Name: measurement of vibration detection threshold and tactile spatial acuity in human subjects
Uploaded: 2016-09-01T13:00:00
Description: Watch this Scientific Journal Video about Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects at JoVE.com

The research and development leading to the above described vibration test was funded by the European Research Council (ERC, ADG 294678) and the German Research Council (grant, SFB665). Thanks go to the Max-Delbr&#252;ck-Center technical and support staff, Mr. R. Fischer, B. Neumann, and Mr. M. Pflaume, who provided invaluable assistance with the project.

The testing protocol was approved by the Charit&#233;-Universit&#228;tsmedizin Ethics Committee.
1. Vibration Detection Threshold (VDT)
<ol>
	<li>Device and Testing Protocol Assembly&#160;&#8211; Pretesting
	<ol>
		<li>Assemble the components of the device according to Figure 1A. Place a smooth-surfaced board (40 cm x 80 cm) on a table. Place the brass bar on the board.</li>
		<li>Connect the piezoelectric actuator (vibration stimulator) to the controller unit.</li>
		<li>Connect the response bo...

<ol>
	<li>Poole, K., Herget, R., Lapatsina, L., Ngo, H. D., Lewin, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+Piezo+ion+channels+to+detect+molecular-scale+movements+relevant+for+fine+touch.">Tuning Piezo ion channels to detect molecular-scale movements relevant for fine touch.</a> Nat Commun. 5, 3520 (2014).</li><li>Lechner, S. G., Lewin, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hairy+sensation.">Hairy sensation.</a> Physiology (Bethesda). 28 (3), 142-150 (2013).</li><li>Heidenreich, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=KCNQ4+K(+)+channels+tune+mechanoreceptors+for+normal+touch+sensation+in+mouse+and+man.">KCNQ4 K(+) channels tune mechanoreceptors for normal touch sensation in mouse and man.</a> Nat Neurosci. 15 (1), 138-145 (2012).</li><li>Mountcastle, V. B., Talbot, W. H., Darian-Smith, I., Kornhuber, H. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+basis+of+the+sense+of+flutter-vibration.">Neural basis of the sense of flutter-vibration.</a> Science. 155 (3762), 597-600 (1967).</li><li>Bolanowski, S. J., Gescheider, G. A., Verrillo, R. T., Checkosky, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Four+channels+mediate+the+mechanical+aspects+of+touch.">Four channels mediate the mechanical aspects of touch.</a> J. Acoust. Soc. Am. 84 (5), 1680-1694 (1988).</li><li>Johansson, R. S., Vallbo, A. A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+tactile+stimuli.+Thresholds+of+afferent+units+related+to+psychophysical+thresholds+in+the+human+hand.">Detection of tactile stimuli. Thresholds of afferent units related to psychophysical thresholds in the human hand.</a> J Physiol. 297 (1), 405-422 (1979).</li><li>Frenzel, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Genetic+Basis+for+Mechanosensory+Traits+in+Humans.">A Genetic Basis for Mechanosensory Traits in Humans.</a> PLoS Biol. 10 (5), (2012).</li><li>Van Boven, R. W., Johnson, K. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+limit+of+tactile+spatial+resolution+in+humans:+grating+orientation+discrimination+at+the+lip,+tongue,+and+finger.">The limit of tactile spatial resolution in humans: grating orientation discrimination at the lip, tongue, and finger.</a> Neurology. 44 (12), 2361-2366 (1994).</li><li>Haseleu, J., Omerba&#353;i&#263;, D., Frenzel, H., Gross, M., Lewin, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Water-induced+finger+wrinkles+do+not+affect+touch+acuity+or+dexterity+in+handling+wet+objects.">Water-induced finger wrinkles do not affect touch acuity or dexterity in handling wet objects.</a> PLoS ONE. 9 (1), e84949 (2014).</li><li>Bensmaia, S. J., Hsiao, S. S., Denchev, P. V., Killebrew, J. H., Craig, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+tactile+perception+of+stimulus+orientation.">The tactile perception of stimulus orientation.</a> Somatosens Mot Res. 25 (1), 49-59 (2008).</li><li>Poole, K., Moroni, M., Lewin, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+mechanotransduction+at+membrane-matrix+interfaces.">Sensory mechanotransduction at membrane-matrix interfaces.</a> Pflugers Arch. , (2014).</li><li>Schrenk-Siemens, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PIEZO2+is+required+for+mechanotransduction+in+human+stem+cell-derived+touch+receptors.">PIEZO2 is required for mechanotransduction in human stem cell-derived touch receptors.</a> Nat. Neurosci. , (2014).</li><li>Woo, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Piezo2+is+required+for+Merkel-cell+mechanotransduction.">Piezo2 is required for Merkel-cell mechanotransduction.</a> Nature. 509 (7502), 622-626 (2014).</li><li>Ranade, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Piezo2+is+the+major+transducer+of+mechanical+forces+for+touch+sensation+in+mice.">Piezo2 is the major transducer of mechanical forces for touch sensation in mice.</a> Nature. 516 (7529), 121-125 (2014).</li><li>Wetzel, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+stomatin-domain+protein+essential+for+touch+sensation+in+the+mouse.">A stomatin-domain protein essential for touch sensation in the mouse.</a> Nature. 445 (7124), 206-209 (2007).</li><li>McMillin, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutations+in+PIEZO2+cause+Gordon+syndrome,+Marden-Walker+syndrome,+and+distal+arthrogryposis+type+5.">Mutations in PIEZO2 cause Gordon syndrome, Marden-Walker syndrome, and distal arthrogryposis type 5.</a> Am. J. Hum. Genet. 94 (5), 734-744 (2014).</li><li>Gandhi, M. S., Sesek, R., Tuckett, R., Bamberg, S. J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress+in+vibrotactile+threshold+evaluation+techniques:+a+review.">Progress in vibrotactile threshold evaluation techniques: a review.</a> J Hand Ther. 24 (3), 240-255 (2011).</li><li>G&#252;&#231;l&#252;, B., Bolanowski, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibrotactile+thresholds+of+the+Non-Pacinian+I+channel:+I.+Methodological+issues.">Vibrotactile thresholds of the Non-Pacinian I channel: I. Methodological issues.</a> Somatosens Mot Res. 22 (1-2), 49-56 (2005).</li><li>Lindsell, C. J., Griffin, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normative+vibrotactile+thresholds+measured+at+five+European+test+centres.">Normative vibrotactile thresholds measured at five European test centres.</a> Int Arch Occup Environ Health. 76 (7), 517-528 (2003).</li><li>Morioka, M., Griffin, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dependence+of+vibrotactile+thresholds+on+the+psychophysical+measurement+method.">Dependence of vibrotactile thresholds on the psychophysical measurement method.</a> Int Arch Occup Environ Health. 75 (1-2), 78-84 (2002).</li><li>Tannan, V., Dennis, R., Tommerdahl, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+device+for+delivering+two-site+vibrotactile+stimuli+to+the+skin.">A novel device for delivering two-site vibrotactile stimuli to the skin.</a> J. Neurosci. Methods. 147 (2), 75-81 (2005).</li><li>Zwislocki, J. J., Relkin, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+a+psychophysical+transformed-rule+up+and+down+method+converging+on+a+75%+level+of+correct+responses.">On a psychophysical transformed-rule up and down method converging on a 75% level of correct responses.</a> Proc. Natl. Acad. Sci. U.S.A. 98 (8), 4811-4814 (2001).</li><li>Gescheider, G. A., Bolanowski, S. J., Pope, J. V., Verrillo, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+four-channel+analysis+of+the+tactile+sensitivity+of+the+fingertip:+frequency+selectivity,+spatial+summation,+and+temporal+summation.">A four-channel analysis of the tactile sensitivity of the fingertip: frequency selectivity, spatial summation, and temporal summation.</a> Somatosens Mot Res. 19 (2), 114-124 (2002).</li><li>Kuroki, S., Watanabe, J., Nishida, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+of+within-+and+cross-channel+information+to+vibrotactile+frequency+discrimination.">Contribution of within- and cross-channel information to vibrotactile frequency discrimination.</a> Brain Res. 1529, 46-55 (2013).</li><li>Levitt, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformed+up-down+methods+in+psychoacoustics.">Transformed up-down methods in psychoacoustics.</a> J. Acoust. Soc. Am. 49 (2), (1971).</li><li>International Organization for Standardization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+vibration-Vibrotactile+perception+thresholds+for+the+assessment+of+nerve+dysfunction-Part+1:+Methods+of+measurement+at+the+fingertips.">Mechanical vibration-Vibrotactile perception thresholds for the assessment of nerve dysfunction-Part 1: Methods of measurement at the fingertips.</a> ISO 13091-1. , (2001).</li><li>International Organization for Standardization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+vibration-Vibrotactile+perception+thresholds+for+the+assessment+of+nerve+dysfunction-Part+2:+Analysis+and+interpretation+of+measurements+at+the+fingertips.">Mechanical vibration-Vibrotactile perception thresholds for the assessment of nerve dysfunction-Part 2: Analysis and interpretation of measurements at the fingertips.</a> ISO 13091-2. , (2003).</li><li>Holden, J. K., Nguyen, R. H., Francisco, E. M., Zhang, Z., Dennis, R. G., Tommerdahl, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+device+for+the+study+of+somatosensory+information+processing.">A novel device for the study of somatosensory information processing.</a> J Neurosci Methods. 204 (2), 215-220 (2012).</li><li>G&#252;&#231;l&#252;, B., Oztek, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tactile+sensitivity+of+children:+effects+of+frequency,+masking,+and+the+non-Pacinian+I+psychophysical+channel.">Tactile sensitivity of children: effects of frequency, masking, and the non-Pacinian I psychophysical channel.</a> J Exp Child Psychol. 98 (2), 113-130 (2007).</li><li>Cohen, J. C., Makous, J. C., Bolanowski, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Under+which+conditions+do+the+skin+and+probe+decouple+during+sinusoidal+vibrations?.">Under which conditions do the skin and probe decouple during sinusoidal vibrations?.</a> Exp Brain Res. 129 (2), 211-217 (1999).</li><li>Makous, J. C., Gescheider, G. A., Bolanowski, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+static+indentation+on+vibrotactile+threshold.">The effects of static indentation on vibrotactile threshold.</a> J. Acoust. Soc. Am. 99 (5), 3149-3153 (1996).</li><li>Goldreich, D., Kanics, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tactile+Acuity+is+Enhanced+in+Blindness.">Tactile Acuity is Enhanced in Blindness.</a> J. Neurosci. 23 (8), 3439-3445 (2003).</li><li>Peters, R. M., Goldreich, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tactile+Spatial+Acuity+in+Childhood:+Effects+of+Age+and+Fingertip+Size.">Tactile Spatial Acuity in Childhood: Effects of Age and Fingertip Size.</a> PLoS One. 8 (12), (2013).</li><li>Tong, J., Mao, O., Goldreich, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-point+orientation+discrimination+versus+the+traditional+two-point+test+for+tactile+spatial+acuity+assessment.">Two-point orientation discrimination versus the traditional two-point test for tactile spatial acuity assessment.</a> Front Hum Neurosci. 7, 579 (2013).</li><li>Goldreich, D., Wong, M., Peters, R. M., Kanics, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Tactile+Automated+Passive-Finger+Stimulator+(TAPS).">A Tactile Automated Passive-Finger Stimulator (TAPS).</a> J Vis Exp. (28), (2009).</li><li>Coste, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Piezo+proteins+are+pore-forming+subunits+of+mechanically+activated+channels.">Piezo proteins are pore-forming subunits of mechanically activated channels.</a> Nature. 483 (7388), 176-181 (2012).</li><li>Martinez-Salgado, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stomatin+and+Sensory+Neuron+Mechanotransduction.">Stomatin and Sensory Neuron Mechanotransduction.</a> J Neurophysiol. 98 (6), 3802-3808 (2007).</li></ol>

The techniques used to evaluate VDT vary as to device specifications, hardware, and testing protocols. The International Organization for Standardization specifies the methods and procedures to analyze and interpret vibrotactile thresholds including recommendations for the various components of a vibrometer (ISO 13091-1 and 226,27) The described testing system abides to the relevant ISO recommendations for testing frequency range (4-125 Hz), method (variant of up-down staircase and forced choice), probe size (...

Specialized mechanosensory receptors in the skin mediate the perception of vibration and grating orientation. Each mechanosensory receptor type is tuned to detect distinct features of tactile stimuli1,2. This property provides the psychophysical basis for a differentiated assessment of mechanosensory function by using tests that deliver simple sinusoidal oscillations (vibration) or fine gratings. It is known that psychophysical thresholds for vibration perception are lower for high than low frequency vibration3,4. Two types of rapidly adapting mechanoreceptors associated with the Meissner and Pacinian corpuscles primarily detect low (10-40 Hz) and high (100-200 Hz) frequency vibration stimuli, respectively5. It is thought that the psychophysical thresholds for vibration perception rely to a considerable extent on the activation of these two sets of mechanoreceptors at their best frequencies6,7. Tactile spatial acuity is tested by the grating orientation task to determine the finest grating whose orientation can be discriminated by a subject7-9. Merkel cell-neurite complex afferents are essential for detecting grating orientation8,10. Interestingly, there has been considerable recent progress in our understanding of the molecular basis of how mechanoreceptors detect extremely small tactile stimuli11. Mechanosensitive ion channels like Piezo2 and modulators like STOML3 have been directly implicated in the detection of fine tactile stimuli in touch receptors12-15. There are already human patients identified with function altering mutations in the Piezo2 gene and it will be important to test whether such patients have touch deficits16. 
The determination of the vibrotactile threshold relies on the delivery of a vibrating stimulus to the skin. Vibration detection thresholds vary with the vibration frequency. Vibration frequency to detection threshold curves were described by von Bekesey, Verillo, and Bolanowski, among many others, from the 1930s up to the 1990s5,17. The devices in the early days were based on shakers and power amplifiers and several devices have been commercialized and there are a lot of variation as to choice of stimulator (testing frequency), the diameter of the probe in contact with skin, the use of a surround to limit the stimulation to one area of the skin, and the testing protocol that determines the threshold (see the following references for more detailed insight on the device and testing features)18-20. Most devices usually test one site; however, there are new devices that use vertical displacement stimulators equipped with 2 probes to deliver vibratory stimuli with separation ranges that can be varied21. Also detection thresholds are measured based on vibration frequency or intensity discrimination with continuous stimulation; or with intermittent vibration stimuli with or without a masking stimulus. Therefore, we recommend that the reader be aware of the plethora of developments in this field. 
Here, we describe the components of the device and a step-by-step guide on how to conduct psychophysical tests to estimate vibration detection threshold in human subjects. We then show how to assess tactile acuity manually by using the tactile acuity cube. We use a two-interval, forced-choice paradigm: the stimulus is always presented during one of two intervals and the subject has to indicate which interval has the vibration stimulus. We employ a transformed-rule up and down as the adaptive method that executes a threshold search by changing the stimulus intensity based on the performance during the test. Both psychophysical protocols can be used by investigators as a screening tool for evaluation of alterations in touch sensitivity.

<table border="0" cellpadding="0" cellspacing="0" width="1381">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="145">
			<td height="145" style="height:145px;width:115px;">Piezo actuator</td>
			<td style="width:83px;">Physik Instrument, Germany</td>
			<td style="width:221px;">P-602.1L</td>
			<td style="width:411px;">The linear piezoelectric actuator, with integrated position sensor and motion amplifier, contains a piezoceramic material that elongates and contracts when voltage is applied. The piezoelectric actuator travels up to100 &#181;m. The actuator is equipped with a flexure guide that ensures straight motion without tilting or lateral offset. The displacement is linear and calibration is done and checked by the manufacturer. It is recommended that on-axis movement of the probe be checked under the microscope. According to the manufacturer, the stimulus amplitude dampens by less than 20% at oscillating frequencies of 1000 Hz. This can be checked by using a force or displacement measuring device (e.g. force transducer from Kleindiek).</td>
			<td style="width:555px;">The linear piezoelectric actuator, with integrated position sensor and motion amplifier, contains a piezoceramic material that elongates and contracts when voltage is applied. The piezoelectric actuator travels up to100 &#181;m. The actuator is equipped with a flexure guide that ensures straight motion without tilting or lateral offset. The displacement is linear and calibration is done and checked by the manufacturer. It is recommended that on-axis movement of the probe be checked under the microscope. According to the manufacturer, the stimulus amplitude dampens by less than 20% at oscillating frequencies of 1000 Hz. This can be checked by using a force or displacement measuring device (e.g. force transducer from Kleindiek).</td>
		</tr>
		<tr height="547">
			<td height="547" style="height:546px;width:115px;">Piezo Amplifier / Servo Controller</td>
			<td style="width:83px;">Physik Instrument, Germany</td>
			<td style="width:221px;">E-665</td>
			<td style="width:411px;">E-665 amplifier/controller drives and controls the displacement of a low-voltage piezoelectric actuator in a system with sensor position feedback (SGS sensors). The servo-controller provides the option for closed loop operation. When applying sinusoidal and oscillating stimuli the amplitude signal deviates from the set amplitude starting from 500 Hz and reaches a maximum decrease of 20% at 1000Hz.&#160;&#160;</td>
			<td style="width:555px;">E-665 amplifier/controller drives and controls the displacement of a low-voltage piezoelectric actuator in a system with sensor position feedback (SGS sensors). The servo-controller provides the option for closed loop operation. When applying sinusoidal and oscillating stimuli the amplitude signal deviates from the set amplitude starting from 500 Hz and reaches a maximum decrease of 20% at 1000Hz. &#160;</td>
		</tr>
		<tr height="39">
			<td height="57" rowspan="2" style="height:57px;width:115px;">LabChart Software</td>
			<td rowspan="2" style="width:83px;">ADInstruments, USA</td>
			<td style="width:221px;">LabChart 7, MLU60/8</td>
			<td style="width:411px;">Can create, store and run macro of the psychophysical testing algorithm.&#160;</td>
			<td rowspan="2" style="width:555px;">Can create, store and run macro of the psychophysical testing algorithm.&#160;&#160;</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:18px;width:221px;"></td>
			<td style="width:411px;"></td>
		</tr>
		<tr height="17">
			<td height="35" rowspan="2" style="height:35px;width:115px;">PowerLab</td>
			<td rowspan="2" style="width:83px;">ADInstruments, USA</td>
			<td style="width:221px;">PowerLab 4/35 PL3504</td>
			<td rowspan="2" style="width:411px;">Data Acquisition Hardware. Used with LabChart software.</td>
			<td rowspan="2" style="width:555px;">Data Acquisition Hardware. Used with LabChart software.</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:18px;width:221px;"></td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:115px;">Brass bar</td>
			<td style="width:83px;">Custom-made</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">Bar made of pure brass, weighs 15.5Kg. When the peizoelectric actuator is mounted on the brass bar it should exert a force of 30 g weight on skin surface.</td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:115px;">Monitor</td>
			<td style="width:83px;">Custom-made</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">To mark the 1st and the 2nd interval. The monitor indicates to the subject the time intervals during which the stimulus may be presented.</td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:115px;">Response box</td>
			<td style="width:83px;">Custom-made</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">The subject indicates the interval at which stimulus occurred.&#160;</td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:115px;">Board&#160;</td>
			<td style="width:83px;">Custom-made</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">Upper surface should be smooth (Plastic), lower surface made of foam to prevent stray vibration ot be transmitted to the stimulating pobe.&#160;</td>
		</tr>
		<tr height="71">
			<td height="71" style="height:71px;width:115px;">Probe</td>
			<td style="width:83px;">Custom-made</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">A flat circular probe with smoothed edges (thermoplastic material) attached to a screw head. The screw should be of appropriate size to be tightened directly to the moving part of piezoelectric actuator. Size of the probe can be according to preference; in our case, diameter 8.21mm and surface area 52.9mm2.</td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;width:115px;">Labchart Script</td>
			<td style="width:83px;"></td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">Can be sent on request. See supplementary code file.&#160;</td>
		</tr>
		<tr height="51">
			<td height="51" style="height:51px;width:115px;">Tactile Acuity Cube</td>
			<td style="width:83px;">MedCore</td>
			<td style="width:221px;"></td>
			<td colspan="2" style="width:965px;">The cube is comprised of 6 sides each containing a grating (bar and groove) whose widths are 0.75, 1.25, 1.75, 3.0, 4.5, and 6.0 mm.&#160;</td>
		</tr>
	</tbody>
</table>

measurement of vibration detection threshold and tactile spatial acuity in human subjects

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about mechanosensory function that are relevant for clinical diagnosis as well as for basic research. Here, we describe two psychophysical tests designed to determine the vibration detection threshold (automated system) and tactile spatial acuity (handheld device). Both procedures implement a two-interval forced-choice and a transformed-rule up and down experimental paradigm. These tests have been used to obtain mechanosensory profiles for individuals from distinct human cohorts such as twins or people with sensorineural deafness.

The piezoelectric actuator provides the vibration stimulus to the subject. The vibration stimulus has a total duration of 1.8 sec and is presented only once during a trial during the first or second interval (Figure 2A). The rise and fall time at the onset and offset of the stimulus is determined by the functions (1-e-bt)&#8729;Amplitude&#8729;sine(frequency), and (e-bt)&#8729;Amplitude&#8729;sine(frequency), respectively, where b is set at 9.1. The ...

Watch this Scientific Journal Video about Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects at JoVE.com

Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects

Here, we present protocols to determine vibration detection thresholds and tactile acuity using psychophysical methods in man.

Tests that allow the precise determination of psychophysical thresholds for vibration and grating orientation provide valuable information about ...

Research

JoVE Journal

Behavior

Quantitative Assessment of Cortical Auditory-tactile Processing in Children with Disabilities

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology ...

Performing Behavioral Tasks in Subjects with Intracranial Electrodes

Patients having stereo-electroencephalography (SEEG) electrode, subdural grid or depth electrode implants have a multitude of electrodes implanted in ...

Testing Tactile Masking between the Forearms

Masking, in which one stimulus affects the detection of another, is a classic technique that has been used in visual, auditory, and tactile research, ...

Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery

Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug&#39;s pharmacology and identify ...

The (Spatial) Memory Game: Testing the Relationship Between Spatial Language, Object Knowledge, and Spatial Cognition

The Spatial Memory Game: Testing the Relationship Between Spatial Language, Object Knowledge, and Spatial Cognition

The memory game paradigm is a behavioral procedure to explore the relationship between language, spatial memory, and object knowledge. Using two different ...

Whole Body Vibration Methods with Survivors of Polio

The purpose of the original study was to examine the use of whole body vibration (WBV) on polio survivors with and without post-polio syndrome as a form ...

Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile ...

Measurement of Spatial Stability in Precision Grip

The purpose of the protocol is to indirectly evaluate the direction of the finger force during manipulation of a handheld object based on the ...

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

An elevation in cardiac troponin T (cTnT), as a highly specific biomarker of cardiomyocyte damage, after moderate-intensity continuous exercise (MCE) has ...

Tactile Semiautomatic Passive-Finger Angle Stimulator (TSPAS)

Tactile Semiautomatic Passive-Finger Angle Stimulator TSPAS

Passive tactile perception is the ability to passively and statically perceive stimulus information coming from the skin; for example, the ability to ...