Significance Our exquisite tactile sensitivity to surface texture allows us distinguish silk from satin or even good cheap silk. We show that the perception of natural textures relies on two neural mechanisms. Coarse textural features, for example, individual elements Braille, are represented in spatial patterns activation across one population mechanoreceptive afferents densely innervate fingertip skin. In contrast, our ability discern fine features is mediated by transduction and...

Significance When we grasp an object, thousands of tactile nerve fibers become activated and inform us about its physical properties (e.g., shape, size, texture). Although the individual have been described, our understanding how object information is encoded in populations remains primitive. To fill this gap, developed a simulation that incorporates much what known skin mechanics fibers. We show simulated match biological ones across wide range conditions sampled from literature. then can...

Electrical connections between nerves and a prosthetic device enable amputees to discern precise, graded sensory intensity ranging from light touch intense pressure.

Sensory systems are designed to extract behaviorally relevant information from the environment. In seeking understand a sensory system, it is important environment within which operates. present study, we seek characterize natural scenes of tactile texture perception. During exploration complex high-frequency vibrations elicited in fingertip skin, and these thought carry about surface manipulated objects. How texture-elicited depend on microgeometry biomechanical properties skin itself...

Our ability to perceive and discriminate textures relies on the transduction processing of complex, high-frequency vibrations elicited in fingertip as it is scanned across a surface. How naturalistic vibrations, by extension texture, are encoded responses neurons primary somatosensory cortex (S1) unknown. Combining single unit recordings awake macaques perceptual judgments obtained from human subjects, we show that vibratory amplitude strength response evoked S1 neurons. In contrast,...

In primates, the sense of touch has traditionally been considered to be a spatial modality, drawing an analogy visual system. this view, stimuli are encoded in patterns activity over sheet receptors embedded skin. We propose that processing mode is complemented by temporal one. Indeed, transduction and complex, high-frequency skin vibrations have shown play important role tactile texture perception, frequency composition shapes evoked percept. Mechanoreceptive afferents innervating glabrous...

Abstract Scientists traditionally use passive stimulation to examine the organisation of primary somatosensory cortex (SI). However, given close, bidirectional relationship between and motor systems, active paradigms involving free movement may uncover alternative SI representational motifs. Here, we used 7 Tesla functional magnetic resonance imaging compare hallmark features digit representation tasks which were unmatched on task or stimulus properties. The spatial location maps,...

The sense of touch comprises multiple sensory channels that each conveys characteristic signals during interactions with objects. These neural must then be integrated in such a way behaviorally relevant information about the objects is preserved. To understand process integration, we implement simple computational model describes how responses neurons somatosensory cortex-recorded from awake, behaving monkeys-are shaped by peripheral input, reconstructed using simulations neuronal...

A hallmark of tactile texture exploration is that it involves movement between skin and surface. When we scan a surface, small texture-specific vibrations are produced in the skin, specialized cutaneous mechanoreceptors convert these into highly repeatable, precise, informative temporal spiking patterns afferents. Both texture-elicited afferent responses dependent on exploratory kinematics, however; indeed, dilate or contract systematically with decreases increases scanning speed,...

Electrophysiological studies in monkeys show that finger amputation triggers local remapping within the deprived primary somatosensory cortex (S1). Human neuroimaging research, however, shows persistent S1 representation of missing hand’s fingers, even decades after amputation. Here, we explore whether this apparent contradiction stems from underestimating distributed peripheral and central fingers hand map. Using pharmacological single-finger nerve block 7-tesla neuroimaging, first...

Skin stretch, induced by bodily movements, offers a potential source of information about the conformation body that can be transmitted to brain via stretch-sensitive mechanoreceptive neurons. While previous studies have primarily focused on skin stretch directly at joints, here we investigate extent and complexity natural across various regions, including face trunk. We used quad-camera set-up image large ink-based speckle patterns stamped participants’ calculated resulting millimetre scale...

Distinguishing our body from the external world is crucial for sense of self, environmental interaction, and sensory processing. Yet accuracy with which we perceive this boundary remains underexplored. Here, developed a novel psychophysical protocol to directly assess how accurately individuals their boundaries. Participants were asked determine whether midpoint between two tactile stimuli applied on skin was inside or outside perceived boundary. 3D scans tested regions used objective...

Although information in tactile afferent neurons represented by firing rates has been studied extensively over nearly a century, recent studies suggest that precise spike timing might be more important than rates. Here, we used theory to compare the content discharges of 92 afferents distributed entire terminal segment fingertip when it was contacted surfaces with different curvatures and force directions representative everyday manipulations. Estimates regard curvature direction based on...

The nervous system achieves stable perceptual representations of objects despite large variations in the activity patterns sensory receptors. Here, we explore constancy sense touch. Specifically, investigate invariance tactile texture perception across changes scanning speed. Texture signals nerve have been shown to be highly dependent on speed: temporal spiking fibers that encode fine textural features contract or dilate systematically with increases decreases speed, respectively, resulting...

While walking and maintaining balance, humans rely on cutaneous feedback from the foot sole. Electrophysiological recordings reveal how this tactile is represented in neural afferent populations, but obtaining them difficult limited to stationary conditions. We developed FootSim model, a realistic replication of mechanoreceptor activation lower limb. The model simulates spiking responses arbitrary mechanical stimuli combined population all four types mechanoreceptors innervating It considers...

The orientation of edges indented into the skin has been shown to be encoded in responses neurons primary somatosensory cortex a manner that draws remarkable analogies their counterparts visual cortex. According classical view, tuning arises from integration untuned input thalamic with aligned but spatially displaced receptive fields (RFs). In recent microneurography study human subjects, precise temporal structure individual mechanoreceptive afferents scanned was found carry information...

The estimation of parameters that affect the dynamics objects—such as viscosity or internal degree freedom—is an important step in autonomous and dexterous robotic manipulation objects. However, accurate efficient these object may be challenging due to complex, highly nonlinear underlying physical processes. To improve on quality otherwise hand-crafted solutions, automatic generation control strategies can helpful. We present a framework uses active learning help with sequential gathering...

One of the main challenges in service robotics is to equip dexterous robotic hands with sensitive tactile sensors order cope inherent problems posed by unknown and unstructured environments.As increasing mechatronic integration complex leaves little additional space for proprioceptive sensors, exteroceptive become more important.We present a novel sensor design, based on piezo-resistive soft material crossed-wire approach.We development first prototype its evaluation various classification...

Sensory information is conveyed by populations of neurons, and coding strategies cannot always be deduced when considering individual neurons. Moreover, depends on the number neurons available composition population multiple classes with different response properties are available. Here, we study in human tactile afferents employing a recently developed simulator mechanoreceptor firing activity. First, highlight interplay within each class. We demonstrate that optimal afferent density to...