We acknowledge all the participants, volunteers, and others involved in the study. We are grateful to Sandra Stolzenbach W&#230;hrens and Wender Bredie (University of Copenhagen) for designing the squares used in the present gratings orientation test. This research was funded by the University of Milan, Piano di sostegno alla ricerca 2018.

An informed, written consent has been signed by all participants. This study was approved by the Ethics Committee of the University of Milan (n. 48/19) and conducted in accordance with the Declaration of Helsinki.
1. Training of experimenters
<ol>
	<li>Take the grating tool and apply a force of 100 g on a sponge placed on a scale. 
	NOTE: Refer to Figure 1 for the schematic of the grating tool used in this study</li>
	<li>Repeat this procedure at least 10 times to reduce variation in the force applied by the grating on the subjects&#39; tongues during testing, both within and across experimenters.</li>
</ol>
2. Assessment procedure
NOTE: Conduct the assessment of tactile acuity following the required health and safety standard to guarantee the subject&#39;s safety (e.g., mask, gloves, and lab coat).
<ol>
	<li>Display all gratings (0.20 mm, 0.25 mm, 0.50 mm, 0.75 mm, 1.00 mm, 1.25 mm) (Figure 2) on a table out of sight of the participant.</li>
	<li>Seat the participant in a comfortable chair and inform them that they can leave the experiment at any time.</li>
	<li>Inform the participant that they will be blindfolded during the experiment and asked to stick out their tongue in a comfortable and relaxed way.</li>
	<li>Prior to the beginning of the experiment, familiarize the subjects with the procedure using the largest grating (1.25 mm) to demonstrate the force applied (100 g for 3 s).</li>
	<li>Notify the participants that they can take a sip of water whenever deemed appropriate.</li>
	<li>Apply each grating onto the subjects&#39; tongue (anterior region of the tongue just around the midline).</li>
	<li>After each touch, ask the subjects to indicate, using their hands, the tool&#39;s orientation (either horizontal or vertical) and their degree of sureness (sure, unsure). Subjects must guess if they do not know.</li>
	<li>After each touch, record all the answers (horizontal, vertical, sure, not sure) for each subject on a spreadsheet (Supplemental Table 1).</li>
	<li>Repeat each grating as many times as deemed necessary for the R-Index cut-off selected, for instance, 6 times, 3 horizontally, and 3 vertically (Supplemental Table 1).</li>
	<li>Sterilize each grating after testing each participant (refer to section 4). 
	NOTE: The tongue should protrude gently from the mouth without effort by the volunteers to avoid excessive fatigue, which would lead to an alteration in their performance results. It is important to note that the higher the repetitions by grating, the more reliable the measurement16.</li>
</ol>
3. Cleaning protocol
<ol>
	<li>Prepare a solution consisting of 20 mL of sodium hypochlorite (see Table of Materials) diluted in 1 L of water according to the manufacturer&#39;s instructions.</li>
	<li>Manually shake the solution for a few seconds.</li>
	<li>Fill 6 cups with approximately 20 mL of the disinfectant solution to fully immerse each tool in the solution.</li>
	<li>Place each tool in the corresponding cup.</li>
	<li>Let the tools soak for 15-20 min.</li>
	<li>Rinse the tools with plenty of water according to the manufacturer&#39;s instructions and scrub them with a toothbrush to ensure removing any sodium hypochlorite residue.</li>
	<li>Allow the tools to air dry.</li>
</ol>
4. R-index calculation
<ol>
	<li>Create a response matrix for each volunteer and for all the tools (Figure 3) based on the response frequencies used to calculate the R-index using the following equation: 
	<img alt="Equation 1" src="/files/ftp_upload/62898/62898eq01.jpg" /> 
	NOTE: R-index expresses individual tactile sensitivity for each tool16. R- index is based on SDT17 and represents an estimated probability of discerning a target stimulus (i.e., the signal) from an alternative stimulus (i.e., the noise). The signal and the noise correspond to the correct or incorrect identification of the horizontal-vertical orientation of the grating. Four response options for both signal and noise can occur: &#34;horizontal-sure&#34;, &#34;horizontal-unsure&#34;, &#34;vertical-unsure&#34; and &#34;vertical-sure&#34;16. R-index values range between 0-1. A higher R-index value indicates better discrimination.</li>
</ol>
5. Sensitivity and threshold determination by the R-index estimates
<ol>
	<li>To determine whether a subject can discriminate the orientation of each tool, calculate the cut-off using a table of critical values for R-index significance tests18 
	NOTE: Considering the present example, corresponding to 36 presentations (i.e., each grating presented 6 times, 3 horizontal and 3 vertical), the cut-off value for discrimination is set to 0.7426 according to the one-sided R-index critical values for &#945; = 0.0518.</li>
	<li>If a sufficiently high number of tools is used (e.g., six different grating dimensions)19, derive R-index threshold estimations.</li>
	<li>To calculate the threshold for each subject, interpolate the two R-indices immediately below and above of the cut-off value20.</li>
</ol>

<ol>
	<li>Guinard, J. X., Mazzucchelli, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sensory+perception+of+texture+and+mouthfeel.">The sensory perception of texture and mouthfeel.</a> Trends in Food Science &amp; Technology. 7 (7), 213-219 (1996).</li><li>Jeltema, M., Beckley, J., Vahalik, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Food+texture+assessment+and+preference+based+on+mouth+behavior.">Food texture assessment and preference based on mouth behavior.</a> Food Quality and Preference. 52, 160-171 (2016).</li><li>Scott, C. L., Downey, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Types+of+food+aversions:+animal,+vegetable,+and+texture.">Types of food aversions: animal, vegetable, and texture.</a> The Journal of Psychology. 141 (2), 127-134 (2007).</li><li>Laureati, 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=Individual+differences+in+texture+preferences+among+European+children:+Development+and+validation+of+the+Child+Food+Texture+Preference+Questionnaire+(CFTPQ).">Individual differences in texture preferences among European children: Development and validation of the Child Food Texture Preference Questionnaire (CFTPQ).</a> Food Quality and Preference. 80, 103828 (2020).</li><li>de Lavergne, M. D., Derks, J. A., Ketel, E. C., de Wijk, R. A., Stieger, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eating+behaviour+explains+differences+between+individuals+in+dynamic+texture+perception+of+sausages.">Eating behaviour explains differences between individuals in dynamic texture perception of sausages.</a> Food Quality and Preference. 41, 189-200 (2015).</li><li>Engelen, L., de Wijk, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+processing+and+texture+perception.">Oral processing and texture perception.</a> Food Oral Processing: Fundamentals of Eating and Sensory Perception. 8, 157-176 (2012).</li><li>Stokes, J. R., Boehm, M. W., Baier, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+processing,+texture+and+mouthfeel:+From+rheology+to+tribology+and+beyond.">Oral processing, texture and mouthfeel: From rheology to tribology and beyond.</a> Current Opinion in Colloid &amp; Interface Science. 18 (4), 349-359 (2013).</li><li>Engelen, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+receptors.">Oral receptors.</a> Food Oral Processing: Fundamentals of Eating and Sensory Perception. , 15-38 (2012).</li><li>Yackinous, C., Guinard, J. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relation+between+PROP+taster+status+and+fat+perception,+touch,+and+olfaction.">Relation between PROP taster status and fat perception, touch, and olfaction.</a> Physiology &amp; Behavior. 72 (3), 427-437 (2001).</li><li>Etter, N. M., Breen, S. P., Alcala, M. I., Ziegler, G. R., Hayes, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+midline+lingual+point-pressure+somatosensation+using+Von+Frey+hair+monofilaments.">Assessment of midline lingual point-pressure somatosensation using Von Frey hair monofilaments.</a> Journal of Visualized Experiments: JoVE. (156), (2020).</li><li>Essick, G. K., Chen, C. C., Kelly, D. 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+letter-recognition+task+to+assess+lingual+tactile+acuity.">A letter-recognition task to assess lingual tactile acuity.</a> Journal of Oral and Maxillofacial Surgery. 57 (11), 1324-1330 (1999).</li><li>Essick, G. K., Chopra, A., Guest, S., McGlone, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lingual+tactile+acuity,+taste+perception,+and+the+density+and+diameter+of+fungiform+papillae+in+female+subjects.">Lingual tactile acuity, taste perception, and the density and diameter of fungiform papillae in female subjects.</a> Physiology &amp; Behavior. 80 (2-3), 289-302 (2003).</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 (1994).</li><li>Moritz, J., Turk, P., Williams, J. D., Stone-Roy, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perceived+intensity+and+discrimination+ability+for+lingual+electrotactile+stimulation+depends+on+location+and+orientation+of+electrodes.">Perceived intensity and discrimination ability for lingual electrotactile stimulation depends on location and orientation of electrodes.</a> Frontiers in Human Neuroscience. 11, 186 (2017).</li><li>Bach-y-Rita, P., Kaczmarek, K. A., Tyler, M. E., Garcia-Lara, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Form+perception+with+a+49-point+electrotactile+stimulus+array+on+the+tongue:+a+technical+note.">Form perception with a 49-point electrotactile stimulus array on the tongue: a technical note.</a> Journal Of Rehabilitation Research and Development. 35, 427-430 (1998).</li><li>O'Mahony, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+discrimination+tests:+A+user-friendly+treatment+of+response+bias,+rating+and+ranking+R-index+tests+and+their+relationship+to+signal+detection.">Understanding discrimination tests: A user-friendly treatment of response bias, rating and ranking R-index tests and their relationship to signal detection.</a> Journal of Sensory Studies. 7 (1), 1-47 (1992).</li><li>Lee, H. S., Van Hout, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantification+of+sensory+and+food+quality:+The+R-index+analysis.">Quantification of sensory and food quality: The R-index analysis.</a> Journal of Food Science. 74 (6), 57-64 (2009).</li><li>Bi, J., O'Mahony, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Updated+and+extended+table+for+testing+the+significance+of+the+R-index.">Updated and extended table for testing the significance of the R-index.</a> Journal of Sensory Studies. 22, 713-720 (2007).</li><li>Bertoli, 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=Taste+sensitivity,+nutritional+status+and+metabolic+syndrome:+Implication+in+weight+loss+dietary+interventions.">Taste sensitivity, nutritional status and metabolic syndrome: Implication in weight loss dietary interventions.</a> World Journal of Diabetes. 5 (5), 717 (2014).</li><li>Robinson, K. M., Klein, B. P., Lee, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utilizing+the+R-index+measure+for+threshold+testing+in+model+caffeine+solutions.">Utilizing the R-index measure for threshold testing in model caffeine solutions.</a> Food Quality and Preference. 16 (4), 283-289 (2005).</li><li>Appiani, M., Rabitti, N. S., Methven, L., Cattaneo, C., Laureati, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+lingual+tactile+sensitivity+in+children+and+adults:+Methodological+suitability+and+challenges.">Assessment of lingual tactile sensitivity in children and adults: Methodological suitability and challenges.</a> Foods. 9 (11), 1594 (2020).</li><li>Cattaneo, C., Liu, J., Bech, A. C., Pagliarini, E., Bredie, W. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cross-cultural+differences+in+lingual+tactile+acuity,+taste+sensitivity+phenotypical+markers,+and+preferred+oral+processing+behaviors.">Cross-cultural differences in lingual tactile acuity, taste sensitivity phenotypical markers, and preferred oral processing behaviors.</a> Food Quality and Preference. 80, 103803 (2020).</li><li>Abraira, V. E., Ginty, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sensory+neurons+of+touch.">The sensory neurons of touch.</a> Neuron. 79 (4), 618-639 (2013).</li><li>Johnson, K. O., Phillips, J. R. <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+resolution.+I.+Two-point+discrimination,+gap+detection,+grating+resolution,+and+letter+recognition.">Tactile spatial resolution. I. Two-point discrimination, gap detection, grating resolution, and letter recognition.</a> Journal of Neurophysiology. 46 (6), 1177-1192 (1981).</li><li>Phillips, J. R., 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=Tactile+spatial+resolution.+II.+Neural+representation+of+bars,+edges,+and+gratings+in+monkey+primary+afferents.">Tactile spatial resolution. II. Neural representation of bars, edges, and gratings in monkey primary afferents.</a> Journal of Neurophysiology. 46 (6), 1192-1203 (1981).</li></ol>

The authors have nothing to disclose.

Few valid instruments are available for measuring tactile acuity10,11,13,22. Von Frey filaments have been shown to be an adequate method for measuring both skin and oral tactile acuity10,21,22. However, these instruments measure a different dimension of lingual tactile acuity than the gratings orientat...

The texture and mouthfeel of food play an important role in liking1,2,3,4, and while research has found differences in texture perception due to factors such as chewing behavior2,5,&#160;saliva flow, and composition6,7, there are limited methods available to assess variation in oral tactile receptors (mechanoreceptors). The oral cavity houses different types of mechanoreceptors found in the mouth: Merkel receptors, Ruffini cylinders, and Meissner corpuscles8. Mechanoreceptors can be classed into two groups: slowly adapting and rapidly adapting. Slowly adapting mechanoreceptors (Ruffini cylinders and Merkel receptors) produce signals continuously while being stimulated. In contrast, rapidly adapting mechanoreceptors (Meissner&#39;s corpuscles) respond to the beginning and end of stimulation with a signal. Tactile acuity varies widely across tongue surfaces and between individuals, possibly due to differences in mechanoreceptor sensitivity. The location and the number of mechanoreceptors in the oral cavity, the differences in the spatial arrangement/density of the mechanoreceptors (spatial acuity), or the differences in their sensitivity when activated could be the cause of this intra- and inter-individual variability. Several methods to evaluate and screen for variation in mechanoreceptor sensitivity in the oral cavity have been published, including von Frey filaments9,10, letter recognition11,12, grating orientation tests13, and flexible electrode array14,15. The gratings orientation test requires square gratings (Figure 1, Figure 2) with different groove widths to be placed on the tongue of a blindfolded subject. They indicate if subjects perceive the gratings to be in either a horizontal or vertical orientation. Responses are used to calculate average thresholds based on the subject&#39;s ability to discriminate the orientation for the different grating sizes.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Custom-made squares</td>
			<td>University of Reading; University of Copenhagen</td>
			<td></td>
			<td>Squares of 1 cm2 from polytetrafluoroethylene (PTFE)</td>
		</tr>
		<tr>
			<td>Disinfenctant solution (20% sodium hypochlorite)</td>
			<td>Amuchina, Angelini S.p.A., Roma, Italy</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Eye masks</td>
			<td>Various</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Gloves</td>
			<td>Various</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lab coat</td>
			<td>Various</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Plastic cup for drinking water</td>
			<td>Various</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Excel</td>
			<td>Microsoft</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

assessment of spatial lingual tactile sensitivity using a gratings orientation test

Individual thresholds by R-index estimates are calculated using a gratings orientation test (6 different tools of increasing grating size from 0.20-1.25 mm) to assess spatial lingual tactile sensitivity. During the experiment, the subjects are blindfolded and asked to specify the orientation of the grating (either horizontal or vertical) placed on the tongue. R-index is based on Signal Detection Theory (SDT), and it is an estimated probability of correctly identifying a target stimulus (the signal, e.g., the correct orientation) compared to an alternative stimulus (the noise, e.g., the incorrect orientation). Once the R-index values for each subject and each tool dimension are calculated, it is possible to derive the individual threshold by interpolating the two R-indices immediately below and above the established cut-off (typically 75%) based on one-sided R-index critical values. This procedure can be helpful in the medical field to study the association between oral tactile sensitivity, speech clarity, and swallowing disorders, as well as in sensory and consumer studies to explore individual variation in texture perception, food preferences, and eating behavior.

A total of 70 healthy adults (age range = 19-33 years; mean age = 22.0; 52.9% women) were involved in the study, as shown in Appiani et al. (2020)21.
As an example, the R-index distribution by age for square 0.75 mm is reported in Figure 4. Each point represents a different subject. Subjects above the dotted line (cut-off value: 0.7426) are those who correctly identify the orientation of the grating (more sensitive).
<p class="jove_cont...

Watch this Scientific Journal Video about Assessment of Spatial Lingual Tactile Sensitivity using a Gratings Orientation Test at JoVE.com

Assessment of Spatial Lingual Tactile Sensitivity using a Gratings Orientation Test

This work illustrates a standard procedure and threshold determination by the R-index to assess spatial lingual tactile sensitivity using a gratings orientation test.

Individual thresholds by R-index estimates are calculated using a gratings orientation test (6 different tools of increasing grating size from 0.20-1.25 ...

assessment-spatial-lingual-tactile-sensitivity-using-gratings

Universidad San Sebastian

Research

JoVE Journal

Behavior

2.5K Views.  University of Milan. This work illustrates a standard procedure and threshold determination by the R-index to assess spatial lingual tactile sensitivity using a gratings orientation test. 

Video: Assessment of Spatial Lingual Tactile Sensitivity using a Gratings Orientation Test

Measuring Sensitivity to Viewpoint Change with and without Stereoscopic Cues

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

We discuss a novel method forviewpoint-rotation of visual stimuli, and demonstrate using a mirror stereoscopethe three-dimensional percept of rotation-in-depth. The technique can be used to investigate the role of stereoscopic cues in encoding viewpoint-rotated figures.

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this ...

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 ...

Assessment of Social Cognition in Non-human Primates Using a Network of Computerized Automated Learning Device (ALDM) Test Systems

Fagot &#38; Paleressompoulle1 and Fagot &#38; Bonte2 have published an automated learning device (ALDM) for the study of cognitive abilities of monkeys maintained in semi-free ranging conditions. Data accumulated during the last five years have consistently demonstrated the efficiency of this protocol to investigate individual/physical cognition in monkeys, and have further shown that this procedure reduces stress level during animal testing3. This paper demonstrates that networks of ALDM can also be used to investigate different facets of social cognition and in-group expressed behaviors in monkeys, and describes three illustrative protocols developed for that purpose. The first study demonstrates how ethological assessments of social behavior and computerized assessments of cognitive performance could be integrated to investigate the effects of socially exhibited moods on the cognitive performance of individuals. The second study shows that batteries of ALDM running in parallel can provide unique information on the influence of the presence of others on task performance. Finally, the last study shows that networks of ALDM test units can also be used to study issues related to social transmission and cultural evolution. Combined together, these three studies demonstrate clearly that ALDM testing is a highly promising experimental tool for bridging the gap in the animal literature between research on individual cognition and research on social cognition.

Assessment of Social Cognition in Non-human Primates Using a Network of Computerized Automated Learning Device ALDM Test Systems

Fagot &#38; Paleressompoulle1 have published an automated learning device (ALDM) aimed at testing individual cognitive abilities in semi-free ranging monkeys. The main goal of our protocol is to use a network of ALDM test units to study social cognition in non-human primates.

Fagot &#38; Paleressompoulle1 and Fagot &#38; Bonte2 have published an automated learning device (ALDM) for the study of cognitive abilities of monkeys ...

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 ...

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.

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 4 Mountains Test: A Short Test of Spatial Memory with High Sensitivity for the Diagnosis of Pre-dementia Alzheimer's Disease

This protocol describes the administration of the 4 Mountains Test (4MT), a short test of spatial memory, in which memory for the topographical layout of four mountains within a computer-generated landscape is tested using a delayed match-to-sample paradigm. Allocentric spatial memory is assessed by altering the viewpoint, colors and textures between the initially presented and target images.
Allocentric spatial memory is a key function of the hippocampus, one of the earliest brain regions to be affected in Alzheimer&#39;s disease (AD) and impairment of hippocampal function predates the onset of dementia. It was hypothesized that performance on the 4MT would aid the diagnosis of predementia AD, which manifests clinically as Mild Cognitive Impairment (MCI).
The 4MT was applied to patients with MCI, stratified further based on cerebrospinal fluid (CSF) AD biomarker status (10 MCI biomarker positive, 9 MCI biomarker negative), and with mild AD dementia, as well as healthy controls. Comparator tests included tests of episodic memory and attention widely accepted as sensitive measures of early AD. Behavioral data were correlated with quantitative MRI measures of the hippocampus, precuneus and posterior cingulate gyrus.
4MT scores were significantly different between the two MCI groups (p = 0.001), with a test score of &#8804;8/15 associated with 100% sensitivity and 78% specificity for the classification of MCI with positive AD biomarkers, i.e., predementia AD. 4MT test scores correlated with hippocampal volume (r = 0.42) and cortical thickness of the precuneus (r = 0.55).
In conclusion, the 4MT is effective in identifying the early stages of AD. The short duration, easy application and scoring, and favorable psychometric properties of the 4MT fulfil the need for a simple but accurate diagnostic test for predementia AD.

The 4 Mountains Test: A Short Test of Spatial Memory with High Sensitivity for the Diagnosis of Pre-dementia Alzheimer&#039;s Disease

This article describes the 4 Mountains Test (4MT), a hippocampus-dependent test of working allocentric spatial memory. The hippocampus is affected early in Alzheimer's disease (AD) and this article outlines the 4MT methodology and results of patient testing, which demonstrates the value of the 4MT in the diagnosis of pre-dementia AD.

This protocol describes the administration of the 4 Mountains Test (4MT), a short test of spatial memory, in which memory for the topographical layout of ...

Assessing Spatial Memory Impairment in a Mouse Model of Traumatic Brain Injury Using a Radial Water Tread Maze

Despite the recent increase in use of mouse models in scientific research, researchers continue to use cognitive tasks that were originally designed and validated for rat use. The Radial Water Tread (RWT) maze test of spatial memory (designed specifically for mice and requiring no swimming) has been shown previously to successfully distinguish between controlled cortical impact-induced TBI mice and sham controls. Here, a detailed protocol for this task is presented. The RWT maze capitalizes on the natural tendency of mice to avoid open areas in favor of hugging the sides of an apparatus (thigmotaxis). The walls of the maze are lined with nine escape holes placed above the floor of the apparatus, and mice are trained to use visual cues to locate the escape hole that leads out of the maze. The maze is filled with an inch of cold water, sufficient to motivate escape but not deep enough to require that the mouse swim. The acquisition period takes only four training days, with a test of memory retention on day five and a long-term memory test on day 12. The results reported here suggest that the RWT maze is a feasible alternative to rat-validated, swimming-based cognitive tests in the assessment of spatial memory deficits in mouse models of TBI.

Here we present a protocol for a mouse-specific test of cognition that does not require swimming. This test can be used to successfully distinguish controlled cortical impact-induced traumatic brain injury mice from sham controls.

Despite the recent increase in use of mouse models in scientific research, researchers continue to use cognitive tasks that were originally designed and ...

Testing for Metacognitive Responding Using an Odor-based Delayed Match-to-Sample Test in Rats

Metamemory involves the cognitive ability to assess the strength of one&#39;s memories. To explore the possibility of metamemory in non-human animals, numerous behavioral tasks have been created, many of which utilize an option to decline memory tests. To assess metamemory in rats, we utilized this decline-test option paradigm by adapting previous visual delayed-match-to-sample tests (DMTS)1,2 developed for primate species to an odor-based test suitable for rodents. First,&#160;rats are given a sample to remember by digging in a cup of scented sand. After a delay, the rat is presented with four distinctly scented cups, one of which contains the identical scent experienced during the sample; if this matching cup is selected, then the rat obtains a preferred, larger reward. Selection of any of the other three non-matching sand-filled scented cups results in no reward. Retention intervals are individually titrated such that subjects perform between 40 and 70% correct, therefore ensuring rats sometimes remember and sometimes forget the sample. Here, the operational definition of metamemory is the ability to distinguish between the presence and absence of memory through behavioral responding. Towards this end, on two-thirds of trials, a decline option is presented in addition to the four choice cups (choice trials). If the decline-test option- an unscented colored sand cup, is selected, the subject receives a smaller less-preferred reward and avoids the memory test. On the remaining third of trials, the decline-test option is not available (forced trials), causing subjects to guess the correct cup when the sample is forgotten. On choice tests, subjects that know when they remember should select the decline option when memory is weak rather than take the test and choose incorrectly. Therefore, significantly higher performance on chosen tests as compared to forced memory tests is indicative of the adaptive use of the decline-test response and metacognitive responding.

This protocol describes a method for investigating the possibility of metamemory, or memory awareness, in rodents. The odor-based delayed-matching-to-sample paradigm is a novel, ecologically-relevant behavioral test useful for determining the extent to which rodents can adaptively respond based on cognitively monitoring the strength of their memory states.

Metamemory involves the cognitive ability to assess the strength of one&#39;s memories. To explore the possibility of metamemory in non-human animals, ...

A Behavioral Test Battery for the Repeated Assessment of Motor Skills, Mood, and Cognition in Mice

Pharmacological and toxicological studies in neurodegeneration require comprehensive behavioral analysis in mice because motor dysfunctions and dysfunctions in mood and cognition are common and often shared symptoms in neurodegenerative diseases. Shown here is a behavioral test battery for motor, mood, and cognition, which can be repeatedly tested in a longitudinal study. This battery assesses the overall behavioral phenotype in mice by examining each domain of behavior with at least two independent well-accepted tests (i.e., open-field test and rotarod test for motor function, social interaction test, elevated plus maze test, and forced swim test for emotional function, and Morris water maze test and novel object recognition test for cognitive function). Therefore, this sensitive and comprehensive test battery is a powerful tool for the study of behavioral alternation in neurodegeneration.

A comprehensive behavioral test battery of motor skills, mood&#8212;including social interaction, depression, and anxiety&#8212;and cognition is designed for the repeated assessment of neurodegeneration-related behavioral changes in mice.

Pharmacological and toxicological studies in neurodegeneration require comprehensive behavioral analysis in mice because motor dysfunctions and ...

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we recorded the eye position of human participants engaged in a saccade task via eye tracking and assessed visual orientation discrimination performance at various locations during saccade preparation. Importantly, instead of using a single saccade target paradigm for which the saccade endpoint typically coincides roughly with the target, this protocol comprised the presentation of two nearby saccade targets, leading to a distinct spatial dissociation between target locations and saccade endpoint on a substantial number of trials. The paradigm allowed us to compare presaccadic visual discrimination performance at the endpoint of accurate saccades (landing at one of the saccade targets) and of averaging saccades (landing at an intermediate location in between the two targets). We observed a selective enhancement of visual sensitivity at the endpoint of accurate saccades but not at the endpoint of averaging saccades. Rather, before the execution of averaging saccades, visual sensitivity was equally enhanced at both targets, suggesting that saccade averaging follows from unresolved attentional selection among the saccade targets. These results argue against a mandatory coupling between visual attention and saccade programming based on a direct measure of presaccadic visual sensitivity rather than saccadic reaction times, which have been used in other protocols to draw similar conclusions. While our protocol provides a useful framework to investigate the relationship between visual attention and saccadic eye movements at the behavioral level, it can also be combined with electrophysiological measures to extend insights at the neuronal level.

This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades.

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we ...