scholarly journals The effect of scanning speed on texture-elicited vibrations

2019 ◽  
Author(s):  
Charles M. Greenspon ◽  
Kristine R. McLellan ◽  
Justin D. Lieber ◽  
Sliman J. Bensmaia
Keyword(s):  
Laser Doppler Vibrometer ◽  
Scanning Speed ◽  
Nerve Fibers ◽  
High Frequencies ◽  
Fine Surface ◽  
Frequency Components ◽  
Neuronal Representation ◽  
Multiplicative Shift ◽  
Human Participants ◽  
Exploratory Strategy

ABSTRACTTo sense the texture of a surface, we run our fingers across it, which leads to the elicitation of skin vibrations that depend both on the surface and on exploratory parameters, particularly scanning speed. The transduction and processing of these vibrations mediates the ability to discern fine surface features. In the present study, we seek to characterize the effect of changes in scanning speed on texture-elicited vibrations to better understand how the exploratory strategy shapes the neuronal representation of texture. To this end, we scanned a variety of textures across the fingertip of human participants at a variety of speeds (10 – 160 mm/s) while measuring the resulting vibrations using a laser Doppler vibrometer. We found that increases in speed led to systematic increases in vibratory intensity and to a systematic upward multiplicative shift in the frequency composition of the vibrations. Furthermore, we showed that the upward shift in frequency composition accounts for the increase in intensity. The enhancement of higher frequency components accounts for the observed increase in the firing rates of nerve fibers, particularly Pacinian corpuscle-associated fibers, which are most sensitive at the high frequencies.

scholarly journals Effect of scanning speed on texture-elicited vibrations

2020 ◽  
Vol 17 (167) ◽  
pp. 20190892
Author(s):  
Charles M. Greenspon ◽  
Kristine R. McLellan ◽  
Justin D. Lieber ◽  
Sliman J. Bensmaia
Keyword(s):  
Root Mean Square ◽  
Laser Doppler Vibrometer ◽  
Scanning Speed ◽  
Mean Square ◽  
Root Mean Square Velocity ◽  
Dependent Change ◽  
Fine Surface ◽  
Neuronal Representation ◽  
Human Participants ◽  
Exploratory Movements

To sense the texture of a surface, we run our fingers across it, which leads to the elicitation of skin vibrations that depend both on the surface and on exploratory parameters, particularly scanning speed. The transduction and processing of these vibrations mediate the ability to discern fine surface features. The objective of the present study is to characterize the effect of changes in scanning speed on texture-elicited vibrations to better understand how the exploratory movements shape the neuronal representation of texture. To this end, we scanned a variety of textures across the fingertip of human participants at a variety of speeds (10–160 mm s −1 ) while measuring the resulting vibrations using a laser Doppler vibrometer. First, we found that the intensity of the vibrations—as indexed by root-mean-square velocity—increases with speed but that the skin displacement remains constant. Second, we found that the frequency composition of the vibrations shifts systematically to higher frequencies with increases in scanning speed. Finally, we show that the speed-dependent shift in frequency composition accounts for the speed-dependent change in intensity.

scholarly journals Sex-related differences in response to masseteric injections of glutamate and nerve growth factor in healthy human participants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdelrahman M. Alhilou ◽  
Akiko Shimada ◽  
Camilla I. Svensson ◽  
Peter Svensson ◽  
Malin Ernberg ◽  
...  
Keyword(s):  
Nmda Receptors ◽  
Nerve Fiber ◽  
Masseter Muscle ◽  
Pain Sensitivity ◽  
Nerve Fibers ◽  
Receptor Expression ◽  
Healthy Human ◽  
Neurophysiological Mechanisms ◽  
Human Participants ◽  
Positive Correlations

AbstractThe neurophysiological mechanisms underlying NGF-induced masseter muscle sensitization and sex-related differences in its effect are not well understood in humans. Therefore, this longitudinal cohort study aimed to investigate the effect of NGF injection on the density and expression of substance P, NMDA-receptors and NGF by the nerve fibers in the human masseter muscle, to correlate expression with pain characteristics, and to determine any possible sex-related differences in these effects of NGF. The magnitude of NGF-induced mechanical sensitization and pain during oral function was significantly greater in women than in men (P < 0.050). Significant positive correlations were found between nerve fiber expression of NMDA-receptors and peak pain intensity (rs = 0.620, P = 0.048), and expression of NMDA-receptors by putative nociceptors and change in temporal summation pain after glutamate injection (rs = 0.561, P = 0.003). In women, there was a significant inverse relationship between the degree of NGF-induced mechanical sensitization and the change in nerve fiber expression of NMDA-receptors alone (rs = − 0.659, P = 0.013), and in combination with NGF (rs = − 0.764, P = 0.001). In conclusion, women displayed a greater magnitude of NGF-induced mechanical sensitization that also was associated with nerve fibers expression of NMDA-receptors, when compared to men. The present findings suggest that, in women, increased peripheral NMDA-receptor expression could be associated with masseter muscle pain sensitivity.

Frequency-Weighted Variable-Length Controllers Using Anytime Control Strategies

2011 ◽  
Author(s):  
Gundula B. Runge ◽  
Al Ferri ◽  
Bonnie Ferri
Keyword(s):  
Time Scale ◽  
Weighting Function ◽  
Control Strategies ◽  
Low Frequency ◽  
Low Frequencies ◽  
High Frequencies ◽  
Frequency Components ◽  
Computational Resources ◽  
Weighted Variable ◽  
Selection Of

This paper considers an anytime strategy to implement controllers that react to changing computational resources. The anytime controllers developed in this paper are suitable for cases when the time scale of switching is in the order of the task execution time, that is, on the time scale found commonly with sporadically missed deadlines. This paper extends the prior work by developing frequency-weighted anytime controllers. The selection of the weighting function is driven by the expectation of the situations that would require anytime operation. For example, if the anytime operation is due to occasional and isolated missed deadlines, then the weighting on high frequencies should be larger than that for low frequencies. Low frequency components will have a smaller change over one sample time, so failing to update these components for one sample period will have less effect than with the high frequency components. An example will be included that applies the anytime control strategy to a model of a DC motor with deadzone and saturation nonlinearities.

scholarly journals Emergence of an invariant representation of texture in primate somatosensory cortex

2019 ◽  
Author(s):  
Justin D. Lieber ◽  
Sliman J. Bensmaia
Keyword(s):  
Cortical Neurons ◽  
Rhesus Macaques ◽  
Scanning Speed ◽  
Nerve Fibers ◽  
Invariant Representation ◽  
Major Function ◽  
Neural Representations ◽  
Wide Range ◽  
Sensory Modalities ◽  
Exploratory Movements

ABSTRACTA major function of sensory processing is to achieve neural representations of objects that are stable across changes in context and perspective. Small changes in exploratory behavior can lead to large changes in signals at the sensory periphery, thus resulting in ambiguous neural representations of objects. Overcoming this ambiguity is a hallmark of human object recognition across sensory modalities. Here, we investigate how the perception of tactile texture remains stable across exploratory movements of the hand, including changes in scanning speed, despite the concomitant changes in afferent responses. To this end, we scanned a wide range of everyday textures across the fingertips of Rhesus macaques at multiple speeds and recorded the responses evoked in tactile nerve fibers and somatosensory cortical neurons. We found that individual cortical neurons exhibit a wider range of speed-sensitivities than do nerve fibers. The resulting representations of speed and texture in cortex are more independent than are their counterparts in the nerve and account for speed-invariant perception of texture. We demonstrate that this separation of speed and texture information is a natural consequence of previously described cortical computations.

scholarly journals Characterizing the Complex Modulus of Asphalt Concrete Using a Scanning Laser Doppler Vibrometer

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3542
Author(s):  
Navid Hasheminejad ◽  
Cedric Vuye ◽  
Alexandros Margaritis ◽  
Wim Van den bergh ◽  
Joris Dirckx ◽  
...  
Keyword(s):  
Asphalt Concrete ◽  
Master Curve ◽  
Complex Modulus ◽  
Optical Measurement ◽  
Laser Doppler Vibrometer ◽  
Beam Theory ◽  
Asphalt Mixtures ◽  
Laser Doppler ◽  
Bending Test ◽  
High Frequencies

Asphalt mixtures are the most common types of pavement material used in the world. Characterizing the mechanical behavior of these complex materials is essential in durable, cost-effective, and sustainable pavement design. One of the important properties of asphalt mixtures is the complex modulus of elasticity. This parameter can be determined using different standardized methods, which are often expensive, complex to perform, and sensitive to the experimental setup. Therefore, recently, there has been considerable interest in developing new, easier, and more comprehensive techniques to investigate the mechanical properties of asphalt. The main objective of this research is to develop an alternative method based on an optical measurement technique (laser Doppler vibrometry). To do this, a frequency domain system identification technique based on analytical formulas (Timoshenko’s beam theory) is used to determine the complex modulus of asphalt concrete at its natural frequencies and to form their master curve. The master curve plotted by this method is compared with the master curve obtained from the standard four-point bending test, and it is concluded that the proposed method is able to produce a master curve similar to the master curve of the standard method. Therefore, the proposed method has the potential to replace the standard stiffness tests. Furthermore, the standard stiffness methods usually conduct experiments up to the maximum frequency of 30 Hz. However, the proposed method can provide accurate complex modulus at high frequencies. This makes an accurate comparison between the properties of the asphalt mixtures in high frequencies and the development of more accurate theoretical models for simulation of specimens possible.

High-frequency atrial electrical activity

1961 ◽  
Vol 16 (2) ◽  
pp. 300-304 ◽  
Author(s):  
Cesar A. Caceres ◽  
George A. Kelser ◽  
Juan Calatayud
Keyword(s):  
High Frequency ◽  
Electrical Potential ◽  
P Wave ◽  
Right Atrial ◽  
High Frequencies ◽  
Pr Interval ◽  
Frequency Components ◽  
Left And Right ◽  
Electronic Filters ◽  
High Frequency Content

Left and right atrial intracavitary and conventional surface leads were used to study electrocardiographic activity during the PR interval. Electronic filters were employed for analysis of wave frequency and harmonic content from 1.7 to 1700 cps. Amplifiers permitting standardization sensitivity to 500 mm/mv were used to obtain oscilloscopic tracings recorded at a paper speed of 75 mm/sec. Frequency analysis of the electrical potential recorded during P wave inscription demonstrated the presence of high-frequency content that is excluded by conventional electrocardiographic amplifiers. The high-frequency components are associated with the time of inscription of the electrocardiographic intrinsic deflection and have a relationship to the characteristics of the pressure-pulse curve. These relationships suggest that intracavitary high frequencies and the electrocardiographic intrinsic deflection originate from electrical discharges associated with initiation of contractile events. Submitted on June 6, 1960

Effect of Changes in Mass on Middle Ear Function

1993 ◽  
Vol 109 (5) ◽  
pp. 899-910 ◽  
Author(s):  
Shinsei Nishihara ◽  
Hiroshi Aritomo ◽  
Richard L. Goode
Keyword(s):  
Middle Ear ◽  
Hearing Threshold ◽  
Laser Doppler Vibrometer ◽  
Ossicular Chain ◽  
High Frequencies ◽  
Before And After ◽  
Ventilation Tubes ◽  
Temporal Bones ◽  
Middle Ear Transfer Function ◽  
Vibrating Systems

Vibrating systems such as the middle ear are affected by changes in mass. After disease or ear surgery, significant changes in mass may contribute positively or negatively to the postoperative hearing threshold. This article describes experiments in 15 human temporal bones of the addition or reduction of mass on the middle ear transfer function. Measurement of stapes and umbo vibration was performed using a Laser Doppler Vibrometer before and after the addition of different masses at several sites on the tympanic membrane (TM) and ossicular chain. The input was 61 pure tones swept from 147 to 19433 Hz at 80 dB SPL. The addition of mass onto the TM produced varying detrimental effects on sound transmission, depending on the location and amount of mass. The insertion of ventilation tubes, weighing 12 to 17 mg each, produced losses at 1.5 to 5.0 kHz compared with tympanotomy alone. Addition of mass to the umbo and malleus head produced a loss at mid and high frequencies, whereas addition of mass on the incus long process and stapes also produced a high-frequency decrease in stapes displacement. Reduction of TM mass by removal of the epithelium produced an increase, especially at 2.0 to 4.0 kHz.

Neural correlates of the pitch of complex tones. I. Pitch and pitch salience

1996 ◽  
Vol 76 (3) ◽  
pp. 1698-1716 ◽  
Author(s):  
P. A. Cariani ◽  
B. Delgutte
Keyword(s):  
Auditory Nerve ◽  
Interspike Interval ◽  
Nerve Fibers ◽  
Central Processor ◽  
Order Interval ◽  
Complex Stimuli ◽  
Complex Tones ◽  
Frequency Components ◽  
Short Time ◽  
Order Intervals

1. The temporal discharge patterns of auditory nerve fibers in Dial-anesthetized cats were studied in response to periodic complex acoustic waveforms that evoke pitches at their fundamental frequencies. Single-formant vowels, amplitude-modulated (AM) and quasi-frequency-modulated tones. AM noise, click trains, and other complex tones were utilized. Distributions of intervals between successive spikes ("1st-order intervals") and between both successive and nonsuccessive spikes ("all-order intervals") were computed from spike trains. Intervals from many fibers were pooled to estimate interspike interval distributions for the entire auditory nerve. Properties of these "pooled interspike interval distributions," such as the positions of interval peaks and their relative heights, were examined for correspondence to the psychophysical data on pitch frequency and pitch salience. 2. For a diverse set of complex stimuli and levels, the most frequent all-order interspike interval present in the pooled distribution corresponded to the pitch heard in psychophysical experiments. Pitch estimates based on pooled interval distributions (30-85 fibers, 100 stimulus presentations per fiber) were highly accurate (within 1%) for harmonic stimuli that produce strong pitches at 60 dB SPL. 3. Although the most frequent intervals in pooled all-order interval distributions were very stable with respect to sound intensity level (40, 60, and 80 dB total SPL), this was not necessarily the case for first-order interval distributions. Because the low pitches of complex tones are largely invariant with respect to level, pitches estimated from all-order interval distributions correspond better to perception. 4. Spectrally diverse stimuli that evoke similar low pitches produce pooled interval distributions with similar most-frequent intervals. This suggests that the pitch equivalence of these different stimuli could result from central auditory processing mechanisms that analyze interspike interval patterns. 5. Complex stimuli that evoke strong or "salient" pitches produce pooled interval distributions with high peak-to-mean ratios. Those stimuli that evoke weak pitches produce pooled interval distributions with low peak-to-mean ratios. 6. Pooled interspike interval distributions for stimuli consisting of low-frequency components generally resembled the short-time auto-correlation function of stimulus waveforms. Pooled interval distributions for stimuli consisting of high-frequency components resembled the short-time autocorrelation function of the waveform envelope. 7. Interval distributions in populations of neurons constitute a general, distributed means of encoding, transmitting, and representing information. Existence of a central processor capable of analyzing these interval patterns could provide a unified explanation for many different aspects of pitch perception.

Cable Fault Recognition Based on the Wavelet Energy Spectrum of Mode Components

2013 ◽  
Vol 427-429 ◽  
pp. 834-837
Author(s):  
Mei Wang ◽  
Jing Wu
Keyword(s):  
Energy Spectrum ◽  
High Frequency ◽  
Transient Current ◽  
Power Cable ◽  
Two Phase ◽  
High Frequencies ◽  
Wavelet Energy ◽  
Fault Recognition ◽  
Frequency Components ◽  
Independent Mode

When a fault appeared in a power cable transmission line, the transient current with high frequencies would be produced in the system. Three independent mode components could be obtained by applying the phase mode transformation to the transient current. For different types of the faults, the three independent mode components have different features. Based on wavelet energy spectrum of mode components, a method for cable fault recognition is developed in this paper. First, the fault current is decomposed by using Karenbaue transformation matrix. Then, wavelet transformation is uses to obtain the coefficients of the high frequency components which reflect the original signal high frequency energy. Finally, based on the wavelet energy spectrum method and the detailed coefficient manipulation, the equivalent norms of the mode components are obtained. Compared with the traditional fault recognition method, the new method depends less on zero mode component in two-phase short to ground state, and it can recognize the fault class in the cases of different fault positions, different fault path resistances and different inception angles.

Tuning in to Very Fast Events

2019 ◽  
pp. 107-134
Author(s):  
Mari Riess Jones
Keyword(s):  
Time Scales ◽  
Pitch Perception ◽  
Fast Time ◽  
Multiple Frequency ◽  
Complex Sound ◽  
High Frequencies ◽  
Frequency Components ◽  
Single Complex ◽  
Virtual Pitch ◽  
Consonance And Dissonance

This chapter demonstrates that entrainment applies to very fast events, namely sounds with high frequencies. To illustrate this, prominent approaches to pitch perception are sketched along with basic pitch perception phenomena (e.g., virtual pitch perception). In this chapter, multiple frequency components comprise a single complex sound, and people must judge the pitch of this collection of frequencies. Both a successful psychoacoustic theory of pitch perception and a dynamic attending approach offer valid explanations of various phenomena surrounding the pitch of such sounds. This suggests the potential of entrainment in describing pitch perception (i.e., entrainments at fast time scales). The perception of consonance and dissonance is also considered, where dissonance is linked to complex synchronicities termed attractors. Finally, this chapter introduces oscillator clusters, a group of endogenously entrained oscillations.

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