants. We finally developed a tactile sensation estimation model for each of the seven samples and evaluated the accuracy of estimating the tactile sensation of unknown samples. We demonstrated that the developed model can properly estimate the tactile sensation for at least four of the seven samples.

Estimation of Tactile Sensation by Two Point Discrimination among 18 Years Old People

Two point discrimination (TPD) is used to distinguish the two point discriminative sense. TPD is most commonly used as neurosensory tests in clinical settings. In tactile sensation, the sensory receptors from the skin reach the somatosensory system and stimulate mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors to give the response to the respective stimuli. The present study was aim to assess the value of tactiles sensation by two point discrimination test among 18 years people. 18 years old people among the normal population were selected, consisting of 17 males and 33 females. 6 sensory areas were selected for the test. Test performed on six regions of the body like fingertips, fingers, palm, forehead, forearm, back of palm. The results were tabulated and statistically analyzed by independent t test. The ability to distinguish the two point discrimination was estimated in millimeters by using a simple hand operated device. The main findings of the study are that females were more sensitive than males in TPD perception.TPD perception was more among 18 years old. The TPD values are more in females when compared to males. The normative values of two point discrimination among 18 years people were established. This study concluded that fingertips in females were more sensitive than other parts of the body.

Mid-Air Tactile Sensations Evoked by Laser-Induced Plasma: A Neurophysiological Study

This study demonstrates the feasibility of a mid-air means of haptic stimulation at a long distance using the plasma effect induced by laser. We hypothesize that the stress wave generated by laser-induced plasma in the air can propagate through the air to reach the nearby human skin and evoke tactile sensation. To validate this hypothesis, we investigated somatosensory responses in the human brain to laser plasma stimuli by analyzing electroencephalography (EEG) in 14 participants. Three types of stimuli were provided to the index finger: a plasma stimulus induced from the laser, a mechanical stimulus transferred through Styrofoam stick, and a sham stimulus providing only the sound of the plasma and mechanical stimuli at the same time. The event-related desynchronization/synchronization (ERD/S) of sensorimotor rhythms (SMRs) in EEG was analyzed. Every participant verbally reported that they could feel a soft tap on the finger in response to the laser stimulus, but not to the sham stimulus. The spectrogram of EEG evoked by laser stimulation was similar to that evoked by mechanical stimulation; alpha ERD and beta ERS were present over the sensorimotor area in response to laser as well as mechanical stimuli. A decoding analysis revealed that classification error increased when discriminating ERD/S patterns between laser and mechanical stimuli, compared to the case of discriminating between laser and sham, or mechanical and sham stimuli. Our neurophysiological results confirm that tactile sensation can be evoked by the plasma effect induced by laser in the air, which may provide a mid-air haptic stimulation method.