Name: testing tactile masking between the forearms
Uploaded: 2016-02-10T15:00:00
Description: Watch this Scientific Journal Video about Testing Tactile Masking between the Forearms at JoVE.com

LRH was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada. SD was partly supported from the NSERC CREATE program.

All of the experiments were approved by the York Ethics board and all participants signed informed consent forms. The experiments were performed in accordance with the Treaty of Helsinki.
1. Stimuli
<ol>
	<li>Tactile Detection Stimulus
	<ol>
		<li>Use a tactor (1.17&#34; diameter and 0.30&#34; thick) to deliver tactile stimuli of 250 Hz vibration for 100 msec. Using a purpose-built tactor provides a linear relationship between the amount of travel and the voltage applied.</li>
		<li>Control ...

<ol>
	<li>von Be&#769;ke&#769;sy, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Sensory Inhibition. , (1967).</li><li>Uttal, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibitory+interaction+of+responses+to+electrical+stimuli+in+the+fingers.">Inhibitory interaction of responses to electrical stimuli in the fingers.</a> J. Comp. Physiol. Psych. 53 (1), 47-51 (1960).</li><li>Schmid, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+aspects+of+cutaneous+interaction+with+two-point+electrical+stimulation.">Temporal aspects of cutaneous interaction with two-point electrical stimulation.</a> J. Exp. Psychol. Gen. 61, 400-409 (1961).</li><li>Abramsky, O., Carmon, A., Bentontt, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Masking+of+and+by+tactile+pressure+stimuli.">Masking of and by tactile pressure stimuli.</a> Percept. Psychophys. 10 (5), 353-355 (1971).</li><li>Sherrick, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+double+simultaneous+stimulation+of+the+skin.">Effects of double simultaneous stimulation of the skin.</a> Am. J. Psychol. 77, 42-53 (1964).</li><li>Gilson, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibrotactile+masking:+effects+of+multiple+maskers.">Vibrotactile masking: effects of multiple maskers.</a> Percept. Psychophys. 95 (4), 2213-2220 (1969).</li><li>Braun, C., Hess, H., Burkhardt, M., W&#252;hle, A., Preissl, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+right+hand+knows+what+the+left+hand+is+feeling.">The right hand knows what the left hand is feeling.</a> Exp. Brain. Res. 162 (3), 366-373 (2005).</li><li>Tam&#232;, L., Farn&#232;, A., Pavani, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+coding+of+touch+at+the+fingers:+Insights+from+double+simultaneous+stimulation+within+and+between.">Spatial coding of touch at the fingers: Insights from double simultaneous stimulation within and between.</a> Neurosci. Lett. 487 (1), 78-82 (2011).</li><li>Tam&#232;, L., Moles, A., Holmes, N. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Within+but+not+between+hands+interactions+in+vibrotactile+detection+thresholds+reflect+somatosensory+receptive+field+organization.">Within but not between hands interactions in vibrotactile detection thresholds reflect somatosensory receptive field organization.</a> Front. Psychol. 5, 1-9 (2014).</li><li>Harris, J. A., Diamond, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ipsilateral+and+contralateral+transfer+of+tactile+learning.">Ipsilateral and contralateral transfer of tactile learning.</a> Neuroreport. 11 (2), 263-266 (2000).</li><li>Fechner, G. 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> Elemente der Psychophysik . , (1860).</li><li>Watson, A., Pelli, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=QUEST-A+Bayesian+adaptive+psychophysical+method.">QUEST-A Bayesian adaptive psychophysical method.</a> Percept. Psychophys. 33, 113-120 (1983).</li><li>D'Amour, S., Harris, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contralateral+tactile+masking+between+forearms.">Contralateral tactile masking between forearms.</a> Exp. Brain. Res. 232 (3), 821-826 (2014).</li><li>D'Amour, S., Harris, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibrotactile+masking+through+the+body.">Vibrotactile masking through the body.</a> Exp. Brain. Res. 232 (9), 2859-2863 (2014).</li><li>Gescheider, G. A., Herman, D. D., Phillips, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Criterion+shifts+in+the+measurement+of+tactile+masking.">Criterion shifts in the measurement of tactile masking.</a> Percept. Psychophys. 8, 433-436 (1970).</li><li>Iwamura, Y., Tanaka, M., Iriki, A., Taoka, M., Toda, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+of+tactile+and+kinesthetic+signals+from+bilateral+sides+of+the+body+in+the+postcentral+gyrus+of+awake+monkeys.">Processing of tactile and kinesthetic signals from bilateral sides of the body in the postcentral gyrus of awake monkeys.</a> Behav. Brain. Res. 135 (1-2), 185-190 (2002).</li><li>Killackey, H. P., Gould, H. J., Cusick, C. G., Pons, T. P., Kaas, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relation+of+corpus+callosum+connections+to+architectonic+fields+and+body+surface+maps+in+sensorimotor+cortex+of+new+and+old+world+monkeys.">The relation of corpus callosum connections to architectonic fields and body surface maps in sensorimotor cortex of new and old world monkeys.</a> J. Comp. Neurol. 219 (4), 384-419 (1983).</li><li>Reed, J. L., Qi, H. X., Kaas, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatiotemporal+properties+of+neuron+response+suppression+in+owl+monkey+primary+somatosensory+cortex+when+stimuli+are+presented+to+both+hands.">Spatiotemporal properties of neuron response suppression in owl monkey primary somatosensory cortex when stimuli are presented to both hands.</a> J. Neurosci. 31 (10), 3589-3601 (2011).</li><li>Hlushchuk, Y., Hari, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transient+suppression+of+ipsilateral+primary+somatosensory+cortex+during+tactile+finger+stimulation.">Transient suppression of ipsilateral primary somatosensory cortex during tactile finger stimulation.</a> J. Neurosci. 26 (21), 5819-5824 (2006).</li><li>Nihashi, T., 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=Contralateral+and+ipsilateral+responses+in+primary+somatosensory+cortex+following+electrical+median+nerve+stimulation--an+fMRI+study.">Contralateral and ipsilateral responses in primary somatosensory cortex following electrical median nerve stimulation--an fMRI study.</a> Clin. Neurophysiol. 116 (4), 842-848 (2005).</li><li>Tam&#232;, L., 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=The+contribution+of+primary+and+secondary+somatosensory+cortices+to+the+representation+of+body+parts+and+body+sides:+an+fMRI+adaptation+study.">The contribution of primary and secondary somatosensory cortices to the representation of body parts and body sides: an fMRI adaptation study.</a> J. Cognitive. Neurosci. 24 (12), 2306-2320 (2012).</li><li>Tam&#232;, L., Farn&#232;, A., Pavani, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+of+the+body+and+the+differentiation+of+perceived+body+side+in+touch.">Vision of the body and the differentiation of perceived body side in touch.</a> Cortex. 49 (5), 1340-1351 (2013).</li><li>Tam&#232;, L., Pavani, F., Papadelis, C., Farn&#232;, A., Braun, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+integration+of+bilateral+touch+in+the+primary+somatosensory+cortex.">Early integration of bilateral touch in the primary somatosensory cortex.</a> Hum. Brain. Mapp. 36 (4), 1506-1523 (2015).</li><li>Gilson, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibrotactile+masking:+Some+spatial+and+temporal+aspects.">Vibrotactile masking: Some spatial and temporal aspects.</a> Percept. Psychophys. 5 (3), 176-180 (1969).</li><li>Alliusi, E., Morgan, B., Hawkes, 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=Masking+of+cutaneous+sensations+in+multiple+stimulus+presentations.">Masking of cutaneous sensations in multiple stimulus presentations.</a> Percept. Motor. Skill. 20, 39-45 (1965).</li><li>Geldard, F. A., Sherrick, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+cutaneous+stimulation:+The+discrimination+of+vibratory+patterns.">Multiple cutaneous stimulation: The discrimination of vibratory patterns.</a> J. Acoust. Soc. Am. 37, 797-801 (1965).</li><li>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=Vibrotactile+loudness+addition.">Vibrotactile loudness addition.</a> Percept. Psychophys. 1, 185-190 (1966).</li></ol>

Here, a detailed protocol for contralateral tactile masking is described and previously published results using the technique to test tactile detection thresholds are shown. The advantage of this method is that thresholds are measured using a psychophysically rigorous technique. The two-alternative forced choice (2AFC) procedure is relatively insensitive to response bias and therefore from attentional effects. The adaptive staircase procedure for honing in on the actual threshold value is very efficient as most of the da...

Tactile masking is where a tactile stimulus at one location on the body alters the perception of a touch at another location. This is a technique pioneered by von Bekesy1to reveal location interactions, especially lateral inhibition, between areas of skin that are adjacent on the body surface. While tactile masking has been studied extensively over the years, research has mainly investigated ipsilateral tactile masking using electrical stimulation2,3, pressure4, and vibrotactile stimulation5,6. In contrast, few studies have looked at contralateral tactile masking in which the masking and probe sites may be far removed. Long-range tactile masking effects have been shown between mirror-symmetric points on the hand and arm5,7-9but these studies have been largely restricted to looking at the hands and fingers7,10, with more extensive parts of the whole body being largely ignored. A goal of such long-range masking experiments is to indicate how components of the body&#39;s representation in the brain may be functionally linked. Here, the phenomenon of long-range tactile masking is explored by investigating how vibration applied to one forearm might affect tactile sensitivity thresholds on the opposite forearm. Threshold refers to the minimum stimulus that is needed to detect a stimulus. We define this as the intensity at which the stimulus is detected 75% of the time. We used a tactile masking technique in which tactile sensitivity (the reciprocal of threshold) on one forearm is measured in the presence of a vibrating stimulus (the mask) on another part of the body. Effective masking is revealed by an increase in the detection threshold i.e., a reduction in sensitivity. The technique can be used in conjunction with other manipulations such as varying limb position or movement to explore their effects on the effectiveness of masking.
Here we used vibrotactile stimuli as the masking stimulus. The advantage of this is that the frequency, and hence the receptor type that it stimulates can be controlled. The technique could be extended to look at pain using electrical stimuli as the probe or mask or both. Also, any site can be used as the masking site allowing the investigation of acupuncture sites for example.

<table border="0" cellpadding="0" cellspacing="0" width="673">
	<tbody>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">C-2 tactor</td>
			<td style="width:127px;">ATAC Technology; Engineering Acoustics, Inc.</td>
			<td style="width:164px;"></td>
			<td style="width:167px;">http://www.atactech.com/PR_tactors.html</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Magic Wand</td>
			<td style="width:127px;">Hitachi</td>
			<td style="width:164px;"></td>
			<td style="width:167px;">http://magicwandoriginal.com/magic-wand-original/</td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:216px;">FC5 Foot Pedals</td>
			<td style="width:127px;">Yamaha Corporation</td>
			<td style="width:164px;"></td>
			<td style="width:167px;">http://ca.yamaha.com/en/products/music-production/accessories/footpedals/fc5/?mode=model</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">MATLAB</td>
			<td style="width:127px;">The Mathworks, Inc.</td>
			<td style="width:164px;"></td>
			<td style="width:167px;">http://www.mathworks.com/products/matlab/</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Velcro</td>
			<td style="width:127px;">Velcro Industries B.V.</td>
			<td style="width:164px;"></td>
			<td>http://www.velcro.com/</td>
		</tr>
	</tbody>
</table>

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, 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.

Analyses of the data was reported in13. Tactile sensitivity (expressed relative to the thresholds measured in the control condition) on the forearm was significantly reduced (thresholds were significantly increased) when vibrotactile masking stimulation was applied to the opposite arm (Figure 2A), demonstrating a contralateral masking effect between forearms. The effect depended on the position of the masking stimulus on the masking arm, with the largest effect...

Watch this Scientific Journal Video about Testing Tactile Masking between the Forearms at JoVE.com

Testing Tactile Masking between the Forearms

Here we explore contralateral tactile masking between the forearms in which tactile detection thresholds are modulated by vibration applied to a remote site. The details of which remote sites have an effect can tell us about how the body is represented in the brain.

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

The overall goal of this psycho-physical experiment is to show how touching one place can affect the perception of a touch at another location. This technique of long-range tactile masking can make important contributions to the field of perception. For example, it can tell us how the brain represents the body's surface.An advantage of this technique is that it is non-invasive, and yet, even though it's a perceptual measure, it can tell us information about how the brain is wired up. Demonstrating this technique will be Sarah. She's a graduate student in my lab, and she developed the techniques that we're demonstrating today as part of her master's thesis.Begin by preparing the tactile detection stimulus system that will be used during this experiment. Use a tactor with a 1.7 inch diameter and 0.30 inch thickness to deliver tactile stimuli with 250 hertz vibration for 100 milliseconds. Also use a 64 bit stereo sound card to control the tactile stimulus delivery.To do this, first connect a stereo audio amplifier to the sound card that will drive the tactor as a loud speaker. Next, connect the tactor to one of the outputs of the amplifier, such as the left speaker out. Then, connect the second channel to a loudspeaker to provide auditory signals.In the computer code that is controlling the experiment, generate the waveform that will be used to vibrate the tactor, and another waveform for the auditory signal. Put each of these two waveforms into a two-dimensional array. Attach the tactor to a strap with a mechanical base fastener so that it can be placed on the participant.For the masking stimulus, use an electric handheld vibrator with a four centimeter diameter, with 83 hertz vibration when set on low. Select the sites where the stimulus is to be applied based on the areas where masking is to be tested. After the tactile detection stimulus system is ready, arrange the computer and other equipment for the experiment on a desk with a chair in front of it for the experimenter.Then, set up a table on which participants will rest their left arm, where tactile stimuli will be applied, and place a chair to the right side of the table. Also place an armrest stand next to the chair, on which the participants rest their right elbow. Add cushioning to the table, and an armrest for comfort.Next, place the loudspeaker on a mechanically isolated surface. Arrange foot pedals that are connected to the left and right buttons of a computer mouse so that the participant's feet can rest comfortably on them. Be sure to make a list of the order in which the conditions will be run, and use this list during the experiment to determine where to hold the masking stimulus for each block.Enter the number of trials into the computer program code and ensure that each block is no longer than 10 minutes to maintain the participant's attention. Program a two alternative forced choice tactile detection task in which stimulus intensity is controlled with Bayesian adaptive psycho-physical staircase psychometric procedure. For each trial, present two one second intervals, marked by three beeps, with a tactile stimulus presented in the middle of one of the intervals.Have the participant indicate in which interval the stimulus was presented by means of the foot pedals. The computer scores the response as correct or wrong, and the adaptive staircase chooses the next value to be presented accordingly. This determines a threshold value for detecting vibration at the test site.Prior to the experiment, obtain written informed consent from the participant. Then, seat them in the chair with their feet resting comfortably on the response foot pedals and explain the experimental procedure. Measure and record the length of the particpant's dorsal surface of the left forearm.Then, apply the strap so the tactor is positioned in the middle of the arm, halfway between the inner angle of the elbow and the wrist crease. Wrap a tensor bandage loosely around the arm several times to hold the tactor in place. Now, instruct the participant to place their right elbow on the arm rest, and rest their left arm on the table.Then, blindfold the participant to prevent them from looking at the stimulus or the masking location, and instruct them to look straight ahead throughout the experiment. Start with a block of 20 practice trials without the masking stimulus, in order to familiarize the participant with the tactile detection task, and to allow them to become familiar with the stimuli. Following the practice run, first ensure that the arms and the masking stimulus are in the correct positions prior to each experimental block.Run the blocks of conditions in a random, counter balanced order. For each condition, refer to the list of conditions made earlier, and cross off each condition as it is run. Be sure to hold the masking stimulus throughout each block of data collection trials, maintaining approximately constant pressure.Run the experimental program with the set number of trials as previously selected, and introduce a two minute rest period after each short trial block. After a given trial block is completed, select the next site for the masking stimulus, and run the program again, and repeat this until all trials are completed. In this figure, the elevation and threshold is plotted as a function of the position of the mask.Tactile sensitivity on the forearm was significantly reduced when vibro-tactile masking stimulation was applied to the opposite arm, demonstrating a contralateral masking effect between forearms. Here, these data show that posture also plays a role on the effectiveness of masking. The masking effect was considerably stronger when the arms were touching, compared to when they were parallel.Once mastered, this technique can be done in about half an hour if it's performed properly. Although it's necessary to repeat the experiment on at least ten participants to obtain statistical validity. While attempting this procedure, it's important to remember to maintain the pressure at the masking site and to keep the participant's attention at a location that does not vary, usually straight ahead.Following the procedure, variations can be performed in order to answer additional questions, such as the dependency of these effects on the characteristics of the masking stimulus. After its development, this technique has paved the way for researchers in the field of tactile research to explore whether this phenomenon might generalize to more than just touch sensations, but also pain. After watching this video, you should have a good understanding of how to test the influence of remote tactile stimulus on touch perception at a specific site.

testing-tactile-masking-between-the-forearms

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 to quantitatively assess children&#39;s cortical processing of light touch, speech sounds and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing children discomfort. To accomplish this we developed a dual channel, time and strength calibrated air puff stimulator that allows both tactile stimulation and sham control. We combined this with the use of event-related potential methodology to allow for high temporal resolution of signals from the primary and secondary somatosensory cortices as well as higher order processing. This methodology also allowed us to measure a multisensory response to auditory-tactile stimulation.

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology to quantitatively assess infants and children&#39;s cortical processing of light touch, speech sounds, and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing discomfort in vulnerable patients.

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

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.

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 ...

A Mouse Model of Subchronic and Mild Social Defeat Stress for Understanding Stress-induced Behavioral and Physiological Deficits

Stressful life events often increase the incidence of depression in humans. To study the mechanisms of depression, the development of animal models of depression is essential. Because there are several types of depression, various animal models are needed for a deeper understanding of the disorder. Previously, a mouse model of subchronic and mild social defeat stress (sCSDS) using a modified chronic social defeat stress (CSDS) paradigm was established. In the paradigm, to reduce physical injuries from aggressors, the duration of physical contact between the aggressor and a subordinate was reduced compared to in the original CSDS paradigm. sCSDS mice showed increased body weight gain, food intake, and water intake during the stress period, and their social behaviors were suppressed after the stress period. In terms of the face validity of the stress-induced overeating and overdrinking following the increased body weight gain, the sCSDS mice may show some features related to atypical depression in humans. Thus, a mouse model of sCSDS may be useful for studying the pathogenic mechanisms underlying depression. This protocol will help establish the sCSDS mouse model, especially for studying the mechanisms underlying stress-induced weight gain and polydipsia- and hyperphagia-like symptoms.

Here, methods for developing a mouse model of subchronic and mild social defeat stress are described and used to investigate the pathogenic features of depression including hyperphagia- and polydipsia-like symptoms following increased body weight.

Stressful life events often increase the incidence of depression in humans. To study the mechanisms of depression, the development of animal models of ...

Comparing the Frequency Effect Between the Lexical Decision and Naming Tasks in Chinese

In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. Usually, only one of those tasks is chosen to examine lexical access in a study. Using two exemplar experiments, this paper introduces an approach to include both the lexical decision task and the naming task in a study. In the first experiment, the stimuli were Chinese characters with frequency and regularity manipulated. In the second experiment, the stimuli were switched to Chinese two-character words, in which the word frequency and the regularity of the leading character were manipulated. The logic of these two exemplar experiments was to explore some important issues such as the role of phonology on recognition by comparing the frequency effect between both the tasks. The results revealed different patterns of lexical access from those reported in the alphabetic systems. The results of Experiment 1 manifested a larger frequency effect in the naming task as compared to the LDT, when the stimuli were Chinese characters. And it is noteworthy that, in Experiment 1, when the stimuli were regular Chinese characters, the frequency effect observed in the naming task was roughly equivalent to that in the LDT. However, a smaller frequency effect was shown in the naming task as compared to the LDT, when the stimuli were switched to Chinese two-character words in Experiment 2. Taking advantage of the respective demands and characteristics in both tasks, researchers can obtain a more complete and precise picture of character/word recognition.

Researchers adopt both the lexical decision task and the naming task to investigate some important topics such as character/word recognition by comparing the frequency effect between these two tasks. This article introduces this approach through two exemplar experiments and elaborates on the underlying logic.

In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. ...

Using Wavelet Entropy to Demonstrate how Mindfulness Practice Increases Coordination between Irregular Cerebral and Cardiac Activities

In both the East and West, traditional teachings say that the mind and heart are somehow closely correlated, especially during spiritual practice. One difficulty in proving this objectively is that the natures of brain and heart activities are quite different. In this paper, we propose a methodology that uses wavelet entropy to measure the chaotic levels of both electroencephalogram (EEG) and electrocardiogram (ECG) data and show how this may be used to explore the potential coordination between the mind and heart under different experimental conditions. Furthermore, Statistical Parametric Mapping (SPM) was used to identify the brain regions in which the EEG wavelet entropy was the most affected by the experimental conditions. As an illustration, the EEG and ECG were recorded under two different conditions (normal rest and mindful breathing) at the beginning of an 8-week standard Mindfulness-based Stress Reduction (MBSR) training course (pretest) and after the course (posttest). Using the proposed method, the results consistently showed that the wavelet entropy of the brain EEG decreased during the MBSR mindful breathing state as compared to that during the closed-eye resting state. Similarly, a lower wavelet entropy of heartrate was found during MBSR mindful breathing. However, no difference in wavelet entropy during MBSR mindful breathing was found between the pretest and posttest. No correlation was observed between the entropy of brain waves and the entropy of heartrate during normal rest in all participants, whereas a significant correlation was observed during MBSR mindful breathing. Additionally, the most well-correlated brain regions were located in the central areas of the brain. This study provides a methodology for the establishment of evidence that mindfulness practice (i.e., mindful breathing) may increase the coordination between mind and heart activities.

This manuscript describes how to use the wavelet entropy index to analyze high-density electroencephalography (EEG) and electrocardiography (ECG) data. We show that the irregularity of cerebral and cardiac activities became more coordinated during mindfulness-based stress reduction practice.

In both the East and West, traditional teachings say that the mind and heart are somehow closely correlated, especially during spiritual practice. One ...

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 versions of the paradigm, spatial language use and memory for object location are tested under different, experimentally manipulated conditions. This allows us to tease apart proposed models explaining the influence of object knowledge on spatial language (e.g., spatial demonstratives), and spatial memory, as well as understanding the parameters that affect demonstrative choice and spatial memory more broadly. Key to the development of the method was the need to collect data on language use (e.g., spatial demonstratives: &#34;this/that&#34;) and spatial memory data under strictly controlled conditions, while retaining a degree of ecological validity. The language version (section 3.1) of the memory game tests how conditions affect language use. Participants refer verbally to objects placed at different locations (e.g., using spatial demonstratives: &#34;this/that red circle&#34;). Different parameters can be experimentally manipulated: the distance from the participant, the position of a conspecific, and for example whether the participant owns, knows, or sees the object while referring to it. The same parameters can be manipulated in the memory version of the memory game (section 3.2). This version tests the effects of the different conditions on object-location memory. Following object placement, participants get 10 seconds to memorize the object&#39;s location. After the object and location cues are removed, participants verbally direct the experimenter to move a stick to indicate where the object was. The difference between the memorized and the actual location shows the direction and strength of the memory error, allowing comparisons between the influences of the respective parameters.

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

We present a protocol to explore the relationship between spatial language production, spatial memory, and object knowledge. The procedure allows experimental manipulation of, and control over, conditions of object knowledge, language at instruction, and physical location, thus teasing apart cognitive and linguistic models describing interactions between these variables.

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

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 feedback (VTF). This protocol aims to test the effect of VTF on the response to incongruent visual-tactile stimuli. The tactile feedback is acquired by grasping a block and moving it across a partition. The visual feedback is a real-time virtual presentation of the moving block, acquired using a motion capture system. The congruent feedback is the reliable presentation of the movement of the block, so that the subject feels that the block is grasped and see it move along with the path of the hand. The incongruent feedback appears as the movement of the block diverts from the actual movement path, so that it seems to drop from the hand when it is actually still held by the subject, thereby contradicting the tactile feedback. Twenty subjects (age 30.2 &#177; 16.3) repeated 16 block transfers, while their hand was hidden. These were repeated with VTF and without VTF (total of 32 block transfers). Incongruent stimuli were presented randomly twice within the 16 repetitions in each condition (with and without VTF). Each subject was asked to rate the difficulty level of performing the task with and without the VTF. There were no statistically significant differences in the length of the hand paths and durations between transfers recorded with congruent and incongruent visual-tactile signals &#8211; with and without the VTF. The perceived difficulty level of performing the task with the VTF significantly correlated with the normalized path length of the block with VTF (r = 0.675, p = 0.002). This setup is used to quantify the additive or reductive value of VTF during motor function that involves incongruent visual-tactile stimuli. Possible applications are prosthetics design, smart sport-wear, or any other garments that incorporate VTF.

We present a protocol to apply incongruent visual-tactile stimuli during an object transfer task. Specifically, during block transfers, performed while the hand is hidden, a virtual presentation of the block shows random occurrences of false block drops. The protocol also describes adding vibrotactile feedback while performing the motor task.

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

Human Circadian Phenotyping and Diurnal Performance Testing in the Real World

In our continuously developing &#39;around the clock&#39; society, there is a need to increase our understanding of how changes in biology, physiology and psychology influence our health and performance. Embedded within this challenge, is the increasing need to account for individual differences in sleep and circadian rhythms, as well as to explore the impact of time of day on performance in the real world. There are a number of ways to measure sleep and circadian rhythms from subjective questionnaire-based methods to objective sleep/wake monitoring, actigraphy and analysis of biological samples. This paper proposes a protocol that combines multiple techniques to categorize individuals into Early, Intermediate or Late circadian phenotype groups (ECPs/ICPs/LCPs) and recommends how to conduct diurnal performance testing in the field. Representative results show large differences in rest-activity patterns derived from actigraphy, circadian phase (dim light melatonin onset and peak time of cortisol awakening response) between circadian phenotypes. In addition, significant differences in diurnal performance rhythms between ECPs and LCPs emphasizes the need to account for circadian phenotype. In summary, despite the difficulties in controlling influencing factors, this protocol allows a real-world assessment of the impact of circadian phenotype on performance. This paper presents a simple method to assess circadian phenotype in the field and supports the need to consider time of day when designing performance studies.

Here, we present a method to investigate diurnal rhythms in performance following accurate categorization of participants into circadian phenotype groups based on the Munich ChronoType Questionnaire, gold standard circadian phase biomarkers and actigraphic measures.

In our continuously developing &#39;around the clock&#39; society, there is a need to increase our understanding of how changes in biology, physiology and ...

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 sense spatial information is the strongest in the skin on the hands. This ability is termed tactile spatial acuity, and is measured by the tactile threshold or discrimination threshold. At present, the two-point threshold is extensively used as a measure of tactile spatial acuity, although many studies have indicated that critical deficits exist in two-point discrimination. Therefore, a computer-controlled tactile stimulus system was developed, the tactile semiautomated passive-finger angle stimulator (TSPAS), using the tactile angle discrimination threshold as a new measure for tactile spatial acuity. The TSPAS is a simple, easily operated system that applies raised angle stimuli to a subject&#39;s passive fingerpad, while controlling movement speed, distance, and contact duration. The components of the TSPAS are described in detail as well as the procedure to calculate the tactile angle discrimination threshold.

Tactile Semiautomatic Passive-Finger Angle Stimulator TSPAS

Presented is the tactile semiautomated passive-finger angle stimulator TSPAS, a new way to assess tactile spatial acuity and tactile angle discrimination using a computer-controlled tactile stimulus system that applies raised angle stimuli to a subject&#39;s passive fingerpad, while controlling for movement speed, distance, and contact duration.

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

Tactile Vibrating Toolkit and Driving Simulation Platform for Driving-Related Research

Collision warning system plays a key role in the prevention of driving distractions and drowsy driving. Previous studies have proven the advantages of tactile warnings in reducing driver&#8217;s brake response time. At the same time, tactile warnings have been proved effective in take-over request (TOR) for partially autonomous vehicles.
How the performance of tactile warnings can be optimized is an ongoing hot research topic in this field. Thus, the presented low-cost driving simulation software and methods are introduced to attract more researchers to take part in the investigation. The presented protocol has been divided into five sections: 1) participants, 2) driving simulation software configuration, 3) driving simulator preparation, 4) vibrating toolkit configuration and preparation, and 5) conducting the experiment.
In the exemplar study, participants wore the tactile vibrating toolkit and performed an established car-following task using the customized driving simulation software. The front vehicle braked intermittently, and vibrating warnings were delivered whenever the front vehicle was braking. Participants were instructed to respond as quickly as possible to the sudden brakes of the front vehicle. Driving dynamics, such as the brake response time and brake response rate, were recorded by the simulation software for data analysis.
The presented protocol offers insight into the exploration of the effectiveness of tactile warnings on different body locations. In addition to the car-following task that is demonstrated in the exemplar experiment, this protocol also provides options&#160;to apply other paradigms to the driving simulation studies by making simple software configuration without any code development. However, it is important to note that due to its affordable price, the driving simulation software and hardware introduced here may not be able to fully compete with other high-fidelity commercial driving simulators. Nevertheless, this protocol can act as an affordable and user-friendly alternative to the general high-fidelity commercial driving simulators.

This protocol describes a driving simulation platform and a tactile vibrating toolkit for the investigation of driving-related research. An exemplar experiment exploring the effectiveness of tactile warnings is also presented.&#160;

Collision warning system plays a key role in the prevention of driving distractions and drowsy driving. Previous studies have proven the advantages of ...