Science.gov

Sample records for active tactile exploration

  1. Active tactile exploration using a brain-machine-brain interface.

    PubMed

    O'Doherty, Joseph E; Lebedev, Mikhail A; Ifft, Peter J; Zhuang, Katie Z; Shokur, Solaiman; Bleuler, Hannes; Nicolelis, Miguel A L

    2011-11-10

    Brain-machine interfaces use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. It is hoped that brain-machine interfaces can be used to restore the normal sensorimotor functions of the limbs, but so far they have lacked tactile sensation. Here we report the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and allows signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex. Monkeys performed an active exploration task in which an actuator (a computer cursor or a virtual-reality arm) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in the primary motor cortex. ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search for and distinguish one of three visually identical objects, using the virtual-reality arm to identify the unique artificial texture associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic or even virtual prostheses. PMID:21976021

  2. Prediction of primary somatosensory neuron activity during active tactile exploration

    PubMed Central

    Campagner, Dario; Evans, Mathew Hywel; Bale, Michael Ross; Erskine, Andrew; Petersen, Rasmus Strange

    2016-01-01

    Primary sensory neurons form the interface between world and brain. Their function is well-understood during passive stimulation but, under natural behaving conditions, sense organs are under active, motor control. In an attempt to predict primary neuron firing under natural conditions of sensorimotor integration, we recorded from primary mechanosensory neurons of awake, head-fixed mice as they explored a pole with their whiskers, and simultaneously measured both whisker motion and forces with high-speed videography. Using Generalised Linear Models, we found that primary neuron responses were poorly predicted by whisker angle, but well-predicted by rotational forces acting on the whisker: both during touch and free-air whisker motion. These results are in apparent contrast to previous studies of passive stimulation, but could be reconciled by differences in the kinematics-force relationship between active and passive conditions. Thus, simple statistical models can predict rich neural activity elicited by natural, exploratory behaviour involving active movement of sense organs. DOI: http://dx.doi.org/10.7554/eLife.10696.001 PMID:26880559

  3. EEG frequency tagging to explore the cortical activity related to the tactile exploration of natural textures

    PubMed Central

    Moungou, Athanasia; Thonnard, Jean-Louis; Mouraux, André

    2016-01-01

    When sliding our fingertip against a textured surface, complex vibrations are produced in the skin. It is increasingly recognised that the neural transduction and processing of these vibrations plays an important role in the dynamic tactile perception of textures. The aim of the present study was to develop a novel means to tag the cortical activity related to the processing of these vibrations, by periodically modulating the amplitude of texture exploration-induced vibrations such as to record a steady-state evoked potential (SS-EP). The EEG was recorded while the right index fingertip was scanned against four different textures using a constant exploration velocity. Amplitude modulation of the elicited vibrations was achieved by periodically modulating the force applied against the finger. Frequency analysis of the recorded EEG signals showed that modulation of the vibrations induced by the fingertip-texture interactions elicited an SS-EP at the frequency of modulation (3 Hz) as well as its second harmonic (6 Hz), maximal over parietal regions contralateral to the stimulated side. Textures generating stronger vibrations also generated SS-EPs of greater magnitude. Our results suggest that frequency tagging using SS-EPs can be used to isolate and explore the brain activity related to the tactile exploration of natural textures. PMID:26853820

  4. EEG frequency tagging to explore the cortical activity related to the tactile exploration of natural textures.

    PubMed

    Moungou, Athanasia; Thonnard, Jean-Louis; Mouraux, André

    2016-01-01

    When sliding our fingertip against a textured surface, complex vibrations are produced in the skin. It is increasingly recognised that the neural transduction and processing of these vibrations plays an important role in the dynamic tactile perception of textures. The aim of the present study was to develop a novel means to tag the cortical activity related to the processing of these vibrations, by periodically modulating the amplitude of texture exploration-induced vibrations such as to record a steady-state evoked potential (SS-EP). The EEG was recorded while the right index fingertip was scanned against four different textures using a constant exploration velocity. Amplitude modulation of the elicited vibrations was achieved by periodically modulating the force applied against the finger. Frequency analysis of the recorded EEG signals showed that modulation of the vibrations induced by the fingertip-texture interactions elicited an SS-EP at the frequency of modulation (3 Hz) as well as its second harmonic (6 Hz), maximal over parietal regions contralateral to the stimulated side. Textures generating stronger vibrations also generated SS-EPs of greater magnitude. Our results suggest that frequency tagging using SS-EPs can be used to isolate and explore the brain activity related to the tactile exploration of natural textures. PMID:26853820

  5. Active tactile exploration enabled by a brain-machine-brain interface

    PubMed Central

    O’Doherty, Joseph E.; Lebedev, Mikhail A.; Ifft, Peter J.; Zhuang, Katie Z.; Shokur, Solaiman; Bleuler, Hannes; Nicolelis, Miguel A. L.

    2011-01-01

    Brain-machine interfaces (BMIs)1,2 use neuronal activity recorded from the brain to establish direct communication with external actuators, such as prosthetic arms. While BMIs aim to restore the normal sensorimotor functions of the limbs, so far they have lacked tactile sensation. Here we demonstrate the operation of a brain-machine-brain interface (BMBI) that both controls the exploratory reaching movements of an actuator and enables the signalling of artificial tactile feedback through intracortical microstimulation (ICMS) of the primary somatosensory cortex (S1). Monkeys performed an active-exploration task in which an actuator (a computer cursor or a virtual-reality hand) was moved using a BMBI that derived motor commands from neuronal ensemble activity recorded in primary motor cortex (M1). ICMS feedback occurred whenever the actuator touched virtual objects. Temporal patterns of ICMS encoded the artificial tactile properties of each object. Neuronal recordings and ICMS epochs were temporally multiplexed to avoid interference. Two monkeys operated this BMBI to search and discriminate one out of three visually undistinguishable objects, using the virtual hand to identify the unique artificial texture (AT) associated with each. These results suggest that clinical motor neuroprostheses might benefit from the addition of ICMS feedback to generate artificial somatic perceptions associated with mechanical, robotic, or even virtual prostheses. PMID:21976021

  6. Learning tactile skills through curious exploration.

    PubMed

    Pape, Leo; Oddo, Calogero M; Controzzi, Marco; Cipriani, Christian; Förster, Alexander; Carrozza, Maria C; Schmidhuber, Jürgen

    2012-01-01

    We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content of the sensory input signals relative to a learner that aims at representing sensory inputs using fewer and fewer computational resources. We show that, from initially random exploration of its environment, the robotic system autonomously develops a small set of basic motor skills that lead to different kinds of tactile input. Next, the system learns how to exploit the learned motor skills to solve supervised texture classification tasks. Our approach demonstrates the feasibility of autonomous acquisition of tactile skills on physical robotic platforms through curiosity-driven reinforcement learning, overcomes typical difficulties of engineered solutions for active tactile exploration and underactuated control, and provides a basis for studying developmental learning through intrinsic motivation in robots. PMID:22837748

  7. Learning tactile skills through curious exploration

    PubMed Central

    Pape, Leo; Oddo, Calogero M.; Controzzi, Marco; Cipriani, Christian; Förster, Alexander; Carrozza, Maria C.; Schmidhuber, Jürgen

    2012-01-01

    We present curiosity-driven, autonomous acquisition of tactile exploratory skills on a biomimetic robot finger equipped with an array of microelectromechanical touch sensors. Instead of building tailored algorithms for solving a specific tactile task, we employ a more general curiosity-driven reinforcement learning approach that autonomously learns a set of motor skills in absence of an explicit teacher signal. In this approach, the acquisition of skills is driven by the information content of the sensory input signals relative to a learner that aims at representing sensory inputs using fewer and fewer computational resources. We show that, from initially random exploration of its environment, the robotic system autonomously develops a small set of basic motor skills that lead to different kinds of tactile input. Next, the system learns how to exploit the learned motor skills to solve supervised texture classification tasks. Our approach demonstrates the feasibility of autonomous acquisition of tactile skills on physical robotic platforms through curiosity-driven reinforcement learning, overcomes typical difficulties of engineered solutions for active tactile exploration and underactuated control, and provides a basis for studying developmental learning through intrinsic motivation in robots. PMID:22837748

  8. Feeling small: exploring the tactile perception limits.

    PubMed

    Skedung, Lisa; Arvidsson, Martin; Chung, Jun Young; Stafford, Christopher M; Berglund, Birgitta; Rutland, Mark W

    2013-01-01

    The human finger is exquisitely sensitive in perceiving different materials, but the question remains as to what length scales are capable of being distinguished in active touch. We combine material science with psychophysics to manufacture and haptically explore a series of topographically patterned surfaces of controlled wavelength, but identical chemistry. Strain-induced surface wrinkling and subsequent templating produced 16 surfaces with wrinkle wavelengths ranging from 300 nm to 90 μm and amplitudes between 7 nm and 4.5 μm. Perceived similarities of these surfaces (and two blanks) were pairwise scaled by participants, and interdistances among all stimuli were determined by individual differences scaling (INDSCAL). The tactile space thus generated and its two perceptual dimensions were directly linked to surface physical properties - the finger friction coefficient and the wrinkle wavelength. Finally, the lowest amplitude of the wrinkles so distinguished was approximately 10 nm, demonstrating that human tactile discrimination extends to the nanoscale. PMID:24030568

  9. Stable phase-shift despite quasi-rhythmic movements: a CPG-driven dynamic model of active tactile exploration in an insect

    PubMed Central

    Harischandra, Nalin; Krause, André F.; Dürr, Volker

    2015-01-01

    An essential component of autonomous and flexible behavior in animals is active exploration of the environment, allowing for perception-guided planning and control of actions. An important sensory system involved is active touch. Here, we introduce a general modeling framework of Central Pattern Generators (CPGs) for movement generation in active tactile exploration behavior. The CPG consists of two network levels: (i) phase-coupled Hopf oscillators for rhythm generation, and (ii) pattern formation networks for capturing the frequency and phase characteristics of individual joint oscillations. The model captured the natural, quasi-rhythmic joint kinematics as observed in coordinated antennal movements of walking stick insects. Moreover, it successfully produced tactile exploration behavior on a three-dimensional skeletal model of the insect antennal system with physically realistic parameters. The effect of proprioceptor ablations could be simulated by changing the amplitude and offset parameters of the joint oscillators, only. As in the animal, the movement of both antennal joints was coupled with a stable phase difference, despite the quasi-rhythmicity of the joint angle time courses. We found that the phase-lead of the distal scape-pedicel (SP) joint relative to the proximal head-scape (HS) joint was essential for producing the natural tactile exploration behavior and, thus, for tactile efficiency. For realistic movement patterns, the phase-lead could vary within a limited range of 10–30° only. Tests with artificial movement patterns strongly suggest that this phase sensitivity is not a matter of the frequency composition of the natural movement pattern. Based on our modeling results, we propose that a constant phase difference is coded into the CPG of the antennal motor system and that proprioceptors are acting locally to regulate the joint movement amplitude. PMID:26347644

  10. Irrelevant tactile stimulation biases visual exploration in external coordinates

    PubMed Central

    Ossandón, José P.; König, Peter; Heed, Tobias

    2015-01-01

    We evaluated the effect of irrelevant tactile stimulation on humans’ free-viewing behavior during the exploration of complex static scenes. Specifically, we address the questions of (1) whether task-irrelevant tactile stimulation presented to subjects’ hands can guide visual selection during free viewing; (2) whether tactile stimulation can modulate visual exploratory biases that are independent of image content and task goals; and (3) in which reference frame these effects occur. Tactile stimulation to uncrossed and crossed hands during the viewing of static images resulted in long-lasting modulation of visual orienting responses. Subjects showed a well-known leftward bias during the early exploration of images, and this bias was modulated by tactile stimulation presented at image onset. Tactile stimulation, both at image onset and later during the trials, biased visual orienting toward the space ipsilateral to the stimulated hand, both in uncrossed and crossed hand postures. The long-lasting temporal and global spatial profile of the modulation of free viewing exploration by touch indicates that cross-modal cues produce orienting responses, which are coded exclusively in an external reference frame. PMID:26021612

  11. Tactile Data Entry for Extravehicular Activity

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.; Olowin, Aaron B.; Hannaford, Blake; Sands, O Scott

    2012-01-01

    In the task-saturated environment of extravehicular activity (EVA), an astronaut's ability to leverage suit-integrated information systems is limited by a lack of options for data entry. In particular, bulky gloves inhibit the ability to interact with standard computing interfaces such as a mouse or keyboard. This paper presents the results of a preliminary investigation into a system that permits the space suit gloves themselves to be used as data entry devices. Hand motion tracking is combined with simple finger gesture recognition to enable use of a virtual keyboard, while tactile feedback provides touch-based context to the graphical user interface (GUI) and positive confirmation of keystroke events. In human subject trials, conducted with twenty participants using a prototype system, participants entered text significantly faster with tactile feedback than without (p = 0.02). The results support incorporation of vibrotactile information in a future system that will enable full touch typing and general mouse interactions using instrumented EVA gloves.

  12. Participation of Parents in the Early Exploration of Tactile Graphics by Children Who Are Visually Impaired

    ERIC Educational Resources Information Center

    Ryles, Ruby; Bell, Edward

    2009-01-01

    Seventy-three children with visual impairments aged 2-10 and their parents participated in a project that examined the children's interest in and exploration of tactile graphics. The parents reported that the children's interest in and conceptual understanding of the project's tactile workbook were high and that the children explored the…

  13. The Effects of Extravehicular Activity (EVA) Glove Pressure on Tactility

    NASA Technical Reports Server (NTRS)

    Thompson, Shelby; Miranda, Mesloh; England, Scott; Benson, Elizabeth; Rajulu, Sudhakar

    2010-01-01

    The purpose of the current study was to quantify finger tactility, while wearing a Phase VI Extravehicular Activity (EVA) glove. Subjects were fully suited in an Extravehicular Mobility Unit (EMU) suit. Data was collected under three conditions: bare-handed, gloved at 0 psi, and gloved at 4.3 psi. In order to test tactility, a series of 30 tactile stimuli (bumps) were created that varied in both height and width. With the hand obscured, subjects applied pressure to each bump until detected tactilely. The amount of force needed to detect each bump was recorded using load cells located under a force-plate. The amount of force needed to detect a bump was positively related to width, but inversely related to height. In addition, as the psi of the glove increased, more force was needed to detect the bump. In terms of application, it was possible to determine the optimal width and height a bump needs to be for a specific amount of force applied for tactility.

  14. Sequences of cortical activation for tactile pattern discrimination using magnetoencephalography.

    PubMed

    Reed, Catherine L; Hagler, Donald J; Marinkovic, Ksenija; Dale, Anders; Halgren, Eric

    2009-07-01

    To observe sequential stages in tactile pattern discrimination and their modification with and without attention, we used whole-head anatomically constrained magnetoencephalography to spatiotemporally map brain responses. Eight, normal, right-handed participants discriminated between two patterns presented on the palm. Latencies of neural activity were determined from stimulus contact with the palm. Early cortical activation moved from sensorimotor cortex (SM1) to secondary somatosensory cortex (SII), Broca's area (BA), and superior parietal cortex by 65 ms. It continued bilaterally to temporal and frontal poles by 290 ms. Subtraction of nonattended from attended conditions removed primarily the early contralateral sensory components. There was some indication of a preferred order of sensory processing that may express and optimize hemispheric computational specializations. Results indicate similar functional organizations for tactile and visual pattern recognition. PMID:19525880

  15. Active movement restores veridical event-timing after tactile adaptation.

    PubMed

    Tomassini, Alice; Gori, Monica; Burr, David; Sandini, Giulio; Morrone, Maria Concetta

    2012-10-01

    Growing evidence suggests that time in the subsecond range is tightly linked to sensory processing. Event-time can be distorted by sensory adaptation, and many temporal illusions can accompany action execution. In this study, we show that adaptation to tactile motion causes a strong contraction of the apparent duration of tactile stimuli. However, when subjects make a voluntary motor act before judging the duration, it annuls the adaptation-induced temporal distortion, reestablishing veridical event-time. The movement needs to be performed actively by the subject: passive movement of similar magnitude and dynamics has no effect on adaptation, showing that it is the motor commands themselves, rather than reafferent signals from body movement, which reset the adaptation for tactile duration. No other concomitant perceptual changes were reported (such as apparent speed or enhanced temporal discrimination), ruling out a generalized effect of body movement on somatosensory processing. We suggest that active movement resets timing mechanisms in preparation for the new scenario that the movement will cause, eliminating inappropriate biases in perceived time. Our brain seems to utilize the intention-to-move signals to retune its perceptual machinery appropriately, to prepare to extract new temporal information. PMID:22832572

  16. Interpersonal stroking touch is targeted to C tactile afferent activation.

    PubMed

    Croy, I; Luong, A; Triscoli, C; Hofmann, E; Olausson, H; Sailer, U

    2016-01-15

    C tactile fibers are a specialized group of fibers innervating the non-glabrous skin that are tuned to light gentle stroking applied with velocities between 1 and 10 cm/s. Those fibers add to the sensation of interpersonal caressing and pleasant touch. It is unclear whether people spontaneously apply touch that is tuned to optimally activate those fibers. This was investigated in three studies. In study one, 45 participants (21.8 ± 2.3 years, 24 women) were asked to stroke an artificial arm. In study two, 32 participants (28.3 ± 8.7 years, 16 women) were asked to stroke their partner. In study three, 11 parents (29.4 ± 5.7 years, 6 women) were asked to stroke their babies. Stroking velocity was tracked in all conditions. Stroking velocities were significantly slower in the partner touch and baby touch condition than in the artificial arm condition and all of the participants stroking their partner or baby used velocities that can activate C tactile fibers. We conclude that human social stroking is optimized for C tactile stimulation. PMID:26433145

  17. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing.

    PubMed

    Ache, Jan M; Dürr, Volker

    2015-07-01

    Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs). First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC) analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs 'coding-space' because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This reveals the versatility

  18. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing

    PubMed Central

    Ache, Jan M.; Dürr, Volker

    2015-01-01

    Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs). First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC) analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs ‘coding-space’ because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This reveals the

  19. Active tactile sampling by an insect in a step-climbing paradigm

    PubMed Central

    Krause, André F.; Dürr, Volker

    2012-01-01

    Many insects actively explore their near-range environment with their antennae. Stick insects (Carausius morosus) rhythmically move their antennae during walking and respond to antennal touch by repetitive tactile sampling of the object. Despite its relevance for spatial orientation, neither the spatial sampling patterns nor the kinematics of antennation behavior in insects are understood. Here we investigate unrestrained bilateral sampling movements during climbing of steps. The main objectives are: (1) How does the antennal contact pattern relate to particular object features? (2) How are the antennal joints coordinated during bilateral tactile sampling? We conducted motion capture experiments on freely climbing insects, using steps of different height. Tactile sampling was analyzed at the level of antennal joint angles. Moreover, we analyzed contact patterns on the surfaces of both the obstacle and the antenna itself. Before the first contact, both antennae move in a broad, mostly elliptical exploratory pattern. After touching the obstacle, the pattern switches to a narrower and faster movement, caused by higher cycle frequencies and lower cycle amplitudes in all joints. Contact events were divided into wall- and edge-contacts. Wall contacts occurred mostly with the distal third of the flagellum, which is flexible, whereas edge contacts often occurred proximally, where the flagellum is stiff. The movement of both antennae was found to be coordinated, exhibiting bilateral coupling of functionally analogous joints [e.g., left head-scape (HS) joint with right scape-pedicel (SP) joint] throughout tactile sampling. In comparison, bilateral coupling between homologous joints (e.g., both HS joints) was significantly weaker. Moreover, inter-joint coupling was significantly weaker during the contact episode than before. In summary, stick insects show contact-induced changes in frequency, amplitude and inter-joint coordination during tactile sampling of climbed obstacles

  20. Texture-induced vibrations in the forearm during tactile exploration

    PubMed Central

    Delhaye, Benoit; Hayward, Vincent; Lefèvre, Philippe; Thonnard, Jean-Louis

    2012-01-01

    Humans can detect and discriminate between fine variations of surface roughness using active touch. It is hitherto believed that roughness perception is mediated mostly by cutaneous and subcutaneous afferents located in the fingertips. However, recent findings have shown that following abolishment of cutaneous afferences resulting from trauma or pharmacological intervention, the ability of subjects to discriminate between textures roughness was not significantly altered. These findings suggest that the somatosensory system is able to collect textural information from other sources than fingertip afference. It follows that signals resulting of the interaction of a finger with a rough surface must be transmitted to stimulate receptor populations in regions far away from the contact. This transmission was characterized by measuring in the wrist vibrations originating at the fingertip and thus propagating through the finger, the hand and the wrist during active exploration of textured surfaces. The spectral analysis of the vibrations taking place in the forearm tissues revealed regularities that were correlated with the scanned surface and the speed of exploration. In the case of periodic textures, the vibration signal contained a fundamental frequency component corresponding to the finger velocity divided by the spatial period of the stimulus. This regularity was found for a wide range of textural length scales and scanning velocities. For non-periodic textures, the spectrum of the vibration did not contain obvious features that would enable discrimination between the different stimuli. However, for both periodic and non-periodic stimuli, the intensity of the vibrations could be related to the microgeometry of the scanned surfaces. PMID:22783177

  1. Physical Factors Influencing Pleasant Touch during Tactile Exploration

    PubMed Central

    Klöcker, Anne; Wiertlewski, Michael; Théate, Vincent; Hayward, Vincent; Thonnard, Jean-Louis

    2013-01-01

    Background When scanning surfaces, humans perceive some of their physical attributes. These percepts are frequently accompanied by a sensation of (un)pleasantness. We therefore hypothesized that aspects of the mechanical activity induced by scanning surfaces with fingertips could be objectively associated with a pleasantness sensation. Previously, we developed a unidimensional measure of pleasantness, the Pleasant Touch Scale, quantifying the pleasantness level of 37 different materials. Findings of this study suggested that the sensation of pleasantness was influenced by the average magnitude of the frictional forces brought about by sliding the finger on the surface, and by the surface topography. In the present study, we correlated (i) characteristics of the fluctuations of frictional forces resulting from the interaction between the finger and the surface asperities as well as (ii) the average friction with the sensation of pleasantness. Results Eight blindfolded participants tactually explored twelve materials of the Pleasant Touch Scale through lateral sliding movements of their index fingertip. During exploration, the normal and tangential interaction force components, fN and fT, as well as the fingertip trajectory were measured. The effect of the frictional force on pleasantness sensation was investigated through the analysis of the ratio fT to fN, i.e. the net coefficient of kinetic friction, μ. The influence of the surface topographies was investigated through analysis of rapid fT fluctuations in the spatial frequency domain. Results showed that high values of μ were anticorrelated with pleasantness. Furthermore, surfaces associated with fluctuations of fT having higher amplitudes in the low frequency range than in the high one were judged to be less pleasant than the surfaces yielding evenly distributed amplitudes throughout the whole spatial frequency domain. Conclusion Characteristics of the frictional force fluctuations and of the net friction

  2. Haptic exploration of fingertip-sized geometric features using a multimodal tactile sensor

    NASA Astrophysics Data System (ADS)

    Ponce Wong, Ruben D.; Hellman, Randall B.; Santos, Veronica J.

    2014-06-01

    Haptic perception remains a grand challenge for artificial hands. Dexterous manipulators could be enhanced by "haptic intelligence" that enables identification of objects and their features via touch alone. Haptic perception of local shape would be useful when vision is obstructed or when proprioceptive feedback is inadequate, as observed in this study. In this work, a robot hand outfitted with a deformable, bladder-type, multimodal tactile sensor was used to replay four human-inspired haptic "exploratory procedures" on fingertip-sized geometric features. The geometric features varied by type (bump, pit), curvature (planar, conical, spherical), and footprint dimension (1.25 - 20 mm). Tactile signals generated by active fingertip motions were used to extract key parameters for use as inputs to supervised learning models. A support vector classifier estimated order of curvature while support vector regression models estimated footprint dimension once curvature had been estimated. A distal-proximal stroke (along the long axis of the finger) enabled estimation of order of curvature with an accuracy of 97%. Best-performing, curvature-specific, support vector regression models yielded R2 values of at least 0.95. While a radial-ulnar stroke (along the short axis of the finger) was most helpful for estimating feature type and size for planar features, a rolling motion was most helpful for conical and spherical features. The ability to haptically perceive local shape could be used to advance robot autonomy and provide haptic feedback to human teleoperators of devices ranging from bomb defusal robots to neuroprostheses.

  3. Bioinspired active whisker sensor for robotic vibrissal tactile sensing

    NASA Astrophysics Data System (ADS)

    Ju, Feng; Ling, Shih-Fu

    2014-12-01

    A whisker transducer (WT) inspired by rat’s vibrissal tactile perception is proposed based on a transduction matrix model characterizing the electro-mechanical transduction process in both forward and backward directions. It is capable of acting as an actuator to sweep the whisker and simultaneously as a sensor to sense the force, motion, and mechanical impedance at whisker tip. Its validity is confirmed by numerical simulation using a finite element model. A prototype is then fabricated and its transduction matrix is determined by parameter identification. The calibrated WT can accurately sense mechanical impedance which is directly related to stiffness, mass and damping. Subsequent vibrissal tactile sensing of sandpaper texture reveals that the real part of mechanical impedance sensed by WT is correlated with sandpaper roughness. Texture discrimination is successfully achieved by inputting the real part to a k-means clustering algorithm. The mechanical impedance sensing ability as well as other features of the WT such as simultaneous-actuation-and-sensing makes it a good solution to robotic tactile sensing.

  4. Functional magnetic resonance imaging can be used to explore tactile and nociceptive processing in the infant brain

    PubMed Central

    Williams, Gemma; Fabrizi, Lorenzo; Meek, Judith; Jackson, Deborah; Tracey, Irene; Robertson, Nicola; Slater, Rebeccah; Fitzgerald, Maria

    2015-01-01

    Aim Despite the importance of neonatal skin stimulation, little is known about activation of the newborn human infant brain by sensory stimulation of the skin. We carried out functional magnetic resonance imaging (fMRI) to assess the feasibility of measuring brain activation to a range of mechanical stimuli applied to the skin of neonatal infants. Methods We studied 19 term infants with a mean age of 13 days. Brain activation was measured in response to brushing, von Frey hair (vFh) punctate stimulation and, in one case, nontissue damaging pinprick stimulation of the plantar surface of the foot. Initial whole brain analysis was followed by region of interest analysis of specific brain areas. Results Distinct patterns of functional brain activation were evoked by brush and vFh punctate stimulation, which were reduced, but still present, under chloral hydrate sedation. Brain activation increased with increasing stimulus intensity. The feasibility of using pinprick stimulation in fMRI studies was established in one unsedated healthy full-term infant. Conclusion Distinct brain activity patterns can be measured in response to different modalities and intensities of skin sensory stimulation in term infants. This indicates the potential for fMRI studies in exploring tactile and nociceptive processing in the infant brain. PMID:25358870

  5. Tactile refreshable screen based on magneto-rheological fluids for map exploration and navigation tasks

    NASA Astrophysics Data System (ADS)

    Bolzmacher, C.; Changeon, G.; Plaud, V.; Roselier, S.; Lozada, J.; Hafez, M.

    2011-06-01

    Human-machine interfaces can convey information via visual, audio and/or haptic cues during a navigation task. The visual and audio technologies are mature, whereas research has to be focused on haptic technologies for mobile devices. In this work, a tactile refreshable screen is proposed which allows its user the exploration of maps and navigational tasks in an egocentric perspective. The proposed device consists of an array of actuators which can display various patterns. The actuation technology is based on a magneto-rheological fluid which is injected in a chamber with an elastomeric membrane using a micro pump. The fluid pressure deforms the membrane in order to display a pattern. The fluid properties are used to form a valve in each cell. A permanent magnet, a ferromagnetic core, and a coil form a closed magnetic circuit with a gap where the magneto-rheological fluid can flow; the magnetic field interacts with the fluid and prevents the filling or draining of the chamber. Applying a current to the coil counteracts the magnetic field generated by the magnet and the fluid can circulate freely in order to inflate or deflate the membrane. The design, fabrication and integration of the device in addition to the results of finite element simulations and experimental measurements are reported.

  6. Investigation and modification of a commercially available tactile sensor suited for robotic applications. Thesis

    NASA Technical Reports Server (NTRS)

    Creus, Carolina

    1991-01-01

    Active (dynamic) tactile sensing was explored using a commercially available tactile array sensor. This task requires the redesign of the sensor interface and a full understanding of the old sensor hardware implementation. There were different stages to this research; the first stage involved the reverse engineering of the old tactile sensor. The second stage had to do with the exploration of the characteristics and behavior of the tactile sensor pad. The next stage dealt with the redesign of the sensor interface using the knowledge gained from the previous two stages. Finally, in the last stage, software to control the tactile sensor was developed to aid in the data acquisition process.

  7. Are We Ready to Build a System for Assisting Blind People in Tactile Exploration of Bas-Reliefs?

    PubMed

    Buonamici, Francesco; Carfagni, Monica; Furferi, Rocco; Governi, Lapo; Volpe, Yary

    2016-01-01

    Nowadays, the creation of methodologies and tools for facilitating the 3D reproduction of artworks and, contextually, to make their exploration possible and more meaningful for blind users is becoming increasingly relevant in society. Accordingly, the creation of integrated systems including both tactile media (e.g., bas-reliefs) and interfaces capable of providing the users with an experience cognitively comparable to the one originally envisioned by the artist, may be considered the next step for enhancing artworks exploration. In light of this, the present work provides a description of a first-attempt system designed to aid blind people (BP) in the tactile exploration of bas-reliefs. In detail, consistent hardware layout, comprising a hand-tracking system based on Kinect(®) sensor and an audio device, together with a number of methodologies, algorithms and information related to physical design are proposed. Moreover, according to experimental test on the developed system related to the device position, some design alternatives are suggested so as to discuss pros and cons. PMID:27563906

  8. An active tactile sensor for detecting mechanical characteristics of contacted objects

    NASA Astrophysics Data System (ADS)

    Hasegawa, Y.; Shikida, M.; Sasaki, H.; Itoigawa, K.; Sato, K.

    2006-08-01

    We propose an active tactile sensor actuated by magnetic force. The tactile sensor has the advantage of being able to detect mechanical characteristics related to a tactile impression of contacted objects using a single sensor structure, much as human skin functions. It consists of a displacement-sensing element of piezoresistors formed on a silicon diaphragm, and a magnetic actuating element (a permanent magnet and a flat coil). The sensor has two modes of operation, quasi-static and vibration, and it can detect contact force, elasticity and damping of contacted objects by choosing between operation modes. We fabricated the piezoresistor sensing and magnetic actuating elements by applying the microelectromechanical systems technologies, and assembled them in a hybrid manner. The size of the sensor was 6.0 mm × 6.0 mm × 10 µm. As contact samples we used three different rubber materials with hardness values ranging from A20 to A60 in Shore A. We experimentally confirmed that both the resonance frequency and the Q-factor of the sensing element in the vibration mode changed with different samples. We were able to calculate the elastic and damping coefficients of the contacted rubber objects by analyzing the vibrational response of the diaphragm. From the results, we concluded that the active sensor can detect mechanical characteristics of contacted objects using a single sensor structure.

  9. Dielectric elastomer vibrissal system for active tactile sensing

    NASA Astrophysics Data System (ADS)

    Conn, Andrew T.; Pearson, Martin J.; Pipe, Anthony G.; Welsby, Jason; Rossiter, Jonathan

    2012-04-01

    Rodents are able to dexterously navigate confined and unlit environments by extracting spatial and textural information with their whiskers (or vibrissae). Vibrissal-based active touch is suited to a variety of applications where vision is occluded, such as search-and-rescue operations in collapsed buildings. In this paper, a compact dielectric elastomer vibrissal system (DEVS) is described that mimics the vibrissal follicle-sinus complex (FSC) found in rodents. Like the vibrissal FSC, the DEVS encapsulates all sensitive mechanoreceptors at the root of a passive whisker within an antagonistic muscular system. Typically, rats actively whisk arrays of macro-vibrissae with amplitudes of up to +/-25°. It is demonstrated that these properties can be replicated by exploiting the characteristic large actuation strains and passive compliance of dielectric elastomers. A prototype DEVS is developed using VHB 4905 and embedded strain gauges bonded to the root of a tapered whisker. The DEVS is demonstrated to produce a maximum rotational output of +/-22.8°. An electro-mechanical model of the DEVS is derived, which incorporates a hyperelastic material model and Euler- Bernoulli beam equations. The model is shown to predict experimental measurements of whisking stroke amplitude and whisker deflection.

  10. Exploring teleimpedance and tactile feedback for intuitive control of the Pisa/IIT SoftHand.

    PubMed

    Ajoudani, Arash; Godfrey, Sasha B; Bianchi, Matteo; Catalano, Manuel G; Grioli, Giorgio; Tsagarakis, Nikos; Bicchi, Antonio

    2014-01-01

    This paper proposes a teleimpedance controller with tactile feedback for more intuitive control of the Pisa/IIT SoftHand. With the aim to realize a robust, efficient and low-cost hand prosthesis design, the SoftHand is developed based on the motor control principle of synergies, through which the immense complexity of the hand is simplified into distinct motor patterns. Due to the built-in flexibility of the hand joints, as the SoftHand grasps, it follows a synergistic path while allowing grasping of objects of various shapes using only a single motor. The DC motor of the hand incorporates a novel teleimpedance control in which the user's postural and stiffness synergy references are tracked in real-time. In addition, for intuitive control of the hand, two tactile interfaces are developed. The first interface (mechanotactile) exploits a disturbance observer which estimates the interaction forces in contact with the grasped object. Estimated interaction forces are then converted and applied to the upper arm of the user via a custom made pressure cuff. The second interface employs vibrotactile feedback based on surface irregularities and acceleration signals and is used to provide the user with information about the surface properties of the object as well as detection of object slippage while grasping. Grasp robustness and intuitiveness of hand control were evaluated in two sets of experiments. Results suggest that incorporating the aforementioned haptic feedback strategies, together with user-driven compliance of the hand, facilitate execution of safe and stable grasps, while suggesting that a low-cost, robust hand employing hardware-based synergies might be a good alternative to traditional myoelectric prostheses. PMID:24968383

  11. Optimizing Populations of SAI Tactile Mechanoreceptors to Enable Activities of Daily Living.

    PubMed

    Rivest, Isabelle I; Gerling, Gregory J

    2011-07-11

    At present, the dense network of peripheral afferents between finger and brain and the large size of engineered sensors preclude the recreation of biologically observed afferent populations. This work uses a validated computational model of cutaneous skin and tactile afferents to evaluate sparse populations in performing tasks required in activities of daily living. Using a model (3D finite element representation of fingertip skin, linear bi-phasic transduction function, and leaky-integrate-and-fire neuronal model), we systematically varied populations of tactile receptors in dimensions of density (100, 45, 20, and 10 sensors/cm(2)) and size (diameter 0.1, 0.2, 0.5, and 1.0 mm) to determine if a given modeled population can discriminate spheres and cylinders representative of objects used in activities of daily living. Using a scoring system which allows for direct comparisons between the populations, our results indicate that a population must have at least 20 sensors per cm(2) to maintain response resolution in these activities of daily living and that larger-sized sensors do not degrade response resolution. PMID:22582034

  12. Optimizing Populations of SAI Tactile Mechanoreceptors to Enable Activities of Daily Living

    PubMed Central

    Rivest, Isabelle I.; Gerling, Gregory J.

    2011-01-01

    At present, the dense network of peripheral afferents between finger and brain and the large size of engineered sensors preclude the recreation of biologically observed afferent populations. This work uses a validated computational model of cutaneous skin and tactile afferents to evaluate sparse populations in performing tasks required in activities of daily living. Using a model (3D finite element representation of fingertip skin, linear bi-phasic transduction function, and leaky-integrate-and-fire neuronal model), we systematically varied populations of tactile receptors in dimensions of density (100, 45, 20, and 10 sensors/cm2) and size (diameter 0.1, 0.2, 0.5, and 1.0 mm) to determine if a given modeled population can discriminate spheres and cylinders representative of objects used in activities of daily living. Using a scoring system which allows for direct comparisons between the populations, our results indicate that a population must have at least 20 sensors per cm2 to maintain response resolution in these activities of daily living and that larger-sized sensors do not degrade response resolution. PMID:22582034

  13. The Effect of Additional Tactile Stimulation in a Perceptual-Motor Treatment Program for School Children

    ERIC Educational Resources Information Center

    McKibbin, Elsie H.

    1973-01-01

    The purpose of this study is to explore the value of a perceptual-motor program using predominantly gross motor activities for children with developmental apraxia and deficits in tactile perception. (Author)

  14. Tactile neural mechanisms in monotremes.

    PubMed

    Rowe, M J; Mahns, D A; Bohringer, R C; Ashwell, K W S; Sahai, V

    2003-12-01

    Monotremes, perhaps more than any other order of mammals, display an enormous behavioural reliance upon the tactile senses. In the platypus, Ornithorhynchus anatinus, this is manifest most strikingly in the special importance of the bill as a peripheral sensory organ, an importance confirmed by electrophysiological mapping that reveals a vast area of the cerebral cortex allocated to the processing of tactile inputs from the bill. Although behavioural evidence in the echidna, Tachyglossus aculeatus, suggests a similar prominence for tactile inputs from the snout, there is also a great reliance upon the distal limbs for digging and burrowing activity, pointing to the importance of tactile information from these regions for the echidna. In recent studies, we have investigated the peripheral tactile neural mechanisms in the forepaw of the echidna to establish the extent of correspondence or divergence that has emerged over the widely different evolutionary paths taken by monotreme and placental mammals. Electrophysiological recordings were made from single tactile sensory nerve fibres isolated in fine strands of the median or ulnar nerves of the forearm. Controlled tactile stimuli applied to the forepaw glabrous skin permitted an initial classification of tactile sensory fibres into two broad divisions, according to their responses to static skin displacement. One displayed slowly adapting (SA) response properties, while the other showed a selective sensitivity to the dynamic components of the skin displacement. These purely dynamically-sensitive tactile fibres could be subdivided according to vibrotactile sensitivity and receptive field characteristics into a rapidly adapting (RA) class, sensitive to low frequency (tactile sensitivity of the three principal fibre classes and their individual coding characteristics, determined by

  15. Electrostatic tactile display with thin film slider and its application to tactile telepresentation systems.

    PubMed

    Yamamoto, Akio; Nagasawa, Shuichi; Yamamoto, Hiroaki; Higuchi, Toshiro

    2006-01-01

    A new electrostatic tactile display is proposed to realize compact tactile display devices that can be incorporated with virtual reality systems. The tactile display of this study consists of a thin conductive film slider with stator electrodes that excite electrostatic forces. Users of the device experience tactile texture sensations by moving the slider with their fingers. The display operates by applying two-phase cyclic voltage patterns to the electrodes. The display is incorporated into a tactile telepresentation system to realize explorations of remote surface textures with real-time tactile feedback. In the system, a PVDF tactile sensor and a DSP controller automatically generate voltage patterns to present surface texture sensations through the tactile display. A sensor, in synchronization with finger motion on the tactile display, scans a texture sample and outputs information about the sample surface. The information is processed by a DSP and fed back to the tactile display in real time. The tactile telepresentation system was evaluated in texture discrimination tests and demonstrated a 79 percent correct answer ratio. A transparent electrostatic tactile display is also reported in which the tactile display is combined with an LCD to realize a visual-tactile integrated display system. PMID:16509376

  16. Differential fMRI Activation Patterns to Noxious Heat and Tactile Stimuli in the Primate Spinal Cord.

    PubMed

    Yang, Pai-Feng; Wang, Feng; Chen, Li Min

    2015-07-22

    Mesoscale local functional organizations of the primate spinal cord are largely unknown. Using high-resolution fMRI at 9.4 T, we identified distinct interhorn and intersegment fMRI activation patterns to tactile versus nociceptive heat stimulation of digits in lightly anesthetized monkeys. Within a spinal segment, 8 Hz vibrotactile stimuli elicited predominantly fMRI activations in the middle part of ipsilateral dorsal horn (iDH), along with significantly weaker activations in ipsilateral (iVH) and contralateral (cVH) ventral horns. In contrast, nociceptive heat stimuli evoked widespread strong activations in the superficial part of iDH, as well as in iVH and contralateral dorsal (cDH) horns. As controls, only weak signal fluctuations were detected in the white matter. The iDH responded most strongly to both tactile and heat stimuli, whereas the cVH and cDH responded selectively to tactile versus nociceptive heat, respectively. Across spinal segments, iDH activations were detected in three consecutive segments in both tactile and heat conditions. Heat responses, however, were more extensive along the cord, with strong activations in iVH and cDH in two consecutive segments. Subsequent subunit B of cholera toxin tracer histology confirmed that the spinal segments showing fMRI activations indeed received afferent inputs from the stimulated digits. Comparisons of the fMRI signal time courses in early somatosensory area 3b and iDH revealed very similar hemodynamic stimulus-response functions. In summary, we identified with fMRI distinct segmental networks for the processing of tactile and nociceptive heat stimuli in the cervical spinal cord of nonhuman primates. Significance statement: This is the first fMRI demonstration of distinct intrasegmental and intersegmental nociceptive heat and touch processing circuits in the spinal cord of nonhuman primates. This study provides novel insights into the local functional organizations of the primate spinal cord for pain and

  17. Differential fMRI Activation Patterns to Noxious Heat and Tactile Stimuli in the Primate Spinal Cord

    PubMed Central

    Yang, Pai-Feng; Wang, Feng

    2015-01-01

    Mesoscale local functional organizations of the primate spinal cord are largely unknown. Using high-resolution fMRI at 9.4 T, we identified distinct interhorn and intersegment fMRI activation patterns to tactile versus nociceptive heat stimulation of digits in lightly anesthetized monkeys. Within a spinal segment, 8 Hz vibrotactile stimuli elicited predominantly fMRI activations in the middle part of ipsilateral dorsal horn (iDH), along with significantly weaker activations in ipsilateral (iVH) and contralateral (cVH) ventral horns. In contrast, nociceptive heat stimuli evoked widespread strong activations in the superficial part of iDH, as well as in iVH and contralateral dorsal (cDH) horns. As controls, only weak signal fluctuations were detected in the white matter. The iDH responded most strongly to both tactile and heat stimuli, whereas the cVH and cDH responded selectively to tactile versus nociceptive heat, respectively. Across spinal segments, iDH activations were detected in three consecutive segments in both tactile and heat conditions. Heat responses, however, were more extensive along the cord, with strong activations in iVH and cDH in two consecutive segments. Subsequent subunit B of cholera toxin tracer histology confirmed that the spinal segments showing fMRI activations indeed received afferent inputs from the stimulated digits. Comparisons of the fMRI signal time courses in early somatosensory area 3b and iDH revealed very similar hemodynamic stimulus–response functions. In summary, we identified with fMRI distinct segmental networks for the processing of tactile and nociceptive heat stimuli in the cervical spinal cord of nonhuman primates. SIGNIFICANCE STATEMENT This is the first fMRI demonstration of distinct intrasegmental and intersegmental nociceptive heat and touch processing circuits in the spinal cord of nonhuman primates. This study provides novel insights into the local functional organizations of the primate spinal cord for pain and

  18. Triboelectric active sensor array for self-powered static and dynamic pressure detection and tactile imaging.

    PubMed

    Lin, Long; Xie, Yannan; Wang, Sihong; Wu, Wenzhuo; Niu, Simiao; Wen, Xiaonan; Wang, Zhong Lin

    2013-09-24

    We report an innovative, large-area, and self-powered pressure mapping approach based on the triboelectric effect, which converts the mechanical stimuli into electrical output signals. The working mechanism of the triboelectric active sensor (TEAS) was theoretically studied by both analytical method and numerical calculation to gain an intuitive understanding of the relationship between the applied pressure and the responsive signals. Relying on the unique pressure response characteristics of the open-circuit voltage and short-circuit current, we realize both static and dynamic pressure sensing on a single device for the first time. A series of comprehensive investigations were carried out to characterize the performance of the TEAS, and high sensitivity (0.31 kPa(-1)), ultrafast response time (<5 ms), long-term stability (30,000 cycles), as well as low detection limit (2.1 Pa) were achieved. The pressure measurement range of the TEAS was adjustable, which means both gentle pressure detection and large-scale pressure sensing were enabled. Through integrating multiple TEAS units into a sensor array, the as-fabricated TEAS matrix was capable of monitoring and mapping the local pressure distribution applied on the device with distinguishable spatial profiles. This work presents a technique for tactile imaging and progress toward practical applications of nanogenerators, providing potential solutions for accomplishment of artificial skin, human-electronic interfacing, and self-powered systems. PMID:23957827

  19. When Sandpaper Is 'Kiki' and Satin Is 'Bouba': an Exploration of the Associations Between Words, Emotional States, and the Tactile Attributes of Everyday Materials.

    PubMed

    Etzi, Roberta; Spence, Charles; Zampini, Massimiliano; Gallace, Alberto

    2016-01-01

    Over the last decade, scientists working on the topic of multisensory integration, as well as designers and marketers involved in trying to understand consumer behavior, have become increasingly interested in the non-arbitrary associations (e.g., sound symbolism) between different sensorial attributes of the stimuli they work with. Nevertheless, to date, little research in this area has investigated the presence of these crossmodal correspondences in the tactile evaluation of everyday materials. Here, we explore the presence and nature of the associations between tactile sensations, the sound of non-words, and people's emotional states. Samples of cotton, satin, tinfoil, sandpaper, and abrasive sponge, were stroked along the participants' forearm at the speed of 5 cm/s. Participants evaluated the materials along several dimensions, comprising scales anchored by pairs of non-words (e.g., Kiki/Bouba) and adjectives (e.g., ugly/beautiful). The results revealed that smoother textures were associated with non-words made up of round-shaped sounds (e.g., Maluma), whereas rougher textures were more strongly associated with sharp-transient sounds (e.g., Takete). The results also revealed the presence of a number of correspondences between tactile surfaces and adjectives related to visual and auditory attributes. For example, smooth textures were associated with features evoked by words such as 'bright' and 'quiet'; by contrast, the rougher textures were associated with adjectives such as 'dim' and 'loud'. The textures were also found to be associated with a number of emotional labels. Taken together, these results further our understanding of crossmodal correspondences involving the tactile modality and provide interesting insights in the applied field of design and marketing. PMID:27311294

  20. The neural basis of tactile motion perception.

    PubMed

    Pei, Yu-Cheng; Bensmaia, Sliman J

    2014-12-15

    The manipulation of objects commonly involves motion between object and skin. In this review, we discuss the neural basis of tactile motion perception and its similarities with its visual counterpart. First, much like in vision, the perception of tactile motion relies on the processing of spatiotemporal patterns of activation across populations of sensory receptors. Second, many neurons in primary somatosensory cortex are highly sensitive to motion direction, and the response properties of these neurons draw strong analogies to those of direction-selective neurons in visual cortex. Third, tactile speed may be encoded in the strength of the response of cutaneous mechanoreceptive afferents and of a subpopulation of speed-sensitive neurons in cortex. However, both afferent and cortical responses are strongly dependent on texture as well, so it is unclear how texture and speed signals are disambiguated. Fourth, motion signals from multiple fingers must often be integrated during the exploration of objects, but the way these signals are combined is complex and remains to be elucidated. Finally, visual and tactile motion perception interact powerfully, an integration process that is likely mediated by visual association cortex. PMID:25253479

  1. A Finger-Shaped Tactile Sensor for Fabric Surfaces Evaluation by 2-Dimensional Active Sliding Touch

    PubMed Central

    Hu, Haihua; Han, Yezhen; Song, Aiguo; Chen, Shanguang; Wang, Chunhui; Wang, Zheng

    2014-01-01

    Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF) film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT) is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA) is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM). The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures. PMID:24618775

  2. A finger-shaped tactile sensor for fabric surfaces evaluation by 2-dimensional active sliding touch.

    PubMed

    Hu, Haihua; Han, Yezhen; Song, Aiguo; Chen, Shanguang; Wang, Chunhui; Wang, Zheng

    2014-01-01

    Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF) film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT) is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA) is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM). The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures. PMID:24618775

  3. Tactile asymbolia.

    PubMed

    Talmasov, Daniel; Ropper, Allan H

    2016-04-01

    Agraphesthesia has been attributed to impairment of the ability to detect more rudimentary directionality of lines written on the skin (directional cutaneous kinesthesia). We examined a patient who had a dissociation between preserved perception of line directionality and the loss of graphesthesia for letters and numbers. A man with a metastatic right parietal lesion was tested for the ability to determine the directionality of lines drawn on the palms and forehead and then evaluated for recognition of letters and numbers in these regions. Our patient could identify the directions of lines, letters and numbers drawn on paper. The ability to detect the direction and shape of lines drawn on the skin of the palms and on the forehead was preserved but he had agraphesthesia for numbers and letters in these same locations. The finding of isolated agraphesthesia for letters and numbers may be assigned to damage in the right parietal lobe. It represents a deficit of somatosensory processing that is of a higher order than detection of line directionality. The term "tactile asymbolia" may capture the dissociation. These clinical findings suggest that tactile cortex in humans, like visual cortex, may be hierarchically organized, as has been demonstrated in primates. PMID:26620569

  4. The Cognitive and Neural Correlates of Tactile Memory

    ERIC Educational Resources Information Center

    Gallace, Alberto; Spence, Charles

    2009-01-01

    Tactile memory systems are involved in the storage and retrieval of information about stimuli that impinge on the body surface and objects that people explore haptically. Here, the authors review the behavioral, neuropsychological, neurophysiological, and neuroimaging research on tactile memory. This body of research reveals that tactile memory…

  5. Tactile Data Entry System

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.

    2015-01-01

    The patent-pending Glove-Enabled Computer Operations (GECO) design leverages extravehicular activity (EVA) glove design features as platforms for instrumentation and tactile feedback, enabling the gloves to function as human-computer interface devices. Flexible sensors in each finger enable control inputs that can be mapped to any number of functions (e.g., a mouse click, a keyboard strike, or a button press). Tracking of hand motion is interpreted alternatively as movement of a mouse (change in cursor position on a graphical user interface) or a change in hand position on a virtual keyboard. Programmable vibro-tactile actuators aligned with each finger enrich the interface by creating the haptic sensations associated with control inputs, such as recoil of a button press.

  6. Effects of late visual impairment on mental representations activated by visual and tactile stimuli.

    PubMed

    Cattaneo, Zaira; Vecchi, Tomaso; Monegato, Maura; Pece, Alfredo; Cornoldi, Cesare

    2007-05-01

    Similarly to sighted people, individuals congenitally affected by a severe visual impairment can maintain and mentally manipulate spatial information about tactile stimuli [Vecchi, T., Cattaneo, Z., Monegato, M., Pece, A., Cornoldi, C., Pietrini, P., 2006. Why Cyclops could not compete with Ulysses: monocular vision and mental images. NeuroReport 17, 723-726]. The aim of the present study was to assess whether the onset timing of a severe (but not total) sight loss may influence spatial imagery abilities based on haptic input. To this purpose, a group of late severe visually impaired people and a matched group of normally sighted participants (all blindfolded) were presented with an imagery task requiring to memorize and retrieve a number of locations presented on tactile matrices. Results indicate that a severe visual deficit occurring later in life significantly impairs spatial imagery abilities to a greater extent than in the case of congenital blindness, probably as a consequence of a modest development of specific compensatory mechanisms associated with congenital deficits. PMID:17368576

  7. Tactile responses in the granule cell layer of cerebellar folium crus IIa of freely behaving rats

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Bower, J. M.

    2001-01-01

    We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

  8. Creating and Using Tactile Experience Books for Young Children with Visual Impairments.

    ERIC Educational Resources Information Center

    Lewis, Sandra; Tolla, Joan

    2003-01-01

    This article explores how tactile experience books can be used to ensure that young children with visual impairments learn to read. It discusses making tactile experience books by collecting artifacts and gluing them to cardboard pages, and the benefits of tactile books. Descriptions of two tactile books are provided. (Contains references.) (CR)

  9. Do "mudsplashes" induce tactile change blindness?

    PubMed

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2007-05-01

    The phenomenon of change blindness (the surprising inability of people to correctly perceive changes between consecutively presented displays), primarily reported in vision, has recently been shown to occur for positional changes presented in tactile displays as well. Here, we studied people's ability to detect changes in the number of tactile stimuli in successively presented displays composed of one to three stimuli distributed over the body surface. In Experiment 1, a tactile mask consisting of the simultaneous activation of all seven possible tactile stimulators was sometimes presented between the two to-be-discriminated tactile displays. In Experiment 2, a "mudsplash" paradigm was used, with a brief irrelevant tactile distractor presented at the moment of change of the tactile display. Change blindness was demonstrated in both experiments, thus showing that the failure to detect tactile change is not necessarily related to (1) the physical disruption between consecutive events, (2) the effect of masking covering the location of the change, or (3) the erasure or resetting of the information contained within an internal representation of the tactile display. These results are interpreted in terms of a limitation in the number of spatial locations/events that can be consciously accessed at any one time. This limitation appears to constrain change-detection performance, no matter the sensory modality in which the stimuli are presented. PMID:17727101

  10. Teacher-Made Tactile Science Materials with Critical and Creative Thinking Activities for Learners Including Those with Visual Impairments

    ERIC Educational Resources Information Center

    Teske, Jolene K.; Gray, Phyllis; Kuhn, Mason A.; Clausen, Courtney K.; Smith, Latisha L.; Alsubia, Sukainah A.; Ghayoorad, Maryam; Rule, Audrey C.; Schneider, Jean Suchsland

    2014-01-01

    Gifted students with visual impairments are twice exceptional learners and may not evidence their advanced science aptitudes without appropriate accommodations for learning science. However, effective tactile science teaching materials may be easily made. Recent research has shown that when tactile materials are used with "all" students…

  11. Activities for Exploring Cultural Diversity.

    ERIC Educational Resources Information Center

    Perry, Susan K.

    1992-01-01

    Presents topics for parents to use when discussing cultural diversity with their children (basic needs, cultural attitudes, body language, the arts, and language). Activities for exploring cultural diversity are suggested, and a list of multicultural resources is included. (SM)

  12. Speechreading with Tactile Supplements.

    ERIC Educational Resources Information Center

    Plant, Geoff

    1988-01-01

    Reviewed is the historical development of tactile aids to supplement speechreading by hearing-impaired individuals, from early use of bone conduction vibrators driven by hearing aids, to multichannel tactile aids representing the full speech spectrum and tactile speechreading aids complementing visual cues. Adequate training in use of tactile…

  13. Optical-to-Tactile Translator

    NASA Technical Reports Server (NTRS)

    Langevin, Maurice L. (Inventor); Moynihan, Philip I. (Inventor)

    2000-01-01

    An optical-to-tactile translator provides an aid for the visually impaired by translating a near-field scene to a tactile signal corresponding to said near-field scene. An optical sensor using a plurality of active pixel sensors (APS) converts the optical image within the near-field scene to a digital signal. The digital signal is then processed by a microprocessor and a simple shape signal is generated based on the digital signal. The shape signal is then communicated to a tactile transmitter where the shape signal is converted into a tactile signal using a series of contacts. The shape signal may be an outline of the significant shapes determined in the near-field scene, or the shape signal may comprise a simple symbolic representation of common items encountered repeatedly. The user is thus made aware of the unseen near-field scene, including potential obstacles and dangers, through a series of tactile contacts. In a preferred embodiment, a range determining device such as those commonly found on auto-focusing cameras is included to limit the distance that the optical sensor interprets the near-field scene.

  14. Acoustic Tactile Representation of Visual Information

    NASA Astrophysics Data System (ADS)

    Silva, Pubudu Madhawa

    Our goal is to explore the use of hearing and touch to convey graphical and pictorial information to visually impaired people. Our focus is on dynamic, interactive display of visual information using existing, widely available devices, such as smart phones and tablets with touch sensitive screens. We propose a new approach for acoustic-tactile representation of visual signals that can be implemented on a touch screen and allows the user to actively explore a two-dimensional layout consisting of one or more objects with a finger or a stylus while listening to auditory feedback via stereo headphones. The proposed approach is acoustic-tactile because sound is used as the primary source of information for object localization and identification, while touch is used for pointing and kinesthetic feedback. A static overlay of raised-dot tactile patterns can also be added. A key distinguishing feature of the proposed approach is the use of spatial sound (directional and distance cues) to facilitate the active exploration of the layout. We consider a variety of configurations for acoustic-tactile rendering of object size, shape, identity, and location, as well as for the overall perception of simple layouts and scenes. While our primary goal is to explore the fundamental capabilities and limitations of representing visual information in acoustic-tactile form, we also consider a number of relatively simple configurations that can be tied to specific applications. In particular, we consider a simple scene layout consisting of objects in a linear arrangement, each with a distinct tapping sound, which we compare to a ''virtual cane.'' We will also present a configuration that can convey a ''Venn diagram.'' We present systematic subjective experiments to evaluate the effectiveness of the proposed display for shape perception, object identification and localization, and 2-D layout perception, as well as the applications. Our experiments were conducted with visually blocked

  15. Brain activations evoked by tactile stimulation varies with the intensity and not with number of receptive fields stimulated: An fMRI study

    NASA Astrophysics Data System (ADS)

    Ramirez Garzón, Y. T.; Pasaye, E. H.; Barrios, F. A.

    2014-11-01

    Using functional Magnetic Resonance Imaging (fMRI) it is possible to study the functional anatomy of primary cortices. Cortical representations in the primary somatosensory cortex have shown discrepancies between activations related to the same body region in some studies; these differences have been more pronounced for lower limb representations. The aim of this study was to observe the influence of the tactile stimulus intensity in somatosensory cortical responses using fMRI. Based in the sensitivity and pain threshold of each subject, we used Von Frey filaments for stimulate 12 control subject in three receptive fields on the right thigh. One filament near to sensitivity threshold (VFS), other close to pain threshold (VFP) and one intermediate filament between the two previous thresholds (VFI). The tactile stimulation with VFS produced no activation on SI, while that the contralateral SI was activated by stimulation with VFI in 5 subjects and with the stimulation of VFP in all subjects. Second level statistical analysis showed significant differences between SI activations related to the stimulation with VFP and VFI (VFP > VFI), in the comparison between the applied different intensities, a small cluster of activation was observed on SI for the unique possible contrast (VFP > VFI). The time course per trial for each subject was extracted and averaged to extract the activation in the contralateral SI and compared across the stimulus modalities, between the sites of field receptive stimulated and the intensities used. The time course of tactile stimulus responses revealed a consistent single peak of activity per cycle (30 s), approximately 12 s after the onset of the stimulus, with exception of the VFI stimulation,_which showed the peak at 10 s. Thus, our results indicate that the cortical representation of a tactile stimulus with fMRI is modulated for the intensity of the stimulus applied.

  16. Evolutionary Specialization of Tactile Perception in Vertebrates.

    PubMed

    Schneider, Eve R; Gracheva, Elena O; Bagriantsev, Slav N

    2016-05-01

    Evolution has endowed vertebrates with the remarkable tactile ability to explore the world through the perception of physical force. Yet the sense of touch remains one of the least well understood senses at the cellular and molecular level. Vertebrates specializing in tactile perception can highlight general principles of mechanotransduction. Here, we review cellular and molecular adaptations that underlie the sense of touch in typical and acutely mechanosensitive vertebrates. PMID:27053733

  17. Tactile Object Familiarity in the Blind Brain Reveals the Supramodal Perceptual-Mnemonic Nature of the Perirhinal Cortex

    PubMed Central

    Cacciamani, Laura; Likova, Lora T.

    2016-01-01

    This study is the first to investigate the neural underpinnings of tactile object familiarity in the blind during both perception and memory. In the sighted, the perirhinal cortex (PRC) has been implicated in the assessment of visual object familiarity—a crucial everyday task—as evidenced by reduced activation when an object becomes familiar. Here, to examine the PRC’s role in tactile object familiarity in the absence of vision, we trained blind participants on a unique memory-guided drawing technique and measured brain activity while they perceptually explored raised-line drawings, drew them from tactile memory, and scribbled (control). Functional magnetic resonance imaging (fMRI) before and after a week of training revealed a significant decrease in PRC activation from pre- to post-training (i.e., from unfamiliar to familiar) during perceptual exploration as well as memory-guided drawing, but not scribbling. This familiarity-based reduction is the first evidence that the PRC represents tactile object familiarity in the blind. Furthermore, the finding of this effect during both tactile perception and tactile memory provides the critical link in establishing the PRC as a structure whose representations are supramodal for both perception and memory. PMID:27148002

  18. Tactile Object Familiarity in the Blind Brain Reveals the Supramodal Perceptual-Mnemonic Nature of the Perirhinal Cortex.

    PubMed

    Cacciamani, Laura; Likova, Lora T

    2016-01-01

    This study is the first to investigate the neural underpinnings of tactile object familiarity in the blind during both perception and memory. In the sighted, the perirhinal cortex (PRC) has been implicated in the assessment of visual object familiarity-a crucial everyday task-as evidenced by reduced activation when an object becomes familiar. Here, to examine the PRC's role in tactile object familiarity in the absence of vision, we trained blind participants on a unique memory-guided drawing technique and measured brain activity while they perceptually explored raised-line drawings, drew them from tactile memory, and scribbled (control). Functional magnetic resonance imaging (fMRI) before and after a week of training revealed a significant decrease in PRC activation from pre- to post-training (i.e., from unfamiliar to familiar) during perceptual exploration as well as memory-guided drawing, but not scribbling. This familiarity-based reduction is the first evidence that the PRC represents tactile object familiarity in the blind. Furthermore, the finding of this effect during both tactile perception and tactile memory provides the critical link in establishing the PRC as a structure whose representations are supramodal for both perception and memory. PMID:27148002

  19. How Does Brain Activation Differ in Children with Unilateral Cerebral Palsy Compared to Typically Developing Children, during Active and Passive Movements, and Tactile Stimulation? An fMRI Study

    ERIC Educational Resources Information Center

    Van de Winckel, Ann; Klingels, Katrijn; Bruyninckx, Frans; Wenderoth, Nici; Peeters, Ron; Sunaert, Stefan; Van Hecke, Wim; De Cock, Paul; Eyssen, Maria; De Weerdt, Willy; Feys, Hilde

    2013-01-01

    The aim of the functional magnetic resonance imaging (fMRI) study was to investigate brain activation associated with active and passive movements, and tactile stimulation in 17 children with right-sided unilateral cerebral palsy (CP), compared to 19 typically developing children (TD). The active movements consisted of repetitive opening and…

  20. Expression of Fos-protein activated by tactile stimulation on the laryngeal vestibulum in the cat's lower brain stem.

    PubMed

    Tanaka, Y; Yoshida, Y; Hirano, M

    1995-01-01

    To demonstrate morphologically the neurons participating in the laryngeal reflex, Fos-expression, activated with tactile stimulation of the laryngeal vestibulum, was mapped in the cat's lower brain stem utilizing immunohistochemistry. In the stimulation group, many Fos-immunoreactive (ir) neurons were recognized in the nucleus tractus solitarii (NTS) from the level of the most rostral portion of the dorsal motor nucleus of the vagus to the level of the most caudal portion of the inferior olivary nucleus (IO), and in the nucleus ambiguus (NA) from the level of the rostral end of the hypoglossal nucleus to the level of the caudal end of the IO, bilaterally. While some Fos-ir cells were found in the spinal nucleus of the trigeminus, they were also found in the reticular nuclei bilaterally. In the control group, Fos-ir cells were distinctly fewer in number than those in the stimulation group. The results suggested that in the brain stem, the laryngeal reflex pathways have more than two synaptic relays through the interneurons in between the NTS and the NA. PMID:7876735

  1. Tactile feedback improves auditory spatial localization.

    PubMed

    Gori, Monica; Vercillo, Tiziana; Sandini, Giulio; Burr, David

    2014-01-01

    Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality. PMID:25368587

  2. Tactile massage and hypnosis as a health promotion for nurses in emergency care-a qualitative study

    PubMed Central

    2011-01-01

    Background This study explores nursing personnel's experiences and perceptions of receiving tactile massage and hypnosis during a personnel health promotion project. Nursing in a short term emergency ward environment can be emotionally and physically exhausting due to the stressful work environment and the high dependency patient care. A health promotion project integrating tactile massage and hypnosis with conventional physical activities was therefore introduced for nursing personnel working in this setting at a large university hospital in Sweden. Methods Four semi-structured focus group discussions were conducted with volunteer nursing personnel participants after the health promotion project had been completed. There were 16 participants in the focus groups and there were 57 in the health promotion intervention. The discussions were transcribed verbatim and analysed with qualitative content analysis. Results The findings indicated that tactile massage and hypnosis may contribute to reduced levels of stress and pain and increase work ability for some nursing personnel. The sense of well-being obtained in relation to health promotion intervention with tactile massage and hypnosis seemed to have positive implications for both work and leisure. Self-awareness, contentment and self-control may be contributing factors related to engaging in tactile massage and hypnosis that might help nursing personnel understand their patients and colleagues and helped them deal with difficult situations that occurred during their working hours. Conclusion The findings indicate that the integration of tactile massage and hypnosis in personnel health promotion may be valuable stress management options in addition to conventional physical activities. PMID:21961762

  3. An overview of tactile sensing

    NASA Technical Reports Server (NTRS)

    Agrawal, Rajeev; Jain, Ramesh

    1986-01-01

    Existing or proposed tactile sensors are reviewed. General considerations involved in tactile sensing and various performance criteria are discussed. Typical specifications to be expected from the sensors are also described. A representative set of present day tactile sensors is studied. Finally, some of the proposed recognition systems using tactile sensing are described.

  4. Enhancing Activity by Means of Tactile Symbols: A Study of a Heterogeneous Group of Pupils with Congenital Blindness, Intellectual Disability and Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Aasen, Gro; Naerland, Terje

    2014-01-01

    This study investigates responses to verbal versus tactile requests in children with congenital blindness, intellectual disability and autism spectrum disorder (ASD). Observation was conducted on two occasions. At T1, requests were given verbally, and at T2, tactile requests were given. All pupils perceived tactile symbols to be explicit requests…

  5. Vibratory tactile display for textures

    NASA Technical Reports Server (NTRS)

    Ikei, Yasushi; Ikeno, Akihisa; Fukuda, Shuichi

    1994-01-01

    We have developed a tactile display that produces vibratory stimulus to a fingertip in contact with a vibrating tactor matrix. The display depicts tactile surface textures while the user is exploring a virtual object surface. A piezoelectric actuator drives the individual tactor in accordance with both the finger movement and the surface texture being traced. Spatiotemporal display control schemes were examined for presenting the fundamental surface texture elements. The temporal duration of vibratory stimulus was experimentally optimized to simulate the adaptation process of cutaneous sensation. The selected duration time for presenting a single line edge agreed with the time threshold of tactile sensation. Then spatial stimulus disposition schemes were discussed for representation of other edge shapes. As an alternative means not relying on amplitude control, a method of augmented duration at the edge was investigated. Spatial resolution of the display was measured for the lines presented both in perpendicular and parallel to a finger axis. Discrimination of texture density was also measured on random dot textures.

  6. Brain Process for Perception of the “Out of the Body” Tactile Illusion for Virtual Object Interaction

    PubMed Central

    Lee, Hye Jin; Lee, Jaedong; Kim, Chi Jung; Kim, Gerard J.; Kim, Eun-Soo; Whang, Mincheol

    2015-01-01

    “Out of the body” tactile illusion refers to the phenomenon in which one can perceive tactility as if emanating from a location external to the body without any stimulator present there. Taking advantage of such a tactile illusion is one way to provide and realize richer interaction feedback without employing and placing actuators directly at all stimulation target points. However, to further explore its potential, it is important to better understand the underlying physiological and neural mechanism. As such, we measured the brain wave patterns during such tactile illusion and mapped out the corresponding brain activation areas. Participants were given stimulations at different levels with the intention to create veridical (i.e., non-illusory) and phantom sensations at different locations along an external hand-held virtual ruler. The experimental data and analysis indicate that both veridical and illusory sensations involve, among others, the parietal lobe, one of the most important components in the tactile information pathway. In addition, we found that as for the illusory sensation, there is an additional processing resulting in the delay for the ERP (event-related potential) and involvement by the limbic lobe. These point to regarding illusion as a memory and recognition task as a possible explanation. The present study demonstrated some basic understanding; how humans process “virtual” objects and the way associated tactile illusion is generated will be valuable for HCI (Human-Computer Interaction). PMID:25835301

  7. In situ patch-clamp recordings from Merkel cells in rat whisker hair follicles, an experimental protocol for studying tactile transduction in tactile-end organs.

    PubMed

    Ikeda, Ryo; Ling, Jennifer; Cha, Myeounghoon; Gu, Jianguo G

    2015-01-01

    Mammals use tactile end-organs to perform sensory tasks such as environmental exploration, social interaction, and tactile discrimination. However, cellular and molecular mechanisms underlying tactile transduction in tactile end-organs remain poorly understood. The patch-clamp recording technique may be the most valuable approach for detecting and studying tactile transduction in tactile end-organs, but it is technically challenging because tactile transduction elements in an end-organ are normally inaccessible by patch-clamp recording electrodes. Here we describe an in situ patch-clamp recording protocol for the study of tactile transduction in Merkel cells of rat whisker hair follicles, one of the most sensitive tactile end-organs in mammals. This technique offers an opportunity to explore the identities and properties of ion channels that are involved in tactile transduction in whisker hair follicles, and it may also lend a useful tool for researchers to study other tactile end-organs. The experimental protocol describes procedures for 1) tissue dissection and whisker hair follicle preparation, 2) device setup and steps for performing patch-clamp recordings from Merkel cells in a whisker hair follicle, 3) methods of delivering mechanical stimuli, and 4) intra-follicle microinjection for receptor knockdown in whisker hair follicles. The main procedures in this protocol, from tissue preparation to whole-cell patch-clamp recordings, can be completed in a few hours. PMID:25907165

  8. Tactile stimulation reduces fear in fish.

    PubMed

    Schirmer, Annett; Jesuthasan, Suresh; Mathuru, Ajay S

    2013-01-01

    Being groomed or touched can counter stress and negative affect in mammals. In two experiments we explored whether a similar phenomenon exists in non-mammals like zebrafish. In Experiment 1, we exposed zebrafish to a natural stressor, a chemical alarm signal released by injured conspecifics. Before moving them into an observation tank, one group of fish was washed and then subjected to a water current that served as the tactile stimulus. The other group was simply washed. Fish with tactile treatment demonstrated fewer fear behaviors (e.g., bottom dwelling) and lower cortisol levels than fish without. In Experiment 2, we ascertained a role of somatosensation in these effects. Using a similar paradigm as in Experiment 1, we recorded fear behaviors of intact fish and fish with damaged lateral line hair cells. Relative to the former, the latter benefited less from the tactile stimulus during fear recovery. Together these findings show that tactile stimulation can calm fish and that tactile receptors, evolutionarily older than those present in mammals, contribute to this phenomenon. PMID:24319415

  9. Tactile stimulation reduces fear in fish

    PubMed Central

    Schirmer, Annett; Jesuthasan, Suresh; Mathuru, Ajay S.

    2013-01-01

    Being groomed or touched can counter stress and negative affect in mammals. In two experiments we explored whether a similar phenomenon exists in non-mammals like zebrafish. In Experiment 1, we exposed zebrafish to a natural stressor, a chemical alarm signal released by injured conspecifics. Before moving them into an observation tank, one group of fish was washed and then subjected to a water current that served as the tactile stimulus. The other group was simply washed. Fish with tactile treatment demonstrated fewer fear behaviors (e.g., bottom dwelling) and lower cortisol levels than fish without. In Experiment 2, we ascertained a role of somatosensation in these effects. Using a similar paradigm as in Experiment 1, we recorded fear behaviors of intact fish and fish with damaged lateral line hair cells. Relative to the former, the latter benefited less from the tactile stimulus during fear recovery. Together these findings show that tactile stimulation can calm fish and that tactile receptors, evolutionarily older than those present in mammals, contribute to this phenomenon. PMID:24319415

  10. Tactile Sensitivity in Asperger Syndrome

    ERIC Educational Resources Information Center

    Blakemore, Sarah-Jayne; Tavassoli, Teresa; Calo, Susana; Thomas, Richard M.; Catmur, Caroline; Frith, Uta; Haggard, Patrick

    2006-01-01

    People with autism and Asperger syndrome are anecdotally said to be hypersensitive to touch. In two experiments, we measured tactile thresholds and suprathreshold tactile sensitivity in a group of adults with Asperger syndrome. In the first experiment, tactile perceptual thresholds were measured. Two frequencies of vibrotactile stimulation were…

  11. Testing Tactile Masking between the Forearms.

    PubMed

    D'Amour, Sarah; Harris, Laurence R

    2016-01-01

    Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, usually using stimuli that are close together to reveal local interactions. Masking effects have also been demonstrated in which a tactile stimulus alters the perception of a touch at a distant location. Such effects can provide insight into how components of the body's representations in the brain may be linked. Occasional reports have indicated that touches on one hand or forearm can affect tactile sensitivity at corresponding contralateral locations. To explore the matching of corresponding points across the body, we can measure the spatial tuning and effect of posture on contralateral masking. Careful controls are required to rule out direct effects of the remote stimulus, for example by mechanical transmission, and also attention effects in which thresholds may be altered by the participant's attention being drawn away from the stimulus of interest. The use of this technique is beneficial as a behavioural measure for exploring which parts of the body are functionally connected and whether the two sides of the body interact in a somatotopic representation. This manuscript describes a behavioural protocol that can be used for studying contralateral tactile masking. PMID:26889736

  12. Learning in Tactile Channels

    ERIC Educational Resources Information Center

    Gescheider, George A.; Wright, John H.

    2012-01-01

    Vibrotactile intensity-discrimination thresholds for sinusoidal stimuli applied to the thenar eminence of the hand declined as a function of practice. However, improvement was confined to the tactile information-processing channel in which learning had occurred. Specifically, improvements in performance with training within the Pacinian-corpuscle…

  13. A Tactile Carina Nebula

    NASA Astrophysics Data System (ADS)

    Grice, Noreen A.; Mutchler, M.

    2010-01-01

    Astronomy was once considered a science restricted to fully sighted participants. But in the past two decades, accessible books with large print/Braille and touchable pictures have brought astronomy and space science to the hands and mind's eye of students, regardless of their visual ability. A new universally-designed tactile image featuring the Hubble mosaic of the Carina Nebula is being presented at this conference. The original dataset was obtained with Hubble's Advanced Camera for Surveys (ACS) hydrogen-alpha filter in 2005. It became an instant icon after being infused with additional color information from ground-based CTIO data, and released as Hubble's 17th anniversary image. Our tactile Carina Nebula promotes multi-mode learning about the entire life-cycle of stars, which is dramatically illustrated in this Hubble mosaic. When combined with descriptive text in print and Braille, the visual and tactile components seamlessly reach both sighted and blind populations. Specific touchable features of the tactile image identify the shapes and orientations of objects in the Carina Nebula that include star-forming regions, jets, pillars, dark and light globules, star clusters, shocks/bubbles, the Keyhole Nebula, and stellar death (Eta Carinae). Visit our poster paper to touch the Carina Nebula!

  14. Tactile-dependant corticomotor facilitation is influenced by discrimination performance in seniors

    PubMed Central

    2010-01-01

    Background Active contraction leads to facilitation of motor responses evoked by transcranial magnetic stimulation (TMS). In small hand muscles, motor facilitation is known to be also influenced by the nature of the task. Recently, we showed that corticomotor facilitation was selectively enhanced when young participants actively discriminated tactile symbols with the tip of their index or little finger. This tactile-dependant motor facilitation reflected, for the large part, attentional influences associated with performing tactile discrimination, since execution of a concomitant distraction task abolished facilitation. In the present report, we extend these observations to examine the influence of age on the ability to produce extra motor facilitation when the hand is used for sensory exploration. Methods Corticomotor excitability was tested in 16 healthy seniors (58-83 years) while they actively moved their right index finger over a surface under two task conditions. In the tactile discrimination (TD) condition, participants attended to the spatial location of two tactile symbols on the explored surface, while in the non discrimination (ND) condition, participants simply moved their finger over a blank surface. Changes in amplitude, in latency and in the silent period (SP) duration were measured from recordings of motor evoked potentials (MEP) in the right first dorsal interosseous muscle in response to TMS of the left motor cortex. Results Healthy seniors exhibited widely varying levels of performance with the TD task, older age being associated with lower accuracy and vice-versa. Large inter-individual variations were also observed in terms of tactile-specific corticomotor facilitation. Regrouping seniors into higher (n = 6) and lower performance groups (n = 10) revealed a significant task by performance interaction. This latter interaction reflected differences between higher and lower performance groups; tactile-related facilitation being observed mainly in

  15. Pure associative tactile agnosia for the left hand: clinical and anatomo-functional correlations.

    PubMed

    Veronelli, Laura; Ginex, Valeria; Dinacci, Daria; Cappa, Stefano F; Corbo, Massimo

    2014-09-01

    Associative tactile agnosia (TA) is defined as the inability to associate information about object sensory properties derived through tactile modality with previously acquired knowledge about object identity. The impairment is often described after a lesion involving the parietal cortex (Caselli, 1997; Platz, 1996). We report the case of SA, a right-handed 61-year-old man affected by first ever right hemispheric hemorrhagic stroke. The neurological examination was normal, excluding major somaesthetic and motor impairment; a brain magnetic resonance imaging (MRI) confirmed the presence of a right subacute hemorrhagic lesion limited to the post-central and supra-marginal gyri. A comprehensive neuropsychological evaluation detected a selective inability to name objects when handled with the left hand in the absence of other cognitive deficits. A series of experiments were conducted in order to assess each stage of tactile recognition processing using the same stimulus sets: materials, 3D geometrical shapes, real objects and letters. SA and seven matched controls underwent the same experimental tasks during four sessions in consecutive days. Tactile discrimination, recognition, pantomime, drawing after haptic exploration out of vision and tactile-visual matching abilities were assessed. In addition, we looked for the presence of a supra-modal impairment of spatial perception and of specific difficulties in programming exploratory movements during recognition. Tactile discrimination was intact for all the stimuli tested. In contrast, SA was able neither to recognize nor to pantomime real objects manipulated with the left hand out of vision, while he identified them with the right hand without hesitations. Tactile-visual matching was intact. Furthermore, SA was able to grossly reproduce the global shape in drawings but failed to extract details of objects after left-hand manipulation, and he could not identify objects after looking at his own drawings. This case

  16. Meet our Neighbours - a tactile experience

    NASA Astrophysics Data System (ADS)

    Canas, L.; Lobo Correia, A.

    2013-09-01

    Planetary science is a key field in astronomy that draws lots of attention and that engages large amounts of enthusiasts. On its essence, it is a visual science and the current resources and activities for the inclusion of visually impaired children, although increasing, are still costly and somewhat scarce. Therefore there is a paramount need to develop more low cost resources in order to provide experiences that can reach all, even the more socially deprived communities. "Meet our neighbours!-a tactile experience", plans to promote and provide inclusion activities for visually impaired children and their non-visually impaired peers through the use of astronomy hands-on low cost activities. Is aimed for children from the ages of 6 to 12 years old and produce data set 13 tactile images of the main objects of the Solar System that can be used in schools, science centres and outreach associations. Accessing several common problems through tactile resources, with this project we present ways to successfully provide low cost solutions (avoiding the expensive tactile printing costs), promote inclusion and interactive hands-on activities for visually impaired children and their non-visually impaired peers and create dynamic interactions based on oral knowledge transmission between them. Here we describe the process of implementing such initiative near target communities: establishing a bridge between scientists, children and teachers. The struggles and challenges perceived during the project and the enrichment experience of engaging astronomy with these specific groups, broadening horizons in an overall experience accessible to all.

  17. Decoding Accuracy in Supplementary Motor Cortex Correlates with Perceptual Sensitivity to Tactile Roughness

    PubMed Central

    Kim, Junsuk; Chung, Yoon Gi; Park, Jang-Yeon; Chung, Soon-Cheol; Wallraven, Christian; Bülthoff, Heinrich H.; Kim, Sung-Phil

    2015-01-01

    Perceptual sensitivity to tactile roughness varies across individuals for the same degree of roughness. A number of neurophysiological studies have investigated the neural substrates of tactile roughness perception, but the neural processing underlying the strong individual differences in perceptual roughness sensitivity remains unknown. In this study, we explored the human brain activation patterns associated with the behavioral discriminability of surface texture roughness using functional magnetic resonance imaging (fMRI). First, a whole-brain searchlight multi-voxel pattern analysis (MVPA) was used to find brain regions from which we could decode roughness information. The searchlight MVPA revealed four brain regions showing significant decoding results: the supplementary motor area (SMA), contralateral postcentral gyrus (S1), and superior portion of the bilateral temporal pole (STP). Next, we evaluated the behavioral roughness discrimination sensitivity of each individual using the just-noticeable difference (JND) and correlated this with the decoding accuracy in each of the four regions. We found that only the SMA showed a significant correlation between neuronal decoding accuracy and JND across individuals; Participants with a smaller JND (i.e., better discrimination ability) exhibited higher decoding accuracy from their voxel response patterns in the SMA. Our findings suggest that multivariate voxel response patterns presented in the SMA represent individual perceptual sensitivity to tactile roughness and people with greater perceptual sensitivity to tactile roughness are likely to have more distinct neural representations of different roughness levels in their SMA. PMID:26067832

  18. The Role of Exploratory Conditions in Bio-Inspired Tactile Sensing of Single Topogical Features

    PubMed Central

    Candelier, Raphaël; Prevost, Alexis; Debrégeas, Georges

    2011-01-01

    We investigate the mechanism of tactile transduction during active exploration of finely textured surfaces using a tactile sensor mimicking the human fingertip. We focus in particular on the role of exploratory conditions in shaping the subcutaneous mechanical signals. The sensor has been designed by integrating a linear array of MEMS micro-force sensors in an elastomer layer. We measure the response of the sensors to the passage of elementary topographical features at constant velocity and normal load, such as a small hole on a flat substrate. Each sensor’s response is found to strongly depend on its relative location with respect to the substrate/skin contact zone, a result which can be quantitatively understood within the scope of a linear model of tactile transduction. The modification of the response induced by varying other parameters, such as the thickness of the elastic layer and the confining load, are also correctly captured by this model. We further demonstrate that the knowledge of these characteristic responses allows one to dynamically evaluate the position of a small hole within the contact zone, based on the micro-force sensors signals, with a spatial resolution an order of magnitude better than the intrinsic resolution of individual sensors. Consequences of these observations on robotic tactile sensing are briefly discussed. PMID:22164054

  19. Slanted joint axes of the stick insect antenna: an adaptation to tactile acuity

    NASA Astrophysics Data System (ADS)

    Mujagic, Samir; Krause, André F.; Dürr, Volker

    2007-04-01

    Like many flightless, obligatory walking insects, the stick insect Carausius morosus makes intensive use of active antennal movements for tactile near range exploration and orientation. The antennal joints of C. morosus have a peculiar oblique and non-orthogonal joint axis arrangement. Moreover, this arrangement is known to differ from that in crickets (Ensifera), locusts (Caelifera) and cockroaches (Blattodea), all of which have an orthogonal joint axis arrangement. Our hypothesis was that the situation found in C. morosus represents an important evolutionary trait of the order of stick and leaf insects (Phasmatodea). If this was true, it should be common to other species of the Phasmatodea. The objective of this comparative study was to resolve this question. We have measured the joint axis orientation of the head scape and scape pedicel joints along with other parameters that affect the tactile efficiency of the antenna. The obtained result was a complete kinematic description of the antenna. This was used to determine the size and location of kinematic out-of-reach zones, which are indicators of tactile acuity. We show that the oblique and non-orthogonal arrangement is common to eight species from six sub-families indicating that it is a synapomorphic character of the Euphasmatodea. This character can improve tactile acuity compared to the situation in crickets, locusts and cockroaches. Finally, because molecular data of a recent study indicate that the Phasmatodea may have evolved as flightless, obligatory walkers, we argue that the antennal joint axis arrangement of the Euphasmatodea reflects an evolutionary adaptation to tactile near range exploration during terrestrial locomotion.

  20. Tactile Signing with One-Handed Perception

    ERIC Educational Resources Information Center

    Mesch, Johanna

    2013-01-01

    Tactile signing among persons with deaf-blindness is not homogenous; rather, like other forms of language, it exhibits variation, especially in turn taking. Early analyses of tactile Swedish Sign Language, tactile Norwegian Sign Language, and tactile French Sign Language focused on tactile communication with four hands, in which partially blind or…

  1. Motor commands induce time compression for tactile stimuli.

    PubMed

    Tomassini, Alice; Gori, Monica; Baud-Bovy, Gabriel; Sandini, Giulio; Morrone, Maria Concetta

    2014-07-01

    Saccades cause compression of visual space around the saccadic target, and also a compression of time, both phenomena thought to be related to the problem of maintaining saccadic stability (Morrone et al., 2005; Burr and Morrone, 2011). Interestingly, similar phenomena occur at the time of hand movements, when tactile stimuli are systematically mislocalized in the direction of the movement (Dassonville, 1995; Watanabe et al., 2009). In this study, we measured whether hand movements also cause an alteration of the perceived timing of tactile signals. Human participants compared the temporal separation between two pairs of tactile taps while moving their right hand in response to an auditory cue. The first pair of tactile taps was presented at variable times with respect to movement with a fixed onset asynchrony of 150 ms. Two seconds after test presentation, when the hand was stationary, the second pair of taps was delivered with a variable temporal separation. Tactile stimuli could be delivered to either the right moving or left stationary hand. When the tactile stimuli were presented to the motor effector just before and during movement, their perceived temporal separation was reduced. The time compression was effector-specific, as perceived time was veridical for the left stationary hand. The results indicate that time intervals are compressed around the time of hand movements. As for vision, the mislocalizations of time and space for touch stimuli may be consequences of a mechanism attempting to achieve perceptual stability during tactile exploration of objects, suggesting common strategies within different sensorimotor systems. PMID:24990936

  2. Tactile Astronomy - a Portuguese case study

    NASA Astrophysics Data System (ADS)

    Canas, L.; Alves, F.; Correia, A.

    2012-09-01

    Although astronomy plays an important role in the most various outreach initiatives, as well as school science curricula, due to its strong visual component in knowledge acquisition, astronomy subjects are not entirely well addressed and accessed by visually impaired students and/or general public. This stresses the need of more tactile material production, still very scarce in an educational context whether formal or informal. This is a case study activity developed based on different schematic tactile images of several objects present in our solar system. These images in relief, highlight, through touch, several relevant features present in the different astronomical objects studied. The scientific knowledge is apprehended through the use of a tactile key, complemented with additional information. Through proper hands-on activities implementation and careful analysis of the outcome, the adapted images associated with an explanatory key prove to be a valuable resource in tactile astronomy domain. Here we describe the process of implementing such initiative near visually impaired students. The struggles and challenges perceived by all involved and the enrichment experience of engaging astronomy with visually impaired audiences, broadening horizons in an overall experience accessible to all.

  3. Compliant Tactile Sensors

    NASA Technical Reports Server (NTRS)

    Torres-Jara, Eduardo R.

    2011-01-01

    Tactile sensors are currently being designed to sense interactions with human hands or pen-like interfaces. They are generally embedded in screens, keyboards, mousepads, and pushbuttons. However, they are not well fitted to sense interactions with all kinds of objects. A novel sensor was originally designed to investigate robotics manipulation where not only the contact with an object needs to be detected, but also where the object needs to be held and manipulated. This tactile sensor has been designed with features that allow it to sense a large variety of objects in human environments. The sensor is capable of detecting forces coming from any direction. As a result, this sensor delivers a force vector with three components. In contrast to most of the tactile sensors that are flat, this one sticks out from the surface so that it is likely to come in contact with objects. The sensor conforms to the object with which it interacts. This augments the contact's surface, consequently reducing the stress applied to the object. This feature makes the sensor ideal for grabbing objects and other applications that require compliance with objects. The operational range of the sensor allows it to operate well with objects found in peoples' daily life. The fabrication of this sensor is simple and inexpensive because of its compact mechanical configuration and reduced electronics. These features are convenient for mass production of individual sensors as well as dense arrays. The biologically inspired tactile sensor is sensitive to both normal and lateral forces, providing better feedback to the host robot about the object to be grabbed. It has a high sensitivity, enabling its use in manipulation fingers, which typically have low mechanical impedance in order to be very compliant. The construction of the sensor is simple, using inexpensive technologies like silicon rubber molding and standard stock electronics.

  4. Tactile perception during action observation.

    PubMed

    Vastano, Roberta; Inuggi, Alberto; Vargas, Claudia D; Baud-Bovy, Gabriel; Jacono, Marco; Pozzo, Thierry

    2016-09-01

    It has been suggested that tactile perception becomes less acute during movement to optimize motor control and to prevent an overload of afferent information generated during action. This empirical phenomenon, known as "tactile gating effect," has been associated with mechanisms of sensory feedback prediction. However, less attention has been given to the tactile attenuation effect during the observation of an action. The aim of this study was to investigate whether and how the observation of a goal-directed action influences tactile perception as during overt action. In a first experiment, we recorded vocal reaction times (RTs) of participants to tactile stimulations during the observation of a reach-to-grasp action. The stimulations were delivered on different body parts that could be either congruent or incongruent with the observed effector (the right hand and the right leg, respectively). The tactile stimulation was contrasted with a no body-related stimulation (an auditory beep). We found increased RTs for tactile congruent stimuli compared to both tactile incongruent and auditory stimuli. This effect was reported only during the observation of the reaching phase, whereas RTs were not modulated during the grasping phase. A tactile two-alternative forced-choice (2AFC) discrimination task was then conducted in order to quantify the changes in tactile sensitivity during the observation of the same goal-directed actions. In agreement with the first experiment, the tactile perceived intensity was reduced only during the reaching phase. These results suggest that tactile processing during action observation relies on a process similar to that occurring during action execution. PMID:27161552

  5. An Activity for Exploring Marital Expectations

    ERIC Educational Resources Information Center

    Saur, William G.

    1976-01-01

    The learning activity, designed for the use of high school students in a family life education course, is designed to explore attitudes towards mate qualities in order to increase the students' awareness of marital expectations. The activity utilizes the format of an auction game and a group discussion. (EC)

  6. Tactile hallucinations: conceptual and historical aspects.

    PubMed Central

    Berrios, G E

    1982-01-01

    A brief historical analysis of the general concept of hallucination is presented and the suggestion is made that it emerged as the unwarranted generalisation of a perceptual model that was meant to apply only to vision and the "distance senses". Against this background the evolution of tactile hallucinations is considered and its interaction with 19th century psychological theory explored. It is concluded that tactile hallucinations are sui generis phenomena which do not fit the conventional model and whose clinical identification rests on criteria so far unclear. A brief review of their taxonomy and diagnostic usefulness is presented. Some wider implications are drawn which should be relevant to the general concept of hallucination. PMID:7042917

  7. Tactile Sun: Bringing an Invisible Universe to the Visually Impaired

    NASA Astrophysics Data System (ADS)

    Isidro, G. M.; Pantoja, C. A.

    2014-07-01

    A tactile model of the Sun has been created as a strategy for communicating astronomy to the blind or visually impaired, and as a useful outreach tool for general audiences. The model design was a collaboration between an education specialist, an astronomy specialist and a sculptor. The tactile Sun has been used at astronomy outreach events in Puerto Rico to make activities more inclusive and to increase public awareness of the needs of those with disabilities.

  8. Tactile warning signals for in-vehicle systems.

    PubMed

    Meng, Fanxing; Spence, Charles

    2015-02-01

    The last few years have seen growing interest in the design of tactile warning signals to direct driver attention to potentially dangerous road situations (e.g. an impending crash) so that they can initiate an avoidance maneuver in a timely manner. In this review, we highlight the potential uses of such warning signals for future collision warning systems and compare them with more traditional visual and auditory warnings. Basic tactile warning signals are capable of promoting driver alertness, which has been demonstrated to be beneficial for forward collision avoidance (when compared to a no warning baseline condition). However, beyond their basic alerting function, directional tactile warning signals are now increasingly being utilized to shift the attention of the driver toward locations of interest, and thus to further facilitate their speeded responses to potential collision events. Currently, many researchers are focusing their efforts on the development of meaningful (iconic) tactile warning signals. For instance, dynamic tactile warnings (varying in their intensity and/or location) can potentially be used to convey meaningful information to drivers. Finally, we highlight the future research that will be needed in order to explore how to present multiple directional warnings using dynamic tactile cues, thus forming an integrated collision avoidance system for future in-vehicle use. PMID:25569607

  9. The Slip Hypothesis: Tactile Perception and its Neuronal Bases.

    PubMed

    Schwarz, Cornelius

    2016-07-01

    The slip hypothesis of epicritic tactile perception interprets actively moving sensor and touched objects as a frictional system, known to lead to jerky relative movements called 'slips'. These slips depend on object geometry, forces, material properties, and environmental factors, and, thus, have the power to incorporate coding of the perceptual target, as well as perceptual strategies (sensor movement). Tactile information as transferred by slips will be encoded discontinuously in space and time, because slips sometimes engage only parts of the touching surfaces and appear as discrete and rare events in time. This discontinuity may have forced tactile systems of vibrissae and fingertips to evolve special ways to convert touch signals to a tactile percept. PMID:27311927

  10. The PHOTON explorations: sixteen activities, many uses

    NASA Astrophysics Data System (ADS)

    Donnelly, Judith; Amatrudo, Kathryn; Robinson, Kathleen; Hanes, Fenna

    2014-07-01

    The PHOTON Explorations were adapted from favorite demonstrations of teacher participants in the PHOTON projects of the New England Board of Higher Education as well as Hands-on-Optics activities and interesting demonstrations found on the web. Since the end of project PHOTON2 in 2006, the sixteen inquiry-based activities have formed the basis for a hands-on "home lab" distance- learning course that has been used for college students, teacher professional development and corporate training. With the support of OSA, they have been brought to life in a series of sixteen short videos aimed at a middle school audience. The Explorations are regularly used as activities in outreach activities for middle and high school students and are introduced yearly to an international audience at an outreach workshop at SPIE's Optics and Photonics meeting. In this paper we will demonstrate the Explorations, trace their origins and explain the content. We will also provide details on the development of the Exploration videos, the online course, and outreach materials and give statistics on their use in each format. Links to online resources will be provided.

  11. Laser application on haptics: Tactile stiffness measurement

    NASA Astrophysics Data System (ADS)

    Scalise, L.; Memeo, M.; Cannella, F.; Valente, M.; Caldwell, D. G.; Tomasini, E. P.

    2012-06-01

    There is a great interest in exploring the proprieties of the sense of the touch, its detailed knowledge in fact is a key issue in the area of robotics, haptics and human-machine interaction. In this paper, the authors focus their attention on a novel measurement method for the assessment of the tactile stiffness based on a original test rig; tactile stiffness is defined as the ratio between force, exerted by the finger, and the displacement of the finger tip operated during the test. To reach this scope, the paper describes a specific experimental test-rig used for the evaluation of subject tactile sensitivity, where finger force applied during tests as well as displacement and velocity of displacement, operated by the subject under investigation, are measured. Results show that tactile stiffness is linear respect to stimuli spatial difference (which is proportional to the difficulty to detect the variation of them). In particular, it has been possible to relate the force and displacement measured during the tests. The relationship between the response of the subject to the grating, velocity and force is determined. These results permit to carry out the further experimental tests on the same subject avoiding the use of a load cell and therefore simplifying the measurement test rig and data post-processing. Indeed, the first aspect (use of a load cell) can be relevant, because the grating positions are different, requiring a specific re-calibration and setting before each trial; while the second aspect allows simplify the test rig complexity and the processing algorithm.

  12. Phalange Tactile Load Cell

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  13. Audio-Tactile Integration and the Influence of Musical Training

    PubMed Central

    Kuchenbuch, Anja; Paraskevopoulos, Evangelos; Herholz, Sibylle C.; Pantev, Christo

    2014-01-01

    Perception of our environment is a multisensory experience; information from different sensory systems like the auditory, visual and tactile is constantly integrated. Complex tasks that require high temporal and spatial precision of multisensory integration put strong demands on the underlying networks but it is largely unknown how task experience shapes multisensory processing. Long-term musical training is an excellent model for brain plasticity because it shapes the human brain at functional and structural levels, affecting a network of brain areas. In the present study we used magnetoencephalography (MEG) to investigate how audio-tactile perception is integrated in the human brain and if musicians show enhancement of the corresponding activation compared to non-musicians. Using a paradigm that allowed the investigation of combined and separate auditory and tactile processing, we found a multisensory incongruency response, generated in frontal, cingulate and cerebellar regions, an auditory mismatch response generated mainly in the auditory cortex and a tactile mismatch response generated in frontal and cerebellar regions. The influence of musical training was seen in the audio-tactile as well as in the auditory condition, indicating enhanced higher-order processing in musicians, while the sources of the tactile MMN were not influenced by long-term musical training. Consistent with the predictive coding model, more basic, bottom-up sensory processing was relatively stable and less affected by expertise, whereas areas for top-down models of multisensory expectancies were modulated by training. PMID:24465675

  14. Audio-tactile integration and the influence of musical training.

    PubMed

    Kuchenbuch, Anja; Paraskevopoulos, Evangelos; Herholz, Sibylle C; Pantev, Christo

    2014-01-01

    Perception of our environment is a multisensory experience; information from different sensory systems like the auditory, visual and tactile is constantly integrated. Complex tasks that require high temporal and spatial precision of multisensory integration put strong demands on the underlying networks but it is largely unknown how task experience shapes multisensory processing. Long-term musical training is an excellent model for brain plasticity because it shapes the human brain at functional and structural levels, affecting a network of brain areas. In the present study we used magnetoencephalography (MEG) to investigate how audio-tactile perception is integrated in the human brain and if musicians show enhancement of the corresponding activation compared to non-musicians. Using a paradigm that allowed the investigation of combined and separate auditory and tactile processing, we found a multisensory incongruency response, generated in frontal, cingulate and cerebellar regions, an auditory mismatch response generated mainly in the auditory cortex and a tactile mismatch response generated in frontal and cerebellar regions. The influence of musical training was seen in the audio-tactile as well as in the auditory condition, indicating enhanced higher-order processing in musicians, while the sources of the tactile MMN were not influenced by long-term musical training. Consistent with the predictive coding model, more basic, bottom-up sensory processing was relatively stable and less affected by expertise, whereas areas for top-down models of multisensory expectancies were modulated by training. PMID:24465675

  15. Activity Planning for the Mars Exploration Rovers

    NASA Technical Reports Server (NTRS)

    Bresina, John L.; Jonsson, Ari K.; Morris, Paul H.; Rajan, Kanna

    2004-01-01

    Operating the Mars Exploration Rovers is a challenging, time-pressured task. Each day, the operations team must generate a new plan describing the rover activities for the next day. These plans must abide by resource limitations, safety rules, and temporal constraints. The objective is to achieve as much science as possible, choosing from a set of observation requests that oversubscribe rover resources. In order to accomplish this objective, given the short amount of planning time available, the MAPGEN (Mixed-initiative Activity Plan GENerator) system was made a mission-critical part of the ground operations system. MAPGEN is a mixed-initiative system that employs automated constraint-based planning, scheduling, and temporal reasoning to assist operations staff in generating the daily activity plans. This paper describes the adaptation of constraint-based planning and temporal reasoning to a mixed-initiative setting and the key technical solutions developed for the mission deployment of MAPGEN.

  16. Infant patterns of reactivity to tactile stimulation during parent-child interaction.

    PubMed

    Mammen, Micah A; Moore, Ginger A; Scaramella, Laura V; Reiss, David; Shaw, Daniel S; Leve, Leslie D; Neiderhiser, Jenae M

    2016-08-01

    Touch is the primary modality infants use to engage with the world; atypical responses to tactile stimuli may indicate risk for disordered outcomes. The current study examined infants' responses to tactile stimulation within parent-child interaction, adding to prior knowledge based on parent report. Nine-month-old infants (N=497) were observed while parents painted and pressed infants' hands and feet to paper to make designs. Positive and negative affect and gazing away, exploring, and resistance behaviors were coded. Latent Class Analysis of observed behaviors yielded four tactile response patterns partially consistent with current nosology for sensory processing patterns: Low Reactive, Sensory Overreactive, Sensory Seeking, and Mixed Over/Underreactive. To evaluate whether patterns made valid distinctions among infants, latent classes were examined in relation to parent-reported temperament. Infants in the Mixed Over/Underreactive class were rated higher in distress to limitations and activity level than other infants. Sensory processing patterns observed in parent-child interaction are consistent with those identified by parent-report and may be used in future research to elucidate relations with temperament and typical and atypical development. PMID:27376866

  17. Occupation-related long-term sensory training enhances roughness discrimination but not tactile acuity.

    PubMed

    Mueller, S; Winkelmann, C; Krause, F; Grunwald, M

    2014-06-01

    Extensive use of sensorimotor properties has been shown to lead to use-dependent plasticity in the human motor cortex as well as sensory areas. The sensory consequences of these cortical changes, however, remain widely unclear. We were interested whether job-related long-term haptic training is measurable in terms of changes in haptic perception (active touch exploration) in manual physiotherapists (PT). To that end, the haptic thresholds of PT (students and employed) and registered osteopathic manual therapists (OMT; PT with postgraduate specialization) were measured and compared to age- and sex-matched control groups. Additionally, tactile acuity (passive static touch) was assessed using grating domes. PT and OMT had superior mean haptic thresholds compared to the control group, suggesting an increase in sensitivity through use. An age-related decline in haptic perception capacity occurred only in the control group, suggesting that the job-related training of the manual therapist groups may have slowed their age-related decline. Contrary to our expectation, we found significantly poorer mean haptic threshold results in the PT student group than for the controls. No significant differences or changes in tactile acuity were found for any of the groups (students and professional). The present results demonstrate use-dependent plasticity in manual therapists. Furthermore, the results underline the known effect of a superior discrimination ability of haptic as opposed to tactile perception. PMID:24609417

  18. Texture- and deformability-based surface recognition by tactile image analysis.

    PubMed

    Khasnobish, Anwesha; Pal, Monalisa; Tibarewala, D N; Konar, Amit; Pal, Kunal

    2016-08-01

    Deformability and texture are two unique object characteristics which are essential for appropriate surface recognition by tactile exploration. Tactile sensation is required to be incorporated in artificial arms for rehabilitative and other human-computer interface applications to achieve efficient and human-like manoeuvring. To accomplish the same, surface recognition by tactile data analysis is one of the prerequisites. The aim of this work is to develop effective technique for identification of various surfaces based on deformability and texture by analysing tactile images which are obtained during dynamic exploration of the item by artificial arms whose gripper is fitted with tactile sensors. Tactile data have been acquired, while human beings as well as a robot hand fitted with tactile sensors explored the objects. The tactile images are pre-processed, and relevant features are extracted from the tactile images. These features are provided as input to the variants of support vector machine (SVM), linear discriminant analysis and k-nearest neighbour (kNN) for classification. Based on deformability, six household surfaces are recognized from their corresponding tactile images. Moreover, based on texture five surfaces of daily use are classified. The method adopted in the former two cases has also been applied for deformability- and texture-based recognition of four biomembranes, i.e. membranes prepared from biomaterials which can be used for various applications such as drug delivery and implants. Linear SVM performed best for recognizing surface deformability with an accuracy of 83 % in 82.60 ms, whereas kNN classifier recognizes surfaces of daily use having different textures with an accuracy of 89 % in 54.25 ms and SVM with radial basis function kernel recognizes biomembranes with an accuracy of 78 % in 53.35 ms. The classifiers are observed to generalize well on the unseen test datasets with very high performance to achieve efficient material

  19. The cognitive and neural correlates of tactile memory.

    PubMed

    Gallace, Alberto; Spence, Charles

    2009-05-01

    Tactile memory systems are involved in the storage and retrieval of information about stimuli that impinge on the body surface and objects that people explore haptically. Here, the authors review the behavioral, neuropsychological, neurophysiological, and neuroimaging research on tactile memory. This body of research reveals that tactile memory can be subdivided into a number of functionally distinct neurocognitive subsystems, just as is the case with auditory and visual memory. Some of these subsystems are peripheral and short lasting and others are more central and long lasting. The authors highlight evidence showing that the representation of tactile information interacts with information about other sensory attributes (e.g., visual, auditory, and kinaesthetic) of objects/events that people perceive. This fact suggests that at least part of the neural network involved in the memory for touch might be shared among different sensory modalities. In particular, multisensory/amodal information-processing networks seem to play a leading role in the storage of tactile information in the brain. (PsycINFO Database Record (c) 2009 APA, all rights reserved). PMID:19379022

  20. Synthetic and Bio-Artificial Tactile Sensing: A Review

    PubMed Central

    Lucarotti, Chiara; Oddo, Calogero Maria; Vitiello, Nicola; Carrozza, Maria Chiara

    2013-01-01

    This paper reviews the state of the art of artificial tactile sensing, with a particular focus on bio-hybrid and fully-biological approaches. To this aim, the study of physiology of the human sense of touch and of the coding mechanisms of tactile information is a significant starting point, which is briefly explored in this review. Then, the progress towards the development of an artificial sense of touch are investigated. Artificial tactile sensing is analysed with respect to the possible approaches to fabricate the outer interface layer: synthetic skin versus bio-artificial skin. With particular respect to the synthetic skin approach, a brief overview is provided on various technologies and transduction principles that can be integrated beneath the skin layer. Then, the main focus moves to approaches characterized by the use of bio-artificial skin as an outer layer of the artificial sensory system. Within this design solution for the skin, bio-hybrid and fully-biological tactile sensing systems are thoroughly presented: while significant results have been reported for the development of tissue engineered skins, the development of mechanotransduction units and their integration is a recent trend that is still lagging behind, therefore requiring research efforts and investments. In the last part of the paper, application domains and perspectives of the reviewed tactile sensing technologies are discussed. PMID:23348032

  1. Virtual environment tactile system

    DOEpatents

    Renzi, R.

    1996-12-10

    A method for providing a realistic sense of touch in virtual reality by means of programmable actuator assemblies is disclosed. Each tactile actuator assembly consists of a number of individual actuators whose movement is controlled by a computer and associated drive electronics. When an actuator is energized, the rare earth magnet and the associated contactor, incorporated within the actuator, are set in motion by the opposing electromagnetic field of a surrounding coil. The magnet pushes the contactor forward to contact the skin resulting in the sensation of touch. When the electromagnetic field is turned off, the rare earth magnet and the contactor return to their neutral positions due to the magnetic equilibrium caused by the interaction with the ferrous outer sleeve. The small size and flexible nature of the actuator assemblies permit incorporation into a glove, boot or body suit. The actuator has additional applications, such as, for example, as an accelerometer, an actuator for precisely controlled actuations or to simulate the sensation of braille letters. 28 figs.

  2. Virtual environment tactile system

    DOEpatents

    Renzi, Ronald

    1996-01-01

    A method for providing a realistic sense of touch in virtual reality by means of programmable actuator assemblies is disclosed. Each tactile actuator assembly consists of a number of individual actuators whose movement is controlled by a computer and associated drive electronics. When an actuator is energized, the rare earth magnet and the associated contactor, incorporated within the actuator, are set in motion by the opposing electromagnetic field of a surrounding coil. The magnet pushes the contactor forward to contact the skin resulting in the sensation of touch. When the electromagnetic field is turned off, the rare earth magnet and the contactor return to their neutral positions due to the magnetic equilibrium caused by the interaction with the ferrous outer sleeve. The small size and flexible nature of the actuator assemblies permit incorporation into a glove, boot or body suit. The actuator has additional applications, such as, for example, as an accelerometer, an actuator for precisely controlled actuations or to simulate the sensation of braille letters.

  3. Future lunar exploration activities in ESA

    NASA Astrophysics Data System (ADS)

    Houdou, B.; Carpenter, J. D.; Fisackerly, R.; Koschny, D.; Pradier, A.; di Pippo, S.; Gardini, B.

    2009-04-01

    Introduction Recent years have seen a resurgence of interest in the Moon and various recent and coming orbital missions including Smart-1, Kaguya, Chandrayaan-1and Lunar Reconnaissance Orbiter are advancing our understanding. In 2004 the US announced a new Vision for Space Exploration [1], whose objectives are focused towards human missions to the Moon and Mars. The European Space Agency has established similar objectives for Europe, described in [2] and approved at the ESA ministerial council (2009). There is considerable potential for international cooperation in these activities, as formulated in the recently agreed Global Exploration Strategy [3]. Present lunar exploration activities at ESA emphasise the development of European technologies and capabilities, to enable European participation in future international human exploration of the Moon. A major element in this contribution has been identified as a large lunar cargo lander, which would fulfill an ATV-like function, providing logistical support to human activities on the Moon, extending the duration of sorties and the capabilities of human explorers. To meet this ultimate goal, ESA is currently considering various possible development approaches, involving lunar landers of different sizes. Lunar Lander Mission Options A high capacity cargo lander able to deliver consumables, equipment and small infrastructure, in both sortie and outpost mission scenarios, would use a full Ariane 5 launch and is foreseen in the 2020-2025 timeframe. ESA is also considering an intermediate, smaller-scale mission beforehand, to mature the necessary landing technologies, to demonstrate human-related capabilities in preparation of human presence on the Moon and in general to gain experience in landing and operating on the lunar surface. Within this frame, ESA is currently leading several feasibility studies of a small lunar lander mission, also called "MoonNEXT". This mission is foreseen to be to be launched from Kourou with a

  4. Active Costorage of Cryogenic Propellants for Exploration

    NASA Technical Reports Server (NTRS)

    Canavan, Edgar R.; Boyle, Rob; Mustafi, Shuvo

    2008-01-01

    Long-term storage of cryogenic propellants is a critical requirement for NASA's effort to return to the moon. Liquid hydrogen and liquid oxygen provide the highest specific impulse of any practical chemical propulsion system, and thus provides the greatest payload mass per unit of launch mass. Future manned missions will require vehicles with the flexibility to remain in orbit for months, necessitating long-term storage of these cryogenic liquids. For decades cryogenic scientific satellites have used cryogens to cool instruments. In many cases, the lifetime of the primary cryogen tank has been extended by intercepting much of the heat incident on the tank at an intermediate-temperature shield cooled either by a second cryogen tank or a mechanical cryocooler. For an LH2/LO2 propellant system, a combination of these ideas can be used, in which the shield around the LO2 tank is attached to, and at the same temperature as, the LO2 tank, but is actively cooled so as to remove all heat impinging on the tank and shield. This configuration eliminates liquid oxygen boil-off and cuts the liquid hydrogen boil-off to a small fraction of the unshielded rate. This paper studies the concept of active costorage as a means of long-term cryogenic propellant storage. The paper describes the design impact of an active costorage system for the Crew Exploration Vehicle (CEV). This paper also compares the spacecraft level impact of the active costorage concept with a passive storage option in relation to two different scales of spacecraft that will be used for the lunar exploration effort, the CEV and the Earth Departure Stage (EDS). Spacecraft level studies are performed to investigate the impact of scaling of the costorage technologies for the different components of the Lunar Architecture and for different mission durations.

  5. Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl

    PubMed Central

    Schneider, Eve R.; Mastrotto, Marco; Laursen, Willem J.; Schulz, Vincent P.; Goodman, Jena B.; Funk, Owen H.; Gallagher, Patrick G.; Gracheva, Elena O.; Bagriantsev, Sviatoslav N.

    2014-01-01

    Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents. PMID:25246547

  6. Active Thermal Control System Development for Exploration

    NASA Technical Reports Server (NTRS)

    Westheimer, David

    2007-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has been actively developing technologies that will enable future missions or will provide significant improvements over the state of the art technologies. These technologies have are targeted for application on the Crew Exploration Vehicle (CEV), or Orion, and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  7. Spectroscopic Active Galaxies and Clusters Explorer

    NASA Astrophysics Data System (ADS)

    Ferrari, L.; Bagliani, D.; Bardi, A.; Battistelli, E.; Birkinshaw, M.; Colafrancesco, S.; Conte, A.; Debernardis, P.; Degregori, S.; Depetris, M.; de Zotti, G.; Donati, A.; Franceschini, A.; Gatti, F.; Gervasi, M.; Gonzalez-Nuevo, J.; Lamagna, L.; Luzzi, G.; Maiolino, M.; Marchegiani, P.; Mariani, A.; Masi, S.; Massardi, M.; Mauskopf, P.; Nati, L.; Nati, F.; Natoli, P.; Piacentini, F.; Polenta, G.; Porciani, M.; Savini, G.; Schillaci, A.; Spinelli, S.; Tartari, A.; Tavanti, M.; Tortora, A.; Vaccari, M.; Vaccarone, R.; Zannoni, M.

    2009-12-01

    We present a concept for the payload SAGACE, the Spectroscopic Active Galaxies And Cluster Explorer, devoted to study the evolution of Universe structures using different observables, all of them in the mm/submm wavelength. The SAGACE payload is made of a passively cooled 3 m telescope, a cryogenic Fourier Transform Spectrometer (FTS) and detector arrays to be operated at 0.3 K by a 3He fridge. The detectors are Ti/Au Transition Edge Sensor (TES) bolometers with a NEP<10-17 W/Hz12. A phase-A study has been recently completed for this experiment, in the framework of the call for small missions of the Italian Space Agency.

  8. Exploring primary care activities in ACT teams.

    PubMed

    Vanderlip, Erik R; Williams, Nancy A; Fiedorowicz, Jess G; Katon, Wayne

    2014-05-01

    People with serious mental illness often receive inadequate primary and preventive care services. Federal healthcare reform endorses team-based care that provides high quality primary and preventive care to at risk populations. Assertive community treatment (ACT) teams offer a proven, standardized treatment approach effective in improving mental health outcomes for the seriously mentally ill. Much is known about the effectiveness of ACT teams in improving mental health outcomes, but the degree to which medical care needs are addressed is not established. The purpose of this study was to explore the extent to which ACT teams address the physical health of the population they serve. ACT team leaders were invited to complete an anonymous, web-based survey to explore attitudes and activities involving the primary care needs of their clients. Information was collected regarding the use of health screening tools, physical health assessments, provision of medical care and collaboration with primary care systems. Data was analyzed from 127 team leaders across the country, of which 55 completed the entire survey. Nearly every ACT team leader believed ACT teams have a role in identifying and managing the medical co-morbidities of their clientele. ACT teams report participation in many primary care activities. ACT teams are providing a substantial amount of primary and preventive services to their population. The survey suggests standardization of physical health identification, management or referral processes within ACT teams may result in improved quality of medical care. ACT teams are in a unique position to improve physical health care by virtue of having medically trained staff and frequent, close contact with their clients. PMID:24337472

  9. Numerosity judgments for tactile stimuli distributed over the body surface.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2006-01-01

    A large body of research now supports the claim that two different and dissociable processes are involved in making numerosity judgments regarding visual stimuli: subitising (fast and nearly errorless) for up to 4 stimuli, and counting (slow and error-prone) when more than 4 stimuli are presented. We studied tactile numerosity judgments for combinations of 1-7 vibrotactile stimuli presented simultaneously over the body surface. In experiment 1, the stimuli were presented once, while in experiment 2 conditions of single presentation and repeated presentation of the stimulus were compared. Neither experiment provided any evidence for a discontinuity in the slope of either the RT or error data suggesting that subitisation does not occur for tactile stimuli. By systematically varying the intensity of the vibrotactile stimuli in experiment 3, we were able to demonstrate that participants were not simply using the 'global intensity' of the whole tactile display to make their tactile numerosity judgments, but were, instead, using information concerning the number of tactors activated. The results of the three experiments reported here are discussed in relation to current theories of counting and subitising, and potential implications for the design of tactile user interfaces are highlighted. PMID:16583769

  10. Biomimetic Active Touch with Fingertips and Whiskers.

    PubMed

    Lepora, Nathan F

    2016-01-01

    This study provides a synthetic viewpoint that compares, contrasts, and draws commonalities for biomimetic perception over a range of tactile sensors and tactile stimuli. Biomimetic active perception is formulated from three principles: (i) evidence accumulation based on leading models of perceptual decision making; (ii) action selection with an evidence-based policy, here based on overt focal attention; and (iii) sensory encoding of evidence based on neural coding. Two experiments with each of three biomimetic tactile sensors are considered: the iCub (capacitive) fingertip, the TacTip (optical) tactile sensor, and BIOTACT whiskers. For each sensor, one experiment considers a similar task (perception of shape and location) and the other a different tactile perception task. In all experiments, active perception with a biomimetic action selection policy based on focal attention outperforms passive perception with static or random action selection. The active perception also consistently reaches superresolved accuracy (hyperacuity) finer than the spacing between tactile elements. Biomimetic active touch thus offers a common approach for biomimetic tactile sensors to accurately and robustly characterize and explore non-trivial, uncertain environments analogous to how animals perceive the natural world. PMID:27168603

  11. Perceptual dimensions for a dynamic tactile display

    NASA Astrophysics Data System (ADS)

    Pappas, Thrasyvoulos N.; Tartter, Vivien C.; Seward, Andrew G.; Genzer, Boris; Gourgey, Karen; Kretzschmar, Ilona

    2009-02-01

    We propose a new approach for converting graphical and pictorial information into tactile patterns that can be displayed in a static or dynamic tactile device. The key components of the proposed approach are (1) an algorithm that segments a scene into perceptually uniform segments; (2) a procedure for generating perceptually distinct tactile patterns; and (3) a mapping of the visual textures of the segments into tactile textures that convey similar concepts. We used existing digital halftoning and other techniques to generate a wide variety of tactile textures. We then conducted formal and informal subjective tests with sighted (but visually blocked) and visually-impaired subjects to determine the ability of human tactile perception to perceive differences among them. In addition to generating perceptually distinguishable tactile patterns, our goal is to identify significant dimensions of tactile texture perception, which will make it possible to map different visual attributes into independent tactile attributes. Our experimental results indicate that it is poosible to generate a number of perceptually distinguishable tactile patterns, and that different dimensions of tactile texture perception can indeed be identified.

  12. Exploration

    USGS Publications Warehouse

    Wilburn, D.R.; Porter, K.E.

    1999-01-01

    This summary of international nonfuel mineral exploration activities for 1998 draws on available data from literature, industry and US Geological Survey (USGS) specialists. Data on exploration budgets by region and commodity are reported, significant mineral discoveries and exploration target areas are identified and government programs affecting the mineral exploration industry are discussed. Inferences and observations on mineral industry direction are drawn from these data and discussions.

  13. Neuroplasticity Associated with Tactile Language Communication in a Deaf-Blind Subject

    PubMed Central

    Obretenova, Souzana; Halko, Mark A.; Plow, Ela B.; Pascual-Leone, Alvaro; Merabet, Lotfi B.

    2009-01-01

    A long-standing debate in cognitive neuroscience pertains to the innate nature of language development and the underlying factors that determine this faculty. We explored the neural correlates associated with language processing in a unique individual who is early blind, congenitally deaf, and possesses a high level of language function. Using functional magnetic resonance imaging (fMRI), we compared the neural networks associated with the tactile reading of words presented in Braille, Print on Palm (POP), and a haptic form of American Sign Language (haptic ASL or hASL). With all three modes of tactile communication, indentifying words was associated with robust activation within occipital cortical regions as well as posterior superior temporal and inferior frontal language areas (lateralized within the left hemisphere). In a normally sighted and hearing interpreter, identifying words through hASL was associated with left-lateralized activation of inferior frontal language areas however robust occipital cortex activation was not observed. Diffusion tensor imaging -based tractography revealed differences consistent with enhanced occipital-temporal connectivity in the deaf-blind subject. Our results demonstrate that in the case of early onset of both visual and auditory deprivation, tactile-based communication is associated with an extensive cortical network implicating occipital as well as posterior superior temporal and frontal associated language areas. The cortical areas activated in this deaf-blind subject are consistent with characteristic cortical regions previously implicated with language. Finally, the resilience of language function within the context of early and combined visual and auditory deprivation may be related to enhanced connectivity between relevant cortical areas. PMID:20130756

  14. 15 CFR 970.2503 - Suspension of exploration activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2503 Suspension of exploration activities. (a) The Administrator may issue an... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Suspension of exploration...

  15. 15 CFR 970.2503 - Suspension of exploration activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2503 Suspension of exploration activities. (a) The Administrator may issue an... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Suspension of exploration...

  16. Tactile Acuity Charts: A Reliable Measure of Spatial Acuity

    PubMed Central

    Bruns, Patrick; Camargo, Carlos J.; Campanella, Humberto; Esteve, Jaume; Dinse, Hubert R.; Röder, Brigitte

    2014-01-01

    For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds. PMID:24504346

  17. Feeling music: integration of auditory and tactile inputs in musical meter perception.

    PubMed

    Huang, Juan; Gamble, Darik; Sarnlertsophon, Kristine; Wang, Xiaoqin; Hsiao, Steven

    2012-01-01

    Musicians often say that they not only hear, but also "feel" music. To explore the contribution of tactile information in "feeling" musical rhythm, we investigated the degree that auditory and tactile inputs are integrated in humans performing a musical meter recognition task. Subjects discriminated between two types of sequences, 'duple' (march-like rhythms) and 'triple' (waltz-like rhythms) presented in three conditions: 1) Unimodal inputs (auditory or tactile alone), 2) Various combinations of bimodal inputs, where sequences were distributed between the auditory and tactile channels such that a single channel did not produce coherent meter percepts, and 3) Simultaneously presented bimodal inputs where the two channels contained congruent or incongruent meter cues. We first show that meter is perceived similarly well (70%-85%) when tactile or auditory cues are presented alone. We next show in the bimodal experiments that auditory and tactile cues are integrated to produce coherent meter percepts. Performance is high (70%-90%) when all of the metrically important notes are assigned to one channel and is reduced to 60% when half of these notes are assigned to one channel. When the important notes are presented simultaneously to both channels, congruent cues enhance meter recognition (90%). Performance drops dramatically when subjects were presented with incongruent auditory cues (10%), as opposed to incongruent tactile cues (60%), demonstrating that auditory input dominates meter perception. We believe that these results are the first demonstration of cross-modal sensory grouping between any two senses. PMID:23119038

  18. Support for the slip hypothesis from whisker-related tactile perception of rats in a noisy environment

    PubMed Central

    Waiblinger, Christian; Brugger, Dominik; Whitmire, Clarissa J.; Stanley, Garrett B.; Schwarz, Cornelius

    2015-01-01

    Rodents use active whisker movements to explore their environment. The “slip hypothesis” of whisker-related tactile perception entails that short-lived kinematic events (abrupt whisker movements, called “slips”, due to bioelastic whisker properties that occur during active touch of textures) carry the decisive texture information. Supporting this hypothesis, previous studies have shown that slip amplitude and frequency occur in a texture-dependent way. Further, experiments employing passive pulsatile whisker deflections revealed that perceptual performance based on pulse kinematics (i.e., signatures that resemble slips) is far superior to the one based on time-integrated variables like frequency and intensity. So far, pulsatile stimuli were employed in a noise free environment. However, the realistic scenario involves background noise (e.g., evoked by rubbing across the texture). Therefore, if slips are used for tactile perception, the tactile neuronal system would need to differentiate slip-evoked spikes from those evoked by noise. To test the animals under these more realistic conditions, we presented passive whisker-deflections to head-fixed trained rats, consisting of “slip-like” events (waveforms mimicking slips occurring with touch of real textures) embedded into background noise. Varying the (i) shapes (ramp or pulse); (ii) kinematics (amplitude, velocity, etc.); and (iii) the probabilities of occurrence of slip-like events, we observed that rats could readily detect slip-like events of different shapes against noisy background. Psychophysical curves revealed that the difference of slip event and noise amplitude determined perception, while increased probability of occurrence (frequency) had barely any effect. These results strongly support the notion that encoding of kinematics dominantly determines whisker-related tactile perception while the computation of frequency or intensity plays a minor role. PMID:26528148

  19. Activities of the COSPAR Panel on Exploration supporting the Global Exploration Roadmap

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, P.; McKay, C. P.

    2014-08-01

    The Global Exploration Roadmap (GER) is driven by several goals and objectives that include space science, the search for life as well as preparatory science activities to enable human space exploration. The Committee on Space Research (COSPAR), through its Commissions and Panels provides an international forum that supports and promotes space exploration worldwide. COSPAR's Panel on Exploration (PEX) investigates a stepwise approach of preparatory research on Earth and in Low Earth Orbit (LEO) to facilitate a future global space exploration program. We summarize recent activities and workshops of PEX in support of the GER.

  20. Remotely deployable aerial inspection using tactile sensors

    NASA Astrophysics Data System (ADS)

    MacLeod, C. N.; Cao, J.; Pierce, S. G.; Sullivan, J. C.; Pipe, A. G.; Dobie, G.; Summan, R.

    2014-02-01

    For structural monitoring applications, the use of remotely deployable Non-Destructive Evaluation (NDE) inspection platforms offer many advantages, including improved accessibility, greater safety and reduced cost, when compared to traditional manual inspection techniques. The use of such platforms, previously reported by researchers at the University Strathclyde facilitates the potential for rapid scanning of large areas and volumes in hazardous locations. A common problem for both manual and remote deployment approaches lies in the intrinsic stand-off and surface coupling issues of typical NDE probes. The associated complications of these requirements are obviously significantly exacerbated when considering aerial based remote inspection and deployment, resulting in simple visual techniques being the preferred sensor payload. Researchers at Bristol Robotics Laboratory have developed biomimetic tactile sensors modelled on the facial whiskers (vibrissae) of animals such as rats and mice, with the latest sensors actively sweeping their tips across the surface in a back and forth motion. The current work reports on the design and performance of an aerial inspection platform and the suitability of tactile whisking sensors to aerial based surface monitoring applications.

  1. Tactile length contraction as Bayesian inference.

    PubMed

    Tong, Jonathan; Ngo, Vy; Goldreich, Daniel

    2016-08-01

    To perceive, the brain must interpret stimulus-evoked neural activity. This is challenging: The stochastic nature of the neural response renders its interpretation inherently uncertain. Perception would be optimized if the brain used Bayesian inference to interpret inputs in light of expectations derived from experience. Bayesian inference would improve perception on average but cause illusions when stimuli violate expectation. Intriguingly, tactile, auditory, and visual perception are all prone to length contraction illusions, characterized by the dramatic underestimation of the distance between punctate stimuli delivered in rapid succession; the origin of these illusions has been mysterious. We previously proposed that length contraction illusions occur because the brain interprets punctate stimulus sequences using Bayesian inference with a low-velocity expectation. A novel prediction of our Bayesian observer model is that length contraction should intensify if stimuli are made more difficult to localize. Here we report a tactile psychophysical study that tested this prediction. Twenty humans compared two distances on the forearm: a fixed reference distance defined by two taps with 1-s temporal separation and an adjustable comparison distance defined by two taps with temporal separation t ≤ 1 s. We observed significant length contraction: As t was decreased, participants perceived the two distances as equal only when the comparison distance was made progressively greater than the reference distance. Furthermore, the use of weaker taps significantly enhanced participants' length contraction. These findings confirm the model's predictions, supporting the view that the spatiotemporal percept is a best estimate resulting from a Bayesian inference process. PMID:27121574

  2. Remotely deployable aerial inspection using tactile sensors

    SciTech Connect

    MacLeod, C. N.; Cao, J.; Pierce, S. G.; Dobie, G.; Summan, R.; Sullivan, J. C.; Pipe, A. G.

    2014-02-18

    For structural monitoring applications, the use of remotely deployable Non-Destructive Evaluation (NDE) inspection platforms offer many advantages, including improved accessibility, greater safety and reduced cost, when compared to traditional manual inspection techniques. The use of such platforms, previously reported by researchers at the University Strathclyde facilitates the potential for rapid scanning of large areas and volumes in hazardous locations. A common problem for both manual and remote deployment approaches lies in the intrinsic stand-off and surface coupling issues of typical NDE probes. The associated complications of these requirements are obviously significantly exacerbated when considering aerial based remote inspection and deployment, resulting in simple visual techniques being the preferred sensor payload. Researchers at Bristol Robotics Laboratory have developed biomimetic tactile sensors modelled on the facial whiskers (vibrissae) of animals such as rats and mice, with the latest sensors actively sweeping their tips across the surface in a back and forth motion. The current work reports on the design and performance of an aerial inspection platform and the suitability of tactile whisking sensors to aerial based surface monitoring applications.

  3. Market study: Tactile paging system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market survey was conducted regarding the commercialization potential and key market factors relevant to a tactile paging system for deaf-blind people. The purpose of the tactile paging system is to communicate to the deaf-blind people in an institutional environment. The system consists of a main console and individual satellite wrist units. The console emits three signals by telemetry to the wrist com (receiving unit) which will measure approximately 2 x 4 x 3/4 inches and will be fastened to the wrist by a strap. The three vibration signals are fire alarm, time period indication, and a third signal which will alert the wearer of the wrist com to the fact that the pin on the top of the wrist is emitting a morse coded message. The Morse code message can be felt and recognized with the finger.

  4. Anterior insula coordinates hierarchical processing of tactile mismatch responses

    PubMed Central

    Allen, Micah; Fardo, Francesca; Dietz, Martin J.; Hillebrandt, Hauke; Friston, Karl J.; Rees, Geraint; Roepstorff, Andreas

    2016-01-01

    The body underlies our sense of self, emotion, and agency. Signals arising from the skin convey warmth, social touch, and the physical characteristics of external stimuli. Surprising or unexpected tactile sensations can herald events of motivational salience, including imminent threats (e.g., an insect bite) and hedonic rewards (e.g., a caressing touch). Awareness of such events is thought to depend upon the hierarchical integration of body-related mismatch responses by the anterior insula. To investigate this possibility, we measured brain activity using functional magnetic resonance imaging, while healthy participants performed a roving tactile oddball task. Mass-univariate analysis demonstrated robust activations in limbic, somatosensory, and prefrontal cortical areas previously implicated in tactile deviancy, body awareness, and cognitive control. Dynamic Causal Modelling revealed that unexpected stimuli increased the strength of forward connections along a caudal to rostral hierarchy—projecting from thalamic and somatosensory regions towards insula, cingulate and prefrontal cortices. Within this ascending flow of sensory information, the AIC was the only region to show increased backwards connectivity to the somatosensory cortex, augmenting a reciprocal exchange of neuronal signals. Further, participants who rated stimulus changes as easier to detect showed stronger modulation of descending PFC to AIC connections by deviance. These results suggest that the AIC coordinates hierarchical processing of tactile prediction error. They are interpreted in support of an embodied predictive coding model where AIC mediated body awareness is involved in anchoring a global neuronal workspace. PMID:26584870

  5. Anterior insula coordinates hierarchical processing of tactile mismatch responses.

    PubMed

    Allen, Micah; Fardo, Francesca; Dietz, Martin J; Hillebrandt, Hauke; Friston, Karl J; Rees, Geraint; Roepstorff, Andreas

    2016-02-15

    The body underlies our sense of self, emotion, and agency. Signals arising from the skin convey warmth, social touch, and the physical characteristics of external stimuli. Surprising or unexpected tactile sensations can herald events of motivational salience, including imminent threats (e.g., an insect bite) and hedonic rewards (e.g., a caressing touch). Awareness of such events is thought to depend upon the hierarchical integration of body-related mismatch responses by the anterior insula. To investigate this possibility, we measured brain activity using functional magnetic resonance imaging, while healthy participants performed a roving tactile oddball task. Mass-univariate analysis demonstrated robust activations in limbic, somatosensory, and prefrontal cortical areas previously implicated in tactile deviancy, body awareness, and cognitive control. Dynamic Causal Modelling revealed that unexpected stimuli increased the strength of forward connections along a caudal to rostral hierarchy-projecting from thalamic and somatosensory regions towards insula, cingulate and prefrontal cortices. Within this ascending flow of sensory information, the AIC was the only region to show increased backwards connectivity to the somatosensory cortex, augmenting a reciprocal exchange of neuronal signals. Further, participants who rated stimulus changes as easier to detect showed stronger modulation of descending PFC to AIC connections by deviance. These results suggest that the AIC coordinates hierarchical processing of tactile prediction error. They are interpreted in support of an embodied predictive coding model where AIC mediated body awareness is involved in anchoring a global neuronal workspace. PMID:26584870

  6. Reduced-Wiring Tactile Sensor

    NASA Technical Reports Server (NTRS)

    Ohm, Timothy R.

    1991-01-01

    Proposed tactile sensor on robot finger puts out multiplexed analog signals transmitted to control computer on fewer wires than needed to transmit equivalent digital signals. Analog output represents data on contact area of object being gripped, on position of object, and on direction and rate of slippage if any. Consists of chains of normally open switches and resistors on surface of finger. Each resistance double preceding resistance in each chain. Constant-current sources supply power to chains.

  7. Computational modeling indicates that surface pressure can be reliably conveyed to tactile receptors even amidst changes in skin mechanics.

    PubMed

    Wang, Yuxiang; Baba, Yoshichika; Lumpkin, Ellen A; Gerling, Gregory J

    2016-07-01

    Distinct patterns in neuronal firing are observed between classes of cutaneous afferents. Such differences may be attributed to end-organ morphology, distinct ion-channel complements, and skin microstructure, among other factors. Even for just the slowly adapting type I afferent, the skin's mechanics for a particular specimen might impact the afferent's firing properties, especially given the thickness and elasticity of skin can change dramatically over just days. Here, we show computationally that the skin can reliably convey indentation magnitude, rate, and spatial geometry to the locations of tactile receptors even amid changes in skin's structure. Using finite element analysis and neural dynamics models, we considered the skin properties of six mice that span a representative cohort. Modeling the propagation of the surface stimulus to the interior of the skin demonstrated that there can be large variance in stresses and strains near the locations of tactile receptors, which can lead to large variance in static firing rate. However, variance is significantly reduced when the stimulus tip is controlled by surface pressure and compressive stress is measured near the end organs. This particular transformation affords the least variability in predicted firing rates compared with others derived from displacement, force, strain energy density, or compressive strain. Amid changing skin mechanics, stimulus control by surface pressure may be more naturalistic and optimal and underlie how animals actively explore the tactile environment. PMID:27098029

  8. The Fabric of Thought: Priming Tactile Properties during Reading Influences Direct Tactile Perception

    ERIC Educational Resources Information Center

    Brunye, Tad T.; Walters, Eliza K.; Ditman, Tali; Gagnon, Stephanie A.; Mahoney, Caroline R.; Taylor, Holly A.

    2012-01-01

    The present studies examined whether implied tactile properties during language comprehension influence subsequent direct tactile perception, and the specificity of any such effects. Participants read sentences that implicitly conveyed information regarding tactile properties (e.g., "Grace tried on a pair of thick corduroy pants while shopping")…

  9. Multisensory effects on somatosensation: a trimodal visuo-vestibular-tactile interaction.

    PubMed

    Kaliuzhna, Mariia; Ferrè, Elisa Raffaella; Herbelin, Bruno; Blanke, Olaf; Haggard, Patrick

    2016-01-01

    Vestibular information about self-motion is combined with other sensory signals. Previous research described both visuo-vestibular and vestibular-tactile bilateral interactions, but the simultaneous interaction between all three sensory modalities has not been explored. Here we exploit a previously reported visuo-vestibular integration to investigate multisensory effects on tactile sensitivity in humans. Tactile sensitivity was measured during passive whole body rotations alone or in conjunction with optic flow, creating either purely vestibular or visuo-vestibular sensations of self-motion. Our results demonstrate that tactile sensitivity is modulated by perceived self-motion, as provided by a combined visuo-vestibular percept, and not by the visual and vestibular cues independently. We propose a hierarchical multisensory interaction that underpins somatosensory modulation: visual and vestibular cues are first combined to produce a multisensory self-motion percept. Somatosensory processing is then enhanced according to the degree of perceived self-motion. PMID:27198907

  10. Multisensory effects on somatosensation: a trimodal visuo-vestibular-tactile interaction

    PubMed Central

    Kaliuzhna, Mariia; Ferrè, Elisa Raffaella; Herbelin, Bruno; Blanke, Olaf; Haggard, Patrick

    2016-01-01

    Vestibular information about self-motion is combined with other sensory signals. Previous research described both visuo-vestibular and vestibular-tactile bilateral interactions, but the simultaneous interaction between all three sensory modalities has not been explored. Here we exploit a previously reported visuo-vestibular integration to investigate multisensory effects on tactile sensitivity in humans. Tactile sensitivity was measured during passive whole body rotations alone or in conjunction with optic flow, creating either purely vestibular or visuo-vestibular sensations of self-motion. Our results demonstrate that tactile sensitivity is modulated by perceived self-motion, as provided by a combined visuo-vestibular percept, and not by the visual and vestibular cues independently. We propose a hierarchical multisensory interaction that underpins somatosensory modulation: visual and vestibular cues are first combined to produce a multisensory self-motion percept. Somatosensory processing is then enhanced according to the degree of perceived self-motion. PMID:27198907

  11. A review exploring biological activities of hydrazones

    PubMed Central

    Verma, Garima; Marella, Akranth; Shaquiquzzaman, Mohammad; Akhtar, Mymoona; Ali, Mohammad Rahmat; Alam, Mohammad Mumtaz

    2014-01-01

    The development of novel compounds, hydrazones has shown that they possess a wide variety of biological activities viz. antimicrobial, anticonvulsant, antidepressant, anti-inflammatory, analgesic, antiplatelet, antimalarial, anticancer, antifungal, antitubercular, antiviral, cardio protective etc., Hydrazones/azomethines/imines possess-NHN = CH- and constitute an important class of compounds for new drug development. A number of researchers have synthesized and evaluated the biological activities of hydrazones. This review aims at highlighting the diverse biological activities of hydrazones. PMID:24741273

  12. [Tactile agnosia and dysfunction of the primary somatosensory area. Data of the study by somatosensory evoked potentials in patients with deficits of tactile object recognition].

    PubMed

    Mauguière, F; Isnard, J

    1995-01-01

    The question as to whether a failure of recognition unrelated to impaired sensory processing or to disorder of naming can occur in the somato-sensory modality has been eagerly debated in the french neurology. Taking as an argument the fact that he had never observed a tactile agnosia in the absence of subtle sensory deficits Dejerine denied the localizing value of tactile agnosia (or asterognosis). Conversely Delay, 20 years later, identified tactile performances such as discrimination of texture and shapes, which he considered as a specific neocortical function, that were lost in parietal syndromes with astereognosis and preserved elementary sensations. He also coined the term "tactile asymbolia" to qualify the patients with astereognosis in whom these performances are preserved. When referring to the definition of agnosias only "tactile asymbolia" should be considered as a "true" tactile agnosia. The recording of early somatosensory evoked potentials (SEPs) now offers the possibility of assessing non invasively the function of the primary somatosensory cortex (in particular area 3b). We have recorded SEPs to median nerve or finger stimulation in 309 subjects with a focal hemispheric lesion presenting with a somatosensory deficit of any type. We could confirm that asterognosis referable to impaired discrimination of textures and/or shapes in the absence of impaired elementary sensation is quite rare since it was observed in only 12 of our patients (3.9%). Moreover early cortical SEPs reflecting the activity of the primary somatosensory area (N20 or/and P27) were clearly abnormal in all of them. A single patient of this group of 12 could be considered as a case of tactile asymbolia but his early cortical SEPs were abnormal. The only condition combining a failure of tactile recognition of objects with normal early SEPs is represented by the "tactile anomia" observed in callosal dysconnexions. Thus, in our patients unable to identify objects by palpation in spite of

  13. Concurrent emotional pictures modulate temporal order judgments of spatially separated audio-tactile stimuli.

    PubMed

    Jia, Lina; Shi, Zhuanghua; Zang, Xuelian; Müller, Hermann J

    2013-11-01

    Although attention can be captured toward high-arousal stimuli, little is known about how perceiving emotion in one modality influences the temporal processing of non-emotional stimuli in other modalities. We addressed this issue by presenting observers spatially uninformative emotional pictures while they performed an audio-tactile temporal-order judgment (TOJ) task. In Experiment 1, audio-tactile stimuli were presented at the same location straight ahead of the participants, who had to judge "which modality came first?". In Experiments 2 and 3, the audio-tactile stimuli were delivered one to the left and the other to the right side, and participants had to judge "which side came first?". We found both negative and positive high-arousal pictures to significantly bias TOJs towards the tactile and away from the auditory event when the audio-tactile stimuli were spatially separated; by contrast, there was no such bias when the audio-tactile stimuli originated from the same location. To further examine whether this bias is attributable to the emotional meanings conveyed by the pictures or to their high arousal effect, we compared and contrasted the influences of near-body threat vs. remote threat (emotional) pictures on audio-tactile TOJs in Experiment 3. The bias manifested only in the near-body threat condition. Taken together, the findings indicate that visual stimuli conveying meanings of near-body interaction activate a sensorimotor functional link prioritizing the processing of tactile over auditory signals when these signals are spatially separated. In contrast, audio-tactile signals from the same location engender strong crossmodal integration, thus counteracting modality-based attentional shifts induced by the emotional pictures. PMID:24041776

  14. In Vivo Tactile Stimulation-Evoked Responses in Caenorhabditis elegans Amphid Sheath Glia

    PubMed Central

    Ding, Gang; Zou, Wenjuan; Zhang, Hu; Xue, Yadan; Cai, Yang; Huang, Guifang; Chen, Lufeng; Duan, Shumin; Kang, Lijun

    2015-01-01

    Glial cells are important components of the nervous system. However, how they respond to physiological stimuli in vivo remains largely unknown. In this study, we investigated the electrophysiological activities and Ca2+ responses of the C. elegans amphid sheath glia (AMsh glia) to tactile stimulation in vivo. We recorded robust inward currents and Ca2+ elevation in the AMsh cell with the delivery of tactile stimuli of varying displacements to the nose tip of the worm. Compared to the adjacent mechanoreceptor ASH neuron, the AMsh cell showed greater sensitivity to tactile stimulation. Amiloride, an epithelial Na+ channel blocker, blocked the touch-induced currents and Ca2+ signaling in the ASH neuron, but not those in the AMsh cell. Taken together, our results revealed that AMsh glial cells actively respond to in vivo tactile stimulation and likely function cell-autonomously as mechanoreceptors. PMID:25671616

  15. Neuronal correlates of tactile speed in primary somatosensory cortex.

    PubMed

    Dépeault, Alexandra; Meftah, El-Mehdi; Chapman, C Elaine

    2013-10-01

    Moving stimuli activate all of the mechanoreceptive afferents involved in discriminative touch, but their signals covary with several parameters, including texture. Despite this, the brain extracts precise information about tactile speed, and humans can scale the tangential speed of moving surfaces as long as they have some surface texture. Speed estimates, however, vary with texture: lower estimates for rougher surfaces (increased spatial period, SP). We hypothesized that the discharge of cortical neurons playing a role in scaling tactile speed should covary with speed and SP in the same manner. Single-cell recordings (n = 119) were made in the hand region of primary somatosensory cortex (S1) of awake monkeys while raised-dot surfaces (longitudinal SPs, 2-8 mm; periodic or nonperiodic) were displaced under their fingertips at speeds of 40-105 mm/s. Speed sensitivity was widely distributed (area 3b, 13/25; area 1, 32/51; area 2, 31/43) and almost invariably combined with texture sensitivity (82% of cells). A subset of cells (27/64 fully tested speed-sensitive cells) showed a graded increase in discharge with increasing speed for testing with both sets of surfaces (periodic, nonperiodic), consistent with a role in tactile speed scaling. These cells were almost entirely confined to caudal S1 (areas 1 and 2). None of the speed-sensitive cells, however, showed a pattern of decreased discharge with increased SP, as found for subjective speed estimates in humans. Thus further processing of tactile motion signals, presumably in higher-order areas, is required to explain human tactile speed scaling. PMID:23843433

  16. The Design of Tactile Thematic Symbols

    ERIC Educational Resources Information Center

    Lawrence, Megan M.; Lobben, Amy K.

    2011-01-01

    The study reported here investigated the design and legibility of tactile thematic maps, focusing on symbolization and the comprehension of spatial patterns on the maps. The results indicate that discriminable and effective tactile thematic maps can be produced using classed data with a microcapsule paper production method. The participants…

  17. Misunderstanding and Repair in Tactile Auslan

    ERIC Educational Resources Information Center

    Willoughby, Louisa; Manns, Howard; Iwasaki, Shimako; Bartlett, Meredith

    2014-01-01

    This article discusses ways in which misunderstandings arise in Tactile Australian Sign Language (Tactile Auslan) and how they are resolved. Of particular interest are the similarities to and differences from the same processes in visually signed and spoken conversation. This article draws on detailed conversation analysis (CA) and demonstrates…

  18. A Tactile Response in Staphylococcus aureus

    PubMed Central

    Lower, Steven K.; Yongsunthon, Ruchirej; Casillas-Ituarte, Nadia N.; Taylor, Eric S.; DiBartola, Alex C.; Lower, Brian H.; Beveridge, Terrance J.; Buck, Andrew W.; Fowler, Vance G.

    2010-01-01

    It is well established that bacteria are able to respond to temporal gradients (e.g., by chemotaxis). However, it is widely held that prokaryotes are too small to sense spatial gradients. This contradicts the common observation that the vast majority of bacteria live on the surface of a solid substrate (e.g., as a biofilm). Herein we report direct experimental evidence that the nonmotile bacterium Staphylococcus aureus possesses a tactile response, or primitive sense of touch, that allows it to respond to spatial gradients. Attached cells recognize their substrate interface and localize adhesins toward that region. Braille-like avidity maps reflect a cell's biochemical sensory response and reveal ultrastructural regions defined by the actual binding activity of specific proteins. PMID:21044577

  19. Exploring Youth Cultures Geographically through Active Learning

    ERIC Educational Resources Information Center

    Chacko, Elizabeth

    2005-01-01

    This paper presents strategies for actively involving students in studying cultural geography through a research project on youth cultures. It provides a basic framework to investigate selected "subcultures" focusing on the origin and diffusion of each culture, its material and non-material aspects and the attributes and meanings of spaces used by…

  20. The display of tactile information

    NASA Technical Reports Server (NTRS)

    Sherrick, Carl E.

    1991-01-01

    There are a number of examples of natural tactile displays that can five us some insights about the solid geometry of touch, and recent experimental work on the subject has extended our thinking considerably. The concern of here is, however, more with synthetic or artificial displays for the production of a virtual environment. Features of synthetic displays that have enjoyed some success in one of the following two enterprises are discussed: the study of the spatio-temporal dimensions of stimuli that afford accurate and rapid processing of environmental information, or the use of displays in the design of sensory aids for disabled persons.

  1. Exploring Active Tectonics in the Dominican Republic

    NASA Astrophysics Data System (ADS)

    Carbó-Gorosabel, A.; Córdoba-Barba, D.; Martín-Dívila, J.; Granja-Bruña, J. L.; Llanes Estrada, P.; Muñoz-Martín, A.; ten Brink, U. S.

    2010-07-01

    The devastating 12 January 2010 Haiti earthquake (M = 7.0), which killed an estimated 230,000 people and caused extensive damage to homes and buildings, drew attention to the crucial need for improved knowledge of the active tectonics of the Caribbean region. But even before this disastrous event, interest in understanding the active and complex northeastern Caribbean plate boundary had been increasing, because this region has experienced significant seismic activity during the past century and has an extensively documented record of historical seismicity and tsunamis. Moreover, this is an easily accessible region in which to study the continuity of seismic faults offshore and to try to understand the transitions between strike-slip and convergent tectonic regimes. Interest in the region has led to several studies that have improved scientists' knowledge of subduction zone tectonics and earthquake and tsunami hazard assessments 005BMann et al., 2002; ten Brink et al., 2006, 2009; Grindlay et al., 2005; Manaker et al., 2008; Granja Bruña et al., 2009; Mondziel et al., 2010].

  2. Tactile-emotion synesthesia.

    PubMed

    Ramachandran, V S; Brang, David

    2008-01-01

    We discuss experiments on two individuals in whom specific textures (e.g., denim, wax, sandpaper, silk, etc.) evoked equally distinct emotions (e.g., depression, embarrassment, relief, and contentment, respectively). The test/retest consistency after 8 months was 100%. A video camera recorded subjects' facial expressions and skin conductance responses (SCR) were monitored as they palpated different textures. Evaluators' ratings significantly correlated with the valence of synesthetes' subjective reports, and SCR was significantly enhanced for negative synesthetic emotions. We suggest this effect arises from increased cross-activation between somatosensory cortex and insula for 'basic' emotions and fronto-limbic hyperactivation for more subtle emotions. It may represent an enhancement of pre-existing evolutionarily primitive interactions between touch and emotions. PMID:18821168

  3. Neural correlates associated with superior tactile symmetry perception in the early blind

    PubMed Central

    Hirsch, Gabriella; Cattaneo, Zaira; Vecchi, Tomaso; Merabet, Lotfi B.

    2014-01-01

    Symmetry is an organizational principle that is ubiquitous throughout the visual world. However, this property can also be detected through non-visual modalities such as touch. The role of prior visual experience on detecting tactile patterns containing symmetry remains unclear. We compared the behavioral performance of early blind and sighted (blindfolded) controls on a tactile symmetry detection task. The tactile patterns used were similar in design and complexity as in previous visual perceptual studies. The neural correlates associated with this behavioral task were identified with functional magnetic resonance imaging (fMRI). In line with growing evidence demonstrating enhanced tactile processing abilities in the blind, we found that early blind individuals showed significantly superior performance in detecting tactile symmetric patterns compared to sighted controls. Furthermore, comparing patterns of activation between these two groups identified common areas of activation (e.g. superior parietal cortex) but key differences also emerged. In particular, tactile symmetry detection in the early blind was also associated with activation that included peri-calcarine cortex, lateral occipital (LO), and middle temporal cortex, as well as inferior temporal and fusiform cortex. These results contribute to the growing evidence supporting superior behavioral abilities in the blind, and the neural correlates associated with crossmodal neuroplasticity following visual deprivation. PMID:25243993

  4. Effects of fusion between tactile and proprioceptive inputs on tactile perception.

    PubMed

    Warren, Jay P; Santello, Marco; Helms Tillery, Stephen I

    2011-01-01

    Tactile perception is typically considered the result of cortical interpretation of afferent signals from a network of mechanical sensors underneath the skin. Yet, tactile illusion studies suggest that tactile perception can be elicited without afferent signals from mechanoceptors. Therefore, the extent that tactile perception arises from isomorphic mapping of tactile afferents onto the somatosensory cortex remains controversial. We tested whether isomorphic mapping of tactile afferent fibers onto the cortex leads directly to tactile perception by examining whether it is independent from proprioceptive input by evaluating the impact of different hand postures on the perception of a tactile illusion across fingertips. Using the Cutaneous Rabbit Effect, a well studied illusion evoking the perception that a stimulus occurs at a location where none has been delivered, we found that hand posture has a significant effect on the perception of the illusion across the fingertips. This finding emphasizes that tactile perception arises from integration of perceived mechanical and proprioceptive input and not purely from tactile interaction with the external environment. PMID:21464943

  5. Temporomandibular disorder modifies cortical response to tactile stimulation

    PubMed Central

    Nebel, Mary Beth; Folger, Stephen; Tommerdahl, Mark; Hollins, Mark; McGlone, Francis; Essick, Gregory

    2010-01-01

    Individuals with temporomandibular disorder (TMD) suffer from persistent facial pain and exhibit abnormal sensitivity to tactile stimulation. To better understand the pathophysiological mechanisms underlying TMD, we investigated cortical correlates of this abnormal sensitivity to touch. Using functional magnetic resonance imaging (fMRI), we recorded cortical responses evoked by low frequency vibration of the index finger in subjects with TMD and in healthy controls (HC). Distinct subregions of contralateral SI, SII, and insular cortex responded maximally for each group. Although the stimulus was inaudible, primary auditory cortex was activated in TMDs. TMDs also showed greater activation bilaterally in anterior cingulate cortex and contralaterally in the amygdala. Differences between TMDs and HCs in responses evoked by innocuous vibrotactile stimulation within SI, SII, and the insula paralleled previously reported differences in responses evoked by noxious and innocuous stimulation, respectively, in healthy individuals. This unexpected result may reflect a disruption of the normal balance between central resources dedicated to processing innocuous and noxious input, manifesting itself as increased readiness of the pain matrix for activation by even innocuous input. Activation of the amygdala in our TMD group could reflect the establishment of aversive associations with tactile stimulation due to the persistence of pain. Perspective This article presents evidence that central processing of innocuous tactile stimulation is abnormal in TMD. Understanding the complexity of sensory disruption in chronic pain could lead to improved methods for assessing cerebral cortical function in these patients. PMID:20462805

  6. SII and the fronto-parietal areas are involved in visually cued tactile top-down spatial attention: a functional MRI study.

    PubMed

    Wu, Qiong; Li, Chunlin; Li, Yujie; Sun, Hongzan; Guo, Qiyong; Wu, Jinglong

    2014-04-16

    Visual cue-oriented, tactile top-down attention (vTA) has been well investigated behaviorally. However, vTA-related brain activation remains unclear, and whether SI (primary somatosensory cortex) or SII (secondary somatosensory cortex) is modulated by the top-down process of tactile cognition remains particularly controversial. We used the Posner paradigm in which a visual spatial cue directed attention to a tactile target [tactile spatial attention (TS) task]. The TS is compared with a visual nonspatially cued, tactile attention task [tactile neutral attention (TN) task]. The behavioral results showed no significant differences between the TS and TN tasks. However, we considered the possibility that the visual spatial hint affected the TS neural network. Brain-imaging data showed that the inferior parietal lobe was activated more during the TS task than during the TN task. Furthermore, we present evidence to support SII modulation by top-down processing during the TS task. PMID:24492653

  7. Follicular DEAs for two-way tactile communication

    NASA Astrophysics Data System (ADS)

    Knoop, Lars E.; Rossiter, Jonathan; Assaf, Tareq

    2015-04-01

    Follicular structures in skin combine sensing and actuation in a soft and compliant continuous surface. We have developed a tactile display device inspired by this structure, using a Dielectric Elastomer Actuator (DEA). DEAs allow for combined sensing and actuation, making possible two-way tactile communication between the user and the device. The device can obtain tactile information about the environment, or a user touching it, and it can also present tactile information to the user. We characterise the sensing properties of the tactile display device, and perform classification of tactile stimuli. We demonstrate two-way tactile interaction between a user and the device.

  8. Exploring Group Activity Therapy with Ethnically Diverse Adolescents

    ERIC Educational Resources Information Center

    Paone, Tina R.; Malott, Krista M.; Maldonado, Jose M.

    2008-01-01

    Group activity therapy has been promoted as an effective means of providing growth opportunities for adolescents through the use of structured, developmentally appropriate activities in a group setting. This article qualitatively explores outcomes of 12 sessions of group activity therapy with ethnically diverse adolescents in a school setting. The…

  9. Spaceship EAC - Fostering Activities Relevant to Lunar Exploration and ISRU

    NASA Astrophysics Data System (ADS)

    Cowley, A.; Haefner, T.; Beltzung, J. C.; Meurisse, A.

    2015-10-01

    This presentation would cover the Spaceship EAC initiative, which aims to foster activities within ESA that are relevant to future human spaceflight and lunar exploration. We present our work in the area of regolith processing to date.

  10. Micro-needle electro-tactile display.

    PubMed

    Tezuka, Mayuko; Kitamura, Norihide; Miki, Norihisa

    2015-08-01

    Haptic feedback is strongly demanded for high-precision robot-assisted surgery and teleoperation. The haptic feedback consists of force and tactile feedback, however tactile feedback has been little studied and the size and weight of the system poses challenges for practical applications. In this paper we propose a sheet-type wearable electro-tactile display which provides tactile sensations to the user as the feedback at a low voltage and power consumption. The display possesses needle-shaped electrodes, which can penetrate through the high-impedance stratum corneum. We developed the fabrication process and, as the first step, we investigated the tactile sensation that can be created to the fingertip by the display. Rough and smooth surfaces were successfully presented to the user. Then, we characterized the tactile display when used on the forearm, in particular, with respect to the spatial resolution. These tactile displays can be used to inform the user of the surface property of the parts of interest, such as tumor tissues, and to guide him in the manipulation of surgery robots. PMID:26737606

  11. Spatial references and audio-tactile interaction in cross-modal dynamic capture.

    PubMed

    Chen, Lihan; Wang, Qingcui; Bao, Ming

    2014-01-01

    In audiotactile dynamic capture, judgment of the direction of an apparent motion stream (such as auditory motion) was impeded (hence 'captured') by the presentation of a concurrent, but directionally opposite apparent motion stream (such as tactile motion) from a distractor modality, leading to a cross-modal dynamic capture (CDC) effect. That is to say, the percentage of correct reporting of the direction of the target motion was reduced. Previous studies have revealed the effect of stimulus onset asynchronies (SOAs) and the potential spatial remapping (by adopting a cross-hands posture) in CDC. However, further exploration of the dynamic capture process under different postures was not available due to the fact that only two levels of time asynchronies were employed (either synchronous or with an SOA of 500 ms). This study introduced a broad range of SOAs (-400 ms to 400 ms, tactile stream preceded auditory stream or vice versa) to explore the time course of audio-tactile interaction in CDC with two spatial references--arms-uncrossed or arms-crossed postures. Participants judged the direction of auditory apparent motion with tactile distractors. The results showed that in the arms-uncrossed condition, the CDC effect was prominent when the auditory-tactile events were in the temporal integration window (0-60 ms). However, with a preceding tactile cueing effect of SOA equal to and above 150 ms, the CDC effect was reduced, and no CDC effect was observed with the arms-crossed posture. These results suggest CDC effect is modulated by both cross-modal interaction and the spatial reference (especially for the distractors). The magnitude of the CDC effects in audiotactile interaction may be accounted for by reliability of tactile spatial-temporal information. PMID:25102666

  12. Auditory and tactile signals combine to influence vision during binocular rivalry.

    PubMed

    Lunghi, Claudia; Morrone, Maria Concetta; Alais, David

    2014-01-15

    Resolution of perceptual ambiguity is one function of cross-modal interactions. Here we investigate whether auditory and tactile stimuli can influence binocular rivalry generated by interocular temporal conflict in human subjects. Using dichoptic visual stimuli modulating at different temporal frequencies, we added modulating sounds or vibrations congruent with one or the other visual temporal frequency. Auditory and tactile stimulation both interacted with binocular rivalry by promoting dominance of the congruent visual stimulus. This effect depended on the cross-modal modulation strength and was absent when modulation depth declined to 33%. However, when auditory and tactile stimuli that were too weak on their own to bias binocular rivalry were combined, their influence over vision was very strong, suggesting the auditory and tactile temporal signals combined to influence vision. Similarly, interleaving discrete pulses of auditory and tactile stimuli also promoted dominance of the visual stimulus congruent with the supramodal frequency. When auditory and tactile stimuli were presented at maximum strength, but in antiphase, they had no influence over vision for low temporal frequencies, a null effect again suggesting audio-tactile combination. We also found that the cross-modal interaction was frequency-sensitive at low temporal frequencies, when information about temporal phase alignment can be perceptually tracked. These results show that auditory and tactile temporal processing is functionally linked, suggesting a common neural substrate for the two sensory modalities and that at low temporal frequencies visual activity can be synchronized by a congruent cross-modal signal in a frequency-selective way, suggesting the existence of a supramodal temporal binding mechanism. PMID:24431437

  13. Introducing the tactile speller: an ERP-based brain-computer interface for communication

    NASA Astrophysics Data System (ADS)

    van der Waal, Marjolein; Severens, Marianne; Geuze, Jeroen; Desain, Peter

    2012-08-01

    In this study, a tactile speller was developed and compared with existing visual speller paradigms in terms of classification performance and elicited event-related potentials (ERPs). The fingertips of healthy participants were stimulated with short mechanical taps while electroencephalographic activity was measured. The letters of the alphabet were allocated to different fingers and subjects could select one of the fingers by silently counting the number of taps on that finger. The offline and online performance of the tactile speller was compared to the overt and covert attention visual matrix speller and the covert attention Hex-o-Spell speller. For the tactile speller, binary target versus non-target classification accuracy was 67% on average. Classification and decoding accuracies of the tactile speller were lower than the overt matrix speller, but higher than the covert matrix speller, and similar to Hex-o-Spell. The average maximum information transfer rate of the tactile speller was 7.8 bits min-1 (1.51 char min-1), with the best subject reaching a bit-rate of 27 bits min-1 (5.22 char min-1). An increased amplitude of the P300 ERP component was found in response to attended stimuli versus unattended stimuli in all speller types. In addition, the tactile and overt matrix spellers also used the N2 component for discriminating between targets and non-targets. Overall, this study shows that it is possible to use a tactile speller for communication. The tactile speller provides a useful alternative to the visual speller, especially for people whose eye gaze is impaired.

  14. Nano opto-mechanical systems (NOMS) as a proposal for tactile displays

    NASA Astrophysics Data System (ADS)

    Campo, E. M.; Roig, J.; Roeder, B.; Wenn, D.; Mamojka, B.; Omastova, M.; Terentjev, E. M.; Esteve, J.

    2011-10-01

    For over a decade, special emphasis has been placed in the convergence of different fields of science and technology, in an effort to serve human needs by way of enhancing human capabilities. The convergence of the Nano-Bio-Info-Cogni (NBIC) quartet will provide unique solutions to specific needs. This is the case of, Nano-opto mechanical Systems (NOMS), presented as a solution to tactile perception, both for the visually-impaired and for the general public. NOMS, based on photoactive polymer actuators and devices, is a much sought-after technology. In this scheme, light sources promote mechanical actuation producing a variety of nano-opto mechanical systems such as nano-grippers. In this paper, we will provide a series of specifications that the NOMS team is targeting towards the development of a tactile display using optically-activated smart materials. Indeed, tactile displays remain mainly mechanical, compromising reload speeds and resolution which inhibit 3D tactile representation of web interfaces. We will also discuss how advantageous NOMS tactile displays could be for the general public. Tactile processing based on stimulation delivered through the NOMS tablet, will be tested using neuropsychology methods, in particular event-related brain potentials. Additionally, the NOMS tablet will be instrumental to the development of basic neuroscience research.

  15. Tactile displays for enhanced performance and safety

    NASA Astrophysics Data System (ADS)

    Castle, Heidi; Dobbins, Trevor D.

    2004-09-01

    Platform performance and safety are dependent on operator situational awareness. This is traditionally achieved via visual and audio displays but an intuitive alternative is the tactile display. A familiar tactile display is the vibrating alert function of the mobile telephone but more complex tactile display applications have been demonstrated in a number of scenarios, including fixed and rotary wing aircraft, high-speed boats, diving, and assisting the visually impaired. The major applications include orientation, navigation, and communication. A recent NATO Research & Technology Organisation symposium on spatial disorientation (La Coruna, Spain, 2002) stated that; 'The most important advance of recent years with the potential to combat spatial disorientation has been the use of tactile stimuli to give information on spatial orientation'.

  16. A Measurement Activity to Encourage Exploration of Calculus Concepts

    ERIC Educational Resources Information Center

    McGuffey, William

    2015-01-01

    This article describes an activity that incorporates measurement in order to lead students to discover and explore fundamental concepts of calculus. Students are provided with an experientially real starting point involving measurement and are encouraged to engage in mathematical discussions in a low-stakes environment. I describe the activity as…

  17. Ubiquitous Crossmodal Stochastic Resonance in Humans: Auditory Noise Facilitates Tactile, Visual and Proprioceptive Sensations

    PubMed Central

    Lugo, Eduardo; Doti, Rafael; Faubert, Jocelyn

    2008-01-01

    Background Stochastic resonance is a nonlinear phenomenon whereby the addition of noise can improve the detection of weak stimuli. An optimal amount of added noise results in the maximum enhancement, whereas further increases in noise intensity only degrade detection or information content. The phenomenon does not occur in linear systems, where the addition of noise to either the system or the stimulus only degrades the signal quality. Stochastic Resonance (SR) has been extensively studied in different physical systems. It has been extended to human sensory systems where it can be classified as unimodal, central, behavioral and recently crossmodal. However what has not been explored is the extension of this crossmodal SR in humans. For instance, if under the same auditory noise conditions the crossmodal SR persists among different sensory systems. Methodology/Principal Findings Using physiological and psychophysical techniques we demonstrate that the same auditory noise can enhance the sensitivity of tactile, visual and propioceptive system responses to weak signals. Specifically, we show that the effective auditory noise significantly increased tactile sensations of the finger, decreased luminance and contrast visual thresholds and significantly changed EMG recordings of the leg muscles during posture maintenance. Conclusions/Significance We conclude that crossmodal SR is a ubiquitous phenomenon in humans that can be interpreted within an energy and frequency model of multisensory neurons spontaneous activity. Initially the energy and frequency content of the multisensory neurons' activity (supplied by the weak signals) is not enough to be detected but when the auditory noise enters the brain, it generates a general activation among multisensory neurons of different regions, modifying their original activity. The result is an integrated activation that promotes sensitivity transitions and the signals are then perceived. A physiologically plausible model for

  18. Tactile imaging of palpable breast cancer

    NASA Astrophysics Data System (ADS)

    Srikanchana, Rujirutana; Wang, Yue J.; Freedman, Matthew T.; Nguyen, Charles C.

    2002-05-01

    This paper presents the development of a prototype Tactile Mapping Device (TMD) system comprised mainly of a tactile sensor array probe (TSAP), a 3-D camera, and a force/torque sensor, which can provide the means to produce tactile maps of the breast lumps during a breast palpation. Focusing on the key tactile topology features for breast palpation such as spatial location, size/shape of the detected lesion, and the force levels used to demonstrate the palpable abnormalities, these maps can record the results of clinical breast examination with a set of pressure distribution profiles and force sensor measurements due to detected lesion. By combining the knowledge of vision based, neural networks and tactile sensing technology; the TMD is integrated for the investigation of soft tissue interaction with tactile/force sensor, where the hard inclusion (breast cancer) can be characterized through neural network learning capability, instead of using simplified complex biomechanics model with many heuristic assumptions. These maps will serve as an objective documentation of palpable lesions for future comparative examinations. Preliminary results of simulated experiments and limited pre-clinical evaluations of the TMD prototype have tested this hypothesis and provided solid promising data showing the feasibility of the TMD in real clinical applications.

  19. Piezoresistive Tactile Sensor Discriminating Multidirectional Forces.

    PubMed

    Jung, Youngdo; Lee, Duck-Gyu; Park, Jonghwa; Ko, Hyunhyub; Lim, Hyuneui

    2015-01-01

    Flexible tactile sensors capable of detecting the magnitude and direction of the applied force together are of great interest for application in human-interactive robots, prosthetics, and bionic arms/feet. Human skin contains excellent tactile sensing elements, mechanoreceptors, which detect their assigned tactile stimuli and transduce them into electrical signals. The transduced signals are transmitted through separated nerve fibers to the central nerve system without complicated signal processing. Inspired by the function and organization of human skin, we present a piezoresistive type tactile sensor capable of discriminating the direction and magnitude of stimulations without further signal processing. Our tactile sensor is based on a flexible core and four sidewall structures of elastomer, where highly sensitive interlocking piezoresistive type sensing elements are embedded. We demonstrate the discriminating normal pressure and shear force simultaneously without interference between the applied forces. The developed sensor can detect down to 128 Pa in normal pressure and 0.08 N in shear force, respectively. The developed sensor can be applied in the prosthetic arms requiring the restoration of tactile sensation to discriminate the feeling of normal and shear force like human skin. PMID:26445045

  20. Piezoresistive Tactile Sensor Discriminating Multidirectional Forces

    PubMed Central

    Jung, Youngdo; Lee, Duck-Gyu; Park, Jonghwa; Ko, Hyunhyub; Lim, Hyuneui

    2015-01-01

    Flexible tactile sensors capable of detecting the magnitude and direction of the applied force together are of great interest for application in human-interactive robots, prosthetics, and bionic arms/feet. Human skin contains excellent tactile sensing elements, mechanoreceptors, which detect their assigned tactile stimuli and transduce them into electrical signals. The transduced signals are transmitted through separated nerve fibers to the central nerve system without complicated signal processing. Inspired by the function and organization of human skin, we present a piezoresistive type tactile sensor capable of discriminating the direction and magnitude of stimulations without further signal processing. Our tactile sensor is based on a flexible core and four sidewall structures of elastomer, where highly sensitive interlocking piezoresistive type sensing elements are embedded. We demonstrate the discriminating normal pressure and shear force simultaneously without interference between the applied forces. The developed sensor can detect down to 128 Pa in normal pressure and 0.08 N in shear force, respectively. The developed sensor can be applied in the prosthetic arms requiring the restoration of tactile sensation to discriminate the feeling of normal and shear force like human skin. PMID:26445045

  1. Feeling Music: Integration of Auditory and Tactile Inputs in Musical Meter Perception

    PubMed Central

    Huang, Juan; Gamble, Darik; Sarnlertsophon, Kristine; Wang, Xiaoqin

    2014-01-01

    Musicians often say that they not only hear, but also “feel” music. To explore the contribution of tactile information in “feeling” musical rhythm, we investigated the degree that auditory and tactile inputs are integrated in humans performing a musical meter recognition task. Subjects discriminated between two types of sequences, ‘duple’ (march-like rhythms) and ‘triple’ (waltz-like rhythms) presented in three conditions: 1) Unimodal inputs (auditory or tactile alone), 2) Various combinations of bimodal inputs, where sequences were distributed between the auditory and tactile channels such that a single channel did not produce coherent meter percepts, and 3) Simultaneously presented bimodal inputs where the two channels contained congruent or incongruent meter cues. We first show that meter is perceived similarly well (70%–85%) when tactile or auditory cues are presented alone. We next show in the bimodal experiments that auditory and tactile cues are integrated to produce coherent meter percepts. Performance is high (70%–90%) when all of the metrically important notes are assigned to one channel and is reduced to 60% when half of these notes are assigned to one channel. When the important notes are presented simultaneously to both channels, congruent cues enhance meter recognition (90%). Performance drops dramatically when subjects were presented with incongruent auditory cues (10%), as opposed to incongruent tactile cues (60%), demonstrating that auditory input dominates meter perception. We believe that these results are the first demonstration of cross-modal sensory grouping between any two senses. PMID:23716252

  2. Feeling Music: Integration of Auditory and Tactile Inputs in Musical Meter Perception

    PubMed Central

    Huang, Juan; Gamble, Darik; Sarnlertsophon, Kristine

    2012-01-01

    Musicians often say that they not only hear, but also “feel” music. To explore the contribution of tactile information in “feeling” musical rhythm, we investigated the degree that auditory and tactile inputs are integrated in humans performing a musical meter recognition task. Subjects discriminated between two types of sequences, ‘duple’ (march-like rhythms) and ‘triple’ (waltz-like rhythms) presented in three conditions: 1) Unimodal inputs (auditory or tactile alone), 2) Various combinations of bimodal inputs, where sequences were distributed between the auditory and tactile channels such that a single channel did not produce coherent meter percepts, and 3) Simultaneously presented bimodal inputs where the two channels contained congruent or incongruent meter cues. We first show that meter is perceived similarly well (70%–85%) when tactile or auditory cues are presented alone. We next show in the bimodal experiments that auditory and tactile cues are integrated to produce coherent meter percepts. Performance is high (70%–90%) when all of the metrically important notes are assigned to one channel and is reduced to 60% when half of these notes are assigned to one channel. When the important notes are presented simultaneously to both channels, congruent cues enhance meter recognition (90%). Performance drops dramatically when subjects were presented with incongruent auditory cues (10%), as opposed to incongruent tactile cues (60%), demonstrating that auditory input dominates meter perception. We believe that these results are the first demonstration of cross-modal sensory grouping between any two senses. PMID:23119038

  3. Tactile display landing safety and precision improvements for the Space Shuttle

    NASA Astrophysics Data System (ADS)

    Olson, John M.

    A tactile display belt using 24 electro-mechanical tactile transducers (tactors) was used to determine if a modified tactile display system, known as the Tactile Situation Awareness System (TSAS) improved the safety and precision of a complex spacecraft (i.e. the Space Shuttle Orbiter) in guided precision approaches and landings. The goal was to determine if tactile cues enhance safety and mission performance through reduced workload, increased situational awareness (SA), and an improved operational capability by increasing secondary cognitive workload capacity and human-machine interface efficiency and effectiveness. Using both qualitative and quantitative measures such as NASA's Justiz Numerical Measure and Synwork1 scores, an Overall Workload (OW) measure, the Cooper-Harper rating scale, and the China Lake Situational Awareness scale, plus Pre- and Post-Flight Surveys, the data show that tactile displays decrease OW, improve SA, counteract fatigue, and provide superior warning and monitoring capacity for dynamic, off-nominal, high concurrent workload scenarios involving complex, cognitive, and multi-sensory critical scenarios. Use of TSAS for maintaining guided precision approaches and landings was generally intuitive, reduced training times, and improved task learning effects. Ultimately, the use of a homogeneous, experienced, and statistically robust population of test pilots demonstrated that the use of tactile displays for Space Shuttle approaches and landings with degraded vehicle systems, weather, and environmental conditions produced substantial improvements in safety, consistency, reliability, and ease of operations under demanding conditions. Recommendations for further analysis and study are provided in order to leverage the results from this research and further explore the potential to reduce the risk of spaceflight and aerospace operations in general.

  4. Auditory, tactile, and audiotactile information processing following visual deprivation.

    PubMed

    Occelli, Valeria; Spence, Charles; Zampini, Massimiliano

    2013-01-01

    We highlight the results of those studies that have investigated the plastic reorganization processes that occur within the human brain as a consequence of visual deprivation, as well as how these processes give rise to behaviorally observable changes in the perceptual processing of auditory and tactile information. We review the evidence showing that visual deprivation affects the establishment of the spatial coordinate systems involved in the processing of auditory and tactile inputs within the peripersonal space around an individual. In blind individuals, the absence of a conjoint activation of external coordinate systems across modalities co-occurs with a higher capacity to direct auditory and tactile attentional resources to different spatial locations and to ignore irrelevant distractors. Both processes could thus contribute to the reduced spatial multisensory binding that has been observed in those who are blind. The interplay between auditory and tactile information in visually deprived individuals is modulated by attentional factors. Blind individuals typically outperform sighted people in those tasks where the target is presented in one sensory modality (and the other modality acts as a distractor). By contrast, they are less efficient in tasks explicitly requiring the combination of information across sensory modalities. The review highlights how these behavioral effects are subserved by extensive plastic changes at the neural level, with brain areas traditionally involved in visual functioning switching and being recruited for the processing of stimuli within the intact residual senses. We also discuss the roles played by other intervening factors with regard to compensatory mechanisms, such as previous visual experience, age at onset of blindness, and learning effects. PMID:22612281

  5. Scalable, MEMS-enabled, vibrational tactile actuators for high resolution tactile displays

    NASA Astrophysics Data System (ADS)

    Xie, Xin; Zaitsev, Yuri; Velásquez-García, Luis Fernando; Teller, Seth J.; Livermore, Carol

    2014-12-01

    The design, fabrication, and characterization of a new type of tactile display for people with blindness or low vision is reported. Each tactile element comprises a piezoelectric extensional actuator that vibrates in plane, with a microfabricated scissor mechanism to convert the in-plane actuations into robust, higher-amplitude, out-of-plane (vertical) vibrations that are sensed with the finger pads. When the tactile elements are formed into a 2D array, information can be conveyed to the user by varying the pattern of vibrations in space and time. Analytical models and finite element analysis were used to design individual tactile elements, which were implemented with PZT actuators and both SU-8 and 3D-printed scissor amplifiers. The measured displacements of these 3 mm × 10 mm, MEMS-enabled tactile elements exceed 10 µm, in agreement with models, with measured forces exceeding 45 mN. The performance of the MEMS-enabled tactile elements is compared with the performance of larger, fully-macroscale tactile elements to demonstrate the scale dependence of the devices. The creation of a 28-element prototype is also reported, and the qualitative user experience with the individual tactile elements and displays is described.

  6. Update on petroleum exploration activities in the Philippines

    SciTech Connect

    Salcedo, B.H.C.; Bausa, G.J.G.; Ocampo. I.U.

    1996-12-31

    The first significant event in Philippine Petroleum exploration dates back to 1896 with the drilling of Toledo-1 in Cebu by Smith & Bell. From the 1950`s to the 1970`s, widespread exploration activities were carried out but it was only eighty years after the first oil drilling in 1896 that oil was finally discovered in commercial quantity in Northwest Palawan. This could be attributed to the fact that serious exploration for petroleum was made with the enactment of Presidential Decree No. 87, better known as the {open_quotes}Oil Exploration and Development Act of 1972{close_quotes}, which takes into effect the current Service Contract System. Amendments to P.D. No. 87 is underway to further improve its incentive package and make it more attractive to explorationists. Petroleum exploration in the Philippines continues to be an energetic industry even if the players are not always rewarded with finds. Frontier areas have become attractive for exploration in view of the continuing research studies resulting to increased database thereat. While Northwest Palawan continues to be the hub of action, frontier areas as well as the more risky deepwater acreages still generate interests, if one wishes to be an active player in a growing energy-hungry economy.

  7. Update on petroleum exploration activities in the Philippines

    SciTech Connect

    Salcedo, B.H.C.; Bausa, G.J.G.; Ocampo. I.U.

    1996-01-01

    The first significant event in Philippine Petroleum exploration dates back to 1896 with the drilling of Toledo-1 in Cebu by Smith Bell. From the 1950's to the 1970's, widespread exploration activities were carried out but it was only eighty years after the first oil drilling in 1896 that oil was finally discovered in commercial quantity in Northwest Palawan. This could be attributed to the fact that serious exploration for petroleum was made with the enactment of Presidential Decree No. 87, better known as the [open quotes]Oil Exploration and Development Act of 1972[close quotes], which takes into effect the current Service Contract System. Amendments to P.D. No. 87 is underway to further improve its incentive package and make it more attractive to explorationists. Petroleum exploration in the Philippines continues to be an energetic industry even if the players are not always rewarded with finds. Frontier areas have become attractive for exploration in view of the continuing research studies resulting to increased database thereat. While Northwest Palawan continues to be the hub of action, frontier areas as well as the more risky deepwater acreages still generate interests, if one wishes to be an active player in a growing energy-hungry economy.

  8. Investigating Visual-Tactile Interactions over Time and Space in Adults with Autism

    ERIC Educational Resources Information Center

    Poole, Daniel; Gowen, Emma; Warren, Paul A.; Poliakoff, Ellen

    2015-01-01

    It has been suggested that the sensory symptoms which affect many people with autism spectrum conditions (ASC) may be related to alterations in multisensory processing. Typically, the likelihood of interactions between the senses increases when information is temporally and spatially coincident. We explored visual-tactile interactions in adults…

  9. Comparing Tactile Maps and Haptic Digital Representations of a Maritime Environment

    ERIC Educational Resources Information Center

    Simonnet, Mathieu; Vieilledent, Steephane; Jacobson, R. Daniel; Tisseau, Jacques

    2011-01-01

    A map exploration and representation exercise was conducted with participants who were totally blind. Representations of maritime environments were presented either with a tactile map or with a digital haptic virtual map. We assessed the knowledge of spatial configurations using a triangulation technique. The results revealed that both types of…

  10. A Population-Based Twin Study of Parentally Reported Tactile and Auditory Defensiveness in Young Children

    ERIC Educational Resources Information Center

    Goldsmith, H. H.; Van Hulle, C. A.; Arneson, C. L.; Schreiber, J. E.; Gernsbacher, M. A.

    2006-01-01

    Some adults and children exhibit defensive behaviors to tactile or auditory stimulation. These symptoms occur not only in subsets of children with ADHD, autism, and Fragile X syndrome, but also in the apparent absence of accompanying disorders. Relatively little research explores the correlates and antecedents of sensory defensiveness. Using a…

  11. Incrementally learning objects by touch: online discriminative and generative models for tactile-based recognition.

    PubMed

    Soh, Harold; Demiris, Yiannis

    2014-01-01

    Human beings not only possess the remarkable ability to distinguish objects through tactile feedback but are further able to improve upon recognition competence through experience. In this work, we explore tactile-based object recognition with learners capable of incremental learning. Using the sparse online infinite Echo-State Gaussian process (OIESGP), we propose and compare two novel discriminative and generative tactile learners that produce probability distributions over objects during object grasping/palpation. To enable iterative improvement, our online methods incorporate training samples as they become available. We also describe incremental unsupervised learning mechanisms, based on novelty scores and extreme value theory, when teacher labels are not available. We present experimental results for both supervised and unsupervised learning tasks using the iCub humanoid, with tactile sensors on its five-fingered anthropomorphic hand, and 10 different object classes. Our classifiers perform comparably to state-of-the-art methods (C4.5 and SVM classifiers) and findings indicate that tactile signals are highly relevant for making accurate object classifications. We also show that accurate "early" classifications are possible using only 20-30 percent of the grasp sequence. For unsupervised learning, our methods generate high quality clusterings relative to the widely-used sequential k-means and self-organising map (SOM), and we present analyses into the differences between the approaches. PMID:25532151

  12. Optimizing the tactile display of physiological information: vibro-tactile vs. electro-tactile stimulation, and forearm or wrist location.

    PubMed

    Ng, G; Barralon, P; Dumont, G; Schwarz, S K W; Ansermino, J M

    2007-01-01

    Anesthesiologists use physiological data monitoring systems with visual and auditory displays of information to monitor patients in the operating room (OR). The efficacy of visual-audio systems may impose an increase in patient risk when the demand for constant switching of attention between the patient and the visual monitoring system is high. This is evidenced by auditory alarms frequently being neglected in a noisy OR environment. Hence, the use of a complementary patient data monitoring system, which utilizes other sensory modalities, could be of great value. In this paper, we describe a series of experiments designed to determine the performances of a tactile display that could be used to convey patient's physiological information to the attending anesthesiologist. We tested both vibro-tactile and electro-tactile display prototypes in their ability to convey information using an alert scheme of four distinct tactile stimuli. Using pseudo-clinical data, the display was designed, for example, to provide an alert when a change in the monitored heart rate occurred. Based on previous research in human physiology and psychophysics, we selected the forearm and wrist of the user's non-dominant hand as the stimulation site. In our study of 30 subjects, we evaluated the response time and accuracy of tactile pattern recognition to compare (1) the performance of a vibro-tactile display on the forearm (VF) and an electro-tactile display on the forearm (EF), and (2) the localization of stimulation between the forearm (VF) and a vibro-tactile display on the wrist (VW). A post-study questionnaire was completed by each subject to assess the comfort and usability of the three prototypes. We found that both VF and VW were superior to the EF in both accuracy and comfort and, that there were no differences between the wrist and the forearm. In conclusion, the tactile-display prototypes designed to alert the clinician of adverse changes in a patient's physiological state

  13. Hand tactile discrimination, social touch and frailty criteria in elderly people: A cross sectional observational study.

    PubMed

    Vieira, Ana Isabel; Nogueira, Dália; de Azevedo Reis, Elisabeth; da Lapa Rosado, Maria; Vânia Nunes, Maria; Castro-Caldas, Alexandre

    2016-01-01

    Frailty is a common syndrome among elderly and sensory decline may exacerbate functional decline. The hand function, the manual dexterity, the performance of the daily living skills and the social interactions are determined, in a large degree, by sensory integrity. However, hand tactile sensory deterioration has been little explored in frailty. We performed a cross sectional observational study with 181 of institutionalized elders. From the initial sample we selected 50 subjects (68-99 years) who met the inclusion/exclusion criteria. Our goals were (1) to analyse the relationship between tactile discrimination (TD) of the hand, avoidance behaviours and attitudes towards social touch (BATST) and phenotype frailty criteria (unintentional weight loss, self-perception of exhaustion, decrease grip strength - GS, slow walking speed, low level of physical activity), (2) to explore whether other variables can contribute to explain the differences between pre-frail and frail elders. The results showed that increasing age is related to decline of TD of the hand (p=0.021) and to decrease in GS (p=0.025); women have significantly lower level of GS (p=0.001); TD decrease is correlated with higher avoidance BATST (p=0.000) and with lower GS (p=0.000); Lower GS corresponds to more avoidance BATST (p=0.003). Hand TD also can differentiate frail and pre-frail elderly subjects in this sample (p=0.037). Decreased TD of the hand may have implications on the functionality and on interpersonal relationships. TD of the hand also explains frailty levels in this sample. Hand TD should be used in assessment and intervention protocols in pre-frail and frail elders. PMID:27259030

  14. A critical experimental study of the classical tactile threshold theory

    PubMed Central

    2010-01-01

    Background The tactile sense is being used in a variety of applications involving tactile human-machine interfaces. In a significant number of publications the classical threshold concept plays a central role in modelling and explaining psychophysical experimental results such as in stochastic resonance (SR) phenomena. In SR, noise enhances detection of sub-threshold stimuli and the phenomenon is explained stating that the required amplitude to exceed the sensory threshold barrier can be reached by adding noise to a sub-threshold stimulus. We designed an experiment to test the validity of the classical vibrotactile threshold. Using a second choice experiment, we show that individuals can order sensorial events below the level known as the classical threshold. If the observer's sensorial system is not activated by stimuli below the threshold, then a second choice could not be above the chance level. Nevertheless, our experimental results are above that chance level contradicting the definition of the classical tactile threshold. Results We performed a three alternative forced choice detection experiment on 6 subjects asking them first and second choices. In each trial, only one of the intervals contained a stimulus and the others contained only noise. According to the classical threshold assumptions, a correct second choice response corresponds to a guess attempt with a statistical frequency of 50%. Results show an average of 67.35% (STD = 1.41%) for the second choice response that is not explained by the classical threshold definition. Additionally, for low stimulus amplitudes, second choice correct detection is above chance level for any detectability level. Conclusions Using a second choice experiment, we show that individuals can order sensorial events below the level known as a classical threshold. If the observer's sensorial system is not activated by stimuli below the threshold, then a second choice could not be above the chance level. Nevertheless, our

  15. Tactile display with dielectric multilayer elastomer actuatorsq

    NASA Astrophysics Data System (ADS)

    Matysek, Marc; Lotz, Peter; Schlaak, Helmut F.

    2009-03-01

    Tactile perception is the human sensation of surface textures through the vibrations generated by stroking a finger over the surface. The skin responds to several distributed physical quantities. Perhaps the most important are high-frequency vibrations, pressure distributions (static shape) and thermal properties. The integration of tactile displays in man-machine interfaces promises a more intuitive handling. For this reason many tactile displays are developed using different technologies. We present several state-of-the-art tactile displays based on different types of dielectric elastomer actuators to clarify the advantages of our matrix display based on multilayer technology. Using this technology perpendicular and hexagonal arrays of actuator elements (tactile stimulators) can be integrated into a PDMS substrate. Element diameters down to 1 mm allow stimuli at the range of the human two-point-discrimination threshold. Driving the elements by column and row addressing enables various stimulation patterns with a reduced number of feeding lines. The transient analysis determines charging times of the capacitive actuators depending on actuator geometry and material parameters. This is very important to ensure an adequate dynamic characteristic of the actuators to stimulate the human skin by vibrations. The suitability of multilayer dielectric elastomer actuators for actuation in tactile displays has been determined. Beside the realization of a static tactile display - where multilayer DEA are integrated as drives for movable contact pins - we focus on the direct use of DEA as a vibrotactile display. Finally, we present the scenario and achieved results of a recognition threshold test. Even relative low voltages in the range of 800 V generate vibrations with 100% recognition ratio within the group of participants. Furthermore, the frequency dependent characteristic of the determined recognition threshold confirms with established literature.

  16. Ambiguity in Tactile Apparent Motion Perception

    PubMed Central

    Liaci, Emanuela; Bach, Michael; Tebartz van Elst, Ludger; Heinrich, Sven P.; Kornmeier, Jürgen

    2016-01-01

    Background In von Schiller’s Stroboscopic Alternative Motion (SAM) stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio (“AR”, i.e. the relation between vertical and horizontal dot distances). Further, with equal horizontal and vertical dot distances (AR = 1) perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion. Methods We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants’ forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames. Results Increasing the tactile SAM’s AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias. Discussion Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual

  17. A data glove with tactile feedback for FMRI of virtual reality experiments.

    PubMed

    Ku, Jeonghun; Mraz, Richard; Baker, Nicole; Zakzanis, Konstantine K; Lee, Jang Han; Kim, In Y; Kim, Sun I; Graham, Simon J

    2003-10-01

    Virtual reality (VR) technology is increasingly recognized as a useful tool for the assessment and rehabilitation of neurologic and psychiatric disorders. The hope that VR can accurately mimic real-life events is also of great interest in basic neuroscience, to identify the brain activity that underlies complex behavior by combining VR with techniques such as functional magnetic resonance imaging (fMRI). Toward these applications, in this study we designed and validated an fMRI-compatible data glove with a built-in vibratory stimulus device for tactile feedback during VR experiments. A simple VR-fMRI experiment was performed at 3.0 Tesla on four young healthy adults involving touching a virtual object with and without tactile feedback. The usefulness of the data glove was subsequently assessed using a series of questionnaires, behavioral performance, and the resulting activation images. Questionnaire scores indicated positive opinions with respect to the data glove, the tactile feedback, and the experimental paradigm. All subjects felt comfortable in the scanner during the VR experiment and were able to perform all aspects of the tasks successfully and with reasonable accuracy. In addition, activation maps showed the anticipated modulations in motor, somatosensory, and parietal cortex. These results support that tactile feedback enhances the realism of virtual hand-object interactions, and that the tactile data glove is suitable for use in other VR-fMRI research applications (e.g., VR physical therapy for stroke recovery). PMID:14583125

  18. Mars Exploration Rover Operations with the Science Activity Planner

    NASA Technical Reports Server (NTRS)

    Jeffrey S. Norris; Powell, Mark W.; Vona, Marsette A.; Backes, Paul G.; Wick, Justin V.

    2005-01-01

    The Science Activity Planner (SAP) is the primary science operations tool for the Mars Exploration Rover mission and NASA's Software of the Year for 2004. SAP utilizes a variety of visualization and planning capabilities to enable the mission operations team to direct the activities of the Spirit and Opportunity rovers. This paper outlines some of the challenging requirements that drove the design of SAP and discusses lessons learned from the development and use of SAP in mission operations.

  19. Collaborative Human Engineering Work in Space Exploration Extravehicular Activities (EVA)

    NASA Technical Reports Server (NTRS)

    DeSantis, Lena; Whitmore, Mihriban

    2007-01-01

    A viewgraph presentation on extravehicular activities in space exploration in collaboration with other NASA centers, industries, and universities is shown. The topics include: 1) Concept of Operations for Future EVA activities; 2) Desert Research and Technology Studies (RATS); 3) Advanced EVA Walkback Test; 4) Walkback Subjective Results; 5) Integrated Suit Test 1; 6) Portable Life Support Subsystem (PLSS); 7) Flex PLSS Design Process; and 8) EVA Information System; 9)

  20. Exploring a Monetary Union among Nations through Active Learning

    ERIC Educational Resources Information Center

    Goma, Ophelia D.

    2002-01-01

    This article presents a classroom project that employs various techniques of active learning including role-playing, collaborative group work and writing. The project explores the recent creation of the European Monetary Union (EMU) with special emphasis on the introduction of the euro. The project assumes that the Americas have begun preliminary…

  1. Exploring the Greenhouse Effect through Physics-Oriented Activities

    ERIC Educational Resources Information Center

    Browne, Kerry P.; Laws, Priscilla W.

    2003-01-01

    We are developing a new activity-based unit on global warming and the environment as part of the "Explorations in Physics Curriculum." We describe the current status of this unit, which focuses on helping students understand the greenhouse effect and its relationship to global warming. We outline several problems encountered in testing the unit…

  2. Millisecond Precision Spike Timing Shapes Tactile Perception

    PubMed Central

    Mackevicius, Emily L.; Best, Matthew D.; Saal, Hannes P.

    2012-01-01

    In primates, the sense of touch has traditionally been considered to be a spatial modality, drawing an analogy to the visual system. In this view, stimuli are encoded in spatial patterns of activity over the sheet of receptors embedded in the skin. We propose that the spatial processing mode is complemented by a temporal one. Indeed, the transduction and processing of complex, high-frequency skin vibrations have been shown to play an important role in tactile texture perception, and the frequency composition of vibrations shapes the evoked percept. Mechanoreceptive afferents innervating the glabrous skin exhibit temporal patterning in their responses, but the importance and behavioral relevance of spike timing, particularly for naturalistic stimuli, remains to be elucidated. Based on neurophysiological recordings from Rhesus macaques, we show that spike timing conveys information about the frequency composition of skin vibrations, both for individual afferents and for afferent populations, and that the temporal fidelity varies across afferent class. Furthermore, the perception of skin vibrations, measured in human subjects, is better predicted when spike timing is taken into account, and the resolution that predicts perception best matches the optimal resolution of the respective afferent classes. In light of these results, the peripheral representation of complex skin vibrations draws a powerful analogy with the auditory and vibrissal systems. PMID:23115169

  3. MEMS tactile display: from fabrication to characterization

    NASA Astrophysics Data System (ADS)

    Miki, Norihisa; Kosemura, Yumi; Watanabe, Junpei; Ishikawa, Hiroaki

    2014-03-01

    We report fabrication and characterization of MEMS-based tactile display that can display users various tactile information, such as Braille codes and surface textures. The display consists of 9 micro-actuators that are equipped with hydraulic displacement amplification mechanism (HDAM) to achieve large enough displacement to stimulate the human tactile receptors. HDAM encapsulates incompressible liquids. We developed a liquid encapsulation process, which we termed as Bonding-in-Liquid Technique, where bonding with a UV-curable resin in glycerin is conducted in the liquid, which prevented interfusion of air bubbles and deformation of the membrane during the bonding. HDAM successfully amplified the displacement generated by piezoelectric actuators by a factor of 6. The display could virtually produce "rough" and "smooth" surfaces, by controlling the vibration frequency, displacement, and the actuation periods of an actuator until the adjacent actuator was driven. We introduced a sample comparison method to characterize the surfaces, which involves human tactile sensation. First, we prepared samples whose mechanical properties are known. We displayed a surface texture to the user by controlling the parameters and then, the user selects a sample that has the most similar surface texture. By doing so, we can correlate the parameters with the mechanical properties of the sample as well as find the sets of the parameters that can provide similar tactile information to many users. The preliminary results with respect to roughness and hardness is presented.

  4. Factors Affecting Traceability of Lines for Tactile Graphics.

    ERIC Educational Resources Information Center

    Bentzen, Billie Louise; Peck, Alec F.

    1979-01-01

    To facilitate appropriate line choice for tactile graphic displays, 42 visually impaired Ss traced four types of tactile lines in a simple display (without intersections), and in a complex display (having intersections). (Author)

  5. Experimental quantification of the tactile spatial responsivity of human cornea.

    PubMed

    Beiderman, Yevgeny; Belkin, Michael; Rotenstreich, Ygal; Zalevsky, Zeev

    2015-01-01

    We present the first experimental quantification of the tactile spatial responsivity of the cornea and we teach a subject to recognize spatial tactile shapes that are stimulated on their cornea. PMID:26158088

  6. Human spatial navigation via a visuo-tactile sensory substitution system.

    PubMed

    Segond, Hervé; Weiss, Déborah; Sampaio, Eliana

    2005-01-01

    Spatial navigation within a real 3-D maze was investigated to study space perception on the sole basis of tactile information transmitted by means of a 'tactile vision substitution system' (TVSS) allowing the conversion of optical images-collected by a micro camera-into 'tactile images' via a matrix in contact with the skin. The development of such a device is based on concepts of cerebral and functional plasticity, enabling subjective reproduction of visual images from tactile data processing. Blindfolded sighted subjects had to remotely control the movements of a robot on which the TVSS camera was mounted. Once familiarised with the cues in the maze, the subjects were given two exploration sessions. Performance was analysed according to an objective point of view (exploration time, discrimination capacity), as well as a subjective one (speech). The task was successfully carried out from the very first session. As the subjects took a different path during each navigation, a gradual improvement in performance (discrimination and exploration time) was noted, generating a phenomenon of learning. Moreover, subjective analysis revealed an evolution of the spatialisation process towards distal attribution. Finally, some emotional expressions seemed to reflect the genesis of 'qualia' (emotional qualities of stimulation). PMID:16309117

  7. Influences on preschool children's physical activity: exploration through focus groups.

    PubMed

    Hinkley, Trina; Salmon, Jo; Okely, Anthony D; Crawford, David; Hesketh, Kylie

    2011-01-01

    This study explored mothers' perceptions of influences on preschoolers' physical activity. Six semistructured focus groups with 23 mothers were conducted across a range of socioeconomic position locations. Mothers identified 4 key areas of influence: child fundamentals (eg, sex, personality), parent power (eg, rules, support), people to share with (eg, peers, adults), and places and things (eg, physical environments, toys). No substantial differences in themes were identified among socioeconomic position groups. Influences on preschoolers' physical activity are multidimensional, multifactorial, and support the use of ecological models to conceptualize and understand the influencing factors. Associations among factors influencing preschoolers' physical activity should be further investigated through quantitative research. PMID:21135627

  8. Tactile dispay based on smart fluids

    NASA Astrophysics Data System (ADS)

    Liu, Y. J.; Davidson, R. I.; Taylor, P. M.

    2007-07-01

    A tactile display is programmable device to be detected by human touch. It has great potential applications in the field of virtual environment. The current research is the first step to develop a programmable tactile array based on ER/MR fluid technology. Prototypes of display incorporating controllable fluids such as electrrheological (ER) fluid and magnetorheological (MR) fluid have been developed and investigated. Surface force responses of these tactile displays under various electric/magnetic fields have been measured while a probe moving across the upper surface. As the applied external electric or magnetic field varied, the sensed surface profiles changed in synchronisation with the field strength. With the controllable fluid actuator, the displayed surface information is stable and repeatable.

  9. Tactile sensing means for prosthetic limbs

    NASA Technical Reports Server (NTRS)

    Scott, W. L. (Inventor)

    1973-01-01

    An improved prosthetic device characterized by a frame and a socket for mounting on the stump of a truncated human appendage is described. Flexible digits extend from the distal end and transducers located within the digits act as sensing devices for detecting tactile stimuli. The transducers are connected through a power circuit with a slave unit supported by a strap and fixed to the stump. The tactile stimuli detected at the sensing devices are reproduced and applied to the skin of the appendage in order to stimulate the sensory organs located therein.

  10. Power Subsystem for Extravehicular Activities for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle

    2005-01-01

    The NASA Glenn Research Center has the responsibility to develop the next generation space suit power subsystem to support the Vision for Space Exploration. Various technology challenges exist in achieving extended duration missions as envisioned for future lunar and Mars mission scenarios. This paper presents an overview of ongoing development efforts undertaken at the Glenn Research Center in support of power subsystem development for future extravehicular activity systems.

  11. Mineral exploration and soil analysis using in situ neutron activation

    USGS Publications Warehouse

    Senftle, F.E.; Hoyte, A.F.

    1966-01-01

    A feasibility study has been made to operate by remote control an unshielded portable positive-ion accelerator type neutron source to induce activities in the ground or rock by "in situ" neutron irradiation. Selective activation techniques make it possible to detect some thirty or more elements by irradiating the ground for periods of a few minutes with either 3-MeV or 14-MeV neutrons. The depth of penetration of neutrons, the effect of water content of the soil on neutron moderation, gamma ray attenuation in the soil and other problems are considered. The analysis shows that, when exploring for most elements of economic interest, the reaction 2H(d,n)3He yielding ??? 3-MeV neutrons is most practical to produce a relatively uniform flux of neutrons of less than 1 keV to a depth of 19???-20???. Irradiation with high energy neutrons (??? 14 MeV) can also be used and may be better suited for certain problems. However, due to higher background and lower sensitivity for the heavy minerals, it is not a recommended neutron source for general exploration use. Preliminary experiments have been made which indicate that neutron activation in situ is feasible for a mineral exploration or qualititative soil analysis. ?? 1976.

  12. Whisking Kinematics Enables Object Localization in Head-Centered Coordinates Based on Tactile Information from a Single Vibrissa

    PubMed Central

    Yang, Anne E. T.; Hartmann, Mitra J. Z.

    2016-01-01

    During active tactile exploration with their whiskers (vibrissae), rodents can rapidly orient to an object even though there are very few proprioceptors in the whisker muscles. Thus a long-standing question in the study of the vibrissal system is how the rat can localize an object in head-centered coordinates without muscle-based proprioception. We used a three-dimensional model of whisker bending to simulate whisking motions against a peg to investigate the possibility that the 3D mechanics of contact from a single whisker are sufficient for localization in head-centered coordinates. Results show that for nearly all whiskers in the array, purely tactile signals at the whisker base – as would be measured by mechanoreceptors, in whisker-centered coordinates – could be used to determine the location of a vertical peg in head-centered coordinates. Both the “roll” and the “elevation” components of whisking kinematics contribute to the uniqueness and resolution of the localization. These results offer an explanation for a behavioral study showing that rats can more accurately determine the horizontal angle of an object if one column, rather than one row, of whiskers is spared. PMID:27486390

  13. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury.

    PubMed

    Watson, Jaime L; Hala, Tamara J; Putatunda, Rajarshi; Sannie, Daniel; Lepore, Angelo C

    2014-01-01

    In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI). SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation), persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression), and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to neuropathic pain

  14. Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

    PubMed

    Bufalari, Ilaria; Di Russo, Francesco; Aglioti, Salvatore Maria

    2014-07-01

    While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception. PMID:23438449

  15. The effect of volumetric (3D) tactile symbols within inclusive tactile maps.

    PubMed

    Gual, Jaume; Puyuelo, Marina; Lloveras, Joaquim

    2015-05-01

    Point, linear and areal elements, which are two-dimensional and of a graphic nature, are the morphological elements employed when designing tactile maps and symbols for visually impaired users. However, beyond the two-dimensional domain, there is a fourth group of elements - volumetric elements - which mapmakers do not take sufficiently into account when it comes to designing tactile maps and symbols. This study analyses the effect of including volumetric, or 3D, symbols within a tactile map. In order to do so, the researchers compared two tactile maps. One of them uses only two-dimensional elements and is produced using thermoforming, one of the most popular systems in this field, while the other includes volumetric symbols, thus highlighting the possibilities opened up by 3D printing, a new area of production. The results of the study show that including 3D symbols improves the efficiency and autonomous use of these products. PMID:25683526

  16. Summary of Tactile User Interfaces Techniques and Systems

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly

    2004-01-01

    Mental workload can be defined as the ratio of demand to allocated resources. Multiple- resource theory stresses the importance of distribution of tasks and information across various sensory channels of the human to reduce mental workload. One sensory channel that has been of interest since the late 1800s is touch. Unlike the more typical displays that target vision or hearing, tactile displays present information to the user s sense of touch. We present a summary of different methods for tactile display; historic and more recent systems that incorporate tactile display for information presentation; advantages and disadvantages of targeting the tactile channel; and future directions in tactile display research.

  17. Summary of Tactile User Interfaces Techniques and Systems

    NASA Technical Reports Server (NTRS)

    Spirkovska, Lilly

    2005-01-01

    Mental workload can be de.ned as the ratio of demand to allocated resources. Multiple-resource theory stresses the importance of distribution of tasks and information across various human sensory channels to reduce mental workload. One sensory channel that has been of interest since the late 1800s is touch. Unlike the more typical displays that target vision or hearing, tactile displays present information to the user s sense of touch. We present a summary of different methods for tactile display, historic and more recent systems that incorporate tactile display for information presentation, advantages and disadvantages of targeting the tactile channel, and future directions in tactile display research.

  18. Tactile perception of skin and skin cream by friction induced vibrations.

    PubMed

    Ding, Shuyang; Bhushan, Bharat

    2016-11-01

    Skin cream smooths, softens, and moistens skin by altering surface roughness and tribological properties of skin. Sliding generates vibrations that activate mechanoreceptors located in skin. The brain interprets tactile information to identify skin feel. Understanding the tactile sensing mechanisms of skin with and without cream treatment is important to numerous applications including cosmetics, textiles, and robotics sensors. In this study, frequency spectra of friction force and friction induced vibration signals were carried out to investigate tactile perception by an artificial finger sliding on skin. The influence of normal load, velocity, and cream treatment time were studied. Coherence between friction force and vibration signals were found. The amplitude of vibration decreased after cream treatment, leading to smoother perception. Increasing normal load or velocity between contacting surfaces generated a smoother perception with cream treatment, but rougher perception without treatment. As cream treatment time increases, skin becomes smoother. The related mechanisms are discussed. PMID:27474814

  19. A voice coil motor based measuring force control system for tactile scanning profiler

    NASA Astrophysics Data System (ADS)

    Feng, Shengdong; Liu, Xiaojun; Chen, Liangzhou; Zhou, Liping; Lu, Wenlong

    2015-02-01

    In tactile scanning profiler, the measuring force would change in a wide range when it was used for profile measurement in a large range, which could possibly destroy the measured surface. To solve the problem, measuring force control system for tactile scanning profiler was needed. In the paper, a voice coil motor-based measuring force control system for tactile scanning profiler was designed. In the design, a low stiffness coefficient spring was used to provide contact force, while a voice coil motor (VCM) to balance the spring force so that the contact force could be kept for constant measuring force. A VCM was designed specially, and for active measuring force control, a precision current source circuit under the control of a DSP unit was designed to drive the VCM. The performance of voice coil motor based measuring force control system had been tested, and its good characteristics were verified.

  20. The failure to detect tactile change: a tactile analogue of visual change blindness.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Spence, Charles

    2006-04-01

    A large body of empirical research now shows that people are surprisingly poor at detecting significant changes in visually presented scenes. This phenomenon is known as change blindness in vision. A similar phenomenon occurs in audition, but to date no such effect has been documented in touch. In the present study, we explored the ability of people to detect changes introduced between two consecutively presented vibrotactile patterns presented over the body surface. The patterns consisted of two or three vibrotactile stimuli presented for 200 msec. The position of one of the vibrotactile stimuli composing the display was repeatedly changed (alternating between two different positions) on 50% of the trials, but the same pattern was presented repeatedly on the remaining trials. Three conditions were investigated: No interval between the patterns, an empty interval between the patterns, and a masked interval between the patterns. Change detection was near perfect in the no-interval block. Performance deteriorated somewhat in the empty-interval block, but by far the worst change detection performance occurred in the masked-interval block. These results demonstrate that "change blindness" can also affect tactile perception. PMID:16892998

  1. A tactile sensor made of graphene-cellulose nanocomposite

    NASA Astrophysics Data System (ADS)

    Kafy, Abdullahil; Sadasivuni, Kishor Kumar; Mun, Seongcheonl; Kim, Jaehwan

    2015-04-01

    Development of tactile sensing technology has promoted intelligent human-machine interaction and recently has evolved out as one of the most promising area of electronics. Tactile sensing is a milestone in this field as it can extend the detection mode of tactile sensor through air. In this paper, we fabricated a tactile sensor using cellulose nanocrystal modified with graphene by isocyanate grafting. The new material is transparent, ecofriendly and integrated the capability of tactile sensing with fast response, high stability and high reversibility. Various materials from conducting metals to a human hand were checked for tactile sensing capability. It is found that the fabricated sensor could detect a human hand at a distance up to 6 mm away from the sensor. Combining the results, the discrete, flexible dual-mode tactile sensor fulfilled the technical and operational objectives of this work .

  2. Compact Tactile Sensors for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.; Lussy, David; Gaudiano, Frank; Hulse, Aaron; Diftler, Myron A.; Rodriguez, Dagoberto; Bielski, Paul; Butzer, Melisa

    2004-01-01

    Compact transducer arrays that measure spatial distributions of force or pressure have been demonstrated as prototypes of tactile sensors to be mounted on fingers and palms of dexterous robot hands. The pressure- or force-distribution feedback provided by these sensors is essential for the further development and implementation of robot-control capabilities for humanlike grasping and manipulation.

  3. Dynamic Tactile Diagram Simplification on Refreshable Displays

    ERIC Educational Resources Information Center

    Rastogi, Ravi; Pawluk, Dianne T. V.

    2013-01-01

    The increasing use of visual diagrams in educational and work environments, and even our daily lives, has created obstacles for individuals who are blind or visually impaired to "independently" access the information they represent. Although physical tactile pictures can be created to convey the visual information, it is typically a slow,…

  4. Seeing the Body Distorts Tactile Size Perception

    ERIC Educational Resources Information Center

    Longo, Matthew R.; Sadibolova, Renata

    2013-01-01

    Vision of the body modulates somatosensation, even when entirely non-informative about stimulation. For example, seeing the body increases tactile spatial acuity, but reduces acute pain. While previous results demonstrate that vision of the body modulates somatosensory sensitivity, it is unknown whether vision also affects metric properties of…

  5. Self-organization via active exploration in robotic applications

    NASA Technical Reports Server (NTRS)

    Ogmen, H.; Prakash, R. V.

    1992-01-01

    We describe a neural network based robotic system. Unlike traditional robotic systems, our approach focussed on non-stationary problems. We indicate that self-organization capability is necessary for any system to operate successfully in a non-stationary environment. We suggest that self-organization should be based on an active exploration process. We investigated neural architectures having novelty sensitivity, selective attention, reinforcement learning, habit formation, flexible criteria categorization properties and analyzed the resulting behavior (consisting of an intelligent initiation of exploration) by computer simulations. While various computer vision researchers acknowledged recently the importance of active processes (Swain and Stricker, 1991), the proposed approaches within the new framework still suffer from a lack of self-organization (Aloimonos and Bandyopadhyay, 1987; Bajcsy, 1988). A self-organizing, neural network based robot (MAVIN) has been recently proposed (Baloch and Waxman, 1991). This robot has the capability of position, size rotation invariant pattern categorization, recognition and pavlovian conditioning. Our robot does not have initially invariant processing properties. The reason for this is the emphasis we put on active exploration. We maintain the point of view that such invariant properties emerge from an internalization of exploratory sensory-motor activity. Rather than coding the equilibria of such mental capabilities, we are seeking to capture its dynamics to understand on the one hand how the emergence of such invariances is possible and on the other hand the dynamics that lead to these invariances. The second point is crucial for an adaptive robot to acquire new invariances in non-stationary environments, as demonstrated by the inverting glass experiments of Helmholtz. We will introduce Pavlovian conditioning circuits in our future work for the precise objective of achieving the generation, coordination, and internalization

  6. Differences in Early Stages of Tactile ERP Temporal Sequence (P100) in Cortical Organization during Passive Tactile Stimulation in Children with Blindness and Controls.

    PubMed

    Ortiz Alonso, Tomás; Santos, Juan Matías; Ortiz Terán, Laura; Borrego Hernández, Mayelin; Poch Broto, Joaquín; de Erausquin, Gabriel Alejandro

    2015-01-01

    Compared to their seeing counterparts, people with blindness have a greater tactile capacity. Differences in the physiology of object recognition between people with blindness and seeing people have been well documented, but not when tactile stimuli require semantic processing. We used a passive vibrotactile device to focus on the differences in spatial brain processing evaluated with event related potentials (ERP) in children with blindness (n = 12) vs. normally seeing children (n = 12), when learning a simple spatial task (lines with different orientations) or a task involving recognition of letters, to describe the early stages of its temporal sequence (from 80 to 220 msec) and to search for evidence of multi-modal cortical organization. We analysed the P100 of the ERP. Children with blindness showed earlier latencies for cognitive (perceptual) event related potentials, shorter reaction times, and (paradoxically) worse ability to identify the spatial direction of the stimulus. On the other hand, they are equally proficient in recognizing stimuli with semantic content (letters). The last observation is consistent with the role of P100 on somatosensory-based recognition of complex forms. The cortical differences between seeing control and blind groups, during spatial tactile discrimination, are associated with activation in visual pathway (occipital) and task-related association (temporal and frontal) areas. The present results show that early processing of tactile stimulation conveying cross modal information differs in children with blindness or with normal vision. PMID:26225827

  7. Differences in Early Stages of Tactile ERP Temporal Sequence (P100) in Cortical Organization during Passive Tactile Stimulation in Children with Blindness and Controls

    PubMed Central

    Ortiz Alonso, Tomás; Santos, Juan Matías; Ortiz Terán, Laura; Borrego Hernández, Mayelin; Poch Broto, Joaquín; de Erausquin, Gabriel Alejandro

    2015-01-01

    Compared to their seeing counterparts, people with blindness have a greater tactile capacity. Differences in the physiology of object recognition between people with blindness and seeing people have been well documented, but not when tactile stimuli require semantic processing. We used a passive vibrotactile device to focus on the differences in spatial brain processing evaluated with event related potentials (ERP) in children with blindness (n = 12) vs. normally seeing children (n = 12), when learning a simple spatial task (lines with different orientations) or a task involving recognition of letters, to describe the early stages of its temporal sequence (from 80 to 220 msec) and to search for evidence of multi-modal cortical organization. We analysed the P100 of the ERP. Children with blindness showed earlier latencies for cognitive (perceptual) event related potentials, shorter reaction times, and (paradoxically) worse ability to identify the spatial direction of the stimulus. On the other hand, they are equally proficient in recognizing stimuli with semantic content (letters). The last observation is consistent with the role of P100 on somatosensory-based recognition of complex forms. The cortical differences between seeing control and blind groups, during spatial tactile discrimination, are associated with activation in visual pathway (occipital) and task-related association (temporal and frontal) areas. The present results show that early processing of tactile stimulation conveying cross modal information differs in children with blindness or with normal vision. PMID:26225827

  8. Short term memory for tactile stimuli.

    PubMed

    Gallace, Alberto; Tan, Hong Z; Haggard, Patrick; Spence, Charles

    2008-01-23

    Research has shown that unreported information stored in rapidly decaying visual representations may be accessed more accurately using partial report than using full report procedures (e.g., [Sperling, G., 1960. The information available in brief visual presentations. Psychological Monographs, 74, 1-29.]). In the 3 experiments reported here, we investigated whether unreported information regarding the actual number of tactile stimuli presented in parallel across the body surface can be accessed using a partial report procedure. In Experiment 1, participants had to report the total number of stimuli in a tactile display composed of up to 6 stimuli presented across their body (numerosity task), or else to detect whether or not a tactile stimulus had previously been presented in a position indicated by a visual probe given at a variable delay after offset of a tactile display (i.e., partial report). The results showed that participants correctly reported up to 3 stimuli in the numerosity judgment task, but their performance was significantly better than chance when up to 5 stimuli were presented in the partial report task. This result shows that short-lasting tactile representations can be accessed using partial report procedures similar to those used previously in visual studies. Experiment 2 showed that the duration of these representations (or the time available to consciously access them) depends on the number of stimuli presented in the display (the greater the number of stimuli that are presented, the faster their representation decays). Finally, the results of a third experiment showed that the differences in performance between the numerosity judgment and partial report tasks could not be explained solely in terms of any difference in task difficulty. PMID:18083147

  9. International oil and gas exploration and development activities

    SciTech Connect

    Not Available

    1990-10-29

    This report is part of an ongoing series of quarterly publications that monitors discoveries of oil and natural gas in foreign countries and provides an analysis of the reserve additions that result. The report is prepared by the Energy Information Administration (EIA) of the US Department of Energy (DOE) under the Foreign Energy Supply Assessment Program (FESAP). It presents a summary of discoveries and reserve additions that result from recent international exploration and development activities. It is intended for use by petroleum industry analysts, various government agencies, and political leaders in the development, implementation, and evaluation of energy plans, policy, and legislation. 25 refs., 8 figs., 4 tabs.

  10. Blind Students' Learning of Probability through the Use of a Tactile Model

    ERIC Educational Resources Information Center

    Vita, Aida Carvalho; Kataoka, Verônica Yumi

    2014-01-01

    The objective of this paper is to discuss how blind students learn basic concepts of probability using the tactile model proposed by Vita (2012). Among the activities were part of the teaching sequence "Jefferson's Random Walk", in which students built a tree diagram (using plastic trays, foam cards, and toys), and pictograms in 3D…

  11. Cognitive and Tactile Factors Affecting Human Haptic Performance in Later Life

    PubMed Central

    Kalisch, Tobias; Kattenstroth, Jan-Christoph; Kowalewski, Rebecca; Tegenthoff, Martin; Dinse, Hubert R.

    2012-01-01

    Background Vision and haptics are the key modalities by which humans perceive objects and interact with their environment in a target-oriented manner. Both modalities share higher-order neural resources and the mechanisms required for object exploration. Compared to vision, the understanding of haptic information processing is still rudimentary. Although it is known that haptic performance, similar to many other skills, decreases in old age, the underlying mechanisms are not clear. It is yet to be determined to what extent this decrease is related to the age-related loss of tactile acuity or cognitive capacity. Methodology/Principal Findings We investigated the haptic performance of 81 older adults by means of a cross-modal object recognition test. Additionally, we assessed the subjects' tactile acuity with an apparatus-based two-point discrimination paradigm, and their cognitive performance by means of the non-verbal Raven-Standard-Progressive matrices test. As expected, there was a significant age-related decline in performance on all 3 tests. With the exception of tactile acuity, this decline was found to be more distinct in female subjects. Correlation analyses revealed a strong relationship between haptic and cognitive performance for all subjects. Tactile performance, on the contrary, was only significantly correlated with male subjects' haptic performance. Conclusions Haptic object recognition is a demanding task in old age, especially when it comes to the exploration of complex, unfamiliar objects. Our data support a disproportionately higher impact of cognition on haptic performance as compared to the impact of tactile acuity. Our findings are in agreement with studies reporting an increase in co-variation between individual sensory performance and general cognitive functioning in old age. PMID:22291952

  12. Immobilization impairs tactile perception and shrinks somatosensory cortical maps.

    PubMed

    Lissek, Silke; Wilimzig, Claudia; Stude, Philipp; Pleger, Burkhard; Kalisch, Tobias; Maier, Christoph; Peters, Sören A; Nicolas, Volkmar; Tegenthoff, Martin; Dinse, Hubert R

    2009-05-26

    Use is a major factor driving plasticity of cortical processing and cortical maps. As demonstrated of blind Braille readers and musicians, long-lasting and exceptional usage of the fingers results in the development of outstanding sensorimotor skills and in expansions of the cortical finger representations. However, how periods of disuse affect cortical representations and perception in humans remains elusive. Here, we report that a few weeks of hand and arm immobilization by cast wearing significantly reduced hand use and impaired tactile acuity, associated with reduced activation of the respective finger representations in the somatosensory cortex (SI), measured by functional magnetic resonance imaging. Hemodynamic responses in the SI correlated positively with hand-use frequency and negatively with discrimination thresholds, indicating that reduced activation was most prominent in subjects with severe perceptual impairment. We found, strikingly, compensatory effects on the contralateral, healthy hand consisting of improved perceptual performance compared to healthy controls. Two to three weeks after cast removal, perceptual and cortical changes recovered, whereas tactile acuity on the healthy side remained superior to that on the formerly immobilized side. These findings suggest that brief periods of reduced use of a limb have overt consequences and thus constitute a significant driving force of brain organization equivalent to enhanced use. PMID:19398335

  13. Somatosensory Event-Related Potentials and Association with Tactile Behavioral Responsiveness Patterns in Children with ASD.

    PubMed

    Cascio, Carissa J; Gu, Chang; Schauder, Kimberly B; Key, Alexandra P; Yoder, Paul

    2015-11-01

    The goal of this study was to explore neural response to touch in children with and without autism spectrum disorder (ASD). Patterns of reduced (hypo-responsiveness) and enhanced (hyper-responsiveness) behavioral reaction to sensory input are prevalent in ASD, but their neural mechanisms are poorly understood. We measured event-related potentials (ERP) to a puff of air on the fingertip and collected parent report of tactile hypo- and hyper-responsiveness in children with ASD (n = 21, mean (SD) age 11.25 (3.09), 2 female), and an age-matched typically developing comparison group (n = 28, mean (SD) age 10.1 (3.08, 2 female). A global measure of ERP response strength approximately 220-270 ms post-stimulus was associated with tactile hypo-responsiveness in ASD, while tactile hyper-responsiveness was associated with earlier neural response (approximately 120-220 ms post-stimulus) in both groups. These neural responses also related to autism severity. These results suggest that, in ASD, tactile hypo- and hyper-responsiveness may reflect different waypoints in the neural processing stream of sensory input. The timing of the relationship for hyper-responsiveness is consistent with somatosensory association cortical response, while that for hypo-responsiveness is more consistent with later processes that may involve allocation of attention or emotional valence to the stimulus. PMID:26016951

  14. Using Tactile Strategies with Students Who Are Blind and Have Severe Disabilities.

    ERIC Educational Resources Information Center

    Downing, June E.; Chen, Deborah

    2003-01-01

    This article suggests ways to use tactile teaching strategies with students who have severe and multiple disabilities including blindness. Guidelines address tactile modeling, tactile mutual attention, presenting tactile information, providing effective tactile representation, hypersensitivity to touch, and a team approach. (Contains references.)…

  15. Juggling reveals a decisional component to tactile suppression.

    PubMed

    Juravle, Georgiana; Spence, Charles

    2011-08-01

    Goal-directed movements are characterized by sensory suppression, that is, by decreased sensitivity to tactile stimuli. In the present study, we investigated tactile suppression during movement using a complex motor task: basic 3-ball juggling. It was hypothesized that a decrease in tactile sensitivity would be observed, together with a shift in participants' response bias while juggling. In a first experiment, participants had to detect a short gap in an otherwise continuous vibratory stimulus, which was delivered to their wrist under conditions of rest or else while juggling. In a second experiment, participants detected a short time gap in a continuous auditory signal, under the same conditions. In a final control experiment performed at rest, participants detected a short time gap in an auditory or tactile signal. In an additional condition, the detection of a gap in tactile stimulation was required under conditions of intramodal tactile interference. Participants were significantly less sensitive to detect a gap in tactile stimulation whilst juggling. Most importantly, these results were paired with a significant shift toward participants adopting a more conservative criterion when responding to the presence of the gap (i.e. they were more likely to say that a gap was not present). Taken together, these results demonstrate movement-related tactile sensory suppression and point to a decisional component in tactile suppression, thus suggesting that tactile suppression could already be triggered in the brain ahead of the motor command. PMID:21717097

  16. Active Exploration of Large 3D Model Repositories.

    PubMed

    Gao, Lin; Cao, Yan-Pei; Lai, Yu-Kun; Huang, Hao-Zhi; Kobbelt, Leif; Hu, Shi-Min

    2015-12-01

    With broader availability of large-scale 3D model repositories, the need for efficient and effective exploration becomes more and more urgent. Existing model retrieval techniques do not scale well with the size of the database since often a large number of very similar objects are returned for a query, and the possibilities to refine the search are quite limited. We propose an interactive approach where the user feeds an active learning procedure by labeling either entire models or parts of them as "like" or "dislike" such that the system can automatically update an active set of recommended models. To provide an intuitive user interface, candidate models are presented based on their estimated relevance for the current query. From the methodological point of view, our main contribution is to exploit not only the similarity between a query and the database models but also the similarities among the database models themselves. We achieve this by an offline pre-processing stage, where global and local shape descriptors are computed for each model and a sparse distance metric is derived that can be evaluated efficiently even for very large databases. We demonstrate the effectiveness of our method by interactively exploring a repository containing over 100 K models. PMID:26529460

  17. Exploring human epileptic activity at the single-neuron level.

    PubMed

    Tankus, Ariel

    2016-05-01

    Today, localization of the seizure focus heavily relies on EEG monitoring (scalp or intracranial). However, current technology enables much finer resolutions. The activity of hundreds of single neurons in the human brain can now be simultaneously explored before, during, and after a seizure or in association with an interictal discharge. This technology opens up new horizons to understanding epilepsy at a completely new level. This review therefore begins with a brief description of the basis of the technology, the microelectrodes, and the setup for their implantation in patients with epilepsy. Using these electrodes, recent studies provide novel insights into both the time domain and firing patterns of epileptic activity of single neurons. In the time domain, seizure-related activity may occur even minutes before seizure onset (in its current, EEG-based definition). Seizure-related neuronal interactions exhibit complex heterogeneous dynamics. In the seizure-onset zone, changes in firing patterns correlate with cell loss; in the penumbra, neurons maintain their spike stereotypy during a seizure. Hence, investigation of the extracellular electrical activity is expected to provide a better understanding of the mechanisms underlying the disease; it may, in the future, serve for a more accurate localization of the seizure focus; and it may also be employed to predict the occurrence of seizures prior to their behavioral manifestation in order to administer automatic therapeutic interventions. PMID:26994366

  18. Investigating visual-tactile interactions over time and space in adults with autism.

    PubMed

    Poole, Daniel; Gowen, Emma; Warren, Paul A; Poliakoff, Ellen

    2015-10-01

    It has been suggested that the sensory symptoms which affect many people with autism spectrum conditions (ASC) may be related to alterations in multisensory processing. Typically, the likelihood of interactions between the senses increases when information is temporally and spatially coincident. We explored visual-tactile interactions in adults with ASC for the first time in two experiments using low-level stimuli. Both participants with ASC and matched neurotypical controls only produced crossmodal interactions to near simultaneous stimuli, suggesting that temporal modulation is unaffected in the adult population. We also provide preliminary evidence that visual-tactile interactions may occur over greater spatial distances in participants with ASC, which merits further exploration. PMID:26063447

  19. Remote tactile sensing glove-based system.

    PubMed

    Culjat, Martin O; Son, Ji; Fan, Richard E; Wottawa, Christopher; Bisley, James W; Grundfest, Warren S; Dutson, Erik P

    2010-01-01

    A complete glove-based master-slave tactile feedback system was developed to provide users with a remote sense of touch. The system features a force-sensing master glove with piezoresistive force sensors mounted at each finger tip, and a pressure-transmitting slave glove with silicone-based pneumatically controlled balloon actuators, mounted at each finger tip on another hand. A control system translates forces detected on the master glove, either worn by a user or mounted on a robotic hand, to discrete pressure levels at the fingers of another user. System tests demonstrated that users could accurately identify the correct finger and detect three simultaneous finger stimuli with 99.3% and 90.2% accuracy, respectively, when the subjects were located in separate rooms. The glove-based tactile feedback system may have application to virtual reality, rehabilitation, remote surgery, medical simulation, robotic assembly, and military robotics. PMID:21096379

  20. A Study on Tactile Friction and Wear

    NASA Astrophysics Data System (ADS)

    Sugishita, Junji; Usami, Hatsuhiko; Hattori, Tomokazu

    The tactile wear (“tezure” in Japanese) is an abrasion phenomenon of material surfaces caused by the contact of human hand over a long period of time. Though this phenomenon has been the focus of various articles, an extensive study with regard to the wear characteristics is of a profound importance. To date, we have several remarkable examples such as the statue of Pindola Bharadvaja (Buddhist) and the St. Peter statue (Christian). Followers of the respective religions who are deeply attached and rooted have been touching the statues as part of their rituals for many generations over centuries. In this study, an attempt is done to verify the friction and wear characteristics of various soft metals with contact of human finger. The results of our experiments show that the friction coefficient upon the contact of the human finger and pure copper are very high and thus proving tactile wear of soft metals can be generated easily.

  1. Computational Intelligence Techniques for Tactile Sensing Systems

    PubMed Central

    Gastaldo, Paolo; Pinna, Luigi; Seminara, Lucia; Valle, Maurizio; Zunino, Rodolfo

    2014-01-01

    Tactile sensing helps robots interact with humans and objects effectively in real environments. Piezoelectric polymer sensors provide the functional building blocks of the robotic electronic skin, mainly thanks to their flexibility and suitability for detecting dynamic contact events and for recognizing the touch modality. The paper focuses on the ability of tactile sensing systems to support the challenging recognition of certain qualities/modalities of touch. The research applies novel computational intelligence techniques and a tensor-based approach for the classification of touch modalities; its main results consist in providing a procedure to enhance system generalization ability and architecture for multi-class recognition applications. An experimental campaign involving 70 participants using three different modalities in touching the upper surface of the sensor array was conducted, and confirmed the validity of the approach. PMID:24949646

  2. Development of a tactile sensor for evaluation of detergents

    NASA Astrophysics Data System (ADS)

    Tsuchimi, Daisuke; Tanaka, Mami

    2007-12-01

    This paper is concerned with the development of a tactile sensor using PVDF (Polyvinylidene Fluoride) film as a receptor of the sensor to evaluate a detergent. Tactile sense is the most important sense in the sensation receptor of the human body along with eyesight. When the dish which washed cleanly is rubbed with a finger of human, good tactile sense and sound (vibration signal) like "Kyu-kyu" are obtained. From this tactile sense and sound, we judge that a dish becomes squeaky-clean. This tactile sense and sound are evaluation parameters when consumer selects a detergent. In this study, a tactile sensor using PVDF film as the receptor is fabricated. Sensory test of detergents was conducted. Measurement experiment by the sensor is carried out. Experiment results show that sensor output have good correlation with the result of human sensory test of detergent.

  3. Method and device for producing a tactile display using an electrorheological fluid

    NASA Technical Reports Server (NTRS)

    Garner, H. Douglas (Inventor)

    1996-01-01

    A tactile display device utilizes an electrorheological fluid to activate a plurality of tactile dots. A voltage is selectively produced uniformly across an electrorheological fluid flowing between a common ground electrode and a plurality of conductive dot electrodes, thereby producing an increase in the fluid's viscosity to the extent that fluid flow between the two electrodes is restricted. The flow restriction produces a build-up of electrorheological fluid in a corresponding dot actuator chamber. The resulting pressure increase in the chamber displaces an elastic diaphragm fixed to a display surface to form a lump which can be perceived by the reader as one dot in a Braille character cell. A flow regulation system provides a continually pressurized flow system and provides for free flow of the electrorheological fluid through the plurality of dot actuator chambers when they are not activated. The device is adaptable to printed circuit techniques and can simultaneously display tactile dots representative of a full page of Braille characters stored on a medium such as a tape cassette or to display tactile dots representative of non-Braille data appearing on a computer monitor or contained on another data storage medium. In an alternate embodiment, the elastic diaphragm drives a plurality of spring-loaded pins provided with positive stops to maintain consistent displacements of the pins in both their actuated and nonactuated positions.

  4. Modulation of the ∽20-Hz motor-cortex rhythm to passive movement and tactile stimulation

    PubMed Central

    Parkkonen, Eeva; Laaksonen, Kristina; Piitulainen, Harri; Parkkonen, Lauri; Forss, Nina

    2015-01-01

    Background Integration of afferent somatosensory input with motor-cortex output is essential for accurate movements. Prior studies have shown that tactile input modulates motor-cortex excitability, which is reflected in the reactivity of the ∽20-Hz motor-cortex rhythm. ∽20-Hz rebound is connected to inhibition or deactivation of motor cortex whereas suppression has been associated with increased motor cortex activity. Although tactile sense carries important information for controlling voluntary actions, proprioception likely provides the most essential feedback for motor control. Methods To clarify how passive movement modulates motor-cortex excitability, we studied with magnetoencephalography (MEG) the amplitudes and peak latencies of suppression and rebound of the ∽20-Hz rhythm elicited by tactile stimulation and passive movement of right and left index fingers in 22 healthy volunteers. Results Passive movement elicited a stronger and more robust ∽20-Hz rebound than tactile stimulation. In contrast, the suppression amplitudes did not differ between the two stimulus types. Conclusion Our findings suggest that suppression and rebound represent activity of two functionally distinct neuronal populations. The ∽20-Hz rebound to passive movement could be a suitable tool to study the functional state of the motor cortex both in healthy subjects and in patients with motor disorders. PMID:25874163

  5. Tactile sensors based on conductive polymers

    NASA Astrophysics Data System (ADS)

    Castellanos-Ramos, Julian; Navas-Gonzalez, Rafael; Macicior, Haritz; Ochoteco, Estibalitz; Vidal-Verdú, Fernando

    2009-05-01

    This paper presents results from a few tactile sensors we have designed and fabricated. These sensors are based on a common approach that consists of placing a sheet of piezoresistive material on the top of a set of electrodes. If a force is exerted against the surface of the so obtained sensor, the contact area between the electrodes and the piezoresistive material changes. Therefore, the resistance at the interface changes. This is exploited as transconduction principle to measure forces and build advanced tactile sensors. For this purpose, we use a thin film of conductive polymers as the piezoresistive material. Specifically, a conductive water-based ink of these polymers is deposited by spin coating on a flexible plastic sheet, giving as a result a smooth, homogeneous and conducting thin film on it. The main interest in this procedure is it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work we present results from sensors made with two technologies. First, we have used a Printed Circuit Board technology to fabricate the set of electrodes and addressing tracks. Then we have placed the flexible plastic sheet with the conductive polymer film on them to obtain the sensor. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with a screen printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. There is a very interesting difference with the other sensors, that consists of the use of an elastomer as insulation material between conductive layers. Besides of its role as insulator, this elastomer allows the modification of the force versus resistance relationship. It also improves the dynamic response of the sensor because it implements a restoration force that helps the sensor to relax quicker when the force is taken off.

  6. Evaluating Three Active Thermal Architectures for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Cross, Cynthia D.; Hong, Andrew E.; Sheth, Rubik B.; Navarro, Moses; Marett, Susan J.

    2012-01-01

    Mass and cost are typically the two biggest challenges facing space craft designers. Active thermal control systems for crewed space-craft are typically among the more massive and costly systems on the vehicle. A study was completed evaluating three different thermal control system architectures to evaluate overall performance, mass and cost for a typical exploration mission profile. The architectures that were evaluated were 1 - a two-loop system using an internal liquid loop interfacing with an external liquid loop and flow loop with flow through radiators; 2 - a-single loop architecture with flow through radiators utilizing a regenerative heat exchanger and heater; and 3 - a single-loop architecture with heat pipe radiators. Environmental conditions, calculated for a given lunar exploration mission, and mission heat load profiles, generated based on previous Orion time lines, were evalauated through the phases of the on orbit mission. Performance for each of the architectures was evaluated along with the resultant mass of each system. Recommendations include adding a thermal topping system to lunar missions due to the extreme hot environments encountered in near-lunar approaches.

  7. Effectiveness of sensory stimulation on tactile extinction.

    PubMed

    Nico, D

    1999-07-01

    Eleven brain-damaged patients with extinction were asked to report double tactile stimuli before, during, and after optokinetic stimulation and transcutaneous electrical stimulation of the posterior neck region. The goal of the study was to test whether tactile extinction is sensitive to these experimental manipulations in order to better understand the nature of the disorder. Both of these sensory stimulations are known to be effective in modulating only higher-order (cognitive) disorders of spatial coding, such as visual hemineglect, deficit of position sense, hemianesthesia, etc. When applied to the side contralateral to the cerebral lesion, both optokinetic and transcutaneous electrical stimulation significantly affected patients' performances, increasing the amount of detections of contralesional double stimuli. A tendency towards worse performance was observed when sensory stimulation was applied to the ipsilesional side. The reported effectiveness in reducing tactile extinction suggests that the deficit can not be fully ascribed to a peripheral sensory disorder and that it reflects damage to a higher-order cognitive function involved in contralesional space representation or in the deployment of attention to that side of space. The nature of the close relationship between extinction and hemineglect is also discussed from the point of view of extinction as a deficit of space coding. PMID:10424416

  8. Development of polyimide flexible tactile sensor skin

    NASA Astrophysics Data System (ADS)

    Engel, Jonathan; Chen, Jack; Liu, Chang

    2003-05-01

    We present the development of a polyimide-based two-dimensional tactile sensing array realized using a novel inverted fabrication technique. Thermal silicon oxide or Pyrex® substrates are treated such that their surfaces are OH group terminated, allowing good adhesion between such substrates and a spun-on polyimide film during processing through what are suspected to be hydrogen bonds that can be selectively broken when release is desired. The release of the continuous polyimide film is rapidly accomplished by breaking these bonds. This process results in robust, low-cost and continuous polymer-film devices. The developed sensor skin contains an array of membrane-based tactile sensors (taxels). Micromachined thin-film metal strain gauges are positioned on the edges of polyimide membranes. The change in resistance from each strain gauge resulting from normal forces applied to tactile bumps on the top of the membranes is used to image force distribution. Response of an individual taxel is characterized. The effective gauge factor of the taxels is found to be approximately 1.3. Sensor array output is experimentally obtained. The demonstrated devices are robust enough for direct contact with humans, everyday objects and contaminants without undue care.

  9. An optical fiber Bragg grating tactile sensor

    NASA Astrophysics Data System (ADS)

    Cowie, Barbara; Allsop, Thomas; Williams, John; Webb, David; Bennion, Ian; Fisher, Matthew

    2007-05-01

    Tactile sensors are needed for many emerging robotic and telepresence applications such as keyhole surgery and robot operation in unstructured environments. We have proposed and demonstrated a tactile sensor consisting of a fibre Bragg grating embedded in a polymer "finger". When the sensor is placed in contact with a surface and translated tangentially across it measurements on the changes in the reflectivity spectrum of the grating provide a measurement of the spatial distribution of forces perpendicular to the surface and thus, through the elasticity of the polymer material, to the surface roughness. Using a sensor fabricated from a Poly Siloxane polymer (Methyl Vinyl Silicone rubber) spherical cap 50 mm in diameter, 6 mm deep with an embedded 10 mm long Bragg grating we have characterised the first and second moment of the grating spectral response when scanned across triangular and semicircular periodic structures both with a modulation depth of 1 mm and a period of 2 mm. The results clearly distinguish the periodicity of the surface structure and the differences between the two different surface profiles. For the triangular structure a central wavelength modulation of 4 pm is observed and includes a fourth harmonic component, the spectral width is modulated by 25 pm. Although crude in comparison to human senses these results clearly shown the potential of such a sensor for tactile imaging and we expect that with further development in optimising both the grating and polymer "finger" properties a much increased sensitivity and spatial resolution is achievable.

  10. Bio-inspired tactile sensing arrays

    NASA Astrophysics Data System (ADS)

    Dahiya, Ravinder S.; Valle, Maurizio; Metta, Giorgio; Lorenzelli, Leandro

    2009-05-01

    This work presents the development of tactile sensing arrays, inspired by cutaneous sensing in humans, for the fingertips of a humanoid robot. The tactile sensing arrays have been developed in two phases. Microelectrode arrays (MEA), having 32 sensing elements - each epoxy adhered with 25μm thick piezoelectric polymer (PVDF-TrFE) film, were fabricated in the first phase. When connected to the gate of FET devices (external to the chip), each element on MEA acts like an extended gate; thereby facilitating modulation of charge in the induced channel by the charge generated in PVDF-TrFE film - as a result of applied force. Thus, each sensing element converts force into voltage. The tactile sensing arrays developed in second phase work on the same principle but are free from any extended gate. These arrays (having 25 sensing elements) use POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistors) touch sensing elements - in which, piezoelectric polymer film is directly spin coated on the gate area of the FET devices. Thus, a POSFET touch sensing element 'senses and partially processes at same site' - as is done by receptors in human skin. The spatial-temporal performance of these chips is similar to that of skin in the human fingertips.

  11. System of Personal Identification by Using Tactile Stimuli

    NASA Astrophysics Data System (ADS)

    Park, Young-Il; Uchida, Masafumi

    In present, personal identfication system have been used to input identification-numbers and passwords by keyboards and touch panels. When a user enters their identification-numbers and passwords an observer could easily see the user's secret details. In this report, new personal identification, which system constitutes tactile sense information using tactile stimuli and based on the cardinal trait of the tactile sense, is proposed.

  12. Seeing by Touch: Evaluation of a Soft Biologically-Inspired Artificial Fingertip in Real-Time Active Touch

    PubMed Central

    Assaf, Tareq; Roke, Calum; Rossiter, Jonathan; Pipe, Tony; Melhuish, Chris

    2014-01-01

    Effective tactile sensing for artificial platforms remains an open issue in robotics. This study investigates the performance of a soft biologically-inspired artificial fingertip in active exploration tasks. The fingertip sensor replicates the mechanisms within human skin and offers a robust solution that can be used both for tactile sensing and gripping/manipulating objects. The softness of the optical sensor's contact surface also allows safer interactions with objects. High-level tactile features such as edges are extrapolated from the sensor's output and the information is used to generate a tactile image. The work presented in this paper aims to investigate and evaluate this artificial fingertip for 2D shape reconstruction. The sensor was mounted on a robot arm to allow autonomous exploration of different objects. The sensor and a number of human participants were then tested for their abilities to track the raised perimeters of different planar objects and compared. By observing the technique and accuracy of the human subjects, simple but effective parameters were determined in order to evaluate the artificial system's performance. The results prove the capability of the sensor in such active exploration tasks, with a comparable performance to the human subjects despite it using tactile data alone whereas the human participants were also able to use proprioceptive cues. PMID:24514881

  13. A Modified Tactile Brush Algorithm for Complex Touch Gestures

    SciTech Connect

    Ragan, Eric

    2015-01-01

    Several researchers have investigated phantom tactile sensation (i.e., the perception of a nonexistent actuator between two real actuators) and apparent tactile motion (i.e., the perception of a moving actuator due to time delays between onsets of multiple actuations). Prior work has focused primarily on determining appropriate Durations of Stimulation (DOS) and Stimulus Onset Asynchronies (SOA) for simple touch gestures, such as a single finger stroke. To expand upon this knowledge, we investigated complex touch gestures involving multiple, simultaneous points of contact, such as a whole hand touching the arm. To implement complex touch gestures, we modified the Tactile Brush algorithm to support rectangular areas of tactile stimulation.

  14. Separate Mechanisms for Audio-Tactile Pitch and Loudness Interactions

    PubMed Central

    Yau, Jeffrey M.; Weber, Alison I.; Bensmaia, Sliman J.

    2010-01-01

    A major goal in perceptual neuroscience is to understand how signals from different sensory modalities are combined to produce stable and coherent representations. We previously investigated interactions between audition and touch, motivated by the fact that both modalities are sensitive to environmental oscillations. In our earlier study, we characterized the effect of auditory distractors on tactile frequency and intensity perception. Here, we describe the converse experiments examining the effect of tactile distractors on auditory processing. Because the two studies employ the same psychophysical paradigm, we combined their results for a comprehensive view of how auditory and tactile signals interact and how these interactions depend on the perceptual task. Together, our results show that temporal frequency representations are perceptually linked regardless of the attended modality. In contrast, audio-tactile loudness interactions depend on the attended modality: Tactile distractors influence judgments of auditory intensity, but judgments of tactile intensity are impervious to auditory distraction. Lastly, we show that audio-tactile loudness interactions depend critically on stimulus timing, while pitch interactions do not. These results reveal that auditory and tactile inputs are combined differently depending on the perceptual task. That distinct rules govern the integration of auditory and tactile signals in pitch and loudness perception implies that the two are mediated by separate neural mechanisms. These findings underscore the complexity and specificity of multisensory interactions. PMID:21887147

  15. Walking guide robot with tactile display for the blind

    NASA Astrophysics Data System (ADS)

    Yoon, Myoung-Jong; Yu, Kee-Ho; Kang, Jeong-Ho; Kim, Nam-Gyun

    2005-12-01

    A prototype of a walking guide robot with tactile display was introduced, and the psychophysical experiment of the tactile recognition for a tactile display was carried out and analyzed. The objective of this research is the development of a walking guide robot for the blind to walk safely. The walking guide robot consists of a guide vehicle for the obstacle detection and a tactile display device for the transfer of the obstacle information. The guide vehicle, located in the front of the walking blind, detects the obstacle using ultrasonic and infrared ray sensors. The processed information makes a obstacle map and transmits safe path and emergency situation to the blind by the tactile display. The guide vehicle offers the information of position and walking direction acquired from GPS module to the walking blind by voice. The tactile display device, located in the handle which is connected with the guide vehicle by cane, offers the processed obstacle information such as position, size, moving, shape of obstacle and safe path, etc.. The psychophysical experiments for the threshold of perception and recognition ability of tactile stimulation were carried out by the estimation of the subject group. As a result, the appropriate tactile stimulus intensity and frequency to recognize tactile stimulation effectively were discussed and derived.

  16. Real-time edge tracking using a tactile sensor

    NASA Technical Reports Server (NTRS)

    Berger, Alan D.; Volpe, Richard; Khosla, Pradeep K.

    1989-01-01

    Object recognition through the use of input from multiple sensors is an important aspect of an autonomous manipulation system. In tactile object recognition, it is necessary to determine the location and orientation of object edges and surfaces. A controller is proposed that utilizes a tactile sensor in the feedback loop of a manipulator to track along edges. In the control system, the data from the tactile sensor is first processed to find edges. The parameters of these edges are then used to generate a control signal to a hybrid controller. Theory is presented for tactile edge detection and an edge tracking controller. In addition, experimental verification of the edge tracking controller is presented.

  17. International oil and gas exploration and development activities

    SciTech Connect

    Not Available

    1991-09-01

    This report is part of an ongoing series of quarterly publications that monitors discoveries of oil and natural gas in foreign countries and provides an analysis of the resulting reserve additions. The report is prepared by the Energy Information Administration (EIA) of the US Department of Energy (DOE) under the Foreign Energy Supply Assessment Program (FESAP). Presented is summary of discoveries and reserve additions that result from recent international exploration and development activities. A discovery, as used in this publication, is a published estimate of the ultimately recoverable reserves for either a new field, reservoir, or well. Ultimate recovery is defined in this report as cumulative production plus remaining plus reserves. Discoveries are obtained from various oil industry periodicals and company annual or quarterly reports. The discoveries are not verified by EIA but simply restated in this publication. There are four tables and six figures showing oil production, oil and gas reserve additions, active rotary rigs, and crude oil prices. The data are presented by country, geographic region, or economic sector such as the Organization of Petroleum Exporting Countries (OPEC), the Non-OPEC Market Economics (Non-OPEC ME), and the Centrally Planned Economies (CPE). A few of the more significant discoveries are discussed in this report, and their approximate locations are shown on three continental maps. The appendices list discoveries reported in industry periodicals and company reports, Petroconsultants oil and gas reserve additions, remaining oil and gas reserves, and a glossary of abbreviations. 19 refs., 7 figs., 4 tabs.

  18. Active Learning for Directed Exploration of Complex Systems

    NASA Technical Reports Server (NTRS)

    Burl, Michael C.; Wang, Esther

    2009-01-01

    Physics-based simulation codes are widely used in science and engineering to model complex systems that would be infeasible to study otherwise. Such codes provide the highest-fidelity representation of system behavior, but are often so slow to run that insight into the system is limited. For example, conducting an exhaustive sweep over a d-dimensional input parameter space with k-steps along each dimension requires k(sup d) simulation trials (translating into k(sup d) CPU-days for one of our current simulations). An alternative is directed exploration in which the next simulation trials are cleverly chosen at each step. Given the results of previous trials, supervised learning techniques (SVM, KDE, GP) are applied to build up simplified predictive models of system behavior. These models are then used within an active learning framework to identify the most valuable trials to run next. Several active learning strategies are examined including a recently-proposed information-theoretic approach. Performance is evaluated on a set of thirteen synthetic oracles, which serve as surrogates for the more expensive simulations and enable the experiments to be replicated by other researchers.

  19. Peripheral NMDA Receptors Mediate Antidromic Nerve Stimulation-Induced Tactile Hypersensitivity in the Rat

    PubMed Central

    Jang, Jun Ho; Nam, Taick Sang; Jun, Jaebeom; Jung, Se Jung; Kim, Dong-Wook; Leem, Joong Woo

    2015-01-01

    We investigated the role of peripheral NMDA receptors (NMDARs) in antidromic nerve stimulation-induced tactile hypersensitivity outside the skin area innervated by stimulated nerve. Tetanic electrical stimulation (ES) of the decentralized L5 spinal nerve, which induced enlargement of plasma extravasation, resulted in tactile hypersensitivity in the L4 plantar dermatome of the hind-paw. When intraplantar (i.pl.) injection was administered into the L4 dermatome before ES, NMDAR and group-I metabotropic Glu receptor (mGluR) antagonists and group-II mGluR agonist but not AMPA/kainate receptor antagonist prevented ES-induced hypersensitivity. I.pl. injection of PKA or PKC inhibitors also prevented ES-induced hypersensitivity. When the same injections were administered after establishment of ES-induced hypersensitivity, hypersensitivity was partially reduced by NMDAR antagonist only. In naïve animals, i.pl. Glu injection into the L4 dermatome induced tactile hypersensitivity, which was blocked by NMDAR antagonist and PKA and PKC inhibitors. These results suggest that the peripheral release of Glu, induced by antidromic nerve stimulation, leads to the expansion of tactile hypersensitive skin probably via nociceptor sensitization spread due to the diffusion of Glu into the skin near the release site. In addition, intracellular PKA- and PKC-dependent mechanisms mediated mainly by NMDAR activation are involved in Glu-induced nociceptor sensitization and subsequent hypersensitivity. PMID:26770021

  20. Object recognition and localization: the role of tactile sensors.

    PubMed

    Aggarwal, Achint; Kirchner, Frank

    2014-01-01

    Tactile sensors, because of their intrinsic insensitivity to lighting conditions and water turbidity, provide promising opportunities for augmenting the capabilities of vision sensors in applications involving object recognition and localization. This paper presents two approaches for haptic object recognition and localization for ground and underwater environments. The first approach called Batch Ransac and Iterative Closest Point augmented Particle Filter (BRICPPF) is based on an innovative combination of particle filters, Iterative-Closest-Point algorithm, and a feature-based Random Sampling and Consensus (RANSAC) algorithm for database matching. It can handle a large database of 3D-objects of complex shapes and performs a complete six-degree-of-freedom localization of static objects. The algorithms are validated by experimentation in ground and underwater environments using real hardware. To our knowledge this is the first instance of haptic object recognition and localization in underwater environments. The second approach is biologically inspired, and provides a close integration between exploration and recognition. An edge following exploration strategy is developed that receives feedback from the current state of recognition. A recognition by parts approach is developed which uses the BRICPPF for object sub-part recognition. Object exploration is either directed to explore a part until it is successfully recognized, or is directed towards new parts to endorse the current recognition belief. This approach is validated by simulation experiments. PMID:24553087

  1. Object Recognition and Localization: The Role of Tactile Sensors

    PubMed Central

    Aggarwal, Achint; Kirchner, Frank

    2014-01-01

    Tactile sensors, because of their intrinsic insensitivity to lighting conditions and water turbidity, provide promising opportunities for augmenting the capabilities of vision sensors in applications involving object recognition and localization. This paper presents two approaches for haptic object recognition and localization for ground and underwater environments. The first approach called Batch Ransac and Iterative Closest Point augmented Particle Filter (BRICPPF) is based on an innovative combination of particle filters, Iterative-Closest-Point algorithm, and a feature-based Random Sampling and Consensus (RANSAC) algorithm for database matching. It can handle a large database of 3D-objects of complex shapes and performs a complete six-degree-of-freedom localization of static objects. The algorithms are validated by experimentation in ground and underwater environments using real hardware. To our knowledge this is the first instance of haptic object recognition and localization in underwater environments. The second approach is biologically inspired, and provides a close integration between exploration and recognition. An edge following exploration strategy is developed that receives feedback from the current state of recognition. A recognition by parts approach is developed which uses the BRICPPF for object sub-part recognition. Object exploration is either directed to explore a part until it is successfully recognized, or is directed towards new parts to endorse the current recognition belief. This approach is validated by simulation experiments. PMID:24553087

  2. Extravehicular Activity Asteroid Exploration and Sample Collection Capability

    NASA Technical Reports Server (NTRS)

    Scoville, Zebulon; Sipila, Stephanie; Bowie, Jonathan

    2014-01-01

    NASA's Asteroid Redirect Crewed Mission (ARCM) is challenged with primary mission objectives of demonstrating deep space Extravehicular Activity (EVA) and tools, and obtaining asteroid samples to return to Earth for further study. Although the Modified Advanced Crew Escape Suit (MACES) is used for the EVAs, it has limited mobility which increases fatigue and decreases the crews' capability to perform EVA tasks. Furthermore, previous Shuttle and International Space Station (ISS) spacewalks have benefited from EVA interfaces which have been designed and manufactured on Earth. Rigid structurally mounted handrails, and tools with customized interfaces and restraints optimize EVA performance. For ARCM, some vehicle interfaces and tools can leverage heritage designs and experience. However, when the crew ventures onto an asteroid capture bag to explore the asteroid and collect rock samples, EVA complexity increases due to the uncertainty of the asteroid properties. The variability of rock size, shape and composition, as well as bunching of the fabric bag will complicate EVA translation, tool restraint and body stabilization. The unknown asteroid hardness and brittleness will complicate tool use. The rock surface will introduce added safety concerns for cut gloves and debris control. Feasible solutions to meet ARCM EVA objectives were identified using experience gained during Apollo, Shuttle, and ISS EVAs, terrestrial mountaineering practices, NASA Extreme Environment Mission Operations (NEEMO) 16 mission, and during Neutral Buoyancy Laboratory testing in the MACES suit. The proposed concept utilizes expandable booms and integrated features of the asteroid capture bag to position and restrain the crew at the asteroid worksite. These methods enable the capability to perform both finesse, and high load tasks necessary to collect samples for scientific characterization of the asteroid. This paper will explore the design trade space and options that were examined for EVA, the

  3. Sustained maintenance of somatotopic information in brain regions recruited by tactile working memory.

    PubMed

    Katus, Tobias; Müller, Matthias M; Eimer, Martin

    2015-01-28

    To adaptively guide ongoing behavior, representations in working memory (WM) often have to be modified in line with changing task demands. We used event-related potentials (ERPs) to demonstrate that tactile WM representations are stored in modality-specific cortical regions, that the goal-directed modulation of these representations is mediated through hemispheric-specific activation of somatosensory areas, and that the rehearsal of somatotopic coordinates in memory is accomplished by modality-specific spatial attention mechanisms. Participants encoded two tactile sample stimuli presented simultaneously to the left and right hands, before visual retro-cues indicated which of these stimuli had to be retained to be matched with a subsequent test stimulus on the same hand. Retro-cues triggered a sustained tactile contralateral delay activity component with a scalp topography over somatosensory cortex contralateral to the cued hand. Early somatosensory ERP components to task-irrelevant probe stimuli (that were presented after the retro-cues) and to subsequent test stimuli were enhanced when these stimuli appeared at the currently memorized location relative to other locations on the cued hand, demonstrating that a precise focus of spatial attention was established during the selective maintenance of tactile events in WM. These effects were observed regardless of whether participants performed the matching task with uncrossed or crossed hands, indicating that WM representations in this task were based on somatotopic rather than allocentric spatial coordinates. In conclusion, spatial rehearsal in tactile WM operates within somatotopically organized sensory brain areas that have been recruited for information storage. PMID:25632117

  4. Sustained Maintenance of Somatotopic Information in Brain Regions Recruited by Tactile Working Memory

    PubMed Central

    Katus, Tobias; Eimer, Martin

    2015-01-01

    To adaptively guide ongoing behavior, representations in working memory (WM) often have to be modified in line with changing task demands. We used event-related potentials (ERPs) to demonstrate that tactile WM representations are stored in modality-specific cortical regions, that the goal-directed modulation of these representations is mediated through hemispheric-specific activation of somatosensory areas, and that the rehearsal of somatotopic coordinates in memory is accomplished by modality-specific spatial attention mechanisms. Participants encoded two tactile sample stimuli presented simultaneously to the left and right hands, before visual retro-cues indicated which of these stimuli had to be retained to be matched with a subsequent test stimulus on the same hand. Retro-cues triggered a sustained tactile contralateral delay activity component with a scalp topography over somatosensory cortex contralateral to the cued hand. Early somatosensory ERP components to task-irrelevant probe stimuli (that were presented after the retro-cues) and to subsequent test stimuli were enhanced when these stimuli appeared at the currently memorized location relative to other locations on the cued hand, demonstrating that a precise focus of spatial attention was established during the selective maintenance of tactile events in WM. These effects were observed regardless of whether participants performed the matching task with uncrossed or crossed hands, indicating that WM representations in this task were based on somatotopic rather than allocentric spatial coordinates. In conclusion, spatial rehearsal in tactile WM operates within somatotopically organized sensory brain areas that have been recruited for information storage. PMID:25632117

  5. Exploring the Exploratorium.

    ERIC Educational Resources Information Center

    Neill, Shirley Boes

    1978-01-01

    Describes a San Francisco, California, science museum whose design is based on the exploration of perception. The museum is arranged in sections on patterns, light color, eye logic, third dimension, sound, hearing, electricity, and the tactile gallery. Programs include teacher training, student learning experience, field trips and study projects,…

  6. Adult developmental trajectories of pseudoneglect in the tactile, visual and auditory modalities and the influence of starting position and stimulus length.

    PubMed

    Brooks, Joanna L; Darling, Stephen; Malvaso, Catia; Della Sala, Sergio

    2016-03-01

    Pseudoneglect is a tendency to pay more attention to the left side of space, typically demonstrated on tasks like visuo-spatial line bisection, tactile rod bisection and the mental representation of numbers. The developmental trajectory of this bias on these three tasks is not fully understood. In the current study younger participants aged between 18 and 40 years of age and older participants aged between 55 and 90 years conducted three spatial tasks: (1) visuospatial line bisection - participants were asked to bisect visually presented lines of different lengths at the perceived midpoint; (2) touch-driven tactile rod bisection in the absence of vision - participants were asked to feel the length of a wooden rod with their index finger and bisect the rod at the perceived centre; and (3) mental number line bisection in the absence of vision - participants were asked to listen to a pair of numbers and respond with the numerical midpoint between the pair. The results showed that both younger and older participants demonstrated pseudoneglect (leftward biases) in the visual, tactile and mental number line tasks and that the magnitude of pseudoneglect for each group was influenced by physical or mentally represented starting side (start left versus start right) and stimulus length. We provide an exploration of pseudoneglect in younger and older adults in different tasks that vary in the degree to which mental representations are accessed and argue that pseudoneglect is a result of a right hemisphere attentional orienting process that is retained throughout adulthood. Our results indicate that, contrary to some current models of cognitive ageing, asymmetrical patterns of hemispheric activity may occur in older age. PMID:26799680

  7. Galfenol tactile sensor array and visual mapping system

    NASA Astrophysics Data System (ADS)

    Hale, Kathleen; Flatau, Alison

    2006-03-01

    The smart material, Galfenol, is being explored for its uses as a magnetostrictive material. This project seeks to determine if Galfenol can be used as a tactile sensor in a 2-D grid array, magnetic circuit system. When used within a magnetic circuit, Galfenol indicates induced stress and force as a change in flux, due to a change in permeability of the material. The change in flux is detected by Giant MagnetoResistive (GMR) Sensors, which produce a voltage change proportional to the field change. By using Galfenol in an array, this research attempts to create a sensory area. Galfenol is an alloy made of Iron and Gallium. Fe 100-xGa x, where 15 <= x <= 28, creates a material with useful mechanical and transduction attributes (Clark et al. and Kellogg). Galfenol is also distinguished by the crystalline structure of the material. Two types currently exist: single crystal and polycrystalline. Single crystal has higher transduction coefficients than polycrystalline, but is more costly. Polycrystalline Galfenol is currently available as either production or research grade. The designations are related to the sample growth rate with the slower rate being the research grade. The slower growth rate more closely resembles the single crystal Galfenol properties. Galfenol 17.5-18% research grade is used for this experiment, provided by Etrema Products Inc. The magnetic circuit and sensor array is first built at the macro scale so that the design can be verified. After the macro scale is proven, further development will move the system to the nano-level. Recent advances in nanofabrication have enabled Galfenol to be grown as nanowires. Using the nanowires, research will seek to create high resolution tactile sensors with spatial resolutions similar to human finger tips, but with greater force ranges and sensitivity capabilities (Flatau & Stadler). Possible uses of such systems include robotics and prosthetics.

  8. Exploring the sheep rumen microbiome for carbohydrate-active enzymes.

    PubMed

    Lopes, Lucas Dantas; de Souza Lima, André Oliveira; Taketani, Rodrigo Gouvêa; Darias, Phillip; da Silva, Lília Raquel Fé; Romagnoli, Emiliana Manesco; Louvandini, Helder; Abdalla, Adibe Luiz; Mendes, Rodrigo

    2015-07-01

    The rumen is a complex ecosystem enriched for microorganisms able to degrade biomass during the animal's digestion process. The recovery of new enzymes from naturally evolved biomass-degrading microbial communities is a promising strategy to overcome the inefficient enzymatic plant destruction in industrial production of biofuels. In this context, this study aimed to describe the bacterial composition and functions in the sheep rumen microbiome, focusing on carbohydrate-active enzymes (CAE). Here, we used phylogenetic profiling analysis (inventory of 16S rRNA genes) combined with metagenomics to access the rumen microbiome of four sheep and explore its potential to identify fibrolytic enzymes. The bacterial community was dominated by Bacteroidetes and Firmicutes, followed by Proteobacteria. As observed for other ruminants, Prevotella was the dominant genus in the microbiome, comprising more than 30 % of the total bacterial community. Multivariate analysis of the phylogenetic profiling data and chemical parameters showed a positive correlation between the abundance of Prevotellaceae (Bacteroidetes phylum) and organic matter degradability. A negative correlation was observed between Succinivibrionaceae (Proteobacteria phylum) and methane production. An average of 2 % of the shotgun metagenomic reads was assigned to putative CAE when considering nine protein databases. In addition, assembled contigs allowed recognition of 67 putative partial CAE (NCBI-Refseq) representing 12 glycosyl hydrolase families (Pfam database). Overall, we identified a total of 28 lignocellulases, 22 amylases and 9 other putative CAE, showing the sheep rumen microbiome as a promising source of new fibrolytic enzymes. PMID:25900454

  9. Use of the Talking Tactile Tablet in Mathematics Testing.

    ERIC Educational Resources Information Center

    Landau, Steven; Russell, Michael; Gourgey, Karen; Erin, Jane N.; Cowan, Jennifer

    2003-01-01

    This article describes an experimental system for administering multiple-choice math tests to students who are visually impaired or have other print disabilities. Using a new audio-tactile computer peripheral device called the Talking Tactile Tablet, a preliminary version of a self-voicing test was created for eight participants. (Contains…

  10. Tactile Perception in Adults with Autism: A Multidimensional Psychophysical Study

    ERIC Educational Resources Information Center

    Cascio, Carissa; McGlone, Francis; Folger, Stephen; Tannan, Vinay; Baranek, Grace; Pelphrey, Kevin A.; Essick, Gregory

    2008-01-01

    Although sensory problems, including unusual tactile sensitivity, are heavily associated with autism, there is a dearth of rigorous psychophysical research. We compared tactile sensation in adults with autism to controls on the palm and forearm, the latter innervated by low-threshold unmyelinated afferents subserving a social/affiliative…

  11. Tactile Functioning in Children Who Are Blind: A Clinical Perspective

    ERIC Educational Resources Information Center

    Withagen, Ans; Vervloed, Mathijs P. J.; Janssen, Neeltje M.; Knoors, Harry; Verhoeven, Ludo

    2010-01-01

    This study of 48 children with congenital blindness who attended mainstream schools focused on the tactile and haptic skills they needed in typical academic and everyday tasks. The results showed that, in general, the children mastered such tactile tasks, but some items posed special problems. (Contains 4 tables.)

  12. Change of Reference Frame for Tactile Localization during Child Development

    ERIC Educational Resources Information Center

    Pagel, Birthe; Heed, Tobias; Roder, Brigitte

    2009-01-01

    Temporal order judgements (TOJ) for two tactile stimuli, one presented to the left and one to the right hand, are less precise when the hands are crossed over the midline than when the hands are uncrossed. This "crossed hand" effect has been considered as evidence for a remapping of tactile input into an external reference frame. Since late, but…

  13. Beneficial Effects of Tactile Stimulation on Early Development.

    ERIC Educational Resources Information Center

    Caulfield, Rick

    2000-01-01

    Reviews selected research on the beneficial effects of tactile stimulation on infants. Examines the results of studies with animals, preterm infants, cocaine- and HIV-exposed preterm infants, and normal full-term infants. Briefly discusses caregiving implications and offers suggestions on how caregivers can incorporate tactile stimulation in…

  14. Tactile feedback display with spatial and temporal resolutions.

    PubMed

    Vishniakou, Siarhei; Lewis, Brian W; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

    2013-01-01

    We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications. PMID:23982053

  15. Tactile Feedback Display with Spatial and Temporal Resolutions

    NASA Astrophysics Data System (ADS)

    Vishniakou, Siarhei; Lewis, Brian W.; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

    2013-08-01

    We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications.

  16. Tactile Feedback Display with Spatial and Temporal Resolutions

    PubMed Central

    Vishniakou, Siarhei; Lewis, Brian W.; Niu, Xiaofan; Kargar, Alireza; Sun, Ke; Kalajian, Michael; Park, Namseok; Yang, Muchuan; Jing, Yi; Brochu, Paul; Sun, Zhelin; Li, Chun; Nguyen, Truong; Pei, Qibing; Wang, Deli

    2013-01-01

    We report the electronic recording of the touch contact and pressure using an active matrix pressure sensor array made of transparent zinc oxide thin-film transistors and tactile feedback display using an array of diaphragm actuators made of an interpenetrating polymer elastomer network. Digital replay, editing and manipulation of the recorded touch events were demonstrated with both spatial and temporal resolutions. Analog reproduction of the force is also shown possible using the polymer actuators, despite of the high driving voltage. The ability to record, store, edit, and replay touch information adds an additional dimension to digital technologies and extends the capabilities of modern information exchange with the potential to revolutionize physical learning, social networking, e-commerce, robotics, gaming, medical and military applications. PMID:23982053

  17. Response requirements modulate tactile spatial congruency effects.

    PubMed

    Gallace, Alberto; Soto-Faraco, Salvador; Dalton, Polly; Kreukniet, Bas; Spence, Charles

    2008-11-01

    Several recent studies have provided support for the view that tactile stimuli/events are remapped into an abstract spatial frame of reference beyond the initial somatotopic representation present in the primary somatosensory cortex. Here, we demonstrate for the first time that the extent to which this remapping of tactile stimuli takes place is dependent upon the particular demands imposed by the task that participants have to perform. Participants in the present study responded to either the elevation (up vs. down) or to the anatomical location (finger vs. thumb) of vibrotactile targets presented to one hand, while trying to ignore distractors presented simultaneously to the other hand. The magnitude and direction of the target-distractor congruency effect was measured as participants adopted one of two different postures with each hand (palm-up or palm-down). When the participants used footpedal responses (toe vs. heel; Experiment 1), congruency effects were determined by the relative elevation of the stimuli in external coordinates (same vs. different elevation), regardless of whether the relevant response feature was defined externally or anatomically. Even when participants responded verbally (Experiment 2), the influence of the relative elevation of the stimuli in external space, albeit attenuated, was still observed. However, when the task involved responding with the stimulated finger (four-alternative forced choice; Experiment 3), congruency effects were virtually eliminated. These findings support the view that tactile events can be remapped according to an abstract frame of reference resulting from multisensory integration, but that the frame of reference that is used while performing a particular task may depend to a large extent on the nature of the task demands. PMID:18709500

  18. Flexibly weighted integration of tactile reference frames.

    PubMed

    Badde, Stephanie; Röder, Brigitte; Heed, Tobias

    2015-04-01

    To estimate the location of a tactile stimulus, the brain seems to integrate different types of spatial information such as skin-based, anatomical coordinates and external, spatiotopic coordinates. The aim of the present study was to test whether the use of these coordinates is fixed, or whether they are weighted according to the task context. Participants made judgments about two tactile stimuli with different vibration characteristics, one applied to each hand. First, they always performed temporal order judgments (TOJ) of the tactile stimuli with respect to the stimulated hands that were either crossed or uncrossed. The resulting crossing effect, that is, impaired performance in crossed compared to uncrossed conditions, was used as a measure of reference frame weighting and was compared across conditions. Second, in dual judgment conditions participants subsequently made judgments about the stimulus vibration characteristics, either with respect to spatial location or with respect to temporal order. Responses in the spatial secondary task either accented anatomical (Experiment 1) or external (Experiment 2) coding. A TOJ crossing effect emerged in all conditions, and secondary tasks did not affect primary task performance in the uncrossed posture. Yet, the spatial secondary task resulted in improved crossed hands performance in the primary task, but only if the secondary judgment stressed the anatomical reference frame (Experiment 1), rather than the external reference frames (Experiment 2). Like the anatomically coded spatial secondary task, the temporal secondary task improved crossed hand performance of the primary task. The differential influence of the varying secondary tasks implies that integration weights assigned to the anatomical and external reference frames are not fixed. Rather, they are flexibly adjusted to the context, presumably through top-down modulation. PMID:25447059

  19. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    ERIC Educational Resources Information Center

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  20. Auditory-tactile echo-reverberating stuttering speech corrector

    NASA Astrophysics Data System (ADS)

    Kuniszyk-Jozkowiak, Wieslawa; Adamczyk, Bogdan

    1997-02-01

    The work presents the construction of a device, which transforms speech sounds into acoustical and tactile signals of echo and reverberation. Research has been done on the influence of the echo and reverberation, which are transmitted as acoustic and tactile stimuli, on speech fluency. Introducing the echo or reverberation into the auditory feedback circuit results in a reduction of stuttering. A bit less, but still significant corrective effects are observed while using the tactile channel for transmitting the signals. The use of joined auditory and tactile channels increases the effects of their corrective influence on the stutterers' speech. The results of the experiment justify the use of the tactile channel in the stutterers' therapy.

  1. Design of tactile device for medical application using magnetorheological fluid

    NASA Astrophysics Data System (ADS)

    Oh, J. S.; Kim, J. K.; Lee, S. R.; Choi, S. B.; Song, B. K.

    2013-02-01

    For the tactile recognition of human organ in minimally invasive surgery (MIS), this paper presents a novel tactile device that incorporates with magnetorheological (MR fluid). The MR fluid is contained by diaphragm and several pins. The operator for MIS can feel different force (or stiffness) from the proposed tactile device by applying different magnetic field or current. In order to generate required force from the device, the repulsive force from the human body is measured as reference data and an appropriate size of tactile device is designed and manufactured. It has been demonstrated via experiment that the repulsive force corresponding to the human body can be achieved by applying proper control input current. In addition, it has been shown that we can control the repulsive force by dividing the tactile device by several sections.

  2. The Hubble Education Program's Tactile Astronomy: Making the Universe Touchable

    NASA Astrophysics Data System (ADS)

    Eisenhamer, Bonnie; Mutchler, M.; Cordes, K.; Weaver, D.; Ryer, H.

    2011-01-01

    Tactile Astronomy supports the Hubble Education Program's efforts in bringing the wonders of the universe to everyone, regardless of their visual ability. This new section of the Amazing Space Website features "Images of the Month;" a collection of the latest Hubble images that can be printed in a tactile format. The images are specifically designed to be downloaded and printed on a thermal paper expansion machine, thus allowing the visually impaired to feel what they cannot see. In addition, there is a "special projects" section that currently features the limited-edition Tactile Carina Nebula booklet and accompanying materials, such as background text about the Carina Nebula and an audio tour. The opening of Tactile Astronomy is in celebration of Hubble's 20th anniversary and features the 20th anniversary image of a small portion of the Carina Nebula. New tactile images and additional projects will continue to be added to the site.

  3. Reorienting driver attention with dynamic tactile cues.

    PubMed

    Ho, Cristy; Gray, Rob; Spence, Charles

    2014-03-01

    A series of three experiments was designed to investigate whether the presentation of moving tactile warning signals that are presented in a particular spatiotemporal configuration may be particularly effective in terms of facilitating a driver's response to a target event. In the experiments reported here, participants' visual attention was manipulated such that they were either attending to the frontal object that might occasionally approach them on a collision course, or else they were distracted by a color discrimination task presented from behind. We measured how rapidly participants were able to initiate a braking response to a looming visual target following the onset of vibrotactile warning signals presented from around their waist. The vibrotactile warning signals consisted of single, double, and triple upward moving cues (Experiment 1), triple upward and downward moving cues (Experiment 2), and triple random cues (Experiment 3). The results demonstrated a significant performance advantage following the presentation of dynamic triple cues over the static single tactile cues, regardless of the specific configuration of the triple cues. These findings point to the potential benefits of embedding dynamic information in warning signals for dynamic target events. These findings have important implications for the design of future vibrotactile warning signals. PMID:24845749

  4. Tactile stimulation of the oropharynx elicits sympathoexcitation in conscious humans

    PubMed Central

    Muller, Matthew D.; Mast, Jessica L.; Cui, Jian; Heffernan, Matthew J.; McQuillan, Patrick M.

    2013-01-01

    Tactile stimulation of the oropharynx (TSO) elicits the gag reflex and increases heart rate (HR) and mean arterial pressure (MAP) in anesthetized patients. However, the interaction between upper-airway defense reflexes and the sympathetic nervous system has not been investigated in conscious humans. In Experiment 1, beat-by-beat measurements of HR, MAP, muscle sympathetic nerve activity (MSNA), and renal vascular resistance (RVR) were measured during TSO and tactile stimulation of the hard palate (Sham) in the supine posture. In Experiment 2, TSO was performed before (pre) and after (post) inhalation of 4% lidocaine via nebulizer. Rate pressure product (RPP) was determined. Compared with Sham, TSO elicited the gag reflex and increased RPP [absolute change (Δ)36 ± 6 vs. 17 ± 5%], MSNA (Δ122 ± 39 vs. 19 ± 19%), and RVR (Δ55 ± 11 vs. 4 ± 4%). This effect occurred within one to two cardiac cycles of TSO. The ΔMAP (12 ± 3 vs. 6 ± 1 mmHg) and the ΔHR (10 ± 3 vs. 3 ± 3 beats/min) were also greater following TSO compared with Sham. Lidocaine inhalation blocked the gag reflex and attenuated increases in MAP (Δpre: 16 ± 2; Δpost: 5 ± 2 mmHg) and HR (Δpre: 12 ± 3; Δpost: 2 ± 2 beats/min) in response to TSO. When mechanically stimulated, afferents in the oropharynx not only serve to protect the airway but also cause reflex increases in MSNA, RVR, MAP, and HR. An augmented sympathoexcitatory response during intubation and laryngoscopy may contribute to perioperative cardiovascular morbidity and mortality. PMID:23599399

  5. Tactile Sensitivity of Children: Effects of Frequency, Masking, and the Non-Pacinian I Psychophysical Channel

    ERIC Educational Resources Information Center

    Guclu, Burak; Oztek, Cigdem

    2007-01-01

    Tactile perception depends on the contributions of four psychophysical tactile channels mediated by four corresponding receptor systems. The sensitivity of the tactile channels is determined by detection thresholds that vary as a function of the stimulus frequency. It has been widely reported that tactile thresholds increase (i.e., sensitivity…

  6. Tactile Stimulation Evokes Long-Lasting Potentiation of Purkinje Cell Discharge In Vivo

    PubMed Central

    Ramakrishnan, K. B.; Voges, Kai; De Propris, Licia; De Zeeuw, Chris I.; D’Angelo, Egidio

    2016-01-01

    In the cerebellar network, a precise relationship between plasticity and neuronal discharge has been predicted. However, the potential generation of persistent changes in Purkinje cell (PC) spike discharge as a consequence of plasticity following natural stimulation patterns has not been clearly determined. Here, we show that facial tactile stimuli organized in theta-patterns can induce stereotyped N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid (GABA-A) receptor-dependent changes in PCs and molecular layer interneurons (MLIs) firing: invariably, all PCs showed a long-lasting increase (Spike-Related Potentiation or SR-P) and MLIs a long-lasting decrease (Spike-Related Suppression or SR-S) in baseline activity and spike response probability. These observations suggests that tactile sensory stimulation engages multiple long-term plastic changes that are distributed along the mossy fiber-parallel fiber (MF-PF) pathway and operate synergistically to potentiate spike generation in PCs. In contrast, theta-pattern electrical stimulation (ES) of PFs indistinctly induced SR-P and SR-S both in PCs and MLIs, suggesting that tactile sensory stimulation preordinates plasticity upstream of the PF-PC synapse. All these effects occurred in the absence of complex spike changes, supporting the theoretical prediction that PC activity is potentiated when the MF-PF system is activated in the absence of conjunctive climbing fiber (CF) activity. PMID:26924961

  7. Long-range tactile masking occurs in the postural body schema.

    PubMed

    D'Amour, Sarah; Harris, Laurence R

    2016-02-01

    Long-range tactile masking has been reported between mirror symmetric body locations. This suggests a general principle of contralateral inhibition between corresponding points on each side of the body that may serve to enhance distinguishing touches on the two halves of the body. Do such effects occur before or after posture is added to the body schema? Here, we address this question by exploring the effect of arm position on long-range tactile masking. The influence of arm position was investigated using different positions of both the test and masking arms. Tactile sensitivity was measured on one forearm, while vibrotactile-masking stimulation was applied to the opposite arm or to a control site on the shoulder. No difference was found in sensitivity when test arm position was varied. Physical contact between the arms significantly increased the effectiveness of a masking stimulus applied to the other arm. Long-range masking between the arms was strongest when the arms were held parallel to each other and was abolished if the position of either the test arm or the masking arm was moved from this position. Modulation of the effectiveness of masking by the position of both the test and masking arms suggests that these effects occur after posture information is added to the body's representation in the brain. PMID:26553240

  8. Single-Grasp Object Classification and Feature Extraction with Simple Robot Hands and Tactile Sensors.

    PubMed

    Spiers, Adam J; Liarokapis, Minas V; Calli, Berk; Dollar, Aaron M

    2016-01-01

    Classical robotic approaches to tactile object identification often involve rigid mechanical grippers, dense sensor arrays, and exploratory procedures (EPs). Though EPs are a natural method for humans to acquire object information, evidence also exists for meaningful tactile property inference from brief, non-exploratory motions (a 'haptic glance'). In this work, we implement tactile object identification and feature extraction techniques on data acquired during a single, unplanned grasp with a simple, underactuated robot hand equipped with inexpensive barometric pressure sensors. Our methodology utilizes two cooperating schemes based on an advanced machine learning technique (random forests) and parametric methods that estimate object properties. The available data is limited to actuator positions (one per two link finger) and force sensors values (eight per finger). The schemes are able to work both independently and collaboratively, depending on the task scenario. When collaborating, the results of each method contribute to the other, improving the overall result in a synergistic fashion. Unlike prior work, the proposed approach does not require object exploration, re-grasping, grasp-release, or force modulation and works for arbitrary object start positions and orientations. Due to these factors, the technique may be integrated into practical robotic grasping scenarios without adding time or manipulation overheads. PMID:26829804

  9. Internet Activities Using Scientific Data. A Self-Guided Exploration.

    ERIC Educational Resources Information Center

    Froseth, Stan; Poppe, Barbara

    This guide is intended for the secondary school teacher (especially math or science) or the student who wants to access and learn about scientific data on the Internet. It is organized as a self-guided exploration. Nine exercises enable the user to access and analyze on-line information from the National Oceanic and Atmospheric Administration…

  10. Auxiliary Propulsion Activities in Support of NASA's Exploration Initiative

    NASA Technical Reports Server (NTRS)

    Best, Philip J.; Unger, Ronald J.; Waits, David A.

    2005-01-01

    The Space Launch Initiative (SLI) procurement mechanism NRA8-30 initiated the Auxiliary Propulsion System/Main Propulsion System (APS/MPS) Project in 2001 to address technology gaps and development risks for non-toxic and cryogenic propellants for auxiliary propulsion applications. These applications include reaction control and orbital maneuvering engines, and storage, pressure control, and transfer technologies associated with on-orbit maintenance of cryogens. The project has successfully evolved over several years in response to changing requirements for re-usable launch vehicle technologies, general launch technology improvements, and, most recently, exploration technologies. Lessons learned based on actual hardware performance have also played a part in the project evolution to focus now on those technologies deemed specifically relevant to the Exploration Initiative. Formal relevance reviews held in the spring of 2004 resulted in authority for continuation of the Auxiliary Propulsion Project through Fiscal Year 2005 (FY05), and provided for a direct reporting path to the Exploration Systems Mission Directorate. The tasks determined to be relevant under the project were: continuation of the development, fabrication, and delivery of three 870 lbf thrust prototype LOX/ethanol reaction control engines; the fabrication, assembly, engine integration and testing of the Auxiliary Propulsion Test Bed at White Sands Test Facility; and the completion of FY04 cryogenic fluid management component and subsystem development tasks (mass gauging, pressure control, and liquid acquisition elements). This paper presents an overview of those tasks, their scope, expectations, and results to-date as carried forward into the Exploration Initiative.

  11. Acquisition of a 250-word vocabulary through a tactile vocoder.

    PubMed

    Brooks, P L; Frost, B J; Mason, J L; Chung, K

    1985-04-01

    In a previous experiment [P. L. Scilley, "Evaluation of a vibrotactile auditory prosthetic device for the profoundly deaf," unpublished Masters thesis, Queen's University, Kingston, Canada (1980)] two normal subjects learned to identify 70 and 150 words, respectively, using the Queen's Tactile Vocoder. In the present experiment, the most advanced subject continued word learning until a tactile vocabulary of 250 words was acquired. At this point randomized tests were given to obtain an indication of final performance level. From these data conditional probabilities of correct response for each stimulus word and significant confusions were obtained, which provides insight into the advantages and present limitations of the tactile vocoder. PMID:3157716

  12. Tactile texture and friction of soft sponge surfaces.

    PubMed

    Takahashi, Akira; Suzuki, Makoto; Imai, Yumi; Nonomura, Yoshimune

    2015-06-01

    We evaluated the tactile texture and frictional properties of five soft sponges with various cell sizes. The frictional forces were measured by a friction meter containing a contact probe with human-finger-like geometry and mechanical properties. When the subjects touched these sponges with their fingers, hard-textured sponges were deemed unpleasant. This tactile feeling changed with friction factors including friction coefficients, their temporal patterns, as well as mechanical and shape factors. These findings provide useful information on how to control the tactile textures of various sponges. PMID:25884490

  13. A tactile sensor using a conductive graphene-sponge composite.

    PubMed

    Chun, Sungwoo; Hong, Ahyoung; Choi, Yeonhoi; Ha, Chunho; Park, Wanjun

    2016-04-28

    For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor. PMID:27076360

  14. Synergistic Activities of Near-Earth Object Exploration

    NASA Technical Reports Server (NTRS)

    Abell, Paul

    2011-01-01

    U.S. President Obama stated on April 15, 2010 that the next goal for human spaceflight will be to send human beings to near-Earth asteroids by 2025. Missions to NEOs would undoubtedly provide a great deal of technical and engineering data on spacecraft operations for future human space exploration while conducting in-depth scientific examinations of these primitive objects. Information obtained from a human investigation of a NEO, together with ground-based observations and prior spacecraft investigations of asteroids and comets, will also provide a real measure of ground truth to data obtained from terrestrial meteorite collections. Major advances in the areas of geochemistry, impact history, thermal history, isotope analyses, mineralogy, space weathering, formation ages, thermal inertias, volatile content, source regions, solar system formation, etc. can be expected from human NEO missions. Samples directly returned from a primitive body would lead to the same kind of breakthroughs for understanding NEOs that the Apollo samples provided for understanding the Earth-Moon system and its formation history. In addition, robotic precursor and human exploration missions to NEOs would allow the NASA and its international partners to gain operational experience in performing complex tasks (e.g., sample collection, deployment of payloads, retrieval of payloads, etc.) with crew, robots, and spacecraft under microgravity conditions at or near the surface of a small body. This would provide an important synergy between the worldwide Science and Exploration communities, which will be crucial for development of future international deep space exploration architectures and has potential benefits for future exploration of other destinations beyond low-Earth orbit.

  15. Seismic exploration of Fuji volcano with active sources in 2003

    NASA Astrophysics Data System (ADS)

    Oikawa, J.; Kagiyama, T.; Tanaka, S.; Miyamachi, H.; Tsutsui, T.; Ikeda, Y.; Katayama, H.; Matsuo, N.; Oshima, H.; Nishimura, Y.; Yamamoto, K.; Watanabe, T.; Yamazaki, F.

    2004-12-01

    Fuji volcano (altitude 3,776 m) is the largest basaltic stratovolcano in Japan. In late August and early September 2003, seismic exploration was conducted around Fuji volcano by the detonation of 500 kg charges of dynamite to investigate the seismic structure of that area. Seismographs with an eigenfrequency of 2 Hz were used for observation, positioned along a WSW-ENE line passing through the summit of the mountain. A total of 469 observation points were installed at intervals of 250-500 m. The data were stored in memory on-site using data loggers. The sampling interval was 4 ms. Charges were detonated at 5 points, one at each end of the observation line and 3 along its length. The first arrival times at each observation point for each detonation were recorded as data. The P-wave velocity structure directly below the observation line was determined by forward calculation using the ray tracing method [Zelt and Smith, 1992]. The P-wave velocity structure below the volcano, assuming a layered structure, was found to be as follows. (1) The first layer extends for about 40 km around the summit and to a depth of 1-2 km. The P-wave velocity is 2.5 km/s on the upper surface of the layer and 3.5 km/s on the lower interface. (2) The second layer has P-wave velocities of 4.0 km/s on the top interface and 5.5 km/s at the lower interface. The layer is 25 km thick to the west of the summit and 1-2 km thick to the east, and forms a dome shape with a peak altitude of 2000 m directly below the summit. (3) The third layer is 5-12 km thick and has P-wave velocities of 5.7 km/s at the top interface and 6.5 km/s at the lower interface. This layer reaches shallower levels to the east of the summit, corresponding to the area where the second layer is thinner. Mt. Fuji is located slightly back from where the Philippine Sea Plate subducts below the Eurasian plate in association with collision with the Izu Peninsula. Matsuda (1971) suggested that Mt. Fuji lies on the same uplifted body as

  16. Tiny Feel: A New Miniature Tactile Module Using Elastic and Electromagnetic Force for Mobile Devices

    NASA Astrophysics Data System (ADS)

    Yang, Tae-Heon; Kim, Sang-Youn; Book, Wayne J.; Kwon, Dong-Soo

    For tactile feedback in mobile devices, the size and the power consumption of tactile modules are the dominant factors. Thus, vibration motors have been widely used in mobile devices to provide tactile sensation. However, the vibration motor cannot sufficiently generate a great amount of tactile sensation because the magnitude and the frequency of the vibration motor are coupled. For the generation of a wide variety of tactile sensations, this paper presents a new tactile actuator that incorporates a solenoid, a permanent magnet and an elastic spring. The feedback force in this actuator is generated by elastic and electromagnetic force. This paper also proposes a tiny tactile module with the proposed actuators. To construct a tiny tactile module, the contactor gap of the module is minimized without decreasing the contactor stroke, the output force, and the working frequency. The elastic springs of the actuators are separated into several layers to minimize the contactor gap without decreasing the performance of the tactile module. Experiments were conducted to investigate each contactor output force as well as the frequency response of the proposed tactile module. Each contactor of the tactile module can generate enough output force to stimulate human mechanoreceptors. As the contactors are actuated in a wide range of frequency, the proposed tactile module can generate various tactile sensations. Moreover, the size of the proposed tactile module is small enough to be embedded it into a mobile device, and its power consumption is low. Therefore, the proposed tactile actuator and module have good potential in many interactive mobile devices.

  17. The Effects of Fine Motor Movement and Tactile Stimulation on the Math Problem Solving of Students with Attention Problems

    ERIC Educational Resources Information Center

    Kercood, Suneeta; Grskovic, Janice A.; Lee, David L.; Emmert, Stacey

    2007-01-01

    This study evaluated the effectiveness of fine motor physical activity with tactile stimulation during two conditions of math problem solving, visual and auditory. Eight 4th and 5th grade students with attention problems participated. Using an alternating treatments design, students solved as many math story problems as they could, presented on…

  18. The Use of a Tactile-Vision Sensory Substitution System as an Augmentative Tool for Individuals with Visual Impairments

    ERIC Educational Resources Information Center

    Williams, Michael D.; Ray, Christopher T.; Griffith, Jennifer; De l'Aune, William

    2011-01-01

    The promise of novel technological strategies and solutions to assist persons with visual impairments (that is, those who are blind or have low vision) is frequently discussed and held to be widely beneficial in countless applications and daily activities. One such approach involving a tactile-vision sensory substitution modality as a mechanism to…

  19. Tri-axial tactile sensing element

    NASA Astrophysics Data System (ADS)

    Castellanos-Ramos, Julián.; Navas-González, Rafael; Vidal-Verdú, F.

    2013-05-01

    A 13 x 13 square millimetre tri-axial taxel is presented which is suitable for some medical applications, for instance in assistive robotics that involves contact with humans or in prosthetics. Finite Element Analysis is carried out to determine what structure is the best to obtain a uniform distribution of pressure on the sensing areas underneath the structure. This structure has been fabricated in plastic with a 3D printer and a commercial tactile sensor has been used to implement the sensing areas. A three axis linear motorized translation stage with a tri-axial precision force sensor is used to find the parameters of the linear regression model and characterize the proposed taxel. The results are analysed to see to what extent the goal has been reached in this specific implementation.

  20. A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing

    PubMed Central

    Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W.F.; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B.-H.; Bao, Zhenan

    2015-01-01

    Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots. PMID:26300307

  1. A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing

    NASA Astrophysics Data System (ADS)

    Chou, Ho-Hsiu; Nguyen, Amanda; Chortos, Alex; To, John W. F.; Lu, Chien; Mei, Jianguo; Kurosawa, Tadanori; Bae, Won-Gyu; Tok, Jeffrey B.-H.; Bao, Zhenan

    2015-08-01

    Some animals, such as the chameleon and cephalopod, have the remarkable capability to change their skin colour. This unique characteristic has long inspired scientists to develop materials and devices to mimic such a function. However, it requires the complex integration of stretchability, colour-changing and tactile sensing. Here we show an all-solution processed chameleon-inspired stretchable electronic skin (e-skin), in which the e-skin colour can easily be controlled through varying the applied pressure along with the applied pressure duration. As such, the e-skin's colour change can also be in turn utilized to distinguish the pressure applied. The integration of the stretchable, highly tunable resistive pressure sensor and the fully stretchable organic electrochromic device enables the demonstration of a stretchable electrochromically active e-skin with tactile-sensing control. This system will have wide range applications such as interactive wearable devices, artificial prosthetics and smart robots.

  2. Testing of tactile sensors for space applications

    NASA Astrophysics Data System (ADS)

    Kogan, Lisa; Weadon, Timothy L.; Evans, Thomas; DeVallance, David B.; Sabolsky, Edward M.

    2015-03-01

    There is a need to integrate tactile sensing into robotic manipulators performing tasks in space environments, including those used to repair satellites. Integration can be achieved by embedding specialized tactile sensors. Reliable and consistent signal interpretation can be obtained by ensuring that sensors with a suitable sensing mechanism are selected based on operational demands, and that materials used within the sensors do not change structurally under vacuum and expected applied pressures, and between temperatures of -80°C to +120°C. The sensors must be able to withstand space environmental conditions and remain adequately sensitive throughout their operating life. Additionally, it is necessary to integrate the sensors into the target system with minimum disturbance while remaining responsive to applied loads. Previous work has been completed to characterize sensors within the selected temperature and pressure ranges. The current work builds on this investigation by embedding these sensors in different geometries and testing the response measured among varying configurations. Embedding material selection was aided by using a dynamic mechanical analyzer (DMA) to determine stress/strain behavior for adhesives and compliant layers used to keep the sensors in place and distribute stresses evenly. Electromechanical characterization of the embedded sensor packages was conducted by using the DMA in tandem with an inductance-capacitance-resistance (LCR) meter. Methods for embedding the sensor packages were developed with the aid of finite element analysis and physical testing to account for specific geometrical constraints. Embedded sensor prototypes were tested within representative models of potential embedding locations to compare final embedded sensor performance.

  3. Extra tactile stimulation of the premature infant.

    PubMed

    Kramer, M; Chamorro, I; Green, D; Knudtson, F

    1975-01-01

    To ascertain whether touch, in the form of extra tactile stimulation, would result in more rapid physical and social development and a greater degree of social development of the premature infant, 48 minutes of extra tactile stimulation, defines as a gentle, nonrhythmic stroking of the greatest possible area of skin surface of the infant's body by the nurse's hand, was given to eight experimental group premature infants daily for a minimum of two weeks while they were confined to an isolette. Six infants formed a control group. Regain of birth weight was used to assess physical development. Scores on the applicable portions of the Gesell Development Schedule and Bayley Scales of Infant Development and plasma cortisol levels were used to measure rate and degree of social development. Data were analyzed in terms of the total group and for pairs of infants matched for gestational age, birth weight, and Apgar score. No significant difference was found between control and experimental groups in rate of physical development as measured by regain of birth weight. Analysis of the relationship between weight gain and gestational age, sex, and Apgar scores indicated that none was a substantial indicator of the rate at which infants gained weight while in the hospital. There was no significant difference in the degree of social development between experimental and control infants, but, as hypothesized, there was significant difference in rate of social development. Plasma cortisol levels as an indication of the infant's adrenocorticol development as evidenced by his ability to respond to stressful situations, and hence indirectly his social development, revealed no significant difference between the two groups. PMID:1041616

  4. Advanced planning activity. [for interplanetary flight and space exploration

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Selected mission concepts for interplanetary exploration through 1985 were examined, including: (1) Jupiter orbiter performance characteristics; (2) solar electric propulsion missions to Mercury, Venus, Neptune, and Uranus; (3) space shuttle planetary missions; (4) Pioneer entry probes to Saturn and Uranus; (5) rendezvous with Comet Kohoutek and Comet Encke; (6) space tug capabilities; and (7) a Pioneer mission to Mars in 1979. Mission options, limitations, and performance predictions are assessed, along with probable configurational, boost, and propulsion requirements.

  5. Mars Exploration Rover: thermal design is a system engineering activity

    NASA Technical Reports Server (NTRS)

    Tsuyuki, Glenn T.; Avila, Arturo; Awaya, Henry I.; Krylo, Robert; Novak, Keith; Phillips, Charles

    2003-01-01

    The Mars Exploration Rovers (MER), were launched in June and July of 2003, repsectively and successfully landed on Mars in early and late January of 2004, repectively. The flight system architecture implemented many successful features of the Mars Pathfinder (MPF) system: A cruise stage that transported an entry vehicle that housed the Lander, which in turn, used airbags to cushion the Rover during the landing event.

  6. Numerical Priming Between Touch and Vision Depends on Tactile Discrimination.

    PubMed

    Faivre, Nathan; Salomon, Roy; Vuillaume, Laurène; Blanke, Olaf

    2016-01-01

    Although the interaction between vision and touch is of crucial importance for perceptual and bodily self-consciousness, only little is known regarding the link between conscious access and tactile processing. Here, we tested whether the numerical encoding of tactile stimuli depends on conscious discrimination. On each trial, participants received between zero and three taps at low, medium, or high intensity and had to enumerate the number of visual items subsequently presented as a visual target. We measured tactovisual numerical priming, that is, the modulation of reaction times according to the numerical distance between the visual target and tactile prime values. While numerical priming and repetition priming were respectively elicited by high and medium intensity stimuli, no effect was found for low intensity stimuli that were not discriminable. This suggests that numerical priming between touch and vision depends on tactile discrimination. We discuss our results considering recent advances in unconscious visual numerical priming. PMID:26562854

  7. Preferential processing of tactile events under conditions of divided attention

    PubMed Central

    Hanson, James V. M.; Whitaker, David; Heron, James

    2012-01-01

    Differences in transduction and transmission latencies of visual, auditory and tactile events cause corresponding differences in simple reaction time. As reaction time is usually measured in unimodal blocks, it is unclear whether such latency differences also apply when observers monitor multiple sensory channels. We investigate this by comparing reaction time when attention is focussed on a single modality, and when attention is divided between multiple modalities. Results show that tactile reaction time is unaffected by dividing attention, whilst visual and auditory reaction times are significantly and asymmetrically increased. These findings show that tactile information is processed preferentially by the nervous system under conditions of divided attention, and suggest that tactile events may be processed pre-attentively. PMID:19738497

  8. The Tactile Vision Substitution System: Applications in Education and Employment

    ERIC Educational Resources Information Center

    Scadden, Lawrence A.

    1974-01-01

    The Tactile Vision Substitution System converts the visual image from a narrow-angle television camera to a tactual image on a 5-inch square, 100-point display of vibrators placed against the abdomen of the blind person. (Author)

  9. Mammalian tactile hair: divergence from a limited distribution.

    PubMed

    Sarko, Diana K; Rice, Frank L; Reep, Roger L

    2011-04-01

    Mammalian species use tactile hairs to address a variety of perceptual challenges in detecting and responding appropriately to environmental stimuli. With a wide range of functional roles that range from object detection, to fine texture discrimination, to hydrodynamic trail perception, tactile hairs have been adapted for a variety of environmental niches to enhance survival through optimizing detection of somatosensory cues. Because the high level of innervation associated with tactile hairs requires a commensurately high dedication of neural resources, their distribution is restricted to specific regions of the body that encounter stimuli of interest--commonly, the face. However, several species--namely bats, naked mole-rats, hyraxes, manatees, and dugongs--are rare exceptions, with tactile hair distribution that has expanded to cover the entire body. This review examines the behavioral advantages conferred by this unusual trait, the neuroanatomical adaptations that accompany it, and how this pattern might have evolved. PMID:21534996

  10. Exploring Extension Involvement in Farm to School Program Activities

    ERIC Educational Resources Information Center

    Benson, Matthew C.

    2014-01-01

    The study reported here examined Extension professionals' involvement in farm-to-school program activities. Results of an online survey distributed to eight state Extension systems indicate that on average, Extension professionals are involved with one farm to school program activity, with most supporting school or community garden programs.…

  11. Exploring Preferences of Mentoring Activities among Generational Groups of Registered Nurses in Florida

    ERIC Educational Resources Information Center

    Posey-Goodwin, Patricia Ann

    2013-01-01

    The purpose of this study was to explore differences in perceptions of mentoring activities from four generations of registered nurses in Florida, using the Alleman Mentoring Activities Questionnaire ® (AMAQ ®). Statistical procedures of analysis of variance (ANOVA) were employed to explore differences among 65 registered nurses in Florida from…

  12. A tactile sensor using a conductive graphene-sponge composite

    NASA Astrophysics Data System (ADS)

    Chun, Sungwoo; Hong, Ahyoung; Choi, Yeonhoi; Ha, Chunho; Park, Wanjun

    2016-04-01

    For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor.For sensors that emulate human tactile perception, we suggest a simple method for fabricating a highly sensitive force sensor using a conductive polyurethane sponge where graphene flakes are self-assembled into the porous structure of the sponge. The complete sensor device shows a sensitive and reliable detection response for a broad range of pressure and dynamic pressure that correspond to human tactile perception. Sensitivity of the sensor to detect vibration is also confirmed with vertical actuations due to slipping over micro-scale ridge structures attached on the sensors. Based on the sensor's ability to detect both pressure and vibration, the sensor can be utilized as a flexible tactile sensor. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00774k

  13. To what extent do Gestalt grouping principles influence tactile perception?

    PubMed

    Gallace, Alberto; Spence, Charles

    2011-07-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli. Although, to date, only a few studies have explicitly investigated the existence of Gestalt grouping principles in the tactile modality, we argue that many more studies have indirectly provided evidence relevant to this topic. Reviewing this body of research, we argue that similar principles to those reported previously in visual and auditory studies also govern the perceptual grouping of tactile stimuli. In particular, we highlight evidence showing that the principles of proximity, similarity, common fate, good continuation, and closure affect tactile perception in both unimodal and crossmodal settings. We also highlight that the grouping of tactile stimuli is often affected by visual and auditory information that happen to be presented simultaneously. Finally, we discuss the theoretical and applied benefits that might pertain to the further study of Gestalt principles operating in both unisensory and multisensory tactile perception. PMID:21574680

  14. Tactile device utilizing a single magnetorheological sponge: experimental investigation

    NASA Astrophysics Data System (ADS)

    Kim, Soomin; Kim, Pyunghwa; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    In the field of medicine, several new areas have been currently introduced such as robot-assisted surgery. However, the major drawback of these systems is that there is no tactile communication between doctors and surgical sites. When the tactile system is brought up, telemedicine including telerobotic surgery can be enhanced much more than now. In this study, a new tactile device is designed using a single magnetorhological (MR) sponge cell to realize the sensation of human organs. MR fluids and an open celled polyurethane foam are used to propose the MR sponge cell. The viscous and elastic sensational behaviors of human organs are realized by the MR sponge cell. Before developing the tactile device, tactile sensation according to touch of human fingers are quantified in advance. The finger is then treated as a reduced beam bundle model (BBM) in which the fingertip is comprised of an elastic beam virtually. Under the reduced BBM, when people want to sense an object, the fingertip is investigated by pushing and sliding. Accordingly, while several magnitudes of magnetic fields are applied to the tactile device, normal and tangential reaction forces and bending moment are measured by 6-axis force/torque sensor instead of the fingertip. These measured data are used to compare with soft tissues. It is demonstrated that the proposed MR sponge cell can realize any part of the organ based on the obtained data.

  15. Simulations of an Optical Tactile Sensor Based on Computer Tomography

    NASA Astrophysics Data System (ADS)

    Ohka, Masahiro; Sawamoto, Yasuhiro; Zhu, Ning

    In order to create a robotic tactile sensor of thin shape, a new optical tactile sensor is developed by applying a CT (Computer Tomography) algorithm. The present tactile sensor is comprised of infrared emitting diode arrays, receiving phototransistor arrays and a transparent acrylic plate and a black rubber sheet with projections. Infrared rays emitted from the diode array are directed into one end of the plate and their intensity distribution is measured by the phototransistor array mounted on the other end. If the CT algorithm is directly applied to the tactile sensor, there are two shortcomings: the shape of the sensing area is limited to a circular region and there is a long calculation time. Thus, a new CT algorithm oriented to tactile sensing is proposed for overcoming these problems. In the present algorithm, a square sensing area is divided into an N-by-N array and algebraic equations are derived from the relationship between the input and output light intensities on the assumed light projections. Several reconstruction methods are considered for obtaining pressure values caused in the squares. In the present study, the ART (Algebraic Reconstruction Technique) and LU decomposition methods were employed, and these methods were compared to select the best reconstruction method. In a series of simulations, it was found that the LU decomposition method held an advantage for the present type of tactile sensor because of its robustness against disturbance and short calculation time.

  16. Differentiated audio-tactile correspondences in sighted and blind individuals.

    PubMed

    Deroy, Ophelia; Fasiello, Irène; Hayward, Vincent; Auvray, Malika

    2016-08-01

    The aim of the present study is to investigate whether the crossmodal correspondence robustly documented between auditory pitch and visual elevation has analogues in the audio-tactile domain. Across 4 experiments, the compatibility effects between intuitively congruent pairs of stimuli (i.e., outward tactile movement, going from the inside of the finger toward the fingertip and increasing pitch, or inward tactile movement and decreasing pitch) and incongruent pairs stimuli (i.e., the reverse associations) were measured. Two methods were compared to assess the behavioral effects of such a correspondence: One where participants have to respond to either the auditory or tactile stimulus presented simultaneously, while ignoring the other (speeded classification task), and the other where the auditory and tactile stimuli are presented sequentially and associated to different response buttons (implicit association test). No significant compatibility effect was observed under the speeded classification task. The implicit association test revealed a significant compatibility effect. This effect was similar in the conditions where the finger was placed vertically and horizontally. However, this implicit association between pitch and tactile movements was not observed in blind participants. These results have methodological implications for the explanation and testing of crossmodal correspondences, and the origin of the widely discussed association between pitch and vertical elevation. (PsycINFO Database Record PMID:26950385

  17. Full-sky Astrometric Mapping Explorer (FAME) Rescope Activities

    NASA Astrophysics Data System (ADS)

    Johnston, K.; Dorland, B.; Gaume, R.; Hajian, A.; Harris, F.; Harris, H.; Hennessy, G.; Kaplan, G.; Levine, S.; Monet, D.; Munn, J.; Murison, M.; Pier, J.; Urban, S.; Zacharias, N.; Seidelmann, P. K.; Lee, J.; Makarov, V.; Olling, R.; Codella, T.; Geary, J.; Latham, D.; Phillips, J.; Johnson, M.; Vassar, R.; Horner, S.

    2001-12-01

    The Full-sky Astrometric Mapping Explorer (FAME) will measure the positions, proper motions, parallaxes, and photometry for 40 million stars between 5 and 15 magnitude, with accuracies of 50 microarcseconds at 9th magnitude and degraded accuracy for fainter stars as faint as 15 magnitude. The mission is planned for an October 2004 launch and a five-year duration. The FAME mission has progressed in its development. Due to budget, weight, and power limitations, the FAME architecture has been rescoped so that it will satisfy the budget limitations and retain the basic science objectives of the mission. The new design and characteristics, the status of developments and tests, and the scientific baseline and minimum mission requirements are presented.

  18. Explorative data analysis for changes in neural activity

    NASA Astrophysics Data System (ADS)

    Blythe, Duncan A. J.; Meinecke, Frank C.; von Bünau, Paul; Müller, Klaus-Robert

    2013-04-01

    Neural recordings are non-stationary time series, i.e. their properties typically change over time. Identifying specific changes, e.g., those induced by a learning task, can shed light on the underlying neural processes. However, such changes of interest are often masked by strong unrelated changes, which can be of physiological origin or due to measurement artifacts. We propose a novel algorithm for disentangling such different causes of non-stationarity and in this manner enable better neurophysiological interpretation for a wider set of experimental paradigms. A key ingredient is the repeated application of Stationary Subspace Analysis (SSA) using different temporal scales. The usefulness of our explorative approach is demonstrated in simulations, theory and EEG experiments with 80 brain-computer interfacing subjects.

  19. Active Dust Mitigation Technology for Thermal Radiators for Lunar Exploration

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Buhler, C. R.; Hogue, M. D.; Johansen, M. R.; Hopkins, J. W.; Holloway, N. M. H.; Connell, J. W.; Chen, A.; Irwin, S. A.; Case, S. O.; VanSuetendael, N. J.; Snyder, S. J.; Clements, J. S.

    2010-01-01

    Dust accumulation on thermal radiator surfaces planned for lunar exploration will significantly reduce their efficiency. Evidence from the Apollo missions shows that an insulating layer of dust accumulated on radiator surfaces could not be removed and caused serious thermal control problems. Temperatures measured at different locations in the magnetometer on Apollo 12 were 38 C warmer than expected due to lunar dust accumulation. In this paper, we report on the application of the Electrodynamic Dust Shield (EDS) technology being developed in our NASA laboratory and applied to thermal radiator surfaces. The EDS uses electrostatic and dielectrophoretic forces generated by a grid of electrodes running a 2 micro A electric current to remove dust particles from surfaces. Working prototypes of EDS systems on solar panels and on thermal radiators have been successfully developed and tested at vacuum with clearing efficiencies above 92%. For this work EDS prototypes on flexible and rigid thermal radiators were developed and tested at vacuum.

  20. Tactile capture of auditory localization: an event-related potential study.

    PubMed

    Bruns, Patrick; Röder, Brigitte

    2010-05-01

    The well-known ventriloquist illusion arises when sounds are mislocalized towards a synchronous but spatially discrepant visual stimulus, and a similar effect of touch on audition has also been reported. By manipulating hand position, we recently demonstrated that this audiotactile ventriloquism effect predominantly operates in an external coordinate system. Using event-related potentials, the present study investigated the neural correlates of this audiotactile ventriloquism effect. Participants reported the perceived location of brief auditory stimuli that were presented either alone or with concurrent tactile stimuli to the fingertips, which were situated at the left and right side of the speaker array. Concurrent electroencephalogram recordings suggested a biasing of cortical activity by the tactile stimuli, which was only observed for trials in which a ventriloquist illusion was elicited. Irrespective of the physical location of the sound source in the bimodal trials, centrally perceived sounds elicited an enhanced centrally distributed negativity, compared to laterally perceived sounds, between 260 and 400 ms following stimulus onset, similar to unimodal auditory stimuli that were actually presented from central and lateral positions, respectively. Moreover, this effect was modulated by hand posture. When external and anatomically centred reference frames were in conflict, the event-related potential effect was reduced for small audiotactile spatial discrepancies, which corresponded to the behavioural finding of a reduced audiotactile ventriloquism effect compared to a parallel hand posture. The present data suggest that the cortical representation of auditory space is adjusted to coincide with spatially disparate tactile input. PMID:20584189

  1. A sensory feedback system for prosthetic hand based on evoked tactile sensation.

    PubMed

    Liu, X X; Chai, G H; Qu, H E; Lan, N

    2015-08-01

    The lack of reliable sensory feedback has been one of the barriers in prosthetic hand development. Restoring sensory function from prosthetic hand to amputee remains a great challenge to neural engineering. In this paper, we present the development of a sensory feedback system based on the phenomenon of evoked tactile sensation (ETS) at the stump skin of residual limb induced by transcutaneous electrical nerve stimulation (TENS). The system could map a dynamic pattern of stimuli to an electrode placed on the corresponding projected finger areas on the stump skin. A pressure transducer placed at the tip of prosthetic fingers was used to sense contact pressure, and a high performance DSP processor sampled pressure signals, and calculated the amplitude of feedback stimulation in real-time. Biphasic and charge-balanced current pulses with amplitude modulation generated by a multi-channel laboratory stimulator were delivered to activate sensory nerves beneath the skin. We tested this sensory feedback system in amputee subjects. Preliminary results showed that the subjects could perceive different levels of pressure at the tip of prosthetic finger through evoked tactile sensation (ETS) with distinct grades and modalities. We demonstrated the feasibility to restore the perceptual sensation from prosthetic fingers to amputee based on the phenomenon of evoked tactile sensation (ETS) with TENS. PMID:26736798

  2. Natural whisker-guided behavior by head-fixed mice in tactile virtual reality.

    PubMed

    Sofroniew, Nicholas J; Cohen, Jeremy D; Lee, Albert K; Svoboda, Karel

    2014-07-16

    During many natural behaviors the relevant sensory stimuli and motor outputs are difficult to quantify. Furthermore, the high dimensionality of the space of possible stimuli and movements compounds the problem of experimental control. Head fixation facilitates stimulus control and movement tracking, and can be combined with techniques for recording and manipulating neural activity. However, head-fixed mouse behaviors are typically trained through extensive instrumental conditioning. Here we present a whisker-based, tactile virtual reality system for head-fixed mice running on a spherical treadmill. Head-fixed mice displayed natural movements, including running and rhythmic whisking at 16 Hz. Whisking was centered on a set point that changed in concert with running so that more protracted whisking was correlated with faster running. During turning, whiskers moved in an asymmetric manner, with more retracted whisker positions in the turn direction and protracted whisker movements on the other side. Under some conditions, whisker movements were phase-coupled to strides. We simulated a virtual reality tactile corridor, consisting of two moveable walls controlled in a closed-loop by running speed and direction. Mice used their whiskers to track the walls of the winding corridor without training. Whisker curvature changes, which cause forces in the sensory follicles at the base of the whiskers, were tightly coupled to distance from the walls. Our behavioral system allows for precise control of sensorimotor variables during natural tactile navigation. PMID:25031397

  3. Natural Whisker-Guided Behavior by Head-Fixed Mice in Tactile Virtual Reality

    PubMed Central

    Sofroniew, Nicholas J.; Cohen, Jeremy D.; Lee, Albert K.

    2014-01-01

    During many natural behaviors the relevant sensory stimuli and motor outputs are difficult to quantify. Furthermore, the high dimensionality of the space of possible stimuli and movements compounds the problem of experimental control. Head fixation facilitates stimulus control and movement tracking, and can be combined with techniques for recording and manipulating neural activity. However, head-fixed mouse behaviors are typically trained through extensive instrumental conditioning. Here we present a whisker-based, tactile virtual reality system for head-fixed mice running on a spherical treadmill. Head-fixed mice displayed natural movements, including running and rhythmic whisking at 16 Hz. Whisking was centered on a set point that changed in concert with running so that more protracted whisking was correlated with faster running. During turning, whiskers moved in an asymmetric manner, with more retracted whisker positions in the turn direction and protracted whisker movements on the other side. Under some conditions, whisker movements were phase-coupled to strides. We simulated a virtual reality tactile corridor, consisting of two moveable walls controlled in a closed-loop by running speed and direction. Mice used their whiskers to track the walls of the winding corridor without training. Whisker curvature changes, which cause forces in the sensory follicles at the base of the whiskers, were tightly coupled to distance from the walls. Our behavioral system allows for precise control of sensorimotor variables during natural tactile navigation. PMID:25031397

  4. Swarming Bristle-Bots: Exploring Properties of Active Matter

    NASA Astrophysics Data System (ADS)

    Forstner, Martin B.; Beasock, Damian

    Active Matter describes an ubiquitous class of non-equilibrium systems that encompasses a diverse range of phenomena in the living and non-living realm. Examples are microscopic bio-filaments and their associated motor proteins, flocks of birds and fish, vibrated rods and disks, or nanoscale colloids actuated by catalytic activity on their surface. What unifies these systems is that they are all composed of self-driven units. In consequence, these systems are not driven into non-equilibrium by energy input at their boundary, but by local energy injection. As fascinating as these systems are, there are currently barely any laboratory systems that allow for controlled experiments in dry active matter. That is, systems not immersed in a fluid that can be observed without specialized equipment. Here we present a two-dimensional `active matter' system consisting of hundreds of macroscopic (~0.05 m long), modified, commercially available bristle-bots. We show that this swarm of toys classifies as active matter as it exhibits properties such as dynamic phase separation. Because of their straight forward implementation, their size and controllability, such swarms can not only answer scientific questions, but they have great potential as educational tools in teaching labs and classrooms.

  5. Lingual tactile acuity and food texture preferences among children and their mothers

    PubMed Central

    Lukasewycz, Laura D.; Mennella, Julie A.

    2012-01-01

    Despite anecdotal reports of children being more sensitive to texture than adults, and of texture being one of the main drivers of food aversions, there is a paucity of scientific knowledge on the influence of texture perception on food choice in children. The primary goals of this study were to assess the use of a modified letter-identification task to study lingual tactile acuity, one aspect of oral sensitivity, in children and to examine age-related differences in sensitivity. The secondary goal was to explore whether lingual tactile acuity and age relate to various measures of food choice and preference. To this end, children 7–10 years old (31 girls, 21 boys) and their mothers were tested using identical procedures. To assess lingual tactile acuity, children and mothers were asked to use the tips of their tongues to identify raised alphabetical letters of varying size (2.5–8.0 mm) on Teflon strips. To relate lingual tactile acuity to food texture preferences, a forced-choice questionnaire assessed preferences for foods similar in flavor but different in texture (e.g., smooth versus crunchy peanut butter). Children were able to complete the lingual acuity task as well as their mothers and took less time to assess each letter stimulus (p < 0.001); however, there were no age-related differences in lingual acuity (p = 0.14). Age, but not lingual acuity, related to food texture preferences: mothers preferred harder foods (p < 0.001) and those containing more particles (p < 0.04) than did children, although children‘s preferences became more adult-like with increasing age. The availability of a rapid, child-friendly method for assessing oral sensitivity opens up new possibilities of examining differences in oral tactile perceptions across the life span. That food preferences changed with age and were not related to oral sensitivity underscores the fact that factors such as experience, culture and family food practices have a significant impact on children

  6. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans.

    PubMed

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition. PMID:27302219

  7. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans

    PubMed Central

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R.

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition. PMID:27302219

  8. Blogs and Social Network Sites as Activity Systems: Exploring Adult Informal Learning Process through Activity Theory Framework

    ERIC Educational Resources Information Center

    Heo, Gyeong Mi; Lee, Romee

    2013-01-01

    This paper uses an Activity Theory framework to explore adult user activities and informal learning processes as reflected in their blogs and social network sites (SNS). Using the assumption that a web-based space is an activity system in which learning occurs, typical features of the components were investigated and each activity system then…

  9. Exploring Patient Activation in the Clinic: Measurement from Three Perspectives

    ERIC Educational Resources Information Center

    Ledford, Christy J. W.; Ledford, Christopher C.; Childress, Marc A.

    2013-01-01

    Objective. To further conceptualize and operationalize patient activation (PA), using measures from patient, physician, and researcher perspectives. Data Source/Study Setting. Multimethod observation in 2010 within a family medicine clinic. Study Design. Part of an intervention with 130 patients with type 2 diabetes, this observational study…

  10. Exploring the Tensions between State Activism and School Autonomy.

    ERIC Educational Resources Information Center

    Malen, Betty; Muncey, Donna

    Since the 1970s, states have substantially and dramatically increased their involvement in education while simultaneously endorsing notions of local control. This paper focuses on the impact of such persistent and pervasive state activism on school autonomy. It describes how the proliferation and accumulation of education policies enacted at the…

  11. Exploring Key Sustainable Development Themes through Learning Activities

    ERIC Educational Resources Information Center

    Cruickshank, Heather; Fenner, Richard

    2012-01-01

    Purpose: The purpose of the paper is to examine how a number of key themes are introduced in the Master's programme in Engineering for Sustainable Development, at Cambridge University, through student-centred activities. These themes include dealing with complexity, uncertainty, change, other disciplines, people, environmental limits, whole life…

  12. Seeing the Sky: 100 Projects, Activities, and Explorations in Astronomy.

    ERIC Educational Resources Information Center

    Schaaf, Fred

    1990-01-01

    Fourteen astronomy activities are presented including classroom procedures and questions. Topics include different investigations of the moon, planets, stars, sunsets, light pollution, and rainbows and halos. Additional information on measurements used for observations in astronomy, and rainbow characteristics is included. (CW)

  13. Meta-Coordination Activities: Exploring Articulation Work in Hospitals

    ERIC Educational Resources Information Center

    Abraham, Joanna

    2010-01-01

    Coordination of distributed activities is central to organizational work. The effective functioning of organizations hinges on their ability to manage interdependencies both within (intra-) and between (inter-) various departments. However, more than just the management of these individual dependencies is required for smooth coordination in…

  14. Exploring Healthy Eating: Activities for Parents and Children Together.

    ERIC Educational Resources Information Center

    Tufts Univ., Medford, MA. Center on Hunger, Poverty and Nutrition Policy.

    This collection of learning units introduces parents to the role of nutrition in their young child's cognitive development. Designed to be easy to read and useful for families with limited resources, the materials help parents teach their young children good eating habits by offering information, feeding tips, creative activities for parents and…

  15. Exploring Formative Assessment Using Cultural Historical Activity Theory

    ERIC Educational Resources Information Center

    Asghar, Mandy

    2013-01-01

    Formative assessment is a pedagogic practice that has been the subject of much research and debate, as to how it can be used most effectively to deliver enhanced student learning in the higher education setting. Often described as a complex concept it embraces activities that range from facilitating students understanding of assessment standards,…

  16. Exploring Predation and Animal Coloration through Outdoor Activity

    ERIC Educational Resources Information Center

    Fontaine, Joseph J.; Decker, Karie L.

    2009-01-01

    Although children often characterize animals by the animals' color or pattern, the children seldom understand the evolutionary and ecological factors that favor particular colors. In this article, we describe two activities that help students understand the distinct evolutionary strategies of warning coloration and camouflage. Because both of…

  17. International oil and gas exploration and development activities

    SciTech Connect

    Not Available

    1990-07-26

    This report is part of an ongoing series of quarterly publications that monitors discoveries of oil and natural gas in foreign countries and provides an analysis of the reserve additions that result. The report is prepared by the Energy Information Administration (EIA) of the US Department of Energy (DOE) under the Foreign Energy Supply Assessment Program (FESAP). It presents a summary of discoveries and reserve additions that result from international exploration and development, implementation, and evaluation of energy plans, policy and legislation. A discovery, as used in this publication, is a published estimate of the ultimately recoverable reserves for either a new field, reservoir, or well. This ultimate recovery is defined in this report as cumulative production plus remaining reserves. These discoveries are obtainable from various oil industry periodicals and company annual or quarterly reports. The discoveries are not verified by EIA but simply restated in this publication. The reported reserves do not necessarily follow the EIA definition of proved reserves. Each reserve entry follows the defining criteria of the originator. Not all discoveries are announced and not all announced discoveries are published. Some discoveries may be exaggerated or understand for political or other reasons. Therefore, the data in this report should be used with caution. 23 refs., 8 figs., 4 tabs.

  18. Exploratory Procedures of Tactile Images in Visually Impaired and Blindfolded Sighted Children: How They Relate to Their Consequent Performance in Drawing

    ERIC Educational Resources Information Center

    Vinter, Annie; Fernandes, Viviane; Orlandi, Oriana; Morgan, Pascal

    2012-01-01

    The aim of the present study was to compare the types of exploratory procedures employed by children when exploring bidimensional tactile patterns and correlate the use of these procedures with the children's shape drawing performance. 18 early blind children, 20 children with low vision and 24 age-matched blindfolded sighted children aged…

  19. Voluntary action and tactile sensory feedback in the intentional binding effect.

    PubMed

    Zhao, Ke; Hu, Li; Qu, Fangbing; Cui, Qian; Piao, Qiuhong; Xu, Hui; Li, Yanyan; Wang, Liang; Fu, Xiaolan

    2016-08-01

    The intentional binding effect refers to a subjective compression over a temporal interval between the start point initialized by a voluntary action and the endpoint signaled by an external sensory (visual or audio) feedback. The present study aimed to explore the influence of tactile sensory feedback on this binding effect by comparing voluntary key-press actions with voluntary key-release actions. In experiment 1, each participant was instructed to report the perceived interval (in ms) between an action and the subsequent visual sensory feedback. In this task, either the action (key-press or key-release) was voluntarily performed by the participant or a kinematically identical movement was passively applied to the left index finger of the participant. In experiment 2, we explored whether the difference in the perception of time was affected by the direction of action. In experiment 3, we developed an apparatus in which two parallel laser beams were generated by a laser emission unit and detected by a laser receiver unit; this allowed the movement of the left index finger to be detected without it touching a keyboard (i.e., without any tactile sensory feedback). Convergent results from all of the experiments showed that the temporal binding effect was only observed when the action was both voluntary and involved physical contact with the key, suggesting that the combination of intention and tactile sensory feedback, as a form of top-down processing, likely distracted attention from temporal events and caused the different binding effects. PMID:27038203

  20. Braille in the Sighted: Teaching Tactile Reading to Sighted Adults.

    PubMed

    Bola, Łukasz; Siuda-Krzywicka, Katarzyna; Paplińska, Małgorzata; Sumera, Ewa; Hańczur, Paweł; Szwed, Marcin

    2016-01-01

    Blind people are known to have superior perceptual abilities in their remaining senses. Several studies suggest that these enhancements are dependent on the specific experience of blind individuals, who use those remaining senses more than sighted subjects. In line with this view, sighted subjects, when trained, are able to significantly progress in relatively simple tactile tasks. However, the case of complex tactile tasks is less obvious, as some studies suggest that visual deprivation itself could confer large advantages in learning them. It remains unclear to what extent those complex skills, such as braille reading, can be learnt by sighted subjects. Here we enrolled twenty-nine sighted adults, mostly braille teachers and educators, in a 9-month braille reading course. At the beginning of the course, all subjects were naive in tactile braille reading. After the course, almost all were able to read whole braille words at a mean speed of 6 words-per-minute. Subjects with low tactile acuity did not differ significantly in braille reading speed from the rest of the group, indicating that low tactile acuity is not a limiting factor for learning braille, at least at this early stage of learning. Our study shows that most sighted adults can learn whole-word braille reading, given the right method and a considerable amount of motivation. The adult sensorimotor system can thus adapt, to some level, to very complex tactile tasks without visual deprivation. The pace of learning in our group was comparable to congenitally and early blind children learning braille in primary school, which suggests that the blind's mastery of complex tactile tasks can, to a large extent, be explained by experience-dependent mechanisms. PMID:27187496

  1. Effects of age and expertise on tactile learning in humans.

    PubMed

    Reuter, Eva-Maria; Voelcker-Rehage, Claudia; Vieluf, Solveig; Godde, Ben

    2014-08-01

    Repetitive tactile stimulation is a well-established tool for inducing somatosensory cortical plasticity and changes in tactile perception. Previous studies have suggested that baseline performance determines the amount of stimulation-induced learning differently in specific populations. Older adults with lower baseline performance than young adults, but also experts, with higher baseline performance than non-experts of the same age, have been found to profit most from such interventions. This begs the question of how age-related and expertise-related differences in tactile learning are reflected in neurophysiological correlates. In two experiments, we investigated how tactile learning depends on age (experiment 1) and expertise (experiment 2). We assessed tactile spatial and temporal discrimination accuracy and event-related potentials (ERPs) in 57 persons of different age and expertise groups before and after a 30-min tactile stimulation intervention. The intervention increased accuracy in temporal (found in experiment 1) and spatial (found in experiment 2) discrimination. Experts improved more than non-experts in spatial discrimination. Lower baseline performance was associated with higher learning gain in experts and non-experts. After the intervention, P300 latencies were reduced in young adults and amplitudes were increased in late middle-aged adults in the temporal discrimination task. Experts showed a steeper P300 parietal-to-frontal gradient after the stimulation. We demonstrated that tactile stimulation partially reverses the age-related decline in late middle-aged adults and increases processing speed in young adults. We further showed that learning gain depends on baseline performance in both non-experts and experts. In experts, however, the upper limit for learning seems to be shifted to a higher level. PMID:24863287

  2. Focal Inflammation Causes Carbenoxolone-Sensitive Tactile Hypersensitivity in Mice

    PubMed Central

    Hanstein, Regina; Zhao, Julie B.; Basak, Rajshekhar; Smith, David N.; Zuckerman, Yonatan Y.; Hanani, Menachem; Spray, David C.; Gulinello, Maria

    2010-01-01

    A focal and transitory inflammation induced by injection of complete Freund's adjuvant (CFA) in the submandibular skin of mice elicits pain behavior that persists for several weeks after the initial inflammation has resolved. Chronic pain, assessed as tactile hypersensitivity to stimulation with von Frey filaments, was evident from 1–7 weeks following CFA injection, although inflammation at the injection site was resolved by 3–4 weeks. In contrast, there were no changes in tactile sensitivity in the paw (un-injected site for comparison), no alterations in open field behavior and no differences in a functional observation battery evident in CFA-treated mice compared to controls (saline-injected) or to baseline (before CFA injection). Neither strain (Balb/c vs. C57BL/6) nor sex differences in baseline tactile threshold were significant in the submandibular skin. CFA-induced tactile hypersensitivity was also not a function of strain or sex. A single intraperitoneal injection of the gap junction blocker carbenoxolone (CBX) restored normal tactile thresholds in CFA-treated mice when administered at the peak of inflammation (1 week), after significant resolution of inflammation (3 weeks) or after total resolution of inflammation (4 and 5 weeks) without altering the tactile threshold of control subjects, tactile threshold in the paw or open field behavior. Thus, in this novel model of post-inflammatory pain, transitory inflammation induced persistent sex- and strain-independent behavioral hypersensitivity that was reversed by the gap junction blocker CBX, suggesting neuronal and/or glial plasticity as a major component of the chronic pain. PMID:21151805

  3. Braille in the Sighted: Teaching Tactile Reading to Sighted Adults

    PubMed Central

    Bola, Łukasz; Siuda-Krzywicka, Katarzyna; Paplińska, Małgorzata; Sumera, Ewa; Hańczur, Paweł; Szwed, Marcin

    2016-01-01

    Blind people are known to have superior perceptual abilities in their remaining senses. Several studies suggest that these enhancements are dependent on the specific experience of blind individuals, who use those remaining senses more than sighted subjects. In line with this view, sighted subjects, when trained, are able to significantly progress in relatively simple tactile tasks. However, the case of complex tactile tasks is less obvious, as some studies suggest that visual deprivation itself could confer large advantages in learning them. It remains unclear to what extent those complex skills, such as braille reading, can be learnt by sighted subjects. Here we enrolled twenty-nine sighted adults, mostly braille teachers and educators, in a 9-month braille reading course. At the beginning of the course, all subjects were naive in tactile braille reading. After the course, almost all were able to read whole braille words at a mean speed of 6 words-per-minute. Subjects with low tactile acuity did not differ significantly in braille reading speed from the rest of the group, indicating that low tactile acuity is not a limiting factor for learning braille, at least at this early stage of learning. Our study shows that most sighted adults can learn whole-word braille reading, given the right method and a considerable amount of motivation. The adult sensorimotor system can thus adapt, to some level, to very complex tactile tasks without visual deprivation. The pace of learning in our group was comparable to congenitally and early blind children learning braille in primary school, which suggests that the blind’s mastery of complex tactile tasks can, to a large extent, be explained by experience-dependent mechanisms. PMID:27187496

  4. Exploring creative activity: a software environment for multimedia systems

    NASA Astrophysics Data System (ADS)

    Farrett, Peter W.; Jardine, David A.

    1992-03-01

    This paper examines various issues related to the theory, design, and implementation of a system that supports creative activity for a multimedia environment. The system incorporates artificial intelligence notions to acquire concepts of the problem domain. This paper investigates this environment by considering a model that is a basis for a system, which supports a history of user interaction. A multimedia system that supports creative activity is problematic. It must function as a tool allowing users to experiment dynamically with their own creative reasoning process--a very nebulous task environment. It should also support the acquisition of domain knowledge so that empirical observation can be further evaluated. This paper aims to illustrate that via the reuse of domain-specific knowledge, closely related ideas can be quickly developed. This approach is useful in the following sense: Multimedia navigational systems hardcode referential links with respect to a web or network. Although users can access or control navigation in a nonlinear (static) manner, these referential links are 'frozen' and can not capture their creative actions, which are essential in tutoring or learning applications. This paper describes a multimedia assistant based on the notion of knowledge- links, which allows users to navigate through creative information in a nonlinear (dynamic) fashion. A selection of prototype code based on object-oriented techniques and logic programming partially demonstrates this.

  5. Wearable tactile sensor based on flexible microfluidics.

    PubMed

    Yeo, Joo Chuan; Yu, Jiahao; Koh, Zhao Ming; Wang, Zhiping; Lim, Chwee Teck

    2016-08-16

    In this work, we develop a liquid-based thin film microfluidic tactile sensor of high flexibility, robustness and sensitivity. The microfluidic elastomeric structure comprises a pressure sensitive region and parallel arcs that interface with screen-printed electrodes. The microfluidic sensor is functionalized with a highly conductive metallic liquid, eutectic gallium indium (eGaIn). Microdeformation on the pressure sensor results in fluid displacement which corresponds to a change in electrical resistance. By emulating parallel electrical circuitry in our microchannel design, we reduced the overall electrical resistance of the sensor, therefore enhancing its device sensitivity. Correspondingly, we report a device workable within a range of 4 to 100 kPa and sensitivity of up to 0.05 kPa(-1). We further demonstrate its robustness in withstanding >2500 repeated loading and unloading cycles. Finally, as a proof of concept, we demonstrate that the sensors may be multiplexed to detect forces at multiple regions of the hand. In particular, our sensors registered unique electronic signatures in object grasping, which could provide better assessment of finger dexterity. PMID:27438370

  6. Shear sensitive silicon piezoresistive tactile sensor prototype

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Beebe, David J.

    1998-09-01

    Shear sensing ability it important in many fields such as robotics, rehabilitation, teleoperation and human computer interfaces. A shear sensitive tactile sensor prototype is developed based on the principles of the piezoresistive effect in silicon, and using microfabrication technology. Analogous to the conventional silicon piezoresistive pressure sensor, piezoresistive resistors embedded in a silicon diaphragm are used to sense stress change. An additional mesa is fabricated on the top of the diaphragm and serves to transform an applied force to a stress. Both the shear and normal components of the force are resolved by measuring the resistance changes of the four resistors placed at the corners of a prism mesa. The prototype is tested both statically and dynamically when a spatial force of 0 - 300 gram is applied. Good linearity (R > 0.98) and high repeatability are observed. In this paper, the force sensing mechanism and force determination approach are described. The fabrication process is presented. The preliminary testing results are presented and discussed.

  7. Nestmate recognition in ants is possible without tactile interaction

    NASA Astrophysics Data System (ADS)

    Brandstaetter, Andreas Simon; Endler, Annett; Kleineidam, Christoph Johannes

    2008-07-01

    Ants of the genus Camponotus are able to discriminate recognition cues of colony members (nestmates) from recognition cues of workers of a different colony (non-nestmates) from a distance of 1 cm. Free moving, individual Camponotus floridanus workers encountered differently treated dummies on a T-bar and their behavior was recorded. Aggressive behavior was scored as mandibular threat towards dummies. Dummies were treated with hexane extracts of postpharyngeal glands (PPGs) from nestmates or non-nestmates which contain long-chain hydrocarbons in ratios comparable to what is found on the cuticle. The cuticular hydrocarbon profile bears cues which are essential for nestmate recognition. Although workers were prevented from antennating the dummies, they showed significantly less aggressive behavior towards dummies treated with nestmate PPG extracts than towards dummies treated with non-nestmate PPG extracts. In an additional experiment, we show that cis-9-tricosene, an alkene naturally not found in C. floridanus’ cuticular profile, is behaviorally active and can interfere with nestmate recognition when presented together with a nestmate PPG extract. Our study demonstrates for the first time that the complex multi-component recognition cues can be perceived and discriminated by ants at close range. We conclude that contact chemosensilla are not crucial for nestmate recognition since tactile interaction is not necessary.

  8. Extravehicular Activity Asteroid Exploration and Sample Collection Capability

    NASA Technical Reports Server (NTRS)

    Sipila, Stephanie A.; Scoville, Zebulon C.; Bowie, Jonathan T.; Buffington, Jesse A.

    2014-01-01

    One of the challenging primary objectives associated with NASA's Asteroid Redirect Crewed Mission (ARCM) is to demonstrate deep space Extravehicular Activity (EVA) and tools and to obtain asteroid samples to return to Earth for further study. Prior Shuttle and International Space Station (ISS) spacewalks have benefited from engineered EVA interfaces which have been designed and manufactured on Earth. Rigid structurally mounted handrails, and tools with customized interfaces and restraints optimize EVA performance. For ARCM, EVA complexity increases due to the uncertainty of the asteroid properties. The variability of rock size, shape and composition, as well as behavior of the asteroid capture mechanism will complicate EVA translation, tool restraint, and body stabilization. The unknown asteroid hardness and brittleness will complicate tool use. The rock surface will introduce added safety concerns for cut gloves and debris control. Feasible solutions to meet ARCM EVA objectives were identified using experience gained during Apollo, Shuttle, and ISS EVAs, terrestrial mountaineering practices, NASA Extreme Environment Mission Operations (NEEMO) 16 mission, and during Neutral Buoyancy Laboratory testing in the Modified Advanced Crew Escape Suit (MACES) suit. This paper will summarize the overall operational concepts for conducting EVAs for the ARCM mission including translation paths and body restraint methods, potential tools used to extract the samples, design implications for the Asteroid Redirect Vehicle (ARV) for EVA, and the results of early development testing of potential EVA tasks.

  9. Nursing practice as bricoleur activity: a concept explored.

    PubMed

    Gobbi, Mary

    2005-06-01

    The debates concerning the nature of nursing practice are often rooted in tensions between artistic, scientific and magical/mythical practice. It is within this context that the case is argued for considering that nursing practice involves bricoleur activity. This stance, which is derived from the work of Levi-Strauss, conceives elements of nursing practice as an embodied, bricoleur practice where practitioners draw on the 'shards and fragments' of the situation-at-hand to resolve the needs of the individual patient for whom they care. This conceptualisation of nursing practice will be analysed with a particular emphasis on its implication for nursing epistemology, pedagogy and praxis. The evidence to support this argument is drawn from empirical work that investigated nurses' use of intuition, the work of Levi-Strauss, and issues in nursing epistemology and ontology. The paper itself is written from the perspective of a bricoleur who uses 'bits and pieces' from the domains of nursing, philosophy, psychology, education, sociology and anthropology. PMID:15892727

  10. 78 FR 27427 - Outer Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... Bureau of Ocean Energy Management Outer Continental Shelf (OCS) Geological and Geophysical Exploration... ] Geological and Geophysical Exploration for Mineral Resources on the Gulf of Mexico Outer Continental Shelf... activities in GOM waters. It will also provide information for future decisions regarding Outer...

  11. 78 FR 33859 - Outer Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... Bureau of Ocean Energy Management Outer Continental Shelf (OCS) Geological and Geophysical Exploration.... SUMMARY: On May 10, 2013, BOEM published a document in the Federal Register (78 FR 27427) entitled ``Outer Continental Shelf Geological and Geophysical Exploration Activities in the Gulf of Mexico.'' This...

  12. Wiki-Based Collaborative Writing Activities in EFL Classrooms: Exploring Teachers' Intervention in the Collaborative Process

    ERIC Educational Resources Information Center

    Alghasab, Maha

    2014-01-01

    This pilot study was designed to explore EFL teachers' and students' online interaction during wiki based collaborative writing activities. It aims to explore the collaborative behaviours that students engaged in and to what extent the teachers' intervention can promote students' collaboration. The study has a multiple qualitative case study…

  13. Attention modulates beta oscillations during prolonged tactile stimulation

    PubMed Central

    Bardouille, T.; Picton, T. W.; Ross, B.

    2016-01-01

    The inter-play between changes in beta-band (14–30-Hz) cortical rhythms and attention during somatosensation informs us about where and when relevant processes occur in the brain. As such, we investigated the effects of attention on somatosensory evoked and induced responses using vibrotactile stimulation and magnetoencephalographic recording. Subjects received trains of vibration at 23 Hz to the right index finger while watching a movie and ignoring the somatosensory stimuli or paying attention to the stimuli to detect a change in the duration of the stimulus. The amplitude of the evoked 23-Hz steady-state response in the contralateral primary somatosensory cortex (SI) was enhanced by attention and the underlying dipole source was located 2 mm more medially, indicating top-down recruitment of additional neuronal populations for the functionally relevant stimulus. Attentional modulation of the somatosensory evoked response indicates facilitation of early processing of the tactile stimulus. Beta-band activity increased after vibration offset in the contralateral primary motor cortex (MI) [event-related synchronization (ERS)] and this increase was larger for attended than ignored stimuli. Beta-band activity decreased in the ipsilateral SI prior to stimulus offset [event-related desynchronization (ERD)] for attended stimuli only. Whereas attention modulation of the evoked response was confined to the contralateral SI, event-related changes of beta-band activity involved contralateral SI–MI and inter-hemispheric SI–SI connections. Modulation of neural activity in such a large sensorimotor network indicates a role for beta activity in higher-order processing. PMID:20384818

  14. EAP application to artificial tactile feel display of virtual reality

    NASA Astrophysics Data System (ADS)

    Konyo, Masashi; Tadokoro, Satoshi; Takamori, Toshi; Oguro, Keisuke

    2001-07-01

    A tactile feel display device for virtual reality was developed using Nafion-Platinum composite type EAP actuator (known as IPMC or ICPF). Conventional tactile displays can hardly express tactile human feeling of the fine touch of the surface of a cloth, because their mechanisms cannot excite minute distributed stimuli on human skin. We propose a new ciliary device using ICPF actuators. The ICPF has sufficient softness, utilizing the passive material property, that complex control is not required. The low drive voltage is safe enough for the touch of fingers. Its simple operation mechanism allows miniaturization for practical equipments. The developed device was designed with a number of cilia consisting of ICPF actuators, where a cilium is 2 mm wide and 5 mm long. An ICPF membrane is cut into pectination, and only the cilium part is plated and has a function of an actuator. An inclined configuration of the cilia produces variety of stimuli to human skin controlling frequencies. We tried to display both pressure and vibration at the same time using modulated low and high frequencies. The result clearly shows that over 80% of the subjects sensed some special tactile feeling. A comparison with real material samples shows that this display can present a subtle distinction of tactile feeling of cloth, especially like a towel and denim.

  15. Speech perception with tactile support in adverse listening conditions

    NASA Astrophysics Data System (ADS)

    Drullman, Rob; Bronkhorst, Adelbert W.

    2002-05-01

    Since long, different methods of vibrotactile stimulation have been used as an aid for speech perception by some people with severe hearing impairment. The fact that experiments have shown (limited) benefits proves that tactile information can indeed give some support. In our research program on multimodal interfaces, we wondered if normal hearing listeners could benefit from tactile information when speech was presented in adverse listening conditions. Therefore, we set up a pilot experiment with a male speaker against a background of one, two, four or eight competing male speakers or speech noise. Sound was presented diotically to the subjects and the speech-reception threshold (SRT) for short sentences was measured. The temporal envelope (0-30 Hz) of the speech signal was computed in real time and led to the tactile transducer (MiniVib), which was fixed to the index finger. First results show a significant drop in SRT of about 3 dB when using tactile stimulation in the condition of one competing speaker. In the other conditions no significant effects were found, but there is a trend of a decrease of the SRT when tactile information is given. We will discuss the results of further experiments.

  16. Microfabricated Tactile Sensors for Biomedical Applications: A Review

    PubMed Central

    Saccomandi, Paola; Schena, Emiliano; Oddo, Calogero Maria; Zollo, Loredana; Silvestri, Sergio; Guglielmelli, Eugenio

    2014-01-01

    During the last decades, tactile sensors based on different sensing principles have been developed due to the growing interest in robotics and, mainly, in medical applications. Several technological solutions have been employed to design tactile sensors; in particular, solutions based on microfabrication present several attractive features. Microfabrication technologies allow for developing miniaturized sensors with good performance in terms of metrological properties (e.g., accuracy, sensitivity, low power consumption, and frequency response). Small size and good metrological properties heighten the potential role of tactile sensors in medicine, making them especially attractive to be integrated in smart interfaces and microsurgical tools. This paper provides an overview of microfabricated tactile sensors, focusing on the mean principles of sensing, i.e., piezoresistive, piezoelectric and capacitive sensors. These sensors are employed for measuring contact properties, in particular force and pressure, in three main medical fields, i.e., prosthetics and artificial skin, minimal access surgery and smart interfaces for biomechanical analysis. The working principles and the metrological properties of the most promising tactile, microfabricated sensors are analyzed, together with their application in medicine. Finally, the new emerging technologies in these fields are briefly described. PMID:25587432

  17. Vibrotactile pattern recognition: a portable compact tactile matrix.

    PubMed

    Thullier, Francine; Bolmont, Benoît; Lestienne, Francis G

    2012-02-01

    Compact tactile matrix (CTM) is a vibrotactile device composed of a seven-by-seven array of electromechanical vibrators "tactip" used to represent tactile patterns applied to a small skin area. The CTM uses a dynamic feature to generate spatiotemporal tactile patterns. The design requirements focus particularly on maximizing the transmission of the vibration from one tactip to the others as well as to the skin over a square area of 16 cm (2) while simultaneously minimizing the transmission of vibrations throughout the overall structure of the CTM. Experiments were conducted on 22 unpracticed subjects to evaluate how the CTM could be used to develop a tactile semantics for communication of instructions in order to test the ability of the subjects to identify: 1) directional prescriptors for gesture guidance and 2) instructional commands for operational task requirements in a military context. The results indicate that, after familiarization, recognition accuracies in the tactile patterns were remarkably precise for more 80% of the subjects. PMID:22084044

  18. Pain facilitates tactile processing in human somatosensory cortices.

    PubMed

    Ploner, Markus; Pollok, Bettina; Schnitzler, Alfons

    2004-09-01

    Touch and pain are intimately related modalities. Despite a substantial overlap in their cortical representations interactions between both modalities are largely unknown at the cortical level. We therefore used magnetoencephalography and selective nociceptive cutaneous laser stimulation to investigate the effects of brief painful stimuli on cortical processing of touch. Using a conditioning test stimulus paradigm, our results show that painful conditioning stimuli facilitate processing of tactile test stimuli applied 500 ms later. This facilitation applies to cortical responses later than 40 ms originating from primary (S1) and secondary (S2) somatosensory cortices but not to earlier S1 responses. By contrast, tactile conditioning stimuli yield a decrease of early as well as late responses to tactile test stimuli. Control experiments show that pain-induced facilitation of tactile processing is not restricted to the site of the painful conditioning stimulus, whereas auditory conditioning does not yield a comparable facilitation. Apart from a lack of spatial specificity, the facilitating effect of pain closely resembles attentional effects on cortical processing of tactile stimuli. Thus these findings may represent a physiological correlate of an alerting function of pain as a change in the internal state to prepare for processing signals of particular relevance. PMID:15115788

  19. Remapping motion across modalities: tactile rotations influence visual motion judgments.

    PubMed

    Butz, Martin V; Thomaschke, Roland; Linhardt, Matthias J; Herbort, Oliver

    2010-11-01

    Multisensory interactions between haptics and vision remain poorly understood. Previous studies have shown that shapes, such as letters of the alphabet, when drawn on the skin, are differently perceived dependent upon which body part is stimulated and on how the stimulated body part, such as the hand, is positioned. Another line of research within this area has investigated multisensory interactions. Tactile perceptions, for example, have the potential to disambiguate visually perceived information. While the former studies focused on explicit reports about tactile perception, the latter studies relied on fully aligned multisensory stimulus dimensions. In this study, we investigated to what extent rotating tactile stimulations on the hand affect directional visual motion judgments implicitly and without any spatial stimulus alignment. We show that directional tactile cues and ambiguous visual motion cues are integrated, thus biasing the judgment of visually perceived motion. We further show that the direction of the tactile influence depends on the position and orientation of the stimulated part of the hand relative to a head-centered frame of reference. Finally, we also show that the time course of the cue integration is very versatile. Overall, the results imply immediate directional cue integration within a head-centered frame of reference. PMID:20878396

  20. A predictive nature for tactile awareness? Insights from damaged and intact central-nervous-system functioning

    PubMed Central

    Pia, Lorenzo; Garbarini, Francesca; Burin, Dalila; Fossataro, Carlotta; Berti, Anna

    2015-01-01

    In the present paper, we will attempt to gain hints regarding the nature of tactile awareness in humans. At first, we will review some recent literature showing that an actual tactile experience can emerge in absence of any tactile stimulus (e.g., tactile hallucinations, tactile illusions). According to the current model of tactile awareness, we will subsequently argue that such (false) tactile perceptions are subserved by the same anatomo-functional mechanisms known to underpin actual perception. On these bases, we will discuss the hypothesis that tactile awareness is strongly linked to expected rather than actual stimuli. Indeed, this hypothesis is in line with the notion that the human brain has a strong predictive, rather than reactive, nature. PMID:26042020

  1. A predictive nature for tactile awareness? Insights from damaged and intact central-nervous-system functioning.

    PubMed

    Pia, Lorenzo; Garbarini, Francesca; Burin, Dalila; Fossataro, Carlotta; Berti, Anna

    2015-01-01

    In the present paper, we will attempt to gain hints regarding the nature of tactile awareness in humans. At first, we will review some recent literature showing that an actual tactile experience can emerge in absence of any tactile stimulus (e.g., tactile hallucinations, tactile illusions). According to the current model of tactile awareness, we will subsequently argue that such (false) tactile perceptions are subserved by the same anatomo-functional mechanisms known to underpin actual perception. On these bases, we will discuss the hypothesis that tactile awareness is strongly linked to expected rather than actual stimuli. Indeed, this hypothesis is in line with the notion that the human brain has a strong predictive, rather than reactive, nature. PMID:26042020

  2. Science Activities for Teachers and Families To Explore with Young Children.

    ERIC Educational Resources Information Center

    Abdi, S. Wali; Freilich, Mark B.; Taylor, Satomi Izumi

    1998-01-01

    Describes science activities for preschool through primary-grade children, focusing on goals of science education, science processes, and characteristics of high-quality science activities. Notes that hands-on activities explore scientific concepts such as volume, gravity, heat conductivity, and condensation. (KB)

  3. Generating STEAM with Engaging Lunar Exploration Education/Public Outreach Activities

    NASA Astrophysics Data System (ADS)

    Runyon, C. J.; Hall, C.; Joyner, E.; Daou, D.; Hurd, D.; Boyce, K.; Garver, K.

    2012-03-01

    Our E/PO activities and programs present the ongoing story of lunar exploration and discovery and help teachers engage students in learning how the Moon and planetary surfaces form. Outreach materials highlight not just STEM, but also fine arts.

  4. An insect-inspired bionic sensor for tactile localization and material classification with state-dependent modulation.

    PubMed

    Patanè, Luca; Hellbach, Sven; Krause, André F; Arena, Paolo; Dürr, Volker

    2012-01-01

    INSECTS CARRY A PAIR OF ANTENNAE ON THEIR HEAD: multimodal sensory organs that serve a wide range of sensory-guided behaviors. During locomotion, antennae are involved in near-range orientation, for example in detecting, localizing, probing, and negotiating obstacles. Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe and basal angular encoders allow tactile localization in a polar coordinate system. Finally, the damping behavior of the registered signal is exploited to determine the most likely material. The tactile sensor is tested in four approaches with increasing neural plausibility: first, we show that peak extraction from the Fourier spectrum is sufficient for tactile localization with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network (ANN) which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorization. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the input signals

  5. An insect-inspired bionic sensor for tactile localization and material classification with state-dependent modulation

    PubMed Central

    Patanè, Luca; Hellbach, Sven; Krause, André F.; Arena, Paolo; Dürr, Volker

    2012-01-01

    Insects carry a pair of antennae on their head: multimodal sensory organs that serve a wide range of sensory-guided behaviors. During locomotion, antennae are involved in near-range orientation, for example in detecting, localizing, probing, and negotiating obstacles. Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe and basal angular encoders allow tactile localization in a polar coordinate system. Finally, the damping behavior of the registered signal is exploited to determine the most likely material. The tactile sensor is tested in four approaches with increasing neural plausibility: first, we show that peak extraction from the Fourier spectrum is sufficient for tactile localization with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network (ANN) which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorization. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the input signals

  6. Bioinspired electronic white cane implementation based on a LIDAR, a tri-axial accelerometer and a tactile belt.

    PubMed

    Pallejà, Tomàs; Tresanchez, Marcel; Teixidó, Mercè; Palacin, Jordi

    2010-01-01

    This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user's forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment. PMID:22163529

  7. Bioinspired Electronic White Cane Implementation Based on a LIDAR, a Tri-Axial Accelerometer and a Tactile Belt

    PubMed Central

    Pallejà, Tomàs; Tresanchez, Marcel; Teixidó, Mercè; Palacin, Jordi

    2010-01-01

    This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user’s forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment. PMID:22163529

  8. Optical based tactile shear and normal load sensor

    SciTech Connect

    Salisbury, Curt Michael

    2015-06-09

    Various technologies described herein pertain to a tactile sensor that senses normal load and/or shear load. The tactile sensor includes a first layer and an optically transparent layer bonded together. At least a portion of the first layer is made of optically reflective material. The optically transparent layer is made of resilient material (e.g., clear silicone rubber). The tactile sensor includes light emitter/light detector pair(s), which respectively detect either normal load or shear load. Light emitter(s) emit light that traverses through the optically transparent layer and reflects off optically reflective material of the first layer, and light detector(s) detect and measure intensity of reflected light. When a normal load is applied, the optically transparent layer compresses, causing a change in reflected light intensity. When shear load is applied, a boundary between optically reflective material and optically absorptive material is laterally displaced, causing a change in reflected light intensity.

  9. Effect of tactile vibration on annoyance to synthesized propfan noise

    NASA Technical Reports Server (NTRS)

    Clevenson, S. A.

    1981-01-01

    Design information that maximizes passenger comfort for propfan aircraft is presented. Predicted noise and vibration environments and the resultant passenger acceptability were studied. The effect of high frequency tactile vibration (i.e., greater than 30 Hz) on passenger reactions was analyzed. Passenger reactions to a wide range of noise with and without tactile vibration was studied. The passenger ride quality simulator was employed using subjects who evaluated either synthesized propeller noises only, or these noises combined with seat/arm vibration. The noises ranging from 80-100 dB consisted of a turbulent boundary layer noise with a factorial combination of five blade passage frequencies (50-200 Hz), two harmonic rolloffs, and three tone/noise ratios. It is indicated that passenger reaction (annoyance) to noise is not significantly changed in the presence of tactile vibration.

  10. Tactile Imaging Markers to Characterize Female Pelvic Floor Conditions

    PubMed Central

    van Raalte, Heather; Egorov, Vladimir

    2015-01-01

    The Vaginal Tactile Imager (VTI) records pressure patterns from vaginal walls under an applied tissue deformation and during pelvic floor muscle contractions. The objective of this study is to validate tactile imaging and muscle contraction parameters (markers) sensitive to the female pelvic floor conditions. Twenty-two women with normal and prolapse conditions were examined by a vaginal tactile imaging probe. We identified 9 parameters which were sensitive to prolapse conditions (p < 0.05 for one-way ANOVA and/or p < 0.05 for t-test with correlation factor r from −0.73 to −0.56). The list of parameters includes pressure, pressure gradient and dynamic pressure response during muscle contraction at identified locations. These parameters may be used for biomechanical characterization of female pelvic floor conditions to support an effective management of pelvic floor prolapse. PMID:26389014

  11. Effects of a Wearable, Tactile Aid on Language Comprehension of Prelingual Profoundly Deaf Children.

    ERIC Educational Resources Information Center

    Proctor, Adele

    Factors influencing the use of nonacoustic aids (such as visual displays and tactile devices) with the hearing impaired are reviewed. The benefits of tactile devices in improving speech reading/lipreading and speech are pointed out. Tactile aids which provide information on rhythm, rate, intensity, and duration of speech increase lipreading and…

  12. Tactile Aids for Speech Perception and Production by Hearing-Impaired People.

    ERIC Educational Resources Information Center

    Weisenberger, Janet

    1989-01-01

    Laboratory results are presented which suggest that hearing-impaired individuals' speech perception can be enhanced through use of tactile aids with a number of tactile transducers conveying information about the spectral content of the speech signal, and speech production can be improved through experience using a multichannel tactile aid.…

  13. A Longitudinal Evaluation of the Speech Perception Capabilities of Children Using Multichannel Tactile Vocoders.

    ERIC Educational Resources Information Center

    Eilers, Rebecca E.; And Others

    1996-01-01

    Thirty children with profound hearing impairments were followed over a three-year period with a semiannual battery of speech perception tests. Testing utilized multichannel tactile vocoders in variations of tactile and/or auditory/visual conditions. Performance in the tactile plus auditory condition generally exceeded that in other conditions,…

  14. Quantifying Different Tactile Sensations Evoked by Cutaneous Electrical Stimulation Using Electroencephalography Features.

    PubMed

    Zhang, Dingguo; Xu, Fei; Xu, Heng; Shull, Peter B; Zhu, Xiangyang

    2016-03-01

    Psychophysical tests and standardized questionnaires are often used to analyze tactile sensation based on subjective judgment in conventional studies. In contrast with the subjective evaluation, a novel method based on electroencephalography (EEG) is proposed to explore the possibility of quantifying tactile sensation in an objective way. The proposed experiments adopt cutaneous electrical stimulation to generate two kinds of sensations (vibration and pressure) with three grades (low/medium/strong) on eight subjects. Event-related potentials (ERPs) and event-related synchronization/desynchronization (ERS/ERD) are extracted from EEG, which are used as evaluation indexes to distinguish between vibration and pressure, and also to discriminate sensation grades. Results show that five-phase P1–N1–P2–N2–P3 deflection is induced in EEG. Using amplitudes of latter ERP components (N2 and P3), vibration and pressure sensations can be discriminated on both individual and grand-averaged ERP (p < 0.05). The grand-average ERPs can distinguish the three sensations grades, but there is no significant difference on individuals. In addition, ERS/ERD features of mu rhythm (8–13 Hz) are adopted. Vibration and pressure sensations can be discriminated on grand-average ERS/ERD (p < 0.05), but only some individuals show significant difference. The grand-averaged results show that most sensation grades can be differentiated, and most pairwise comparisons show significant difference on individuals (p < 0.05). The work suggests that ERP- and ERS/ERD-based EEG features may have potential to quantify tactile sensations for medical diagnosis or engineering applications. PMID:26762865

  15. A Tactile Stimulation Device for EEG Measurements in Clinical Use.

    PubMed

    Pokorny, Christoph; Breitwieser, Christian; Muller-Putz, Gernot R

    2014-06-01

    A tactile stimulation device for EEG measurements in clinical environments is proposed. The main purpose of the tactile stimulation device is to provide tactile stimulation to different parts of the body. To stimulate all four major types of mechanoreceptors, different stimulation patterns with frequencies in the range of 5-250 Hz have to be generated. The device provides two independent channels, delivers enough power to drive different types of electromagnetic transducers, is small and portable, and no expensive components are required to construct this device. The generated stimulation patterns are very stable, and deterministic control of the device is possible. To meet electrical safety requirements, the device was designed to be fully galvanically isolated. Leakage currents of the entire EEG measurement system including the tactile stimulation device were measured by the European Testing and Certifying Body for Medical Products Graz (Notified Body 0636). All measured currents were far below the maximum allowable currents defined in the safety standard EN 60601-1:2006 for medical electrical equipment. The successful operation of the tactile stimulation device was tested during an EEG experiment. The left and right wrist of one healthy subject were randomly stimulated with seven different frequencies. Steady-state somatosensory evoked potential (SSSEPs) could successfully be evoked and significant tuning curves at electrode positions contralateral to the stimulated wrist could be found. The device is ready to be used in clinical environment in a variety of applications to investigate the somatosensory system, in brain-computer interfaces (BCIs), or to provide tactile feedback. PMID:23864261

  16. Tactile sensing in specialized predators - from behavior to the brain.

    PubMed

    Catania, Kenneth C

    2012-04-01

    A number of predators depend heavily on tactile cues for pursuing and capturing prey. Here I describe and discuss the whiskers of carnivorous grasshopper mice and shrews, the sensory rays of the star-nosed mole, and the tactile appendages of the tentacled snake. These diverse sensors are accompanied by remarkable corresponding specializations in the central nervous system. But understanding their function and the significance of the central nervous system correlates requires the careful documentation of behavior inherent to a neuroethological approach. PMID:22209039

  17. Refreshable tactile displays based on bistable electroactive polymer

    NASA Astrophysics Data System (ADS)

    Niu, Xiaofan; Brochu, Paul; Salazar, Brandon; Pei, Qibing

    2011-04-01

    Refreshable tactile displays can significantly improve the education of blind children and the quality of life of people with severe vision impairment. A number of actuator technologies have been investigated. Bistable Electroactive Polymer (BSEP) appears to be well suited for this application. The BSEP exhibits a bistable electrically actuated strain as large as 335%. We present improved refreshable tactile display devices fabricated on thin plastic sheets. Stacked BSEP films were employed to meet the requirements in raised dot height and supporting force. The bistable nature of the actuation reduces the power consumption and simplifies the device operation.

  18. Sensing Senses: Tactile Feedback for the Prevention of Decubitus Ulcers

    PubMed Central

    Verbunt, Marcel

    2009-01-01

    Decubitus ulcers, also known as pressure sores, is a major problem in health care, in particular for patients with spinal cord injuries. These patients cannot feel the discomfort that would urge healthy people to change their posture. We describe a system that uses a sensor mat to detect problematic postures and provides tactile feedback to the user. The results of our preliminary study with healthy subjects show that the tactile feedback is a viable option to spoken feedback. We envision the system being used for rehabilitation games, but also for everyday Decubitus ulcers prevention. PMID:19949852

  19. Bioinspired design of tactile sensors based on Flemion

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Sato, Hiroshi; Xu, Chunye; Taya, Minoru

    2009-04-01

    In this work, we studied experimentally the sensing behavior of ionic membrane-based tactile sensors (Nafion and Flemion). We found from the experimental results that Flemion-based sensor exhibits clearer sensing signals than Nafion-based sensor and signals from Flemion-based sensor are robust under repeated loading. We also found that dome-shaped Flemion sensor can detect three-dimensional forces. We attempted to design an arrayed Flemion sensor system by bioinspiration from the tactile sensor cells on the skin of a cucumber tendril where numbers of the dome-shaped Flemion sensor units are arrayed periodically.

  20. Cortical correlates of perceptual decision making during tactile spatial pattern discrimination.

    PubMed

    Li Hegner, Yiwen; Lindner, Axel; Braun, Christoph

    2015-09-01

    Perceptual decision making involves a distributed cortical network including areas related to sensory feature extraction, decision formation, and finally signalling the decision through a motor response. Although these processing steps are supposed to occur in sequence, the seemingly instant mapping of a perceptual decision onto a motor response renders these processes almost indistinguishable. To dissociate cortical areas related to sensory decision making from areas that prepare the subsequent motor response, we performed functional magnetic resonance imaging during a tactile spatial pattern discrimination task with interleaved immediate and delayed response conditions. Decision difficulty was manipulated parametrically by adding spatial noise to the tactile patterns, resulting in a rise in decision time with increasing noise. We assumed that areas involved in making the decision should show a variation in their activation with decision time and irrespective of whether (immediate response condition) or not (delayed response condition) a motor response could be prepared in advance. To exhibit these putative decision areas, we used response time, as was obtained in the immediate response condition, as parametric predictor for the difficulty-dependent variations of blood oxygenation level-dependent (BOLD)-activity in both response conditions. BOLD activations in right (contralateral) postcentral sulcus, right intraparietal sulcus (IPS) and bilateral anterior insula (aINS) reflected this parametric modulation in both response conditions, suggesting a role of these areas in tactile decisions independent of decision-specific motor preparation. Furthermore, a multivariate pattern analysis performed on the BOLD responses in the delayed response condition for a single difficulty level independently validated IPS and aINS as decision-related areas. PMID:26095426

  1. Bionic Tactile Sensor for Near-Range Search, Localisation and Material Classification

    NASA Astrophysics Data System (ADS)

    Dürr, Volker; Krause, André F.; Neitzel, Matthias; Lange, Oliver; Reimann, Bert

    Insects use their antennae (feelers) as near range sensors for orientation, object localisation and communication. Here, we use the stick insect antenna as a paragon for an actively moved tactile sensor. Our bionic sensor uses vibration signals from contact events for obstacle localisation and classification of material properties. It is shown how distance is coded by salient peaks in the frequency spectrum, and how the damping time constants can be exploited to distinguish between eight objects made of a range of materials. Thus, we demonstrate application of bionic principles for non-visual, reliable, near-range object localisation and material classification that is suitable for autonomous exploratory robots.

  2. Exploring Socio-Ecological Factors Influencing Active and Inactive Spanish Students in Years 12 and 13

    ERIC Educational Resources Information Center

    Devís-Devís, José; Beltrán-Carrillo, Vicente J.; Peiró-Velert, Carmen

    2015-01-01

    This paper explores socio-ecological factors and their interplay that emerge from a qualitative study and influence adolescents' physical activity and sport participation. A total of 13 boys and 7 girls active and inactive adolescents, from years 12 and 13 and different types of school (state and private), participated in semi-structured…

  3. Young Children's Exploration of Semiotic Resources during Unofficial Computer Activities in the Classroom

    ERIC Educational Resources Information Center

    Bjorkvall, Anders; Engblom, Charlotte

    2010-01-01

    The article describes and discusses the learning potential of unofficial techno-literacy activities in the classroom with regards to Swedish 7-8-year-olds' exploration of semiotic resources when interacting with computers. In classroom contexts where every child works with his or her own computer, such activities tend to take up a substantial…

  4. Policy, Pedagogy, and Priorities: Exploring Stakeholder Perspectives on Active Learning in the Maldives

    ERIC Educational Resources Information Center

    Di Biase, Rhonda

    2015-01-01

    Challenges of implementing active-learning reform have been reported across a range of countries and include the need for greater attention to contextual factors and practical realities in the reform process. This study investigates how teachers enact active-learning pedagogy within the Maldives. Using design-based research, it explores--through…

  5. Exploring Ohio Police Preparedness for Active Shooter Incidents in Public Schools

    ERIC Educational Resources Information Center

    Pignatelli, Daniel A.

    2010-01-01

    School shootings, such as Columbine, have prompted police executives to explore response tactics and preparedness efforts for combating active shooters. This qualitative exploratory case study focused on specific preparation initiatives that have been implemented for the purpose of dealing with active shooters. Being prepared is one of the only…

  6. 14 CFR § 1266.104 - Cross-waiver of liability for launch agreements for science or space exploration activities...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... agreements for science or space exploration activities unrelated to the International Space Station. § 1266... exploration activities unrelated to the International Space Station. (a) The purpose of this section is to... exploration activities that are not related to the International Space Station (ISS) but involve a launch....

  7. Tactile Sensors: MoS2 -Based Tactile Sensor for Electronic Skin Applications (Adv. Mater. 13/2016).

    PubMed

    Park, Minhoon; Park, Yong Ju; Chen, Xiang; Park, Yon-Kyu; Kim, Min-Seok; Ahn, Jong-Hyun

    2016-04-01

    A tactile sensor based on a MoS2 strain gauge and a graphene electrode is integrated on a finger tip by M.-S. Kim, J.-H. Ahn, and co-workers, as described on page 2556. The MoS2 and graphene can be conformally attached onto a thumbprint thanks to their outstanding mechanical flexibility. The MoS2 -based tactile sensor, showing excellent sensing properties, is expected to provide great opportunities for electronic-skin and wearable-electronics applications. PMID:27037944

  8. Fluid–Structure Interaction-Based Biomechanical Perception Model for Tactile Sensing

    PubMed Central

    Wang, Zheng

    2013-01-01

    The reproduced tactile sensation of haptic interfaces usually selectively reproduces a certain object attribute, such as the object's material reflected by vibration and its surface shape by a pneumatic nozzle array. Tactile biomechanics investigates the relation between responses to an external load stimulus and tactile perception and guides the design of haptic interface devices via a tactile mechanism. Focusing on the pneumatic haptic interface, we established a fluid–structure interaction-based biomechanical model of responses to static and dynamic loads and conducted numerical simulation and experiments. This model provides a theoretical basis for designing haptic interfaces and reproducing tactile textures. PMID:24260228

  9. The plasmapause revisited. [Explorer 45 observation at various magnetic activity levels

    NASA Technical Reports Server (NTRS)

    Maynard, N. C.; Grebowsky, J. M.

    1977-01-01

    A statistical investigation is conducted concerning the plasmapause behavior observed from Explorer 45 during various levels of magnetic activity. Aspects of data handling are reported and the implications of a constant density level for a plasmapause definition are discussed. The average local time dependence of the gradient saturation events and the sharp saturation events detected on Explorer 45 is shown with the aid of graphs. Other graphs show the results of the statistical processing operations. The significance of the obtained data is discussed.

  10. About Face: Evaluating and Managing Tactile Impairment at the Time of Autism Diagnosis

    PubMed Central

    Silva, Louisa M. T.; Schalock, Mark; Gabrielsen, Kristen R.

    2015-01-01

    Evaluation for sensory impairment is a routine part of autism diagnosis. Sensory impairment of hearing, vision, or touch results in developmental delay and must be addressed before delay can resolve. Recent studies confirm that tactile impairment is present in autism and can be effectively treated with a tactile stimulation protocol. The research suggests a change in management at the time of autism diagnosis to include evaluation and treatment of tactile impairment. Here we validate screening and management tool for tactile impairment, the Autism Touch and Self-Regulation Checklist, in 404 typical and autistic preschool children. The tool assesses tactile impairment by location and severity. Autistic children were distinguished by mixed pain and numbness on multiple areas including the face and mouth (F = 412.1 (1,402);p < .000). Oral-facial tactile impairment interferes with the tactile stimulus to orienting. We hypothesized that oral-facial tactile impairment and difficulty orienting are predictive of ASD and that severity of tactile impairment is predictive of severity of ASD. Questions evaluating oral-facial and orienting responses correctly predicted 91% of the autism group. Severity of tactile impairment correctly predicted 81% of mild versus severe ASD. Results underscore the importance of evaluating and treating tactile impairment at the time of autism diagnosis. PMID:26605086

  11. Tactile soft-sparse mean fluid-flow imaging with a robotic whisker array.

    PubMed

    Tuna, Cagdas; Jones, Douglas L; Kamalabadi, Farzad

    2015-08-01

    An array of whiskers is critical to many mammals to survive in their environment. However, current engineered systems generally employ vision, radar or sonar to explore the surroundings, not having sufficiently benefited from tactile perception. Inspired by the whisking animals, we present here a novel tomography-based tactile fluid-flow imaging technique for the reconstruction of surroundings with an artificial whisker array. The moment sensed at the whisker base is the weighted integral of the drag force per length, which is proportional to the relative velocity squared on a whisker segment. We demonstrate that the 2D cross-sectional mean fluid-flow velocity-field can be successfully mapped out by collecting moment measurements at different angular positions with the whisker array. We use a regularized version of the FOCal underdetermined system solver algorithm with a smoothness constraint to obtain soft-sparse static estimates of the 2D cross-sectional velocity-squared distribution. This new proposed approach has the strong potential to be an alternative environmental sensing technology, particularly in dark or murky environments. PMID:26241787

  12. Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array.

    PubMed

    Hamed, Abbi; Masamune, Ken; Tse, Zion Tsz Ho; Lamperth, Michael; Dohi, Takeyoshi

    2012-07-01

    Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions. PMID:22913103

  13. Flexible PZT thin film tactile sensor for biomedical monitoring.

    PubMed

    Tseng, Hong-Jie; Tian, Wei-Cheng; Wu, Wen-Jong

    2013-01-01

    This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 μm on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV) was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g. PMID:23698262

  14. Reproducibility of Tactile Assessments for Children with Unilateral Cerebral Palsy

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Ware, Robert S.; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2012-01-01

    A systematic review identified tactile assessments used in children with cerebral palsy (CP), but their reproducibility is unknown. Sixteen children with unilateral CP and 31 typically developing children (TDC) were assessed 2-4 weeks apart. Test-retest percent agreements within one point for children with unilateral CP (and TDC) were…

  15. To What Extent Do Gestalt Grouping Principles Influence Tactile Perception?

    ERIC Educational Resources Information Center

    Gallace, Alberto; Spence, Charles

    2011-01-01

    Since their formulation by the Gestalt movement more than a century ago, the principles of perceptual grouping have primarily been investigated in the visual modality and, to a lesser extent, in the auditory modality. The present review addresses the question of whether the same grouping principles also affect the perception of tactile stimuli.…

  16. Tactile feedback to the palm using arbitrarily shaped DEA

    NASA Astrophysics Data System (ADS)

    Mößinger, Holger; Haus, Henry; Kauer, Michaela; Schlaak, Helmut F.

    2014-03-01

    Tactile stimulation enhances user experience and efficiency in human machine interaction by providing information via another sensory channel to the human brain. DEA as tactile interfaces have been in the focus of research in recent years. Examples are (vibro-) tactile keyboards or Braille displays. These applications of DEA focus mainly on interfacing with the user's fingers or fingertips only - demonstrating the high spatial resolution achievable with DEA. Besides providing a high resolution, the flexibility of DEA also allows designing free form surfaces equipped with single actuators or actuator matrices which can be fitted to the surface of the human skin. The actuators can then be used to provide tactile stimuli to different areas of the body, not to the fingertips only. Utilizing and demonstrating this flexibility we designed a free form DEA pad shaped to fit into the inside of the human palm. This pad consists of four single actuators which can provide e.g. directional information such as left, right, up and down. To demonstrate the value of such free form actuators we manufactured a PC-mouse using 3d printing processes. The actuator pad is mounted on the back of the mouse, resting against the palm while operating it. Software on the PC allows control of the vibration patterns displayed by the actuators. This allows helping the user by raising attention to certain directions or by discriminating between different modes like "pick" or "manipulate". Results of first tests of the device show an improved user experience while operating the PC mouse.

  17. Flexible PZT Thin Film Tactile Sensor for Biomedical Monitoring

    PubMed Central

    Tseng, Hong-Jie; Tian, Wei-Cheng; Wu, Wen-Jong

    2013-01-01

    This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 μm on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse topology of various human regions and sense the corresponding signals from human bodies. The measured arterial pulse waveform can be used to diagnose hypertension and cardiac failure in patients. The proposed sensors have several advantages, such as flexibility, reliability, high strain, low cost, simple fabrication, and low temperature processing. The PZT thin-film deposition process includes a pyrolysis process at 150 °C/500 °C for 10/5 min, followed by an annealing process at 650 °C for 10 min. Finally, the consistent pulse wave velocity (PWV) was demonstrated based on human pulse measurements from apical to radial, brachial to radial, and radial to ankle. It is characterized that the sensitivity of our PZT-based tactile sensor was approximately 0.798 mV/g. PMID:23698262

  18. Neonatal Habituation and Dishabituation to Tactile Stimulation during Sleep.

    ERIC Educational Resources Information Center

    Kisilevsky, Barbara S.; Muir, Darwin W.

    1984-01-01

    Two experiments were conducted to (1) replicate the findings of habituation of behavioral responding to a tactile stimulus assuring state control and (2) demonstrate dishabituation either by reinstatement of responding to the original, habituated stimulus or to novel stimuli either within or between modalities. Subjects were newborn Caucasian…

  19. Simultaneous Stimulus Preexposure Enhances Human Tactile Perceptual Learning

    ERIC Educational Resources Information Center

    Rodríguez, Gabriel; Angulo, Rocío

    2014-01-01

    An experiment with human participants established a novel procedure to assess perceptual learning with tactile stimuli. Participants received unsupervised exposure to two sandpaper surfaces differing in roughness (A and B). The ability of the participants to discriminate between the stimuli was subsequently assessed on a same/different test. It…

  20. Tactile Assessment in Children with Cerebral Palsy: A Clinimetric Review

    ERIC Educational Resources Information Center

    Auld, Megan Louise; Boyd, Roslyn Nancy; Moseley, G. Lorimer; Johnston, Leanne Marie

    2011-01-01

    This review evaluates the clinimetric properties of tactile assessments for children with cerebral palsy. Assessment of registration was reported using Semmes Weinstein Monofilaments (SWMs) or exteroception. Assessment of two-point discrimination was reported using the Disk-Criminator[R] or paperclip methods; Single point localization and double…

  1. YES, #NO, Visibility and Variation in ASL and Tactile ASL

    ERIC Educational Resources Information Center

    Petronio, Karen; Dively, Valerie

    2006-01-01

    In American Sign Language (ASL), a receiver watches the signer and receives language visually. In contrast, when using tactile ASL, a variety of ASL, the deaf-blind receiver receives language by placing a hand on top of the signer's hand. In the study described in this article we compared the functions and frequency of the signs YES and #NO in…

  2. Tactile Perception and Braille Letter Recognition: Effects of Developmental Teaching.

    ERIC Educational Resources Information Center

    Mangold, Sally S.

    1978-01-01

    The extent to which a developmental program of tactile perception and braille letter recognition would affect errors in these abilities and reduce scrubbing and backtracking behaviors of 30 legally blind braille users (5-15 years old) was studied. (Author/BD)

  3. Auditory, Tactile, and Audiotactile Information Processing Following Visual Deprivation

    ERIC Educational Resources Information Center

    Occelli, Valeria; Spence, Charles; Zampini, Massimiliano

    2013-01-01

    We highlight the results of those studies that have investigated the plastic reorganization processes that occur within the human brain as a consequence of visual deprivation, as well as how these processes give rise to behaviorally observable changes in the perceptual processing of auditory and tactile information. We review the evidence showing…

  4. A User Study on Tactile Graphic Generation Methods

    ERIC Educational Resources Information Center

    Krufka, S. E.; Barner, K. E.

    2006-01-01

    Methods to automatically convert graphics into tactile representations have been recently investigated, creating either raised-line or relief images. In particular, we briefly review one raised-line method where important features are emphasized. This paper focuses primarily on the effects of such emphasis and on comparing both raised-line and…

  5. Sensing Characteristics of an Experimental CT Tactile Sensor

    NASA Astrophysics Data System (ADS)

    Sawamoto, Yasuhiro; Ohka, Masahiro; Zhu, Ning

    The CT (Computed tomography) method is very effective for making thinner optical waveguide-type tactile sensors. In a previous paper, the authors established the architecture of a CT tactile sensor and evaluated its principle using a series of computer simulations. As a result, the LU decomposition method showed better noise robustness compared to the ART method. On the basis of the simulations, we develop an experimental CT tactile sensor comprised of infrared diodes, phototransistors, an acrylic plate and a black rubber sheet. In the present study, the LU decomposition method is employed and we determine the validity of the algorithm by examining use of a loading machine produced for the CT tactile sensor. In a series of experiments, it is found that absorption of light intensity increases monotonically with increase of applied force and that the present reconstruction method can be applied to not only simply but also multiply connected contact domains. The estimated position of the pressure centroid possesses a rather large error of 4.9 mm, which is 10.8% of a segment of the sensing area.

  6. Durable Tactile Glove for Human or Robot Hand

    NASA Technical Reports Server (NTRS)

    Butzer, Melissa; Diftler, Myron A.; Huber, Eric

    2010-01-01

    A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

  7. A reconfigurable tactile display based on polymer MEMS technology

    NASA Astrophysics Data System (ADS)

    Wu, Xiaosong

    A tactile display provides information such as shape, texture, temperature, and hardness to a user. Ultimately, a tactile display could be used to recreate a virtual object that may be stored in a computer. However, such advanced displays are not yet widely available, primarily due to the lack of low cost, large area, compact actuator arrays that can stimulate the large numbers of receptors of the user and that can also meet the high requirements for user safety and comfort. This research focuses on the development of polymer microfabrication technologies for the realization of two major components of a pneumatic tactile display: a microactuator array and a complementary microvalve (control) array. In this work, the concept, fabrication, and characterization of a kinematically-stabilized polymeric microbubble actuator ("endoskeletal microbubble actuator") is presented. A systematic design and modeling procedure was carried out to generate an optimized geometry of the corrugated diaphragm to satisfy membrane deflection, force, and stability requirements set forth by the tactile display goals. A mass-manufacturable actuator has been fabricated using the approaches of lithography and micromolding. A prototype of a single endoskeletal bubble actuator with a diameter of 2.6mm has been fabricated and characterized. In addition, in order to further reduce the size and cost of the tactile display, a microvalve array can be integrated into the tactile display system to control the pneumatic fluid that actuates the microbubble actuator. A piezoelectrically-driven and hydraulically-amplified polymer microvalve has been designed, fabricated, and tested. An incompressible elastomer was used as a solid hydraulic medium to convert the small axial displacement of a piezoelectric actuator into a large valve head stroke while maintaining a large blocking force. The function of the microvalve as an on-off switch for a pneumatic microbubble tactile actuator has been demonstrated

  8. A tactile sensor translating texture and sliding motion information into electrical pulses

    NASA Astrophysics Data System (ADS)

    Liao, Zhipeng; Liu, Weihua; Wu, You; Zhang, Chen; Zhang, Yan; Wang, Xiaoli; Li, Xin

    2015-06-01

    An electric pulse output by a nanogenerator upon a strain-and-release event resembles a neural impulse. Cutaneous receptors imbedded in skin transduce mechanical forces impinging the skin into neural impulses and the tactile information is encoded into the firing rates of the neural impulses. Here, we report a nanogenerator-type tactile sensor, which records the texture and sliding motion by outputting a sequence of electric pulses. The sensitive component of the device is an NG embedded in a polydimethylsiloxane package. An artificial finger-print serving as a strain introducer mimicking finger prints is integrated over the NG. The electric pulses outputted by the device transmit the texture and sliding motion information. The device demonstrates a capability of detecting punch holes with depth less than 200 μm on a nonwoven cloth. It also shows a perfect reproducibility of the electric pulses as it scans the same area of a band wire and a piece of nonwoven cloth. The artificial finger-print is the key element in transferring the strain direction, which allows the active sensor (a nanogenerator) beneath to detect the bumpy structure during a touch and sliding motion.An electric pulse output by a nanogenerator upon a strain-and-release event resembles a neural impulse. Cutaneous receptors imbedded in skin transduce mechanical forces impinging the skin into neural impulses and the tactile information is encoded into the firing rates of the neural impulses. Here, we report a nanogenerator-type tactile sensor, which records the texture and sliding motion by outputting a sequence of electric pulses. The sensitive component of the device is an NG embedded in a polydimethylsiloxane package. An artificial finger-print serving as a strain introducer mimicking finger prints is integrated over the NG. The electric pulses outputted by the device transmit the texture and sliding motion information. The device demonstrates a capability of detecting punch holes with depth less

  9. Disentangling the External Reference Frames Relevant to Tactile Localization

    PubMed Central

    Backhaus, Jenny; Röder, Brigitte; Badde, Stephanie

    2016-01-01

    Different reference frames appear to be relevant for tactile spatial coding. When participants give temporal order judgments (TOJ) of two tactile stimuli, one on each hand, performance declines when the hands are crossed. This effect is attributed to a conflict between anatomical and external location codes: hand crossing places the anatomically right hand into the left side of external space. However, hand crossing alone does not specify the anchor of the external reference frame, such as gaze, trunk, or the stimulated limb. Experiments that used explicit localization responses, such as pointing to tactile stimuli rather than crossing manipulations, have consistently implicated gaze-centered coding for touch. To test whether crossing effects can be explained by gaze-centered coding alone, participants made TOJ while the position of the hands was manipulated relative to gaze and trunk. The two hands either lay on different sides of space relative to gaze or trunk, or they both lay on one side of the respective space. In the latter posture, one hand was on its "regular side of space" despite hand crossing, thus reducing overall conflict between anatomical and external codes. TOJ crossing effects were significantly reduced when the hands were both located on the same side of space relative to gaze, indicating gaze-centered coding. Evidence for trunk-centered coding was tentative, with an effect in reaction time but not in accuracy. These results link paradigms that use explicit localization and TOJ, and corroborate the relevance of gaze-related coding for touch. Yet, gaze and trunk-centered coding did not account for the total size of crossing effects, suggesting that tactile localization relies on additional, possibly limb-centered, reference frames. Thus, tactile location appears to be estimated by integrating multiple anatomical and external reference frames. PMID:27391805

  10. Disentangling the External Reference Frames Relevant to Tactile Localization.

    PubMed

    Heed, Tobias; Backhaus, Jenny; Röder, Brigitte; Badde, Stephanie

    2016-01-01

    Different reference frames appear to be relevant for tactile spatial coding. When participants give temporal order judgments (TOJ) of two tactile stimuli, one on each hand, performance declines when the hands are crossed. This effect is attributed to a conflict between anatomical and external location codes: hand crossing places the anatomically right hand into the left side of external space. However, hand crossing alone does not specify the anchor of the external reference frame, such as gaze, trunk, or the stimulated limb. Experiments that used explicit localization responses, such as pointing to tactile stimuli rather than crossing manipulations, have consistently implicated gaze-centered coding for touch. To test whether crossing effects can be explained by gaze-centered coding alone, participants made TOJ while the position of the hands was manipulated relative to gaze and trunk. The two hands either lay on different sides of space relative to gaze or trunk, or they both lay on one side of the respective space. In the latter posture, one hand was on its "regular side of space" despite hand crossing, thus reducing overall conflict between anatomical and external codes. TOJ crossing effects were significantly reduced when the hands were both located on the same side of space relative to gaze, indicating gaze-centered coding. Evidence for trunk-centered coding was tentative, with an effect in reaction time but not in accuracy. These results link paradigms that use explicit localization and TOJ, and corroborate the relevance of gaze-related coding for touch. Yet, gaze and trunk-centered coding did not account for the total size of crossing effects, suggesting that tactile localization relies on additional, possibly limb-centered, reference frames. Thus, tactile location appears to be estimated by integrating multiple anatomical and external reference frames. PMID:27391805

  11. Abnormal visual experience during development alters the early stages of visual-tactile integration.

    PubMed

    Niechwiej-Szwedo, Ewa; Chin, Jessica; Wolfe, Paul J; Popovich, Christina; Staines, W Richard

    2016-05-01

    Visual experience during the critical periods in early postnatal life is necessary for the normal development of the visual system. Disruption of visual input during this period results in amblyopia, which is associated with reduced activation of the striate and extrastriate cortices. It is well known that visual input converges with other sensory signals and exerts a significant influence on cortical processing in multiple association areas. Recent work in healthy adults has also shown that task-relevant visual input can modulate neural excitability at very early stages of information processing in the primary somatosensory cortex. Here we used electroencephalography to investigate visual-tactile interactions in adults with abnormal binocular vision due to amblyopia and strabismus. Results showed three main findings. First, in comparison to a visually normal control group, participants with abnormal vision had a significantly lower amplitude of the P50 somatosensory event related potential (ERP) when visual and tactile stimuli were presented concurrently. Second, the amplitude of the P100 somatosensory ERP was significantly greater in participants with abnormal vision. These results indicate that task relevant visual input does not significantly influence the excitability of the primary somatosensory cortex, instead, the excitability of the secondary somatosensory cortex is increased. Third, participants with abnormal vision had a higher amplitude of the P1 visual ERP when a tactile stimulus was presented concurrently. Importantly, these results were not modulated by viewing condition, which indicates that the impact of amblyopia on crossmodal interactions is not simply related to the reduced visual acuity as it was evident when viewing with the unaffected eye and binocularly. These results indicate that the consequences of abnormal visual experience on neurophysiological processing extend beyond the primary and secondary visual areas to other modality

  12. ABT-627, an endothelin ET(A) receptor-selective antagonist, attenuates tactile allodynia in a diabetic rat model of neuropathic pain.

    PubMed

    Jarvis, M F; Wessale, J L; Zhu, C Z; Lynch, J J; Dayton, B D; Calzadilla, S V; Padley, R J; Opgenorth, T J; Kowaluk, E A

    2000-01-24

    Tactile allodynia, the enhanced perception of pain in response to normally non-painful stimulation, represents a common complication of diabetic neuropathy. The activation of endothelin ET(A) receptors has been implicated in diabetes-induced reductions in peripheral neurovascularization and concomitant endoneurial hypoxia. Endothelin receptor activation has also been shown to alter the peripheral and central processing of nociceptive information. The present study was conducted to evaluate the antinociceptive effects of the novel endothelin ET(A) receptor-selective antagonist, 2R-(4-methoxyphenyl)-4S-(1,3-benzodioxol-5-yl)-1-(N, N-di(n-butyl)aminocarbonyl-methyl)-pyrrolidine-3R-carboxylic acid (ABT-627), in the streptozotocin-induced diabetic rat model of neuropathic pain. Rats were injected with 75 mg/kg streptozotocin (i. p.), and drug effects were assessed 8-12 weeks following streptozotocin treatment to allow for stabilization of blood glucose levels (>/=240 mg/dl) and tactile allodynia thresholds (tactile allodynia thresholds. A significant antinociceptive effect (40-50% increase in tactile allodynia thresholds, P<0.05) was observed at the dose of 10 mg/kg, i.p., within 0.5-2-h post-dosing. The antinociceptive effects of ABT-627 (10 mg kg(-1) day(-1), p.o.) were maintained following chronic administration of the antagonist in drinking water for 7 days. In comparison, morphine administered acutely at a dose of 8 mg/kg, i.p., produced a significant 90% increase in streptozotocin-induced tactile allodynia thresholds. The endothelin ET(B) receptor-selective antagonist, 2R-(4-propoxyphenyl)-4S-(1, 3-benzodioxol-5-yl)-1-(N-(2, 6-diethylphenyl)aminocarbonyl-methyl)-pyrrolidine-3R-carboxy lic acid (A-192621; 20 mg/kg, i.p.), did not significantly alter tactile allodynia thresholds in streptozotocin-treated rats. Although combined i.p. administration

  13. Are One-to-One Computers Necessary? An Analysis of Collaborative Web Exploration Activities Supported by Shared Displays

    ERIC Educational Resources Information Center

    Chang, Chia-Jung; Liu, Chen-Chung; Shen, Yan-Jhih

    2012-01-01

    Collaborative web exploration, in which learners work together to explore the World Wide Web, has become a key learning activity in education contexts. Learners can use a shared computer with a shared display to explore the web together. However, such a shared-computer approach may limit active participation among learners. To address this issue,…

  14. A structural fingertip model for simulating of the biomechanics of tactile sensation.

    PubMed

    Wu, J Z; Dong, R G; Rakheja, S; Schopper, A W; Smutz, W P

    2004-03-01

    Tactile performance of human fingertips is associated with activity of the nerve endings and sensitivity of the soft tissue within the fingertip to the static and dynamic skin indentation. The nerve endings in the fingertips sense the stress/strain states developed within the soft tissue, which are affected by the material properties of the tissues. The vibrotactile sensation and tactile performance are thus believed to be strongly influenced by the nonlinear and time-dependent properties of the soft tissues. The purpose of the present research is to simulate the biomechanics of tactile sensation. A two-dimensional model, which incorporates the essential anatomical structures of a finger (i.e. skin, subcutaneous tissue, bone, and nail), has been used for the analysis. The skin tissue is assumed to be hyperelastic and viscoelastic. The subcutaneous tissue is considered to be a nonlinear, biphasic material composed of a hyperelastic solid and an inviscid fluid phase. The nail and bone are considered to be linearly elastic. The advantages of the proposed fingertip model over the previous "waterbed" and "continuum" fingertip models include its ability to predict the deflection profile of the fingertip surface, the stress and strain distributions within the soft tissue, and most importantly, the dynamic response of the fingertip to mechanical stimuli. The proposed model is applied to simulate the mechanical responses of a fingertip under a line load, and in one-point (1PT) and two-point (2PT) tactile discrimination tests. The model's predictions of the deflection profiles of a fingertip surface under a line load agree well with the reported experimental data. Assuming that the mechanoreceptors in the dermis sense the stimuli associated with normal strains (the vertical and horizontal strains) and strain energy density, our numerical results suggest that the threshold of 2PT discrimination may lie between 2.0 and 3.0 mm, which is consistent with the published

  15. An empirical exploration of metacognitive assessment activities in a third-year civil engineering hydraulics course

    NASA Astrophysics Data System (ADS)

    Meyer, Jan H. F.; Knight, David B.; Callaghan, David P.; Baldock, Tom E.

    2015-05-01

    Threshold concepts are transformative, integrative, and provocative; understanding these difficult concepts allows students to be capable of solving advanced problems. This investigation and evaluation of a metacognitive curricular approach explore variation in students' and teachers' discernment of structural complexity of concepts and its potential for enhancing students' learning and conceptual understanding of threshold concepts. Three trials of a metacognitive assessment activity administered to two cohorts of a civil engineering course (n = 276 and n = 264) were investigated. Students were presented with several answers (varying in structural complexity) to a question about a threshold concept and asked to mark each response. Quantitative analyses compared students' and teachers' marking schemes within and across trials, and qualitative analyses explored students' written reflections following the activity. Students' justifications for their marking schemes, their reflections on the activity's usefulness, and the convergence of students' and teachers' marking schemes suggest that the activity supported deep forms of student learning.

  16. Comparison of upper extremity function, pain, and tactile sense between the uneffected side of hemiparetic patients and healthy subjects.

    PubMed

    Balcı, Nilay Comuk; Dogru, Esra; Aytar, Aydan; Gokmen, Ozge; Depreli, Ozde

    2016-07-01

    [Purpose] The aim of this study was to compare the unaffected upper extremity of patients with hemiparesis with that of healthy subjects in terms of function, pain, and tactile sense. [Subjects and Methods] Upper extremity evaluation parameters of 20 patients with hemiparesis were compared with an age-matched control group of 20 healthy subjects. A shorter version of the Disability of Arm and Shoulder Questionnaire, Upper Extremity Functional Index, and Simple Shoulder Test were used to evaluate the upper extremity functionality. The Visual Analog Scale was used to measure pain severity at rest, at night, and during activity. Tactile sensation levels were assessed by Semmes-Weinstein monofilaments at four palmar areas. [Results] A statistically significant difference was found in the upper extremity functionality between the groups. Pain severity at rest was significantly higher in the hemiparetic group. There was no significant difference in night and activity pain severities or tactile sensation levels between the groups. [Conclusion] According to our results, the unaffected side of patients with hemiparesis differs in functionality and pain at rest compared with that of healthy persons. Studies with larger sample size and various evaluation tests are needed to further investigate the unaffected side of patients with hemiparesis. PMID:27512250

  17. Comparison of upper extremity function, pain, and tactile sense between the uneffected side of hemiparetic patients and healthy subjects

    PubMed Central

    Balcı, Nilay Comuk; Dogru, Esra; Aytar, Aydan; Gokmen, Ozge; Depreli, Ozde

    2016-01-01

    [Purpose] The aim of this study was to compare the unaffected upper extremity of patients with hemiparesis with that of healthy subjects in terms of function, pain, and tactile sense. [Subjects and Methods] Upper extremity evaluation parameters of 20 patients with hemiparesis were compared with an age-matched control group of 20 healthy subjects. A shorter version of the Disability of Arm and Shoulder Questionnaire, Upper Extremity Functional Index, and Simple Shoulder Test were used to evaluate the upper extremity functionality. The Visual Analog Scale was used to measure pain severity at rest, at night, and during activity. Tactile sensation levels were assessed by Semmes-Weinstein monofilaments at four palmar areas. [Results] A statistically significant difference was found in the upper extremity functionality between the groups. Pain severity at rest was significantly higher in the hemiparetic group. There was no significant difference in night and activity pain severities or tactile sensation levels between the groups. [Conclusion] According to our results, the unaffected side of patients with hemiparesis differs in functionality and pain at rest compared with that of healthy persons. Studies with larger sample size and various evaluation tests are needed to further investigate the unaffected side of patients with hemiparesis. PMID:27512250

  18. Virtual Active Touch Using Randomly Patterned Intracortical Microstimulation

    PubMed Central

    O’Doherty, Joseph E.; Lebedev, Mikhail A.; Li, Zheng; Nicolelis, Miguel A.L.

    2012-01-01

    Intracortical microstimulation (ICMS) has promise as a means for delivering somatosensory feedback in neuroprosthetic systems. Various tactile sensations could be encoded by temporal, spatial, or spatiotemporal patterns of ICMS. However, the applicability of temporal patterns of ICMS to artificial tactile sensation during active exploration is unknown, as is the minimum discriminable difference between temporally modulated ICMS patterns. We trained rhesus monkeys in an active exploration task in which they discriminated periodic pulse-trains of ICMS (200 Hz bursts at a 10 Hz secondary frequency) from pulse trains with the same average pulse rate, but distorted periodicity (200 Hz bursts at a variable instantaneous secondary frequency). The statistics of the aperiodic pulse trains were drawn from a gamma distribution with mean inter-burst intervals equal to those of the periodic pulse trains. The monkeys distinguished periodic pulse trains from aperiodic pulse trains with coefficients of variation 0.25 or greater. Reconstruction of movement kinematics, extracted from the activity of neuronal populations recorded in the sensorimotor cortex concurrent with the delivery of ICMS feedback, improved when the recording intervals affected by ICMS artifacts were removed from analysis. These results add to the growing evidence that temporally patterned ICMS can be used to simulate a tactile sense for neuroprosthetic devices. PMID:22207642

  19. Learning touch preferences with a tactile robot using dopamine modulated STDP in a model of insular cortex

    PubMed Central

    Chou, Ting-Shuo; Bucci, Liam D.; Krichmar, Jeffrey L.

    2015-01-01

    Neurorobots enable researchers to study how behaviors are produced by neural mechanisms in an uncertain, noisy, real-world environment. To investigate how the somatosensory system processes noisy, real-world touch inputs, we introduce a neurorobot called CARL-SJR, which has a full-body tactile sensory area. The design of CARL-SJR is such that it encourages people to communicate with it through gentle touch. CARL-SJR provides feedback to users by displaying bright colors on its surface. In the present study, we show that CARL-SJR is capable of learning associations between conditioned stimuli (CS; a color pattern on its surface) and unconditioned stimuli (US; a preferred touch pattern) by applying a spiking neural network (SNN) with neurobiologically inspired plasticity. Specifically, we modeled the primary somatosensory cortex, prefrontal cortex, striatum, and the insular cortex, which is important for hedonic touch, to process noisy data generated directly from CARL-SJR's tactile sensory area. To facilitate learning, we applied dopamine-modulated Spike Timing Dependent Plasticity (STDP) to our simulated prefrontal cortex, striatum, and insular cortex. To cope with noisy, varying inputs, the SNN was tuned to produce traveling waves of activity that carried spatiotemporal information. Despite the noisy tactile sensors, spike trains, and variations in subject hand swipes, the learning was quite robust. Further, insular cortex activities in the incremental pathway of dopaminergic reward system allowed us to control CARL-SJR's preference for touch direction without heavily pre-processed inputs. The emerged behaviors we found in this model match animal's behaviors wherein they prefer touch in particular areas and directions. Thus, the results in this paper could serve as an explanation on the underlying neural mechanisms for developing tactile preferences and hedonic touch. PMID:26257639

  20. Distributed Operations for the Mars Exploration Rover Mission with the Science Activity Planner

    NASA Technical Reports Server (NTRS)

    Wick, Justin V.; Callas, John L.; Norris, Jeffrey S.; Powell, Mark W.; Vona, Marsette A., III

    2005-01-01

    Due to the length of the Mars Exploration Rover Mission, most scientists were unable to stay at the central operations facility at the Jet Propulsion Laboratory. This created a need for distributed operations software, in the form of the Distributed Science Activity Planner. The distributed architecture saved a considerable amount of money and increased the number of individuals who could be actively involved in the mission, contributing to its success.

  1. Social Inequalities in Body Weight and Physical Activity: Exploring the Role of Fitness Centers

    ERIC Educational Resources Information Center

    McLaren, Lindsay; Rock, Melanie J.; McElgunn, Jamie

    2012-01-01

    Fitness centers are a viable option for physical activity, particularly in climates with significant weather variation. Due to variation in economic and social expressions of exclusivity, fitness centers may have some relation to social inequalities in physical inactivity and related health outcomes; thus, our objective was to explore this…

  2. Exploring the Moon: A Teacher's Guide with Activities for Earth and Space Sciences.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This educational guide concerns exploring the moon. Activities are divided into three units: Pre-Apollo, Learning from Apollo, and The Future. These correspond, at least roughly, to exercises that can be done before the Lunar Sample Disk (available from NASA) arrives to the school (Pre-Apollo), while it is there (Learning from Apollo), and after…

  3. Uncovering Students' Environmental Identity: An Exploration of Activities in an Environmental Science Course

    ERIC Educational Resources Information Center

    Blatt, Erica

    2014-01-01

    This study at a public high school in the Northeastern United States explores how students' environmental identities are affected by various activities in an Environmental Science course. Data was collected as part of an ethnographic study involving an Environmental Science teacher and her tenth-twelfth grade students. The results focus on…

  4. Activating Metaphors: Exploring the Embodied Nature of Metaphorical Mapping in Political Discourse

    ERIC Educational Resources Information Center

    Giovanelli, Marcello

    2016-01-01

    Metaphor is generally understood as the process of understanding one thing in terms of another. The activity described here is designed to make use of the principles of embodied cognition and meaning, and specifically the embodied nature of metaphor, to explore political discourse and communication. With high-school junior or senior students in…

  5. Popular Culture, Cultural Resistance, and Anticonsumption Activism: An Exploration of Culture Jamming as Critical Adult Education

    ERIC Educational Resources Information Center

    Sandlin, Jennifer A.

    2007-01-01

    This chapter examines popular culture as a site of cultural resistance. Specifically, it explores how "culture jamming," a cultural-resistance activity, can be a form of adult education. It examines adult education and learning as it intersects with both consumerism and popular culture. Focus is placed on a growing social movement of individuals…

  6. Exploring Students' Perceptions about Learning in School: An Activity Theory Based Study

    ERIC Educational Resources Information Center

    Portnov-Neeman, Yelena; Barak, Moshe

    2013-01-01

    In the current study, we used Activity Theory as the conceptual framework for exploring students' perceptions about how learning in school is affected by the following five elements: Object, Tools, Rules, Community and Division of Labor. Data were collected by administrating a semi-structured questionnaire among 70 junior high school students and…

  7. Cross Space: The Exploration of SNS-Based Writing Activities in a Multimodal Learning Environment

    ERIC Educational Resources Information Center

    Lee, Kwang-Soon; Kim, Bong-Gyu

    2016-01-01

    This study explores the positive learning effect of formulating English sentences via Social Network Service (SNS; "Kakao-Talk") on less proficient L2 university students' (LPSs') writing, when the application is utilized as a tool to link in and out-of class activities in a multimodal-learning environment. Its objective is also to…

  8. The Role of Active Exploration of 3D Face Stimuli on Recognition Memory of Facial Information

    ERIC Educational Resources Information Center

    Liu, Chang Hong; Ward, James; Markall, Helena

    2007-01-01

    Research on face recognition has mainly relied on methods in which observers are relatively passive viewers of face stimuli. This study investigated whether active exploration of three-dimensional (3D) face stimuli could facilitate recognition memory. A standard recognition task and a sequential matching task were employed in a yoked design.…

  9. Participation Patterns of Korean Adolescents in School-Based Career Exploration Activities

    ERIC Educational Resources Information Center

    Rojewski, Jay W.; Lee, In Heok; Hill, Roger B.

    2014-01-01

    Variations in the school-based career exploration activities of Korean high school students were examined. Data represented 5,227 Korean adolescents in Grade 11 contained in the Korean Education Longitudinal Study of 2005, a nationally representative longitudinal database administered by the Korean Educational Development Institute. Latent class…

  10. Scaffold explorer: an interactive tool for organizing and mining structure-activity data spanning multiple chemotypes.

    PubMed

    Agrafiotis, Dimitris K; Wiener, John J M

    2010-07-01

    We introduce Scaffold Explorer, an interactive tool that allows medicinal chemists to define hierarchies of chemical scaffolds and use them to explore their project data. Scaffold Explorer allows the user to construct a tree, where each node corresponds to a specific scaffold. Each node can have multiple children, each of which represents a more refined substructure relative to its parent node. Once the tree is defined, it can be mapped onto any collection of compounds and be used as a navigational tool to explore structure-activity relationships (SAR) across different chemotypes. The rich visual analytics of Scaffold Explorer afford the user a "bird's-eye" view of the chemical space spanned by a particular data set, map any physicochemical property or biological activity of interest onto the individual scaffold nodes, serve as an aggregator for the properties of the compounds represented by these nodes, and quickly distinguish promising chemotypes from less interesting or problematic ones. Unlike previous approaches, which focused on automated extraction and classification of scaffolds, the utility of the new tool rests on its interactivity and ability to accommodate the medicinal chemists' intuition by allowing the use of arbitrary substructures containing variable atoms, bonds, and/or substituents such as those employed in substructure search. PMID:20524668

  11. Use of tactile feedback to control exploratory movements to characterize object compliance

    PubMed Central

    Su, Zhe; Fishel, Jeremy A.; Yamamoto, Tomonori; Loeb, Gerald E.

    2012-01-01

    Humans have been shown to be good at using active touch to perceive subtle differences in compliance. They tend to use highly stereotypical exploratory strategies, such as applying normal force to a surface. We developed similar exploratory and perceptual algorithms for a mechatronic robotic system (Barrett arm/hand system) equipped with liquid-filled, biomimetic tactile sensors (BioTac® from SynTouch LLC). The distribution of force on the fingertip was measured by the electrical resistance of the conductive liquid trapped between the elastomeric skin and a cluster of four electrodes on the flat fingertip surface of the rigid core of the BioTac. These signals provided closed-loop control of exploratory movements, while the distribution of skin deformations, measured by more lateral electrodes and by the hydraulic pressure, were used to estimate material properties of objects. With this control algorithm, the robot plus tactile sensor was able to discriminate the relative compliance of various rubber samples. PMID:22855676

  12. Hydrostatically coupled dielectric elastomer actuators for tactile displays and cutaneous stimulators

    NASA Astrophysics Data System (ADS)

    Carpi, Federico; Frediani, Gabriele; De Rossi, Danilo

    2010-04-01

    Hydrostatic coupling has been recently reported as a means to improve versatility and safety of dielectric elastomer (DE) actuators. Hydrostatically coupled DE actuators rely on an incompressible fluid that mechanically couples a DE-based active part to a passive part interfaced to the load. In this paper, we present ongoing development of bubble-like versions of such transducers, made of silicone and oil. In particular, the paper describes millimeter-scale actuators, currently being developed as soft, light, acoustically silent and cheap devices for two types of applications: tactile displays and cutaneous stimulators. In both cases, the most significant advantages of the proposed technology are represented by high versatility for design (due to the fluid based transmission mechanism), tailorable stiffness perceived by the user (obtained by adjusting the internal fluid pressure), and suitable electrical safety (enabled by both a passive interface with the user and the insulating internal fluid). Millimeter-scale prototypes showed a resonance frequency of about 250 Hz, which represents the value at which Pacinian cutaneous mechanoreceptors exhibit maximum sensitivity; this provides an optimum condition to eventually code tactile information dynamically, either in combination or as an alternative to static driving.

  13. Flexible tactile sensing based on piezoresistive composites: a review.

    PubMed

    Stassi, Stefano; Cauda, Valentina; Canavese, Giancarlo; Pirri, Candido Fabrizio

    2014-01-01

    The large expansion of the robotic field in the last decades has created a growing interest in the research and development of tactile sensing solutions for robot hand and body integration. Piezoresistive composites are one of the most widely employed materials for this purpose, combining simple and low cost preparation with high flexibility and conformability to surfaces, low power consumption, and the use of simple read-out electronics. This work provides a review on the different type of composite materials, classified according to the conduction mechanism and analyzing the physics behind it. In particular piezoresistors, strain gauges, percolative and quantum tunnelling devices are reviewed here, with a perspective overview on the most used filler types and polymeric matrices. A description of the state-of-the-art of the tactile sensor solutions from the point of view of the architecture, the design and the performance is also reviewed, with a perspective outlook on the main promising applications. PMID:24638126

  14. A Magnetoresistive Tactile Sensor for Harsh Environment Applications

    PubMed Central

    Alfadhel, Ahmed; Khan, Mohammed Asadullah; Cardoso, Susana; Leitao, Diana; Kosel, Jürgen

    2016-01-01

    A magnetoresistive tactile sensor is reported, which is capable of working in high temperatures up to 140 °C. Hair-like bioinspired structures, known as cilia, made out of permanent magnetic nanocomposite material on top of spin-valve giant magnetoresistive (GMR) sensors are used for tactile sensing at high temperatures. The magnetic nanocomposite, consisting of iron nanowires incorporated into the polymer polydimethylsiloxane (PDMS), is very flexible, biocompatible, has high remanence, and is also resilient to antagonistic sensing ambient. When the cilia come in contact with a surface, they deflect in compliance with the surface topology. This yields a change of the GMR sensor signal, enabling the detection of extremely fine features. The spin-valve is covered with a passivation layer, which enables adequate performance in spite of harsh environmental conditions, as demonstrated in this paper for high temperature. PMID:27164113

  15. A Magnetoresistive Tactile Sensor for Harsh Environment Applications.

    PubMed

    Alfadhel, Ahmed; Khan, Mohammed Asadullah; Cardoso, Susana; Leitao, Diana; Kosel, Jürgen

    2016-01-01

    A magnetoresistive tactile sensor is reported, which is capable of working in high temperatures up to 140 °C. Hair-like bioinspired structures, known as cilia, made out of permanent magnetic nanocomposite material on top of spin-valve giant magnetoresistive (GMR) sensors are used for tactile sensing at high temperatures. The magnetic nanocomposite, consisting of iron nanowires incorporated into the polymer polydimethylsiloxane (PDMS), is very flexible, biocompatible, has high remanence, and is also resilient to antagonistic sensing ambient. When the cilia come in contact with a surface, they deflect in compliance with the surface topology. This yields a change of the GMR sensor signal, enabling the detection of extremely fine features. The spin-valve is covered with a passivation layer, which enables adequate performance in spite of harsh environmental conditions, as demonstrated in this paper for high temperature. PMID:27164113

  16. Development of an endoscopic tactile sensor using PVDF films

    NASA Astrophysics Data System (ADS)

    Okuyama, Takeshi; Sone, Mikiko; Tanahashi, Yoshikatsu; Chonan, Seiji; Tanaka, Mami

    2007-12-01

    In this work, a prototype Polyvinylidene Fluoride (PVDF) tactile sensor for endoscopic application has been developed. The sensor aims to measure hardness, which is one of the information of tactile perceptions, of biomedical tissue. This sensor is composed of two PVDF films, a silicone cylindrical column, and an aluminum cylinder. And the classification of hardness is concerned with the ratio of these PVDF outputs. In this paper, two sensors are fabricated using two silicone cylindrical columns with different Young's modulus. The performance evaluation of each sensor is conducted using 6 silicone rubbers as measuring object. The experimental results correspond with the simplified theoretical analysis and the proposed sensor can distinguish a difference of elastic property.

  17. Soft capacitive tactile sensing arrays fabricated via direct filament casting

    NASA Astrophysics Data System (ADS)

    Li, Bin; Gao, Yang; Fontecchio, Adam; Visell, Yon

    2016-07-01

    Advances in soft electronics are enabling the development of mechanical sensors that can conform to curved surfaces or soft objects, allowing them to interface seamlessly with the human body. In this paper, we report on intrinsically deformable tactile sensing arrays that achieve a unique combination of high spatial resolution, sensitivity, and mechanical stretchability. The devices are fabricated via a casting process that yields arrays of microfluidic channels in low modulus polymer membranes with thickness as small as one millimeter. Using liquid metal alloy as a conductor, we apply matrix-addressed capacitive sensing in order to resolve spatially distributed strain with millimeter precision over areas of several square centimeters. Due to the use of low-modulus polymers, the devices readily achieve stretchability greater than 500%, making them well suited for novel applications in wearable tactile sensing for biomedical applications.

  18. Flexible Tactile Sensing Based on Piezoresistive Composites: A Review

    PubMed Central

    Stassi, Stefano; Cauda, Valentina; Canavese, Giancarlo; Pirri, Candido Fabrizio

    2014-01-01

    The large expansion of the robotic field in the last decades has created a growing interest in the research and development of tactile sensing solutions for robot hand and body integration. Piezoresistive composites are one of the most widely employed materials for this purpose, combining simple and low cost preparation with high flexibility and conformability to surfaces, low power consumption, and the use of simple read-out electronics. This work provides a review on the different type of composite materials, classified according to the conduction mechanism and analyzing the physics behind it. In particular piezoresistors, strain gauges, percolative and quantum tunnelling devices are reviewed here, with a perspective overview on the most used filler types and polymeric matrices. A description of the state-of-the-art of the tactile sensor solutions from the point of view of the architecture, the design and the performance is also reviewed, with a perspective outlook on the main promising applications. PMID:24638126

  19. Three realizations and comparison of hardware for piezoresistive tactile sensors.

    PubMed

    Vidal-Verdú, Fernando; Oballe-Peinado, Óscar; Sánchez-Durán, José A; Castellanos-Ramos, Julián; Navas-González, Rafael

    2011-01-01

    Tactile sensors are basically arrays of force sensors that are intended to emulate the skin in applications such as assistive robotics. Local electronics are usually implemented to reduce errors and interference caused by long wires. Realizations based on standard microcontrollers, Programmable Systems on Chip (PSoCs) and Field Programmable Gate Arrays (FPGAs) have been proposed by the authors for the case of piezoresistive tactile sensors. The solution employing FPGAs is especially relevant since their performance is closer to that of Application Specific Integrated Circuits (ASICs) than that of the other devices. This paper presents an implementation of such an idea for a specific sensor. For the purpose of comparison, the circuitry based on the other devices is also made for the same sensor. This paper discusses the implementation issues, provides details regarding the design of the hardware based on the three devices and compares them. PMID:22163797

  20. Cross-modal tactile-taste interactions in food evaluations.

    PubMed

    Slocombe, B G; Carmichael, D A; Simner, J

    2016-07-29

    Detecting the taste components within a flavoured substance relies on exposing chemoreceptors within the mouth to the chemical components of ingested food. In our paper, we show that the evaluation of taste components can also be influenced by the tactile quality of the food. We first discuss how multisensory factors might influence taste, flavour and smell for both typical and atypical (synaesthetic) populations and we then present two empirical studies showing tactile-taste interactions in the general population. We asked a group of non-synaesthetic adults to evaluate the taste components of flavoured food substances, whilst we presented simultaneous cross-sensory visuo-tactile cues within the eating environment. Specifically, we presented foodstuffs between subjects that were otherwise identical but had a rough versus smooth surface, or were served on a rough versus smooth serving-plate. We found no effect of the serving-plate, but we found the rough/smoothness of the foodstuff itself significantly influenced perception: food was rated as significantly more sour if it had a rough (versus smooth) surface. In modifying taste perception via ostensibly unrelated dimensions, we demonstrate that the detection of tastes within flavours may be influenced by higher level cross-sensory cues. Finally, we suggest that the direction of our cross-sensory associations may speak to the types of hedonic mapping found both in normal multisensory integration, and in the unusual condition of synaesthesia. PMID:26169315

  1. Artificial skin ridges enhance local tactile shape discrimination.

    PubMed

    Salehi, Saba; Cabibihan, John-John; Ge, Shuzhi Sam

    2011-01-01

    One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects' shapes and, more specifically, the objects' surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB), Artificial Neural Networks (ANN), and Support Vector Machines (SVM) were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination. PMID:22164095

  2. Artificial Skin Ridges Enhance Local Tactile Shape Discrimination

    PubMed Central

    Salehi, Saba; Cabibihan, John-John; Ge, Shuzhi Sam

    2011-01-01

    One of the fundamental requirements for an artificial hand to successfully grasp and manipulate an object is to be able to distinguish different objects’ shapes and, more specifically, the objects’ surface curvatures. In this study, we investigate the possibility of enhancing the curvature detection of embedded tactile sensors by proposing a ridged fingertip structure, simulating human fingerprints. In addition, a curvature detection approach based on machine learning methods is proposed to provide the embedded sensors with the ability to discriminate the surface curvature of different objects. For this purpose, a set of experiments were carried out to collect tactile signals from a 2 × 2 tactile sensor array, then the signals were processed and used for learning algorithms. To achieve the best possible performance for our machine learning approach, three different learning algorithms of Naïve Bayes (NB), Artificial Neural Networks (ANN), and Support Vector Machines (SVM) were implemented and compared for various parameters. Finally, the most accurate method was selected to evaluate the proposed skin structure in recognition of three different curvatures. The results showed an accuracy rate of 97.5% in surface curvature discrimination. PMID:22164095

  3. Tactile gating in a reaching and grasping task

    PubMed Central

    Colino, Francisco L.; Buckingham, Gavin; Cheng, Darian T.; van Donkelaar, Paul; Binsted, Gordon

    2014-01-01

    Abstract A multitude of events bombard our sensory systems at every moment of our lives. Thus, it is important for the sensory cortex to gate unimportant events. Tactile suppression is a well‐known phenomenon defined as a reduced ability to detect tactile events on the skin before and during movement. Previous experiments found detection rates decrease just prior to and during finger abduction, and decrease according to the proximity of the moving effector. This study examined how tactile detection changes during a reach to grasp. Fourteen human participants used their right hand to reach and grasp a cylinder. Tactors were attached to the index finger, the fifth digit, and the forearm of both the right and left arm and vibrated at various epochs relative to a “go” tone. Results showed that detection rates at the forearm decreased before movement onset; whereas at the right index finger, right fifth digit and at the left index finger, left fifth digit, and forearm sites did not decrease like in the right forearm. These results indicate that the task affects gating dynamics in a temporally‐ and contextually dependent manner and implies that feed‐forward motor planning processes can modify sensory signals. PMID:24760521

  4. A biomimetic tactile sensing system based on polyvinylidene fluoride film.

    PubMed

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements. PMID:26931883

  5. Evaluation of a compound eye type tactile endoscope

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Kayo; Yamada, Kenji; Sasaki, Nagisa; Takeda, Maki; Shimizu, Sachiko; Nagakura, Toshiaki; Takahashi, Hideya; Ohno, Yuko

    2013-03-01

    Minimally invasive surgical techniques for endoscope become widely used, for example, laparoscopic operation, NOTES (Natural Orifice Translumenal Endoscopic Surgery), robotic surgery and so on. There are so many demand and needs for endoscopic diagnosis. Especially, palpation is most important diagnosis on any surgery. However, conventional endoscopic system has no tactile sensibility. There are many studies about tactile sensor for medical application. These sensors can measure object at a point. It is necessary to sense in areas for palpation. To overcome this problem, we propose compound eye type tactile endoscope. The proposed system consists of TOMBO (Thin Observation Module by Bound Optics) and clear silicon rubber. Our proposed system can estimate hardness of target object by measuring deformation of a projected pattern on the silicon rubber. The purpose of this study is to evaluate the proposed system. At first, we introduce approximated models of the silicone and the object. We formulate the stiffness of object, the deformation of silicone, and the whole object. We investigate the accuracy of measured silicone's lower surface for deformation of silicone by prototype system. Finally, we evaluate the calculated stiffness of the soft object.

  6. A biomimetic tactile sensing system based on polyvinylidene fluoride film

    NASA Astrophysics Data System (ADS)

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements.

  7. A brief taxonomy of tactile illusions and demonstrations that can be done in a hardware store.

    PubMed

    Hayward, Vincent

    2008-04-15

    This paper surveys more than twenty types of tactile illusions and discusses several of their aspects. These aspects include the ease with which they can be demonstrated and whether they have clear visual analogs. The paper also shows how to construct equipment made of simple supplies able to deliver well-controlled tactile signals in order to conveniently demonstrate four different tactile illusions. PMID:18394520

  8. Active Motor Training Has Long-term Effects on Infants' Object Exploration.

    PubMed

    Wiesen, Sarah E; Watkins, Rachel M; Needham, Amy Work

    2016-01-01

    Long-term changes in infants' behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant's experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

  9. Active Motor Training Has Long-term Effects on Infants’ Object Exploration

    PubMed Central

    Wiesen, Sarah E.; Watkins, Rachel M.; Needham, Amy Work

    2016-01-01

    Long-term changes in infants’ behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant’s experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

  10. Consistency in boldness, activity and exploration at different stages of life

    PubMed Central

    2013-01-01

    Background Animals show consistent individual behavioural patterns over time and over situations. This phenomenon has been referred to as animal personality or behavioural syndromes. Little is known about consistency of animal personalities over entire life times. We investigated the repeatability of behaviour in common voles (Microtus arvalis) at different life stages, with different time intervals, and in different situations. Animals were tested using four behavioural tests in three experimental groups: 1. before and after maturation over three months, 2. twice as adults during one week, and 3. twice as adult animals over three months, which resembles a substantial part of their entire adult life span of several months. Results Different behaviours were correlated within and between tests and a cluster analysis showed three possible behavioural syndrome-axes, which we name boldness, exploration and activity. Activity and exploration behaviour in all tests was highly repeatable in adult animals tested over one week. In animals tested over maturation, exploration behaviour was consistent whereas activity was not. Voles that were tested as adults with a three-month interval showed the opposite pattern with stable activity but unstable exploration behaviour. Conclusions The consistency in behaviour over time suggests that common voles do express stable personality over short time. Over longer periods however, behaviour is more flexible and depending on life stage (i.e. tested before/after maturation or as adults) of the tested individual. Level of boldness or activity does not differ between tested groups and maintenance of variation in behavioural traits can therefore not be explained by expected future assets as reported in other studies. PMID:24314274

  11. Activity Sculptures: Exploring the Impact of Physical Visualizations on Running Activity.

    PubMed

    Stusak, Simon; Tabard, Aurélien; Sauka, Franziska; Khot, Rohit Ashok; Butz, Andreas

    2014-12-01

    Data sculptures are a promising type of visualizations in which data is given a physical form. In the past, they have mostly been used for artistic, communicative or educational purposes, and designers of data sculptures argue that in such situations, physical visualizations can be more enriching than pixel-based visualizations. We present the design of Activity Sculptures: data sculptures of running activity. In a three-week field study we investigated the impact of the sculptures on 14 participants' running activity, the personal and social behaviors generated by the sculptures, as well as participants' experiences when receiving these individual physical tokens generated from the specific data of their runs. The physical rewards generated curiosity and personal experimentation but also social dynamics such as discussion on runs or envy/competition. We argue that such passive (or calm) visualizations can complement nudging and other mechanisms of persuasion with a more playful and reflective look at ones' activity. PMID:26356934

  12. Touch activates human auditory cortex.

    PubMed

    Schürmann, Martin; Caetano, Gina; Hlushchuk, Yevhen; Jousmäki, Veikko; Hari, Riitta

    2006-05-01

    Vibrotactile stimuli can facilitate hearing, both in hearing-impaired and in normally hearing people. Accordingly, the sounds of hands exploring a surface contribute to the explorer's haptic percepts. As a possible brain basis of such phenomena, functional brain imaging has identified activations specific to audiotactile interaction in secondary somatosensory cortex, auditory belt area, and posterior parietal cortex, depending on the quality and relative salience of the stimuli. We studied 13 subjects with non-invasive functional magnetic resonance imaging (fMRI) to search for auditory brain areas that would be activated by touch. Vibration bursts of 200 Hz were delivered to the subjects' fingers and palm and tactile pressure pulses to their fingertips. Noise bursts served to identify auditory cortex. Vibrotactile-auditory co-activation, addressed with minimal smoothing to obtain a conservative estimate, was found in an 85-mm3 region in the posterior auditory belt area. This co-activation could be related to facilitated hearing at the behavioral level, reflecting the analysis of sound-like temporal patterns in vibration. However, even tactile pulses (without any vibration) activated parts of the posterior auditory belt area, which therefore might subserve processing of audiotactile events that arise during dynamic contact between hands and environment. PMID:16488157

  13. Virtual Surface Characteristics of a Tactile Display Using Magneto-Rheological Fluids

    PubMed Central

    Lee, Chul-Hee; Jang, Min-Gyu

    2011-01-01

    Virtual surface characteristics of tactile displays are investigated to characterize the feeling of human touch for a haptic interface application. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR) fluid has been developed. Tactile display devices simulate the finger’s skin to feel the sensations of contact such as compliance, friction, and topography of the surface. Thus, the tactile display can provide information on the surface of an organic tissue to the surgeon in virtual reality. In order to investigate the compliance feeling of a human finger’s touch, normal force responses of a tactile display under various magnetic fields have been assessed. Also, shearing friction force responses of the tactile display are investigated to simulate the action of finger dragging on the surface. Moreover, different matrix arrays of magnetic poles are applied to form the virtual surface topography. From the results, different tactile feelings are observed according to the applied magnetic field strength as well as the arrays of magnetic poles combinations. This research presents a smart tactile display technology for virtual surfaces. PMID:22163769

  14. Cross-Modal Sensory Integration of Visual-Tactile Motion Information: Instrument Design and Human Psychophysics

    PubMed Central

    Pei, Yu-Cheng; Chang, Ting-Yu; Lee, Tsung-Chi; Saha, Sudipta; Lai, Hsin-Yi; Gomez-Ramirez, Manuel; Chou, Shih-Wei; Wong, Alice M. K.

    2013-01-01

    Information obtained from multiple sensory modalities, such as vision and touch, is integrated to yield a holistic percept. As a haptic approach usually involves cross-modal sensory experiences, it is necessary to develop an apparatus that can characterize how a biological system integrates visual-tactile sensory information as well as how a robotic device infers object information emanating from both vision and touch. In the present study, we develop a novel visual-tactile cross-modal integration stimulator that consists of an LED panel to present visual stimuli and a tactile stimulator with three degrees of freedom that can present tactile motion stimuli with arbitrary motion direction, speed, and indentation depth in the skin. The apparatus can present cross-modal stimuli in which the spatial locations of visual and tactile stimulations are perfectly aligned. We presented visual-tactile stimuli in which the visual and tactile directions were either congruent or incongruent, and human observers reported the perceived visual direction of motion. Results showed that perceived direction of visual motion can be biased by the direction of tactile motion when visual signals are weakened. The results also showed that the visual-tactile motion integration follows the rule of temporal congruency of multi-modal inputs, a fundamental property known for cross-modal integration. PMID:23727955

  15. Power analysis for the design of a large area ultrasonic tactile touch panel

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Lemaire-Semail, Betty; Giraud, Frédéric; Amberg, Michel; Zhang, Yuru; Giraud-Audine, Christophe

    2015-10-01

    Tactile interfaces are intuitive but lack of haptic feedback. One method to provide tactile feedback is to change the friction coefficient of the touch surface. Several small-size tactile devices have been developed to provide programmable friction coefficient based on the squeeze air film effect. This effect is produced by ultrasonic vibration of the tactile plate thanks to piezoceramics. In order to design larger embedded tactile feedback areas, a key issue is the power consumption. In this paper, we present the power analysis of a tactile device which is based on the squeeze film effect. We first investigate the source of power consumption by a series of measurements. Then, an analytical model is developed to estimate the power, which gives the conclusion that, when the vibration amplitude is constant, the power consumption is not related to the number of piezoelectric actuators. According to this result, we design a large area (198 mm × 138 mm) tactile plate with only eight piezoelectric actuators. Experimental results show that the power consumption of the large tactile plate is less than 2 W. Moreover, we also find that the power consumption of the large tactile plate was predictable with the measurement results from small plates with an average error of less than 10%.

  16. Virtual surface characteristics of a tactile display using magneto-rheological fluids.

    PubMed

    Lee, Chul-Hee; Jang, Min-Gyu

    2011-01-01

    Virtual surface characteristics of tactile displays are investigated to characterize the feeling of human touch for a haptic interface application. In order to represent the tactile feeling, a prototype tactile display incorporating Magneto-Rheological (MR) fluid has been developed. Tactile display devices simulate the finger's skin to feel the sensations of contact such as compliance, friction, and topography of the surface. Thus, the tactile display can provide information on the surface of an organic tissue to the surgeon in virtual reality. In order to investigate the compliance feeling of a human finger's touch, normal force responses of a tactile display under various magnetic fields have been assessed. Also, shearing friction force responses of the tactile display are investigated to simulate the action of finger dragging on the surface. Moreover, different matrix arrays of magnetic poles are applied to form the virtual surface topography. From the results, different tactile feelings are observed according to the applied magnetic field strength as well as the arrays of magnetic poles combinations. This research presents a smart tactile display technology for virtual surfaces. PMID:22163769

  17. Using RSVP for analyzing state and previous activities for the Mars Exploration Rovers

    NASA Technical Reports Server (NTRS)

    Cooper, Brian K.; Hartman, Frank; Maxwell, Scott; Wright, John; Yen, Jeng

    2004-01-01

    Current developments in immersive environments for mission planning include several tools which make up a system for performing and rehearsing missions. This system, known as the Rover Sequencing and Visualization Program (RSVP), includes tools for planning long range sorties for highly autonomous rovers, tools for planning operations with robotic arms, and advanced tools for visualizing telemetry from remote spacecraft and landers. One of the keys to successful planning of rover activities is knowing what the rover has accomplished to date and understanding the current rover state. RSVP builds on the lessons learned and the heritage of the Mars Pathfinder mission This paper will discuss the tools and methodologies present in the RSVP suite for examining rover state, reviewing previous activities, visually comparing telemetered results to rehearsed results, and reviewing science and engineering imagery. In addition we will present how this tool suite was used on the Mars Exploration Rovers (MER) project to explore the surface of Mars.

  18. Summary of geothermal exploration activity in the State of Washington from 1978 to 1983. Final report

    SciTech Connect

    Korosec, M.A.

    1984-01-01

    Project activity is summarized with references to the publications produced. Project findings are reported as they relate to specific geothermal resource target areas. Some major projects of the goethermal exploration program are: thermal and mineral spring chemistry, heat flow drilling, temperature gradient measurements, Cascade Range regional gravity, geohydrology study of the Yakima area, low temperature geothermal resources, geology, geochemistry of Cascade Mountains volcanic rocks, and soil mercury studies. (MHR)

  19. Explorations of electric current system in solar active regions. I - Empirical inferences of the current flows

    NASA Technical Reports Server (NTRS)

    Ding, Y. J.; Hong, Q. F.; Hagyard, M. J.; Deloach, A. C.; Liu, X. P.

    1987-01-01

    Techniques to identify sources of electric current systems and their channels of flow in solar active regions are explored. Measured photospheric vector magnetic fields together with high-resolution white-light and H-alpha filtergrams provide the data base to derive the current systems in the photosphere and chromosphere. As an example, the techniques are then applied to infer current systems in AR 2372 in early April 1980.

  20. Rasch-Built Measure of Pleasant Touch through Active Fingertip Exploration

    PubMed Central

    Klöcker, Anne; Arnould, Carlyne; Penta, Massimo; Thonnard, Jean-Louis

    2012-01-01

    Background: Evidence suggests that somatic sensation has a modality for pleasant touch. Objective: To investigate pleasant touch at the fingertip level (i.e., glabrous skin site) through the elaboration of a linear unidimensional scale that measures (i) various materials according to the level of pleasantness they elicit through active fingertip explorations and (ii) subjects according to their pleasantness leniency levels. Subjects: We enrolled 198 healthy subjects without any neurological disease. Methods: Blindfolded subjects actively explored 48 materials with their index fingertips and reported the perceived pleasantness of each on a 4-level scale. The fingertip moisture levels on each subject were measured before the experimental session. Data were analyzed using the Rasch model. Results: We elaborated unidimensional linear scale that included 37 materials according to their pleasantness of touch. The pleasantness level of 21 materials was perceived differently, depending on the fingertip moisture levels of the subjects. Conclusion: Based on our findings, we formulated a Pleasant Touch Scale. Fingertip moisture levels appeared to be a major factor for (un)pleasant feelings during active exploration. PMID:22737122

  1. The effects of intensive bimanual training with and without tactile training on tactile function in children with unilateral spastic cerebral palsy: A pilot study

    PubMed Central

    Kuo, Hsing-Ching; Gordon, Andrew M.; Henrionnet, Aline; Hautfenne, Sylvie; Friel, Kathleen M.; Bleyenheuft, Yannick

    2016-01-01

    Children with unilateral spastic cerebral palsy (USCP) often have tactile impairments. Intensive bimanual training improves the motor abilities, but the effects on the sensory system have not been studied. Here we compare the effects of bimanual training with and without tactile training on tactile impairments. Twenty children with USCP (6–15.5 years; MACS: I–III) were randomized to receive either bimanual therapy (HABIT) or HABIT + tactile training (HABIT + T). All participants received 82 h of standardized HABIT. In addition 8 sessions of 1 h were provided to both groups. The HABIT + T group received tactile training (without vision) using materials of varied shapes and textures. The HABIT group received training with the same materials without tactile directed training (full vision). Primary outcomes included grating orientation task/GOT and stereognosis. Secondary outcomes included two-point discrimination/TPD, Semmes-Weinstein monofilaments/SWM. The GOT improved in both groups after training, while stereognosis of the more-affected hand tended to improve (but p = 0.063). No changes were found in the TPD and the SWM. There were no group × test interactions for any measure. We conclude tactile spatial resolution can improve after bimanual training. Either intensive bimanual training alone or incorporation of materials with a diversity of shapes/textures may drive these changes. PMID:26698408

  2. Learning in Activity: Exploring the Methodological Potential of Action Research in Activity Theorising of Social Practice

    ERIC Educational Resources Information Center

    Darwin, Stephen

    2011-01-01

    Cultural-historical activity theory (CHAT), founded on the seminal work of Vygotsky and evolving in the subsequent work of Leont'ev and Engestrom, continues to emerge as a robust and increasingly widely used conceptual framework for the research and analysis of the complex social mediation of human learning and development. Yet there remains…

  3. Exploring the activation modes of a rotaxane-based switchable organocatalyst.

    PubMed

    Blanco, Victor; Leigh, David A; Lewandowska, Urszula; Lewandowski, Bartosz; Marcos, Vanesa

    2014-11-01

    The reactivity of a rotaxane that acts as an aminocatalyst for the functionalization of carbonyl compounds through HOMO and LUMO activation pathways has been studied. Its catalytic activity is explored for C-C and C-S bond forming reactions through iminium catalysis, in nucleophilic substitutions and additions through enamine intermediates, in Diels-Alder reactions via trienamine catalysis, and in a tandem iminium-ion/enamine reaction. The catalyst can be switched "on" or "off", effectively controlling the rate of all of these chemical transformations, by the in situ change of the position of the macrocycle between two different binding sites on the rotaxane thread. PMID:25285667

  4. Effects of passive tactile and auditory stimuli on left visual neglect.

    PubMed

    Hommel, M; Peres, B; Pollak, P; Memin, B; Besson, G; Gaio, J M; Perret, J

    1990-05-01

    Patients with left-sided visual neglect fail to copy the left part of drawings or the drawings on the left side of a sheet of paper. Our aim was to study the variations in copying drawings induced by passive stimulation in patients with left-sided visual neglect. No stimulation at all, tactile unilateral and bilateral, binaural auditory verbal, and nonverbal stimuli were randomly applied to 14 patients with right-hemisphere strokes. Only nonverbal stimuli decreased the neglect. As nonverbal stimuli mainly activate the right hemisphere, the decrease in neglect suggests right-hemispheric hypoactivity at rest in these patients. The absence of modification of neglect during verbal stimulation suggests a bilateral hemispheric activation and the persistence of interhemispheric imbalance. Our results showed that auditory pathways take part in the network involved with neglect. Passive nonverbal auditory stimuli may be of interest in the rehabilitation of patients with left visual neglect. PMID:2334306

  5. Employing a Participatory Research Approach to Explore Physical Activity among Older African American Women.

    PubMed

    Sebastião, Emerson; Ibe-Lamberts, Kelechi; Bobitt, Julie; Schwingel, Andiara; Chodzko-Zajko, Wojtek

    2014-01-01

    Introduction. Older African American women are particularly vulnerable to unhealthy lifestyle behaviors such as physical inactivity and the resultant chronic diseases and conditions. This study explored older African American women's perception of physical activity as well as facilitators of and barriers to being physically active in their local environment. Methods. Using a participatory research approach, a total of 7 women aged 65 years and over had their PA level assessed objectively through accelerometry. In addition, physical activity was discussed through the photo-elicitation procedure, which was supplemented by semistructured interviews. Qualitative thematic analysis was used to identify patterns and themes emerging from participants' interview. Results. Participants exhibited low levels of physical activity and viewed "physical activity" to be a broadly defined, nonspecific construct. Interviews revealed that many participants lack important knowledge about physical activity. A variety of personal, social, and environmental facilitators and barriers were reported by the participants. Conclusion. Efforts should be made towards clarifying information on physical activity in this population in order to help them incorporate physical activity into their routines, overcome barriers, and make use of opportunities to be active. PMID:25210628

  6. The kinin B1 receptor antagonist SSR240612 reverses tactile and cold allodynia in an experimental rat model of insulin resistance

    PubMed Central

    Dias, J P; Ismael, M A; Pilon, M; de Champlain, J; Ferrari, B; Carayon, P; Couture, R

    2007-01-01

    Background and purpose: Diabetes causes sensory polyneuropathy with associated pain in the form of tactile allodynia and thermal hyperalgesia which are often intractable and resistant to current therapy. This study tested the beneficial effects of the non-peptide and orally active kinin B1 receptor antagonist SSR240612 against tactile and cold allodynia in a rat model of insulin resistance. Experimental approach: Rats were fed with 10% D-glucose for 12 weeks and effects of orally administered SSR240612 (0.3–30 mg kg−1) were determined on the development of tactile and cold allodynia. Possible interference of SSR240612 with vascular oxidative stress and pancreatic function was also addressed. Key results: Glucose-fed rats exhibited tactile and cold allodynia, increases in systolic blood pressure and higher plasma levels of insulin and glucose, at 12 weeks. SSR240612 blocked tactile and cold allodynia at 3 h (ID50=5.5 and 7.1 mg kg−1, respectively) in glucose-fed rats but had no effect in control rats. The antagonist (10 mg kg−1) had no effect on plasma glucose and insulin, insulin resistance (HOMA index) and aortic superoxide anion production in glucose-fed rats. Conclusions and implications: We provide the first evidence that the B1 receptors are involved in allodynia in an experimental rat model of insulin resistance. Allodynia was alleviated by SSR240612 most likely through a direct inhibition of B1 receptors affecting spinal cord and/or sensory nerve excitation. Thus, orally active non-peptide B1 receptor antagonists should have clinical therapeutic potential in the treatment of sensory polyneuropathy. PMID:17618300

  7. Tactile roughness perception in the presence of olfactory and trigeminal stimulants

    PubMed Central

    Koijck, Lara A.; Van Erp, Jan B.F.

    2015-01-01

    Previous research has shown that odorants consistently evoke associations with textures and their tactile properties like smoothness and roughness. Also, it has been observed that olfaction can modulate tactile perception. We therefore hypothesized that tactile roughness perception may be biased towards the somatosensory connotation of an ambient odorant. We performed two experiments to test this hypothesis. In the first experiment, we investigated the influence of ambient chemosensory stimuli with different roughness connotations on tactile roughness perception. In addition to a pleasant odor with a connotation of softness (PEA), we also included a trigeminal stimulant with a rough, sharp or prickly connotation (Ethanol). We expected that—compared to a No-odorant control condition—tactile texture perception would be biased towards smoothness in the presence of PEA and towards roughness in the presence of Ethanol. However, our results show no significant interaction between chemosensory stimulation and perceived tactile surface roughness. It could be argued that ambient odors may be less effective in stimulating crossmodal associations, since they are by definition extraneous to the tactile stimuli. In an attempt to optimize the conditions for sensory integration, we therefore performed a second experiment in which the olfactory and tactile stimuli were presented in synchrony and in close spatial proximity. In addition, we included pleasant (Lemon) and unpleasant (Indole) odorants that are known to have the ability to affect tactile perception. We expected that tactile stimuli would be perceived as less rough when simultaneously presented with Lemon or PEA (both associated with softness) than when presented with Ethanol or Indole (odors that can be associated with roughness). Again, we found no significant main effect of chemosensory condition on perceived tactile roughness. We discuss the limitations of this study and we present suggestions for future research

  8. Rain Forest: The Latest Information and Hands-on Activities To Explore Animals, Plants, and Geography. Grades 2-5.

    ERIC Educational Resources Information Center

    Bernard, Robin

    This book contains information and activities to help make the study of rainforests an exciting exploration for teachers and students. Students explore the animals, plants, and geography of the rainforest by completing hands-on activities from various disciplines. This book contains five units: (1) "Living Layers"; (2) "Animals, Animals, Animals";…

  9. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  10. 48 CFR 1852.228-78 - Cross-waiver of liability for science or space exploration activities unrelated to the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Space Act agreement that contains the cross-waiver of liability provision authorized in 14 CFR 1266.104... for science or space exploration activities unrelated to the International Space Station. 1852.228-78... Cross-waiver of liability for science or space exploration activities unrelated to the...

  11. Physical Activity: Exploring Views of Older Russian-Speaking Slavic Immigrants

    PubMed Central

    Purath, Janet; Van Son, Catherine; Corbett, Cynthia F.

    2011-01-01

    Many of the 1.3 million Russian-speaking immigrants in the US have chronic conditions such as cardiovascular disease, diabetes, obesity, and depression. They engage in physical activity less often than other groups, and little is known about their views of physical activity. This qualitative study explored physical activity attitudes, beliefs, motivators, and barriers among older Russian-speaking immigrants. In four focus group interviews, 23 participants discussed physical activity. “Movement is life” was a theme throughout all interviews. Walking was the most frequently mentioned activity. Increased energy and decreased pain were described as health benefits. Motivators for physical activity were maintaining function, improved health, and the support of God and family. Barriers included poor health and environmental safety concerns. Participants suggested community walking groups and church-supported programs as useful methods to promote physical activity. Future research includes developing culturally appropriate interventions that utilize physical activity to prevent and manage chronic illness with ethnic minority older adults. PMID:22135733

  12. Physical Activity in South Asians: An In-Depth Qualitative Study to Explore Motivations and Facilitators

    PubMed Central

    Jepson, Ruth; Harris, Fiona M.; Bowes, Alison; Robertson, Roma; Avan, Ghizala; Sheikh, Aziz

    2012-01-01

    Background People of South Asian backgrounds living in the UK have a five-fold increased risk of diabetes and a two-fold increased risk of heart disease when compared to the general population. Physical activity can reduce the risk of premature death from a range of conditions. The aim of the study was to explore the motivating and facilitating factors likely to increase physical activity for South Asian adults and their families, in order to develop successful interventions and services. Methodology/Principal Findings This was a qualitative study using focus groups and in-depth interviews. Participants were 59 purposively selected Bangladeshi-, Indian- and Pakistani-origin men and women with an additional 10 key informants. The setting was three urban areas of Scotland: Aberdeen, Glasgow and Edinburgh. We undertook a theoretically informed thematic analysis of data. Study participants described engaging in a range of physical activities, particularly football and the gym for men, and walking and swimming for women. The main motivators for taking part in physical activity were external motivators – i.e. undertaking physical activity as a means to an end, which included the opportunities that physical activity provided for social activity and enjoyment. The goals of weight reduction and improving mental and physical health and were also mentioned. Role models were seen as important to inspire and motivate people to undertake activities that they may otherwise lack confidence in. Few people undertook physical activity for its own sake (intrinsic motivation). Conclusions/Significance Attempts at promoting physical activity in people of South Asian origin need to take account of the social context of people's lives and the external motivators that encourage them to engage in physical activity. Undertaking group based physical activity is important and can be facilitated through religious, community, friendship or family networks. Role models may also prove

  13. Venus Mobile Explorer with RPS for Active Cooling: A Feasibility Study

    NASA Technical Reports Server (NTRS)

    Leifer, Stephanie D.; Green, Jacklyn R.; Balint, Tibor S.; Manvi, Ram

    2009-01-01

    We present our findings from a study to evaluate the feasibility of a radioisotope power system (RPS) combined with active cooling to enable a long-duration Venus surface mission. On-board power with active cooling technology featured prominently in both the National Research Council's Decadal Survey and in the 2006 NASA Solar System Exploration Roadmap as mission-enabling for the exploration of Venus. Power and cooling system options were reviewed and the most promising concepts modeled to develop an assessment tool for Venus mission planners considering a variety of future potential missions to Venus, including a Venus Mobile Explorer (either a balloon or rover concept), a long-lived Venus static lander, or a Venus Geophysical Network. The concepts modeled were based on the integration of General Purpose Heat Source (GPHS) modules with different types of Stirling cycle heat engines for power and cooling. Unlike prior investigations which reported on single point design concepts, this assessment tool allows the user to generate either a point design or parametric curves of approximate power and cooling system mass, power level, and number of GPHS modules needed for a "black box" payload housed in a spherical pressure vessel.

  14. Overview of ESA life support activities in preparation of future exploration

    NASA Astrophysics Data System (ADS)

    Lasseur, Christophe; Paille, Christel

    2016-07-01

    Since 1987, the European Space Agency has been active in the field of Life Support development. When compare to its international colleagues, it is clear that ESA started activities in the field with a "delay of around 25 years. Due to this situation and to avoid duplication, ESA decided to focus more on long term manned missions and to consider more intensively regenerative technologies as well as the associated risks management ( e.g. physical, chemical and contaminants). Fortunately or not, during the same period, no clear plan of exploration and consequently not specific requirements materialized. This force ESA to keep a broader and generic approach of all technologies. Today with this important catalogue of technologies and know-how, ESA is contemplating the different scenario of manned exploration beyond LEO. In this presentation we review the key scenario of future exploration, and identify the key technologies who loo the more relevant. An more detailed status is presented on the key technologies and their development plan for the future.

  15. NASA safety program activities in support of the Space Exploration Initiatives Nuclear Propulsion program

    NASA Technical Reports Server (NTRS)

    Sawyer, J. C., Jr.

    1993-01-01

    The activities of the joint NASA/DOE/DOD Nuclear Propulsion Program Technical Panels have been used as the basis for the current development of safety policies and requirements for the Space Exploration Initiatives (SEI) Nuclear Propulsion Technology development program. The Safety Division of the NASA Office of Safety and Mission Quality has initiated efforts to develop policies for the safe use of nuclear propulsion in space through involvement in the joint agency Nuclear Safety Policy Working Group (NSPWG), encouraged expansion of the initial policy development into proposed programmatic requirements, and suggested further expansion into the overall risk assessment and risk management process for the NASA Exploration Program. Similar efforts are underway within the Department of Energy to ensure the safe development and testing of nuclear propulsion systems on Earth. This paper describes the NASA safety policy related to requirements for the design of systems that may operate where Earth re-entry is a possibility. The expected plan of action is to support and oversee activities related to the technology development of nuclear propulsion in space, and support the overall safety and risk management program being developed for the NASA Exploration Program.

  16. Co-benefits of designing communities for active living: an exploration of literature.

    PubMed

    Sallis, James F; Spoon, Chad; Cavill, Nick; Engelberg, Jessa K; Gebel, Klaus; Parker, Mike; Thornton, Christina M; Lou, Debbie; Wilson, Amanda L; Cutter, Carmen L; Ding, Ding

    2015-01-01

    To reverse the global epidemic of physical inactivity that is responsible for more than 5 million deaths per year, many groups recommend creating "activity-friendly environments." Such environments may have other benefits, beyond facilitating physical activity, but these potential co-benefits have not been well described. The purpose of the present paper is to explore a wide range of literature and conduct an initial summary of evidence on co-benefits of activity-friendly environments. An extensive but non-systematic review of scientific and "gray" literature was conducted. Five physical activity settings were defined: parks/open space/trails, urban design, transportation, schools, and workplaces/buildings. Several evidence-based activity-friendly features were identified for each setting. Six potential outcomes/co-benefits were searched: physical health, mental health, social benefits, safety/injury prevention, environmental sustainability, and economics. A total of 418 higher-quality findings were summarized. The overall summary indicated 22 of 30 setting by outcome combinations showed "strong" evidence of co-benefits. Each setting had strong evidence of at least three co-benefits, with only one occurrence of a net negative effect. All settings showed the potential to contribute to environmental sustainability and economic benefits. Specific environmental features with the strongest evidence of multiple co-benefits were park proximity, mixed land use, trees/greenery, accessibility and street connectivity, building design, and workplace physical activity policies/programs. The exploration revealed substantial evidence that designing community environments that make physical activity attractive and convenient is likely to produce additional important benefits. The extent of the evidence justifies systematic reviews and additional research to fill gaps. PMID:25886356

  17. Gating of tactile information through gamma band during passive arm movement in awake primates

    PubMed Central

    Song, Weiguo; Francis, Joseph T.

    2015-01-01

    To make precise and prompt action in a dynamic environment, the sensorimotor system needs to integrate all related information. The inflow of somatosensory information to the cerebral cortex is regulated and mostly suppressed by movement, which is commonly referred to as sensory gating or gating. Sensory gating plays an important role in preventing redundant information from reaching the cortex, which should be considered when designing somatosensory neuroprosthetics. Gating can occur at several levels within the sensorimotor pathway, while the underlying mechanism is not yet fully understood. The average sensory evoked potential is commonly used to assess sensory information processing, however the assumption of a stereotyped response to each stimulus is still an open question. Event related spectral perturbation (ERSP), which is the power spectrum after time-frequency decomposition on single trial evoked potentials (total power), could overcome this limitation of averaging and provide additional information for understanding the underlying mechanism. To this aim, neural activities in primary somatosensory cortex (S1), primary motor cortex (M1), and ventral posterolateral (VPL) nucleus of thalamus were recorded simultaneously in two areas (S1 and M1 or S1 and VPL) during passive arm movement and rest in awake monkeys. Our results showed that neural activity at different recording areas demonstrated specific and unique response frequency characteristics. Tactile input induced early high frequency responses followed by low frequency oscillations within sensorimotor circuits, and passive movement suppressed these oscillations either in a phase-locked or non-phase-locked manner. Sensory gating by movement was non-phase-locked in M1, and complex in sensory areas. VPL showed gating of non-phase-locked at gamma band and mix of phase-locked and non-phase-locked at low frequency, while S1 showed gating of phase-locked and non-phase-locked at gamma band and an early phase

  18. Exploring Physical Activity Behaviour of Persons with Multiple Sclerosis: A Qualitative Pilot Study

    PubMed Central

    Resnik, Linda; Allen, Susan

    2015-01-01

    Purpose Identify facilitators and barriers to physical activity (PA), and explore the utility of Social Cognitive Theory (SCT) and Transactional Model of Stress and Coping (TMSC) in understanding PA behaviour among persons with multiple sclerosis (MS). Methods Thirteen participants from a clinical trial were interviewed and classified as physically active, sometimes active, or inactive based on the Health-Promoting Lifestyle Profile-II. Interviews were analysed using analytical induction, which consisted of coding data into pre-established categories and then exploring similarities and differences between groups. Pre-established coding categories were constructs from SCT (i.e. environment, expectations, self-efficacy, and self-regulation) and TMSC (i.e. stress appraisal and coping style). Results Inactive and active participants differed in their self-regulation skills, self-efficacy, and coping styles. Common barriers to PA included symptoms and the physical and social environment. Facilitators of PA included strong self-regulation skills, confidence to overcome symptoms to engage in PA (i.e. barrier self-efficacy), and positive coping styles. Conclusion Results from this pilot study suggest that PA interventions will need to implement multiple strategies that target self-efficacy, social environment, and coping styles. We found SCT and TMSC useful in understanding PA behaviour among persons with MS; however, a limitation to these theories is that they are not explicit in the relationship between health and cognitions. Future research will need to explore how to incorporate models of health and function into existing behaviour change theories. PMID:19479491

  19. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

    NASA Astrophysics Data System (ADS)

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency.

  20. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration.

    PubMed

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency. PMID:26819083

  1. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

    PubMed Central

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency. PMID:26819083

  2. Validation of housing standards addressing accessibility: exploration of an activity-based approach.

    PubMed

    Helle, Tina; Iwarsson, Susanne; Brandt, Ase

    2014-10-01

    The aim was to explore the use of an activity-based approach to determine the validity of a set of housing standards addressing accessibility. This included examination of the frequency and the extent of accessibility problems among older people with physical functional limitations who used no mobility device (n = 10) or who used a wheelchair (n = 10) or a rollator (n = 10). The setting was a kitchen designed according to present housing standards. The participants prepared lunch in the kitchen. Accessibility problems were assessed by observation and self-report. Differences between the three participant groups were examined. Performing well-known kitchen activities was associated with accessibility problems for all three participant groups, in particular those using a wheelchair. The overall validity of the housing standards examined was poor. Observing older people interacting with realistic environments while performing real everyday activities seems to be an appropriate method for assessing accessibility problems. PMID:24652904

  3. Enzyme activity in terrestrial soil in relation to exploration of the Martian surface

    NASA Technical Reports Server (NTRS)

    Ardakani, M. S.; Mclaren, A. D.; Pukite, A. H.

    1972-01-01

    An exploration was made of enzyme activities in soil, including abundance, persistence and localization of these activities. An attempt was made to develop procedures for the detection and assaying of enzymes in soils suitable for presumptive tests for life in planetary soils. A suitable extraction procedure for soil enzymes was developed and measurements were made of activities in extracts in order to study how urease is complexed in soil organic matter. Mathematical models were developed, based on enzyme action and microbial growth in soil, for rates of oxidation of nitrogen as nitrogen compounds are moved downward in soil by water flow. These biogeochemical models should be applicable to any percolating system, with suitable modification for special features, such as oxygen concetrations, and types of hydrodynamic flow.

  4. Advances in Distributed Operations and Mission Activity Planning for Mars Surface Exploration

    NASA Technical Reports Server (NTRS)

    Fox, Jason M.; Norris, Jeffrey S.; Powell, Mark W.; Rabe, Kenneth J.; Shams, Khawaja

    2006-01-01

    A centralized mission activity planning system for any long-term mission, such as the Mars Exploration Rover Mission (MER), is completely infeasible due to budget and geographic constraints. A distributed operations system is key to addressing these constraints; therefore, future system and software engineers must focus on the problem of how to provide a secure, reliable, and distributed mission activity planning system. We will explain how Maestro, the next generation mission activity planning system, with its heavy emphasis on portability and distributed operations has been able to meet these design challenges. MER has been an excellent proving ground for Maestro's new approach to distributed operations. The backend that has been developed for Maestro could benefit many future missions by reducing the cost of centralized operations system architecture.

  5. A Best-Evidence Synthesis of Research on Orientation and Mobility Involving Tactile Maps and Models

    ERIC Educational Resources Information Center

    Wright, Tessa; Harris, Beth; Sticken, Eric

    2010-01-01

    A review of the literature from 1965 to 2008 on tactile maps and models in orientation and mobility yielded four pre-experimental and three experimental articles. The articles were analyzed via best-evidence synthesis--a combined narrative and statistical approach--allowing for recommendations for the most effective use of tactile maps and models.…

  6. Physical and psychological effects of 6-week tactile massage on elderly patients with severe dementia.

    PubMed

    Suzuki, Mizue; Tatsumi, Asami; Otsuka, Toshiko; Kikuchi, Keiko; Mizuta, Akiko; Makino, Kimiko; Kimoto, Akie; Fujiwara, Kiyoe; Abe, Toshihiko; Nakagomi, Toshihiro; Hayashi, Tatsuya; Saruhara, Takayuki

    2010-12-01

    Tactile massage is a soft massage that improves physical relaxation and psychological well-being. The purpose of this study was to clarify the effects of a 6-week tactile massage on changes in physical and mental function, symptoms of behavioral and psychological symptoms of dementia (BPSD) among elderly patients with dementia. In addition, chromogranin A (CgA) levels as an index of stress examined the effects of tactile massage intervention. A tactile massage group consisting of elderly patients with dementia received tactile massage therapy a total of 30 times each for about 20 minutes between 16:00 and 17:00 hours. In the control group, the mean scores for ''intellectual'' and ''emotional function'' score decreased significantly after 6 weeks (P < .05); however, no change was observed in the tactile massage group. Both the ''aggressiveness'' score (P < .05) and CgA levels decreased significantly after 6 weeks in the tactile massage group. These results suggest that tactile massage reduces aggressiveness and stress level in patients with dementia. PMID:21131675

  7. How Do Batters Use Visual, Auditory, and Tactile Information about the Success of a Baseball Swing?

    ERIC Educational Resources Information Center

    Gray, Rob

    2009-01-01

    Bat/ball contact produces visual (the ball leaving the bat), auditory (the "crack" of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation…

  8. Tactile reception in the outer head cover of goldfish (Carassius auratus gibelio).

    PubMed

    Devitsina, G V; Lapshin, D N

    2016-01-01

    The first data on the responses of tactile receptors of the tonic, phasic, and mixed types to mechanic stimulation of the surface of head skin of fish obtained by means of noninvasive recording of potentials are presented. The sensitivity of skin tactile receptors is the highest in the circumoral and gular zones, which reflects their functional role in foraging behavior. PMID:27021364

  9. Young Children's Ability to Differentiate Appearance-Reality and Level 2 Perspectives in the Tactile Modality.

    ERIC Educational Resources Information Center

    Flavell, John H.; And Others

    1989-01-01

    Examines the ability to differentiate appearance-reality and Level Two perspective-taking in tactile modality among a total of 92 children aged two-four years in three studies. The results indicate that three-year-olds find tactile appearance-reality and Level Two perspective-taking tasks easier than visual ones. (RJC)

  10. Presentation of Various Tactile Sensations Using Micro-Needle Electrotactile Display.

    PubMed

    Tezuka, Mayuko; Kitamura, Norihide; Tanaka, Kohei; Miki, Norihisa

    2016-01-01

    Tactile displays provoke tactile sensations by artificially stimulating tactile receptors. While many types of tactile displays have been developed, electrotactile displays that exploit electric stimulation can be designed to be thin, light, flexible and thus, wearable. However, the high voltages required to stimulate tactile receptors and limited varieties of possible sensations pose problems. In our previous work, we developed an electrotactile display using a micro-needle electrode array that can drastically reduce the required voltage by penetrating through the high-impedance stratum corneum painlessly, but displaying various tactile sensations was still a challenge. In this work, we demonstrate presentation of tactile sensation of different roughness to the subjects, which is enabled by the arrangement of the electrodes; the needle electrodes are on the fingertip and the ground electrode is on the fingernail. With this arrangement, the display can stimulate the tactile receptors that are located not only in the shallow regions of the finger but also those in the deep regions. It was experimentally revealed that the required voltage was further reduced compared to previous devices and that the roughness presented by the display was controlled by the pulse frequency and the switching time, or the stimulation flow rate. The proposed electrotactile display is readily applicable as a new wearable haptic device for advanced information communication technology. PMID:26845336

  11. Weber's Illusion and Body Shape: Anisotropy of Tactile Size Perception on the Hand

    ERIC Educational Resources Information Center

    Longo, Matthew R.; Haggard, Patrick

    2011-01-01

    The perceived distance between touches on a single skin surface is larger on regions of high tactile sensitivity than those with lower acuity, an effect known as "Weber's illusion". This illusion suggests that tactile size perception involves a representation of the perceived size of body parts preserving characteristics of the somatosensory…

  12. Integration of Hand and Finger Location in External Spatial Coordinates for Tactile Localization

    ERIC Educational Resources Information Center

    Heed, Tobias; Backhaus, Jenny; Roder, Brigitte

    2012-01-01

    Tactile stimulus location is automatically transformed from somatotopic into external spatial coordinates, rendering information about the location of touch in three-dimensional space. This process is referred to as tactile remapping. Whereas remapping seems to occur automatically for the hands and feet, the fingers may constitute an exception in…

  13. An Evaluation of Substrates for Tactile Maps and Diagrams: Scanning Speed and Users' Preferences

    ERIC Educational Resources Information Center

    Jehoel, Sandra; Ungar, Simon; McCallum, Don; Rowell, Jonathan

    2005-01-01

    This study evaluated the relative suitability of a range of base materials for producing tactile maps and diagrams via a new ink-jet process. The visually impaired and sighted participants tactilely scanned arrays of symbols that were printed on seven substrate materials, including paper, plastic, and aluminum. In general, the rougher substrates…

  14. Sensory Responsiveness and the Effects of Equal Subjective Rewards on Tactile Learning and Memory of Honeybees

    ERIC Educational Resources Information Center

    Scheiner, Ricarda; Kuritz-Kaiser, Anthea; Menzel, Randolf; Erber, Joachim

    2005-01-01

    In tactile learning, sucrose is the unconditioned stimulus and reward, which is usually applied to the antenna to elicit proboscis extension and which the bee can drink when it is subsequently applied to the extended proboscis. The conditioned stimulus is a tactile object that the bee can scan with its antennae. In this paper we describe the…

  15. Using Visual and Tactile Sensory Aids to Remediate Monotone Voice in Hearing-Impaired Speakers.

    ERIC Educational Resources Information Center

    Youdelman, Karen; And Others

    1989-01-01

    Sixteen severely-to-profoundly hearing-impaired students, aged 7-8, received training using a curriculum for remediating monotone voice. Some students also used visual or tactile sensory aids. All students evidenced marked improvement in remediating monotonous pitch, with those using the curriculum in conjunction with a tactile display showing the…

  16. Presentation of Various Tactile Sensations Using Micro-Needle Electrotactile Display

    PubMed Central

    Tanaka, Kohei; Miki, Norihisa

    2016-01-01

    Tactile displays provoke tactile sensations by artificially stimulating tactile receptors. While many types of tactile displays have been developed, electrotactile displays that exploit electric stimulation can be designed to be thin, light, flexible and thus, wearable. However, the high voltages required to stimulate tactile receptors and limited varieties of possible sensations pose problems. In our previous work, we developed an electrotactile display using a micro-needle electrode array that can drastically reduce the required voltage by penetrating through the high-impedance stratum corneum painlessly, but displaying various tactile sensations was still a challenge. In this work, we demonstrate presentation of tactile sensation of different roughness to the subjects, which is enabled by the arrangement of the electrodes; the needle electrodes are on the fingertip and the ground electrode is on the fingernail. With this arrangement, the display can stimulate the tactile receptors that are located not only in the shallow regions of the finger but also those in the deep regions. It was experimentally revealed that the required voltage was further reduced compared to previous devices and that the roughness presented by the display was controlled by the pulse frequency and the switching time, or the stimulation flow rate. The proposed electrotactile display is readily applicable as a new wearable haptic device for advanced information communication technology. PMID:26845336

  17. Design and Performance of a Low-Cost Telemetric Laparoscopic Tactile Grasper.

    PubMed

    Schostek, Sebastian; Zimmermann, Melanie; Schurr, Marc O; Prosst, Ruediger L

    2016-06-01

    Tactile feedback is completely lost in laparoscopic surgery, which would provide information about tissue compliance, texture, structural features, and foreign bodies. We developed a system with artificial tactile feedback for laparoscopic surgery that consists of a telemetric tactile laparoscopic grasper, a remote PC with customized software, and a commercial video-mixer. A standard, nonsensorized laparoscopic grasper was customized to allow the integration of a tactile sensor and its electronics. The tactile sensor and the electronics module were designed to be detachable from the instrument. These parts are lightweight and wireless, thus not impeding the use of the device as surgical instrument. The remaining system components used to generate visualization of the tactile data do not influence the workflow in the operating room. The overall system design of the described instrumentation allows for easy implementation in an operating room environment. The fabrication of the tactile sensor is relatively easy and the production costs are low. With this telemetric laparoscopic grasper instrument, systematic preclinical studies can be performed in which surgeons execute surgical tasks that are derived from clinical reality. The experience gained from these investigations could then be used to define the requirements for any further development of artificial tactile feedback systems. PMID:26546367

  18. Experimental test of MR fluid based tactile device for minimally invasive surgery

    NASA Astrophysics Data System (ADS)

    Oh, Jong-Seok; Kim, Jin-Kyu; Choi, Seung-Bok

    2013-04-01

    Recently, it is very popular in modern medical industry to adopt robotic technology such as robotic minimally invasive surgery (RMIS). Compared with open surgery, the RMIS needs the robot to perform surgery through the usage of long surgical instruments that are inserted through incision points. This causes the surgeon not to feel viscosity and stiffness of the tissue or organ. So, for the tactile recognition of human organ in RMIS, this work proposes a novel tactile device that incorporates with magnetorheological (MR) fluid. The MR fluid is fully contained by diaphragm and several pins. By applying different magnetic field, the operator can feel different force from the proposed tactile device. In order to generate required force from the device, the repulsive force of human body is firstly measured as reference data and an appropriate size of tactile device is designed. Pins attached with the diaphragm are controlled by shape-memory-alloy (SMA). Thus, the proposed tactile device can realize repulsive force and shape of organ. It has been demonstrated via experiment whether the measured force can be achieved by applying proper control input current. In addition, psychophysical experiments are conducted to evaluate performance on the tactile rendering of the proposed tactile device. From these results, the practical feasibility of the tactile device is verified.

  19. Time Course of Tactile Gating in a Reach-to-Grasp and Lift Task.

    PubMed

    Colino, Francisco L; Binsted, Gordon

    2016-01-01

    Humans' sensory systems are bombarded by myriad events every moment of our lives. Thus, it is crucial for sensory systems to choose and process critical sensory events deemed important for a given task and, indeed, those that affect survival. Tactile gating is well known, and defined as a reduced ability to detect and discriminate tactile events before and during movement. Also, different locations of the effector exhibit different magnitudes of sensitivity changes. The authors examined that time course of tactile gating in a reaching and grasping movement to characterize its behavior. Tactile stimulators were attached to the right and left mid-forearms and the right index finger and fifth digit. When participants performed reach-to-grasp and lift targets, tactile acuity decreased at the right forearm before movement onset (F. L. Colino, G. Buckingham, D. T. Cheng, P. van Donkelaar, & G. Binsted, 2014 ). However, tactile sensitivity at the right index finger decreased by nearly 20% contrary to expectations. This result reflecting that there may be an additional source acting to reduce inhibition related to tactile gating. Additionally, sensitivity improved as movement end approached. Collectively, the present results indicate that predictive and postdictive mechanisms strongly influence tactile gating. PMID:27254788

  20. Enjoyment of tactile play is associated with lower food neophobia in preschool children.

    PubMed

    Coulthard, Helen; Thakker, Dipti

    2015-07-01

    Previous research has shown that parental reports of food neophobia and tactile sensitivity are associated with lower fruit and vegetable (F/V) intake in children. This study aimed to pilot a behavioral observation measure of tactile play in young children. The primary aim of the study was to see whether children's enjoyment of tactile play was associated with higher F/V consumption, as well as lower food neophobia. Seventy 2- to 5-year-old children (37 males and 33 females) and their parents were recruited through children's centers in the Leicester region of the United Kingdom during July to October 2012. Children's engagement in two tactile play tasks using sticky foods (mashed potatoes and vegetarian gelatin) was observed and rated by both the researcher and parent. Parents were asked to complete a series of questionnaires measuring F/V consumption, food neophobia, and sensory processing. It was found that lower child food neophobia was significantly related to enjoyment of tactile play, whereas child F/V consumption was associated with parental F/V consumption, but not enjoyment of tactile play. The findings strengthen the idea that tactile processing may be associated with the acceptance of food variety, but not the total amount of F/V consumed. Additional research is indicated to determine whether tactile play tasks can be used to lower child food neophobia. PMID:25935569

  1. Gamma-range synchronization of fast-spiking interneurons can enhance detection of tactile stimuli

    PubMed Central

    Siegle, Joshua H.; Pritchett, Dominique L.; Moore, Christopher I.

    2014-01-01

    We tested the sensory impact of repeated synchronization of fast-spiking interneurons (FS), an activity pattern thought to underlie neocortical gamma oscillations. We optogenetically drove “FS-gamma” while mice detected naturalistic vibrissal stimuli and found enhanced detection of less salient stimuli and impaired detection of more salient ones. Prior studies have predicted that the benefit of FS-gamma is generated when sensory neocortical excitation arrives in a specific temporal window 20-25 ms after FS synchronization. To systematically test this prediction, we aligned periodic tactile and optogenetic stimulation. We found that the detection of less salient stimuli was improved only when peripheral drive led to the arrival of excitation 20-25 ms after synchronization and that other temporal alignments either had no effects or impaired detection. These results provide causal evidence that FS-gamma can enhance processing of less salient stimuli, those that benefit from the allocation of attention. PMID:25151266

  2. A tactile paging system for deaf-blind people, phase 1. [human factors engineering of bioinstrumentation

    NASA Technical Reports Server (NTRS)

    Baer, J. A.

    1976-01-01

    A tactile paging system for deaf-blind people has been brought from the concept stage to the development of a first model. The model consists of a central station that transmits coded information via radio link to an on-body (i.e., worn on the wrist) receiving unit, the output from which is a coded vibrotactile signal. The model is a combination of commercially available equipment, customized electronic circuits, and electromechanical transducers. The paging system facilitates communication to deaf-blind clients in an institutional environment as an aid in their training and other activities. Several subunits of the system were individually developed, tested, and integrated into an operating system ready for experimentation and evaluation. The operation and characteristics of the system are described and photographs are shown.

  3. Watching what's coming near increases tactile sensitivity: An experimental investigation.

    PubMed

    Van der Biest, Lien; Legrain, Valéry; Paepe, Annick De; Crombez, Geert

    2016-01-15

    During medical examinations, doctors regularly investigate a patient's somatosensory system by approaching the patient with a medical device (e.g. Von Frey hairs, algometer) or with their hands. It is assumed that the obtained results reflect the true capacities of the somatosensory system. However, evidence from crossmodal spatial research suggests that sensory experiences in one modality (e.g. touch) can be influenced by concurrent information from other modalities (e.g. vision), especially near the body (i.e. in peripersonal space). Hence, we hypothesized that seeing someone approaching your body could alter tactile sensitivity in that body-part. In the In Vivo Approaching Object (IVAO) paradigm, participants detected and localized threshold-level vibrotactile stimuli administered on the left of right hand (=tactile targets). In Experiment 1, this was always preceded by the experimenter approaching the same (congruent trials) or the other (incongruent trials) hand with a pen (=visual cue). In Experiment 2, a condition was added in which a point further away from the hands (also left vs. right) was approached. Response Accuracy was calculated for congruent and incongruent trials (Experiment 1 & 2) and compared between the close and far condition (Experiment 2). As expected, Response Accuracy was higher in congruent trials compared to incongruent trials, but only near the body. As a result, evidence was found for a crossmodal interaction effect between visual and tactile information in peripersonal space. These results suggest that somatosensory evaluations-both medical or research-based-may be biased by viewing an object approaching the body. PMID:26475955

  4. Tactile perception and manual dexterity in computer users.

    PubMed

    Tremblay, François; Mireault, Annie-Claude; Létourneau, Julie; Pierrat, Audrey; Bourrassa, Shannon

    2002-01-01

    Recent studies suggest that sensory input generated during highly repetitive tasks can degrade the sensory representation of the hand and eventually lead to sensory and motor problems. In this study, we investigated whether early changes in tactile perception and manual dexterity could be detected in persons exposed to computer tasks. Performance in tests designed to assess tactile perception (grating orientation task for spatial acuity and roughness discrimination) and manual dexterity (grooved pegboard test) was compared between two groups of healthy individuals, matched for age, gender, and experience, who differed in terms of computer habits. One group consisted of frequent users (FU, > 2 h/day, n = 36) and the other of non or occasional users (OU, < 2 h/day, n = 28). Comparison of performance between groups with subjects sorted by gender revealed significant differences (t-test, p < 0.05) in female, but not male, participants. Grating resolution thresholds at the tip on the second and fifth digits were, on average, 40% higher in female FU (n = 13) than in female OU (n = 10) and performance scores on the dexterity test were significantly higher for the left hand. The results of this study indicate that early signs of deterioration in hand function can be present in persons constantly exposed to computer tasks and that these signs are more readily apparent in women than in men. The loss of tactile spatial acuity found in female FU possibly reflect an early consequence of the degraded sensory representation of the hand resulting from constant repetitions of fine motor tasks. PMID:12088383

  5. Exploring the active site structure of photoreceptor proteins by Raman optical activity

    NASA Astrophysics Data System (ADS)

    Unno, Masashi

    2015-03-01

    Understanding protein function at the atomic level is a major challenge in a field of biophysics and requires the combined efforts of structural and functional methods. We use photoreceptor proteins as a model system to understand in atomic detail how a chromophore and a protein interact to sense light and send a biological signal. A potential technique for investigating molecular structures is Raman optical activity (ROA), which is a spectroscopic method with a high sensitivity to the structural details of chiral molecules. However, its application to photoreceptor proteins has not been reported. Thus we have constructed ROA spectrometer using near-infrared (NIR) laser excitation at 785 nm. The NIR excitation enables us to measure ROA spectra for a variety of biological samples, including photoreceptor proteins, without fluorescence from the samples. In the present study, we have applied the NIR-ROA to bacteriorhodopsin (BR) and photoactive yellow protein (PYP). BR is a light-driven proton pump and contains a protonated Schiff base of retinal as a chromophore. PYP is a blue light receptor, and this protein has the 4-hydroxycinnamyl chromophore, which is covalently linked to Cys69 through a thiolester bond. We have successfully obtained the ROA spectra of the chromophore within a protein environment. Furthermore, calculations of the ROA spectra utilizing density functional theory provide detailed structural information, such as data on out-of-plane distortions of the chromophore. The structural information obtained from the ROA spectra includes the positions of hydrogen atoms, which are usually not detected in the crystal structures of biological samples.

  6. An Examination of the Potential for Blissymbolics to Serve as the Foundation for a Tactile Symbol System

    ERIC Educational Resources Information Center

    Isaacson, Mickey

    2012-01-01

    The primary purpose of this study was to determine whether Blissymbolics have the potential for being developed into a tactile symbol communication system. Tactile techniques are used by many individuals with augmentative and alternative communication (AAC) needs. Tactile processing is optimized by the use of minimalistic stimuli, i.e., stimuli…

  7. Cassini Scientist for a Day: a tactile experience

    NASA Astrophysics Data System (ADS)

    Canas, L.; Altobelli, N.

    2012-09-01

    In September 2011, the Cassini spacecraft took images of three targets and a challenge was launched to all students: to choose the one target they thought would provide the best science and to write an essay explaining their reasons (more information on the "Cassini Scientist for a Day" essay contest official webpage in: http://saturn.jpl.nasa.gov/education/scientistforaday10thedition/, run by NASA/JPL) The three targets presented were: Hyperion, Rhea and Titan, and Saturn. The idea behind "Cassini Scientist for a Day: a tactile experience" was to transform each of these images into schematic tactile images, highlighting relevant features apprehended through a tactile key, accompanied by a small text in Braille with some additional information. This initial approach would allow reach a broader community of students, more specifically those with visual impairment disabilities. Through proper implementation and careful study cases the adapted images associated with an explanatory key provide more resources in tactile astronomy. As the 2012 edition approaches a new set of targeted objet images will be once again transformed and adapted to visually impaired students and will aim to reach more students into participate in this international competition and to engage them in a quest to expand their knowledge in the amazing Cassini discoveries and the wonders of Saturn and its moons. As the winning essays will be published on the Cassini website and contest winners invited to participate in a dedicated teleconference with Cassini scientists from NASA's Jet Propulsion Laboratory, this initiative presents a great chance to all visually impaired students and teachers to participate in an exciting experience. These initiatives must be complemented with further information to strengthen the learning experience. However they stand as a good starting point to tackle further astronomical concepts in the classroom, especially this field that sometimes lacks the resources. Although

  8. Compliant tactile sensor that delivers a force vector

    NASA Technical Reports Server (NTRS)

    Torres-Jara, Eduardo (Inventor)

    2010-01-01

    Tactile Sensor. The sensor includes a compliant convex surface disposed above a sensor array, the sensor array adapted to respond to deformation of the convex surface to generate a signal related to an applied force vector. The applied force vector has three components to establish the direction and magnitude of an applied force. The compliant convex surface defines a dome with a hollow interior and has a linear relation between displacement and load including a magnet disposed substantially at the center of the dome above a sensor array that responds to magnetic field intensity.

  9. Distributive tactile sensing using fibre Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Cowie, Barbara M.; Webb, David J.; Tam, Betty; Slack, Paul; Brett, Peter N.

    2006-04-01

    Two distributive tactile sensing systems are presented, based on fibre Bragg grating sensors. The first is a onedimensional metal strip with an array of 4 sensors, which is capable of detecting the magnitude and position of a contacting load. This system is compared experimentally with a similar system using resistive strain gauges. The second is a two-dimensional steel plate with 9 sensors which is able to distinguish the position and shape of a contacting load. This system is compared with a similar system using 16 infrared displacement sensors. Each system uses neural networks to process the sensor data to give information concerning the type of contact.

  10. Tactile MEMS-based sensor for delicate microsurgery

    NASA Astrophysics Data System (ADS)

    Park, Young Soo; Lee, Wooho; Gopalsami, Nachappa; Gundeti, Mohan

    2014-06-01

    This paper presents development of a new MEMS-based tactile microsensor to replicate the delicate sense of touch in robotic surgery. Using an epoxy-based photoresist, SU-8, as substrate, the piezoresistive type sensor is flexible, robust, and easy to fabricate in mass. Sensor characteristic tests indicate adequate sensitivity and linearity, and the multiple sensor elements can match full range of surgical tissue stiffness. Such characteristic nearly match the most delicate sense of touch at the human fingertip. It is expected such a sensor is essential for delicate surgeries, such as handling delicate tissues and microsurgery.

  11. MAPGEN: Mixed-Initiative Activity Planning for the Mars Exploration Rover Mission

    NASA Technical Reports Server (NTRS)

    Ai-Chang, Mitchell; Bresina, John; Hsu, Jennifer; Jonsson, Ari; Kanefsky, Bob; McCurdy, Michael; Morris, Paul; Rajan, Kanna; Vera, Alonso; Yglesias, Jeffrey

    2004-01-01

    This document describes the Mixed initiative Activity Plan Generation system MAPGEN. This system is one of the critical tools in the Mars Exploration Rover mission surface operations, where it is used to build activity plans for each of the rovers, each Martian day. The MAPGEN system combines an existing tool for activity plan editing and resource modeling, with an advanced constraint-based reasoning and planning framework. The constraint-based planning component provides active constraint and rule enforcement, automated planning capabilities, and a variety of tools and functions that are useful for building activity plans in an interactive fashion. In this demonstration, we will show the capabilities of the system and demonstrate how the system has been used in actual Mars rover operations. In contrast to the demonstration given at ICAPS 03, significant improvement have been made to the system. These include various additional capabilities that are based on automated reasoning and planning techniques, as well as a new Constraint Editor support tool. The Constraint Editor (CE) as part of the process for generating these command loads, the MAPGEN tool provides engineers and scientists an intelligent activity planning tool that allows them to more effectively generate complex plans that maximize the science return each day. The key to the effectiveness of the MAPGEN tool is an underlying constraint-based planning and reasoning engine.

  12. Active oil seep at Nevada gold mine holds intrigue for more exploration

    SciTech Connect

    Pinnell, M.L.; Blake, J.G. ); Hulen, J.B. )

    1991-07-15

    This paper reports on an active oil seep has been discovered in one of Nevada's famous Carlin-type low grade disseminated gold deposits. This unique seep, at the Yankee gold mine in White Pine County, may have important implications for both oil and gas and gold exploration in the Basin and Range province of the western U.S. The open pit Yankee mine, near the western margin of Long Valley, exploits one of numerous Carlin-type gold ore bodies in the alligator Ridge mining district; all are currently owned and operated by USMX Corp.

  13. Apollo Program Summary Report: Synopsis of the Apollo Program Activities and Technology for Lunar Exploration

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Overall program activities and the technology developed to accomplish lunar exploration are discussed. A summary of the flights conducted over an 11-year period is presented along with specific aspects of the overall program, including lunar science, vehicle development and performance, lunar module development program, spacecraft development testing, flight crew summary, mission operations, biomedical data, spacecraft manufacturing and testing, launch site facilities, equipment, and prelaunch operations, and the lunar receiving laboratory. Appendixes provide data on each of the Apollo missions, mission type designations, spacecraft weights, records achieved by Apollo crewmen, vehicle histories, and a listing of anomalous hardware conditions noted during each flight beginning with Apollo 4.

  14. Exploration of amphoteric and negative refraction imaging of acoustic sources via active metamaterials

    NASA Astrophysics Data System (ADS)

    Wen, Jihong; Shen, Huijie; Yu, Dianlong; Wen, Xisen

    2013-11-01

    The present work describes the design of three flat superlens structures for acoustic source imaging and explores an active acoustic metamaterial (AAM) to realise such a design. The first two lenses are constructed via the coordinate transform method (CTM), and their constituent materials are anisotropic. The third lens consists of a material that has both a negative density and a negative bulk modulus. In these lenses, the quality of the images is “clear” and sharp; thus, the diffraction limit of classical lenses is overcome. Finally, a multi-control strategy is developed to achieve the desired parameters and to eliminate coupling effects in the AAM.

  15. Outreach and capacity building activities for engaging youth and public in Exploration

    NASA Astrophysics Data System (ADS)

    Foing, Bernard H.

    We report to the COSPAR Panel on Education and relevant community on activities, pilot projects and results relevant for outreach and engagement in exploration. Number of activities were developed in the frame of the International Lunar Exploration Working Group (ILEWG) including the participation of students in lunar symposia, space conferences or ICEUM International Conferences on Exploration and Utilisation of the Moon* ILEWG with support from various space agencies, universities and institutions has organized events for young professionals with a wide background (including scientist, engineers, humanistic, law, art students) a Moon academy, lunar and planetary students work-shops, technical training workshops, international observe the Moon sessions. ILEWG has organised or sponsored participants to a series of field training and research campaigns in Utah desert research station, Eifel volcanic park, Iceland, Rio Tinto, La Reunion island. Education and outreach projects used space missions data (SMART-1 views of the Moon, Earth views from space, Mars views, Mars crowdsourcing games, astronomy data analysis) to engage the public in citizen science and exploration. Artistic and sociological projects (e.g. "social lunar telescope, lunar zen garden, Moon academy, MoonLife, MoonLife concept store, Moon republic, artscience projects, space science in the arts, artists in residence, artists in MoonMars base") were also initiated with artists to engage the wide public in exploration. A number of projects have been developed with support from ITACCUS IAF committee. We shall discuss how these pilot projects could be expanded for the benefit of future space projects, young professionals, the space community and the public. Acknowledgements: we thank collaborators from ILEWG community and partner institutes for the different projects mentioned http://sci.esa.int/ilewg/ http://sci.esa.int/ilewg/47170-gluc-iceum11-beijing-2010lunar-declaration/ Foing B., Stoker C

  16. Using Hydrothermal Plumes and Their Chemical Composition to Identify and Understand Hydrothermal Activity at Explorer Ridge

    NASA Astrophysics Data System (ADS)

    Resing, J.; Lebon, G.; Baker, E.; Walker, S.; Nakamura, K.; Silvers, B.

    2002-12-01

    During June and July, 2002, an extensive survey of the hydrothermal systems of the Explorer Ridge was made aboard the R/V Thomas Thompson. This survey employed hydrocasts and the Autonomous Benthic Explorer (ABE) to locate and map hydrothermal vent fields. A total of 28 hydrocasts (17 verticals and 11 tow-yos) were used to search for hydrothermal activity from 49.5°N to 50.3°N on the Explorer Ridge. During the hydrocasts continuous measurements were made of conductivity, temperature, pressure, light backscatter, eH, Fe, Mn, and pH. Discrete samples were collected for total dissolved Fe and Mn, methane, pH, total CO2, and particulate matter. Most of the strong hydrothermal venting was near the Magic Mountain area of the Explorer Ridge at ~49.76° N, 130.26° W, where strong particulate backscatter signals (~0.130 NTUs) and moderate temperature anomalies (~ 0.05 °C) were detected. The particulate matter causing the backscatter was made up primarily of volatile particulate sulfur (PS) with little to no hydrothermal PFe. PS:PFe ratios exceeded 25 in the areas of most intense venting, . These PFe and PS data suggest that the hydrothermal Fe, if any, is deposited as sulfide minerals beneath the sea floor and that S is far in excess of Fe in the hydrothermal fluids. In the most intense plumes,total dissolvable Fe and Mn were between 20 and 30 nM, pH anomalies exceeded 0.025 pH units (indicating an increase of ~10uM CO2), and methane reached 16nM. These results suggest that the fluids exiting the sea floor are metal-poor and moderately gas-rich.

  17. Barriers for recess physical activity: a gender specific qualitative focus group exploration

    PubMed Central

    2014-01-01

    Background Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender differences in children’s perceptions of barriers to recess physical activity. Based on the socio-ecological model four types of environmental barriers were distinguished: natural, social, physical and organizational environment. Methods Data were collected through 17 focus groups (at 17 different schools) with in total 111 children (53 boys) from fourth grade, with a mean age of 10.4 years. The focus groups included an open group discussion, go-along group interviews, and a gender segregated post-it note activity. A content analysis of the post-it notes was used to rank the children’s perceived barriers. This was verified by a thematic analysis of transcripts from the open discussions and go-along interviews. Results The most frequently identified barriers for both boys and girls were weather, conflicts, lack of space, lack of play facilities and a newly-found barrier, use of electronic devices. While boys and girls identified the same barriers, there were both inter- and intra-gender differences in the perception of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly by those boys who played ballgames. Girls said they would like to have more secluded areas added to the school playground, even in large schoolyards where lack of space was not a barrier. This aligned with girls’ requests for more “hanging-out” facilities, whereas boys primarily wanted activity promoting facilities. Conclusion Based on the results from this study, we recommend promoting recess physical activity through a combination of actions, addressing barriers within the natural, social, physical and

  18. Explorations of Substituted Urea Functionality for Discovery of New Activators of the Heme Regulated Inhibitor Kinase

    PubMed Central

    Chen, Ting; Takrouri, Khuloud; Hee-Hwang, Sung; Rana, Sandeep; Yefidoff-Freedman, Revital; Halperin, Jose; Natarajan, Amarnath; Morisseau, Christophe; Hammock, Bruce; Chorev, Michael; Aktas, Bertal H.

    2014-01-01

    Heme-regulated inhibitor kinase (HRI), an eukaryotic translation initiation factor 2 alpha (eIF2α) kinase, plays critical roles in cell proliferation, differentiation, and adaptation to cytoplasmic stress. HRI is also a critical modifier of hemoglobin disorders such as β-thalassemia. We previously identified N,N′-diarylureas as potent activators of HRI suitable for studying biology of this important kinase. To expand the repertoire of chemotypes that activate HRI we screened a ~1,900 member N,N′-disubstituted urea library in the surrogate eIF2α phosphorylation assay identifying N-aryl,N′-cyclohexylphenoxyurea as a promising scaffold. We validated hit compounds as a bona-fide HRI activators in secondary assays and explored contributions of substitutions on the N-aryl and N′-cyclohexylphenoxy groups to their activity by studying focused libraries of complementing analogs. We tested these N-aryl,N′-cyclohexylphenoxyureas in the surrogate eIF2α phosphorylation and cell proliferation assays, demonstrating significantly improved bioactivities and specificities. We consider these compounds to represent lead candidates for the development of potent and specific HRI activators. PMID:24261904

  19. Exploration Of Activity Measurements And Equilibrium Checks For Sediment Dating Using Thick-Window Germanium Detectors

    SciTech Connect

    Warner, Jacob A.; Gladkis, Laura G.; Timmers, Heiko; Fitzsimmons, Kathryn E.; Reynolds, Eva M.

    2011-06-01

    Activity measurements on sediment samples for trapped-charge geological dating using gamma-ray spectroscopy are an important verification of the field-site dose rate determination. Furthermore gamma-ray spectroscopy can check if the natural decay series are in secular equilibrium which is a crucial assumption in such dating. Typically the activities of leading members of the Thorium and Uranium decay series are measured, which requires Germanium detectors with thin windows and good energy resolution in order to effectively detect the associated low energy gamma-rays. Such equipment is not always readily available. The potential of conventional Germanium detectors with thick entrance window has been explored towards routine gamma-ray spectroscopy of sediment samples using higher energy gamma-rays. Alternative isotopes, such as Ac-228 and Pb-212 for the Thorium series, and Pa-234m, Ra-226 and Bi-214 for the Uranium series, have been measured in order to determine the mass-specific activity for the respective series and possibly provide a check of secular equilibrium. In addition to measurements of the K-40 activity, with the alternative approach, the activities of both decay series can be accurately determined. The secular equilibrium condition may be tested for the Thorium series. Measurement accuracy for Pa-234m is, however, not sufficient to permit also a reliable check of equilibrium for the Uranium series.

  20. Exploration of the antiplatelet activity profile of betulinic acid on human platelets

    PubMed Central

    Tzakos, Andreas G.; Kontogianni, Vassiliki G.; Tsoumani, Maria; Kyriakou, Eleni; Hwa, John; Rodrigues, Francisco A.; Tselepis, Alexandros D.

    2013-01-01

    Betulinic acid, a natural pentacyclic triterpene acid, presents a diverse mode of biological actions including anti-retroviral, antibacterial, antimalarial and anti-inflammatory activities. The potency of betulinic acid as an inhibitor of human platelet activation was evaluated and its antiplatelet profile against in vitro platelet aggregation, induced by several platelet agonists (Adenosine Diphosphate, Thrombin Receptor Activator Peptide-14 and Arachidonic Acid), was explored. Flow cytometric analysis was performed to examine the effect of betulinic acid on P-selectin membrane expression and PAC-1 binding to activated platelets. Betulinic acid potently inhibits platelet aggregation and also reduced PAC-1 binding and the membrane expression of P-selectin. Principal component analysis was used to screen, on the chemical property space, for potential common pharmacophores of betulinic acid with approved antithrombotic drugs. A common pharmacophore was defined between the NMR derived structure of betulinic acid and prostacyclin agonists (PGI2) and the importance of its carboxylate group in its antiplatelet activity was determined. The present results indicate that betulinic acid has potential use as an antithrombotic compound and suggest that the mechanism underlying the antiplatelet effects of betulinic acid is similar to that of the PGI2 receptor agonists, a hypothesis that reserves further investigation. PMID:22720759