scholarly journals Compression of dynamic tactile information in the human hand

2020 ◽  
Vol 6 (16) ◽  
pp. eaaz1158 ◽  
Author(s):  
Yitian Shao ◽  
Vincent Hayward ◽  
Yon Visell
Keyword(s):  
Perceptual Processing ◽  
Human Hand ◽  
Sense Organs ◽  
Tactile Information ◽  
Naturally Occurring ◽  
Tactile Stimuli ◽  
Mechanical Waves ◽  
Wave Patterns ◽  
Optimal Encoding ◽  
Entire Dataset

A key problem in the study of the senses is to describe how sense organs extract perceptual information from the physics of the environment. We previously observed that dynamic touch elicits mechanical waves that propagate throughout the hand. Here, we show that these waves produce an efficient encoding of tactile information. The computation of an optimal encoding of thousands of naturally occurring tactile stimuli yielded a compact lexicon of primitive wave patterns that sparsely represented the entire dataset, enabling touch interactions to be classified with an accuracy exceeding 95%. The primitive tactile patterns reflected the interplay of hand anatomy with wave physics. Notably, similar patterns emerged when we applied efficient encoding criteria to spiking data from populations of simulated tactile afferents. This finding suggests that the biomechanics of the hand enables efficient perceptual processing by effecting a preneuronal compression of tactile information.

Tactile information from the human hand reaches the ipsilateral primary somatosensory cortex

1995 ◽  
Vol 200 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Alfons Schnitzler ◽  
Riitta Salmelin ◽  
Stephan Salenius ◽  
Veikko Jousmäki ◽  
Riitta Hari
Keyword(s):  
Somatosensory Cortex ◽  
Primary Somatosensory Cortex ◽  
Human Hand ◽  
Tactile Information

scholarly journals Glucosinolate Content in Brassica Genetic Resources and Their Distribution Pattern within and between Inner, Middle, and Outer Leaves

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1421
Author(s):  
Ju-Hee Rhee ◽  
Susanna Choi ◽  
Jae-Eun Lee ◽  
On-Sook Hur ◽  
Na-Young Ro ◽  
...  
Keyword(s):  
Genetic Resources ◽  
Defense Mechanism ◽  
Multiple Reaction Monitoring ◽  
Principal Component ◽  
Brassica Species ◽  
Glucosinolate Content ◽  
Proximal Half ◽  
Naturally Occurring ◽  
Low Concentrations ◽  
Entire Dataset

Glucosinolates (GSLs) are sulfur-containing secondary metabolites naturally occurring in Brassica species. The purpose of this study was to identify the GSLs, determine their content, and study their accumulation patterns within and between leaves of kimchi cabbage (Brassica rapa L.) cultivars. GSLs were analyzed using UPLC-MS/MS in negative electron-spray ionization (ESI−) and multiple reaction monitoring (MRM) mode. The total GSL content determined in this study ranged from 621.15 to 42434.21 μmolkg−1 DW. Aliphatic GSLs predominated, representing from 4.44% to 96.20% of the total GSL content among the entire samples. Glucobrassicanapin (GBN) contributed the greatest proportion while other GSLs such as glucoerucin (ERU) and glucotropaeolin (TRO) were found in relatively low concentrations. Principal component analysis (PCA) yielded three principal components (PCs) with eigenvalues ≥ 1, altogether representing 74.83% of the total variation across the entire dataset. Three kimchi cabbage (S/No. 20, 4, and 2), one leaf mustard (S/No. 26), and one turnip (S/No. 8) genetic resources were well distinguished from other samples. The GSL content varied significantly among the different positions (outer, middle, and inner) of the leaves and sections (top, middle, bottom, green/red, and white) within the leaves. In most of the samples, higher GSL content was observed in the proximal half and white sections and the middle layers of the leaves. GSLs are regarded as allelochemicals; hence, the data related to the patterns of GSLs within the leaf and between leaves at a different position could be useful to understand the defense mechanism of Brassica plants. The observed variability could be useful for breeders to develop Brassica cultivars with high GSL content or specific profiles of GSLs.

scholarly journals Integration of visual and tactile information in reproduction of traveled distance

2017 ◽  
Vol 118 (3) ◽  
pp. 1650-1663 ◽  
Author(s):  
Jan Churan ◽  
Johannes Paul ◽  
Steffen Klingenhoefer ◽  
Frank Bremmer
Keyword(s):  
Visual Information ◽  
Tactile Stimulus ◽  
Visual Motion ◽  
Air Flow ◽  
Natural World ◽  
Sources Of Information ◽  
Reproduction Task ◽  
Tactile Information ◽  
Tactile Stimuli ◽  
Self Motion

In the natural world, self-motion always stimulates several different sensory modalities. Here we investigated the interplay between a visual optic flow stimulus simulating self-motion and a tactile stimulus (air flow resulting from self-motion) while human observers were engaged in a distance reproduction task. We found that adding congruent tactile information (i.e., speed of the air flow and speed of visual motion are directly proportional) to the visual information significantly improves the precision of the actively reproduced distances. This improvement, however, was smaller than predicted for an optimal integration of visual and tactile information. In contrast, incongruent tactile information (i.e., speed of the air flow and speed of visual motion are inversely proportional) did not improve subjects’ precision indicating that incongruent tactile information and visual information were not integrated. One possible interpretation of the results is a link to properties of neurons in the ventral intraparietal area that have been shown to have spatially and action-congruent receptive fields for visual and tactile stimuli. NEW & NOTEWORTHY This study shows that tactile and visual information can be integrated to improve the estimates of the parameters of self-motion. This, however, happens only if the two sources of information are congruent—as they are in a natural environment. In contrast, an incongruent tactile stimulus is still used as a source of information about self-motion but it is not integrated with visual information.

scholarly journals Analysis of different vibration patterns to guide blind people

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3082 ◽  
Author(s):  
Juan V. Durá-Gil ◽  
Bruno Bazuelo-Ruiz ◽  
David Moro-Pérez ◽  
Fernando Mollà-Domenech
Keyword(s):  
Human Body ◽  
Blind People ◽  
Back Side ◽  
Front Side ◽  
Tactile Information ◽  
Tactile Stimuli ◽  
Lack Of Knowledge

The literature indicates the best vibration positions and frequencies on the human body where tactile information is transmitted. However, there is a lack of knowledge about how to combine tactile stimuli for navigation. The aim of this study is to compare different vibration patterns outputted to blind people and to determine the most intuitive vibration patterns to indicate direction for navigation purposes through a tactile belt. The vibration patterns that stimulate the front side of the waist are preferred for indicating direction. Vibration patterns applied on the back side of the waist could be suitable for sending messages such as stop.

Biomimetic Tactile Sensor

2007 ◽  
Author(s):  
Nicholas Wettels ◽  
Djordje Popovic ◽  
Gerald E. Loeb
Keyword(s):  
Tactile Sensor ◽  
Robotic Manipulators ◽  
Human Hand ◽  
Force Sensors ◽  
Tactile Information ◽  
Prosthetic Hands ◽  
Sharp Edges

The performance of prosthetic hands and robotic manipulators is severely limited by their having little or no tactile information compared to the human hand. Technologies such as MEMS, microfluidics, and nanoparticles have been used to produce arrays of force sensors, but these are generally not robust enough to mount on curved, deformable finger pads or to use in environments that include dust, fluids, sharp edges and wide temperature swings. Furthermore, it is not clear how the prosthetic controller will use the tactile information, so it is difficult to generate specifications for these sensors.

Orienting Attention to Points in Time Improves Stimulus Processing Both within and across Modalities

2006 ◽  
Vol 18 (5) ◽  
pp. 715-729 ◽  
Author(s):  
Kathrin Lange ◽  
Brigitte Röder
Keyword(s):  
Reaction Time ◽  
Spatial Attention ◽  
Event Related Potentials ◽  
Perceptual Processing ◽  
Auditory Stimuli ◽  
Reaction Time Experiment ◽  
Tactile Stimuli ◽  
Related Potentials ◽  
Efficient Processing ◽  
Task Irrelevant

Spatial attention affects the processing of stimuli of both a task-relevant and a task-irrelevant modality. The present study investigated if similar cross-modal effects exist when attention is oriented to a point in time. Short (600 msec) and long (1200 msec) empty intervals, marked by a tactile onset and an auditory or a tactile offset marker, were presented. In each block, the participants had to attend one interval and one modality. Event-related potentials (ERPs) to auditory and tactile offset markers of attended as compared to unattended intervals were characterized by an enhancement of early negative deflections of the auditory and somatosensory ERPs (audition, 100–140 msec; touch, 130–180 msec) when audition or touch was task relevant, respectively. Similar effects were found for auditory stimuli when touch was task relevant. An additional reaction time experiment revealed faster responses to both auditory and tactile stimuli at the attended as compared to the unattended point in time, irrespective of which modality was primary. Both behavioral and ERP data show that attention can be focused on a point in time, which results in a more efficient processing of auditory and tactile stimuli. The ERP data further suggest that a relative enhancement at perceptual processing stages contributes to the processing advantage for temporally attended stimuli. The existence of cross-modal effects of temporal attention underlines the importance of time as a feature for binding input across different modalities.

scholarly journals Continuous, multidimensional coding of 3D complex tactile stimuli by primary sensory neurons of the vibrissal system

2021 ◽  
Vol 118 (32) ◽  
pp. e2020194118
Author(s):  
Nicholas E. Bush ◽  
Sara A. Solla ◽  
Mitra J. Z. Hartmann
Keyword(s):  
Sensory Neurons ◽  
Three Dimensional ◽  
Primary Sensory Neurons ◽  
Tactile Information ◽  
Central Neurons ◽  
Information Bottleneck ◽  
Tactile Stimuli ◽  
Functional Classes ◽  
Stimulus Features ◽  
Multidimensional Representation

Across all sensory modalities, first-stage sensory neurons are an information bottleneck: they must convey all information available for an animal to perceive and act in its environment. Our understanding of coding properties of primary sensory neurons in the auditory and visual systems has been aided by the use of increasingly complex, naturalistic stimulus sets. By comparison, encoding properties of primary somatosensory afferents are poorly understood. Here, we use the rodent whisker system to examine how tactile information is represented in primary sensory neurons of the trigeminal ganglion (Vg). Vg neurons have long been thought to segregate into functional classes associated with separate streams of information processing. However, this view is based on Vg responses to restricted stimulus sets which potentially underreport the coding capabilities of these neurons. In contrast, the current study records Vg responses to complex three-dimensional (3D) stimulation while quantifying the complete 3D whisker shape and mechanics, thereby beginning to reveal their full representational capabilities. The results show that individual Vg neurons simultaneously represent multiple mechanical features of a stimulus, do not preferentially encode principal components of the stimuli, and represent continuous and tiled variations of all available mechanical information. These results directly contrast with proposed codes in which subpopulations of Vg neurons encode select stimulus features. Instead, individual Vg neurons likely overcome the information bottleneck by encoding large regions of a complex sensory space. This proposed tiled and multidimensional representation at the Vg directly constrains the computations performed by more central neurons of the vibrissotrigeminal pathway.

Parallel processing in rabbit first (SI) and second (SII) somatosensory cortical areas: effects of reversible inactivation by cooling of SI on responses in SII

1992 ◽  
Vol 68 (3) ◽  
pp. 703-710 ◽  
Author(s):  
G. M. Murray ◽  
H. Q. Zhang ◽  
A. N. Kaye ◽  
T. Sinnadurai ◽  
D. H. Campbell ◽  
...  
Keyword(s):  
Mammalian Species ◽  
Receptive Fields ◽  
Activity Levels ◽  
Tactile Information ◽  
Reversible Inactivation ◽  
Cortical Areas ◽  
Tactile Stimuli ◽  
The Face ◽  
Somatosensory Cortical Areas ◽  
Hierarchical Scheme

1. Previous observations on the effect of ablation or inactivation of the primary somatosensory cortex (SI) on the responses of neurons within the second somatosensory area (SII) to tactile stimuli point to profound differences between monkeys and certain other mammals in the organization of thalamocortical systems. In the cat, for example, tactile information appears to be conveyed in parallel from the thalamus to both SI and SII, whereas, in macaque and marmoset monkeys, it is conveyed in a serial (or hierarchical) scheme from the thalamus to SI and thence to SII. The present study examined the responses of individual SII neurons during reversible, cooling-induced inactivation of SI in another nonprimate placental mammal, the rabbit, to obtain further evidence on whether the above differences might reflect a fundamental distinction between simian primates and other mammalian species. 2. When the temperature at the face of a silver cooling block over the forepaw and hindpaw regions of SI was lowered to 5–13 degrees C, the SI surface potentials evoked by brief tactile stimuli were abolished (indicative of SI inactivation), whereas SII potentials remained intact. 3. The responses of 25 SII neurons to controlled tactile stimuli (consisting of 1- to 1.5-s trains of vibration or rectangular mechanical pulses) were studied before, during, and after inactivation of SI. The effects on the spontaneous activity of a further three SII neurons that lacked identified receptive fields were also studied. 4. The response or activity levels of 26 of the 28 SII neurons examined (93%) were unaffected by SI inactivation.(ABSTRACT TRUNCATED AT 250 WORDS)

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