LRH è stato sostenuto dal Natural Scienze e ingegneria Research Council (NSERC) del Canada. SD è stato in parte sostenuto dal NSERC CREATE programma.

Tutti gli esperimenti sono stati approvati dal Consiglio York Etica e tutti i partecipanti hanno firmato moduli di consenso informato. Gli esperimenti sono stati eseguiti in conformità con il trattato di Helsinki. 1. stimoli <ol><li> Tattili rilevamento Stimolo <ol><li> Utilizzare un contattore (1.17 &quot;di diametro e 0,30&quot; di spessore) per fornire stimoli tattili di 250 vibrazioni Hz per 100 msec. Utilizzando un contattore appositamente costruito fornisce una relazione lineare tra la quantità di corsa e la tensione applicata. </li><li> Controllare la consegna stimolo tattile con una scheda audio a 64 bit. <ol><li> Per guidare il contattore, trattarlo come un altoparlante. Collegare un amplificatore audio stereo a una scheda audio stereo computer a 64 bit. Collegare il contattore a una delle uscite dell&#39;amplificatore (ad esempio, il &#39;altoparlante sinistro out&#39;). Collegare il secondo canale (per esempio, il &#39;altoparlante destro out&#39;) dell&#39;amplificatore ad un altoparlante regolare per fornire segnali uditivi al parparteci-. </li><li> Nel codice computer che controlla l&#39;esperimento, generare la forma d&#39;onda che verrà utilizzato per vibrare il contattore (ad esempio, una sinusoide 250 Hz di durata 100 msec), e un&#39;altra forma d&#39;onda per il segnale audio (per esempio, una sinusoide 3.000 Hz con durata 100 msec). Vedere l&#39;esempio di codice 1 nel file di codice supplementare. </li><li> Mettere ciascuna di queste due forme d&#39;onda in una matrice bidimensionale. Per la matrice tactor mettere il segnale nella prima dimensione e impostare la seconda dimensione a tutti zeri. Per la matrice suono portare il segnale nella seconda dimensione e impostare il primo a tutti zeri. Gioca la matrice appropriata alla scheda audio nel punto appropriato nel programma. Vedere l&#39;esempio di codice 1 nel file di codice supplementare per una dimostrazione di come questo è fatto. </li></ol></li><li> Fissare il contattore di una cinghia con un prodotto a base di meccanico di fissaggio. </li></ol></li><li> mascheratura Stimolo <ol><li> Fornire lo stimolo mascheramento da un elettrico, ahND-tenuta (diametro di 4 cm, 83 Hz quando è impostato su &quot;basso&quot;) vibratore. </li><li> Sulla base delle zone in cui il mascheramento è da testare, selezionare i siti in cui lo stimolo mascheramento deve essere applicato. </li></ol></li></ol> 2. apparato sperimentale e Design <ol><li> Disporre il computer e apparecchi su una scrivania, con una sedia di fronte ad esso, per lo sperimentatore. </li><li> Impostare un tavolo su cui poggiano i partecipanti loro sinistra (test) del braccio. Inserire una sedia al lato destro della tabella. Mettere uno stand bracciolo accanto alla sedia su cui poggiano i partecipanti il ​​loro diritto (braccio mascheramento) gomito. Aggiungere ammortizzazione al tavolo e bracciolo per il comfort. </li><li> Disporre un altoparlante su una superficie meccanicamente isolato. Disporre pedali (collegato ai pulsanti sinistro e destro di un mouse del computer) in modo che i piedi del partecipante riposare comodamente su di loro (Figura 1). </li><li> Scegliere i parametri dello studio, compreso il numero appropriato di prove richiesteper ottenere una stima affidabile della soglia (tipicamente, tra 40-50 prove) e il numero di blocchi in cui l&#39;esperimento deve essere divisa (ad esempio, due blocchi di 20-25 prove per condizione). </li><li> Fare una lista dell&#39;ordine in cui saranno eseguite le condizioni. Utilizzare questo elenco per determinare dove tenere lo stimolo di mascheramento per ogni blocco. </li><li> Inserire il numero di prove direttamente nel codice del programma del computer (ad esempio, ntrials = 25; Vedere file di codice supplementare). Assicurarsi che ogni blocco non è più di 10 minuti per mantenere l&#39;attenzione. </li><li> Programmare una forzata di due alternative-scelta compito di rilevamento tattile 11 in cui stimolo intensità è controllata con un Bayesiano adattivo scala psicofisico procedura psicometrica 12. <ol><li> Per ogni prova, presenti due intervalli di 1 sec, segnato da tre segnali acustici (5 kHz, 3 kHz e 5 kHz, durata 100 msec), con lo stimolo tattile presentato nel bel mezzo di uno degli intervalli. Avere l&#39;i partecipantindicate in cui intervallo lo stimolo è stato presentato per mezzo di pedali (a sinistra per prima, a destra per il secondo). Vedi Esempio di codice 2, che mostra come gli intervalli vengono eseguiti e ha ottenuto. Nota: I punteggi del computer la risposta come &quot;corretto&quot; o &quot;sbagliato&quot; e la scala di adattamento sceglie il valore successivo da presentare di conseguenza. Nota: Questo metodo determina un valore di soglia per rilevare la vibrazione al sito di prova. </li></ol></li></ol><img alt="Figura 1" src="/files/ftp_upload/53733/53733fig1.jpg" /> Figura 1. Disegno sperimentale. Questa figura mostra il set up della sperimentazione e dei materiali utilizzati. Vedere il testo per i dettagli. 3. Procedura sperimentale <ol><li> Ottenere il consenso informato scritto. Sedile del partecipante sulla sedia con i piedi appoggiata comodamente sulle pedali di risposta e spiegare la procedura sperimentale. &lt;/ Li&gt; <li> Misurare e registrare la lunghezza della superficie dorsale dell&#39;avambraccio sinistro. Applicare la cinghia in modo che il contattore è posizionato al centro della metà del braccio tra l&#39;angolo interno del gomito e piega del polso. </li><li> Avvolgere un bendaggio tensore liberamente intorno al braccio più volte per tenere il contattore in posizione. </li><li> Istruire i partecipanti a mettere il loro braccio sinistro sul tavolo e riposare il gomito destro sul bracciolo. Benda il partecipante per evitare che guardando lo stimolo o la posizione di mascheramento e di istruirli a guardare dritto davanti a sé tutto l&#39;esperimento. </li><li> Inizia con un blocco di 20 prove pratiche (senza lo stimolo di mascheramento), al fine di familiarizzare i partecipanti con il compito di rilevamento tattile e per consentire loro di acquisire familiarità con gli stimoli tattili. </li><li> Dopo le prove di pratica, iniziare l&#39;esperimento, l&#39;esecuzione dei blocchi di condizioni in un caso, l&#39;ordine controbilanciato. Prima di iniziare ogni blocco, in modo che le braccia e la stimu mascheramentolus sono nelle posizioni corrette. <ol><li> Per ciascuna condizione, tenere lo stimolo mascheratura sul sito scelto, facendo riferimento alla lista di condizioni fatte in precedenza. Attraversare fuori di ogni condizione viene eseguito. Tenere lo stimolo di mascheramento nel corso di ogni blocco di prove di raccolta dei dati mantenendo la pressione approssimativamente costante. Lo stimolo mascheramento può essere applicato attraverso i vestiti sottili. </li><li> Eseguire il programma sperimentale che si svolgerà attraverso un certo numero di prove come precedentemente selezionato. Introdurre un periodo di riposo 2 minuti dopo ogni breve blocco di prove. Dopo un determinato blocco di prove è stata completata, selezionare il sito successivo per lo stimolo di mascheratura ed eseguire nuovamente il programma. Ripetere fino a quando tutte le prove sono stati completati. </li></ol></li></ol> Analisi 4. I dati <ol><li> Per visualizzare e confermare la stima del valore di soglia restituito dal programma di scala adattivo 12, inserire i dati dei partecipanti con una gaussiana cumulativa La formula per una gaussiana cumulativa(Sigma) che va dal 50% (livello di probabilità - numero uguale di 0 - sbagliato e 1&#39;s- corretta) al 100% (tutti 1, tutti corretti) è: probabilità di una risposta corretta = 0,5 + 0,5 / (1 + exp (- (x-x0) / std)) dove x è il valore di intensità testato, x0 è il valore di soglia del 75%, e std è la deviazione standard della stima. Questa formula può essere montato ai dati utilizzando qualsiasi software curva-montaggio ed il valore risultante x0 rispetto al valore adattativo scala. <ol><li> Assicurarsi che la curva va tra il 50% (performance probabilità) e il 100%. Condurre analisi statistiche (ad esempio, t-test o ANOVA) sui valori di soglia del 75% ottenuti in ciascuna condizione dell&#39;esperimento (ad esempio, tra i vari siti di mascheratura) per determinare se ci sono delle differenze tra le condizioni testate. </li></ol></li><li> Per identificare valori anomali, calcolare la media e la deviazione standard per una data condizione. Confrontare il punteggio di ogni partecipante con la media ese un punteggio individuale è più di 2 deviazioni standard da dire allora considerare questo segno come un valore erratico e rimuoverlo dall&#39;analisi. criteri alternativi possono essere utilizzati se lo si desidera. </li><li> Per uniformare i valori di intensità dei contattori (che sono in in unità arbitrarie), convertire loro di decibel rispetto alle soglie di controllo (misurati quando lo stimolo mascheramento viene applicato al sito di controllo, ad esempio, la spalla). Utilizzare questa formula: dB = 10 x log 10 (valore di soglia valore di soglia / di controllo). </li></ol>

<ol>
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Gli autori dichiarano di non avere interessi finanziari concorrenti.

Qui, un protocollo dettagliato per mascheratura tattile controlaterale è descritto e sono presenti risultati precedentemente pubblicati, utilizzando la tecnica di testare soglie di rilevamento tattili. Il vantaggio di questo metodo è che le soglie vengono misurati utilizzando una tecnica psicofisica rigoroso. La scelta forzata procedura in due alternative (2AFC) è relativamente insensibile a bias di risposta e quindi da effetti di attenzione. La procedura scala adattativo per focalizzando sul valore di soglia attuale...

mascheramento tattile è dove un stimolo tattile in un punto del corpo altera la percezione di un tocco in un altro luogo. Questa è una tecnica introdotta da von Bekesy 1 per rivelare le interazioni spilli, soprattutto inibizione laterale, tra le aree di pelle che sono adiacenti sulla superficie del corpo. Mentre mascheramento tattile è stata ampiamente studiata negli anni, la ricerca ha indagato principalmente omolaterale mascheramento tattile usando stimolazione elettrica 2, 3, 4 di pressione, e la stimolazione vibrotattile 5, 6. Al contrario, pochi studi hanno esaminato mascheramento tattile controlaterale in cui i siti di mascheramento e sonda possono essere rimossi lontano. Lungo raggio effetti di schermo tattile è stato dimostrato tra i punti specchio simmetrico sulla mano e del braccio 5, 7 - 9 ma questi studi sono stati in gran parte limitato a guardare le mani e le dita 7, 10, con più ampie parti del corpo essendo largamente ignorato. Un obiettivo di tali esperimenti di mascheramento a lungo raggio è quello di indicare come i componenti della rappresentazione del corpo nel cervello possono essere funzionalmente collegati. Qui, il fenomeno di lungo raggio tattili mascheramento viene esplorato studiando come vibrazione applicata ad un avambraccio potrebbe influenzare soglie di sensibilità tattile sull&#39;avambraccio opposta. Threshold riferisce allo stimolo minimo necessario per rilevare uno stimolo. Definiamo questo come l&#39;intensità in cui viene rilevato lo stimolo 75% del tempo. Abbiamo usato una tecnica di mascheramento tattile, in cui la sensibilità tattile (il reciproco della soglia) su un avambraccio è misurato in presenza di uno stimolo vibrante (maschera) su un&#39;altra parte del corpo. Mascheratura efficace è rivelato da un aumento della soglia di rilevamento cioè, una riduzione della sensibilità. La tecnica può essere utilizzata in combinazione con altre manipolazioni come variando la posizione arto omovimento r per esplorare i loro effetti sulla efficacia di mascheramento. Qui abbiamo usato stimoli vibrotattili come stimolo mascheramento. Il vantaggio di questo è che la frequenza, e quindi il tipo di recettore che stimola possono essere controllati. La tecnica potrebbe essere esteso a considerare il dolore usando stimoli elettrici come la sonda o maschera o entrambi. Inoltre, qualsiasi sito può essere utilizzato come sede mascheratura consente la ricerca di siti di agopuntura per esempio.

<table><tbody><tr><td>C-2 tactor</td><td>ATAC Technology; Engineering Acoustics, Inc.</td><td></td><td>http://www.atactech.com/PR_tactors.html</td></tr><tr><td>Magic Wand</td><td>Hitachi</td><td></td><td>http://magicwandoriginal.com/magic-wand-original/</td></tr><tr><td>FC5 Foot Pedals</td><td>Yamaha Corporation</td><td></td><td>http://ca.yamaha.com/en/products/music-production/accessories/footpedals/fc5/?mode=model</td></tr><tr><td>MATLAB</td><td>The Mathworks, Inc.</td><td></td><td>http://www.mathworks.com/products/matlab/</td></tr><tr><td>Velcro</td><td>Velcro Industries B.V.</td><td></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.

L&#39;analisi dei dati è stata riportata nel 13. Sensibilità tattile (espressa rispetto alle soglie misurate in condizione di controllo) sull&#39;avambraccio è stata significativamente ridotta (soglie erano significativamente aumentati) quando la stimolazione vibrotattile mascheramento è stato applicato al braccio opposto (Figura 2A), dimostrando un effetto di mascheramento controlaterale tra avambracci. L&#39;effetto dipendeva dalla posizione dello stimol...

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

Testing Tactile Masking between the Forearms

Test tattile mascheramento tra gli avambracci

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, ...

testing-tactile-masking-between-the-forearms

Universidad San Sebastian

Research

JoVE Journal

Behavior

6.3K Views.  York University. 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. 

Video: Testing Tactile Masking between the Forearms

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.

Misura di rilevamento delle vibrazioni Soglia e tattile spaziale Acuity in soggetti umani

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

Ricerca

Comportamento

Creating Virtual-hand and Virtual-face Illusions to Investigate Self-representation

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional rubber-hand illusion or the more recently discovered enfacement illusion. However, these examples require rather artificial experimental setups, in which the artificial effector needs to be stroked in synchrony with the participants&#39; real hand or face&#8212;a situation in which participants have no control over the stroking or the movements of their real or artificial effector. Here, we describe a technique to establish ownership illusions in a setup that is more realistic, more intuitive, and of presumably higher ecological validity. It allows creating the virtual-hand illusion by having participants control the movements of a virtual hand presented on a screen or in virtual space in front of them. If the virtual hand moves in synchrony with the participants&#39; own real hand, they tend to perceive the virtual hand as part of their own body. The technique also creates the virtual-face illusion by having participants control the movements of a virtual face in front of them, again with the effect that they tend to perceive the face as their own if it moves in synchrony with their real face. Studying the circumstances that illusions of this sort can be created, increased, or reduced provides important information about how people create and maintain representations of themselves.

Here, we describe virtual-hand and virtual-face illusion paradigms that can be used to study body-related self-perception/-representation. They have already been used in various studies to demonstrate that, under specific conditions, a virtual hand or face can be incorporated into one&#39;s body representation, suggesting that body representations are rather flexible.

Creazione virtuale a mano e Virtual-face Illusions per Indagare Autorappresentazione

Studies investigating how people represent themselves and their own body often use variants of &#34;ownership illusions&#34;, such as the traditional ...

A Simple Non-invasive Method for Temporary Knockdown of Upper Limb Proprioception

Proprioception may be the least well measured of all contributors to the neural control of movement. New precise, reliable measures of proprioception are needed for clinical diagnosis of impairment, and to measure outcomes of proprioceptive training. The purpose of this simple, non-invasive method is to temporarily knockdown upper limb proprioception in healthy adults, to an extent that would be useful in the development and testing of upper limb proprioception measures. Knockdown models have two main advantages over studying humans with impaired proprioception: participant availability and the ability to control the extent of impairment across participants. Current published methods of temporary proprioception knockdown of the upper limb, such as ischemic nerve blocks and cryotherapy, are invasive, impractical, or uncomfortable for the participant. Here, vibration over the ulnar groove was used to reduce upper limb proprioception. High frequency vibration may reduce proprioceptive acuity by inhibiting pacinian corpuscle-induced input. The effect of vibration used in this protocol was confirmed using two quantitative measures. This method was simple to administer, comfortable for participants, and practical.

The goal of this protocol is to demonstrate a practical method to temporarily interfere with proprioception in the upper limb of healthy humans.

Un metodo semplice e Non invasivo per atterramento temporaneo di propriocezione degli arti superiori

Proprioception may be the least well measured of all contributors to the neural control of movement. New precise, reliable measures of proprioception are ...

Using Facial Electromyography to Assess Facial Muscle Reactions to Experienced and Observed Affective Touch in Humans

"Affective" touch is believed to be processed in a manner distinct from discriminatory touch and to involve activation of C-tactile (CT) afferent fibers. Touch that optimally activates CT fibers is consistently rated as hedonically pleasant. Patient groups with impaired social-emotional functioning also show disordered affective touch ratings. However, relying on self-reported ratings of touch has many limitations, including recall bias and communication barriers. Here, we describe a methodological approach to study affective responses to touch via facial electromyography (EMG) that circumvents the reliance on self-report ratings. Facial EMG is an objective, quantitative, and non-invasive method to measure facial muscle activity indicative of affective responses. Responses can be assessed across healthy and patient populations without the need for verbal communication. Here, we provide two separate datasets demonstrating that CT-optimal and non-optimal touch elicit distinct facial muscle reactions. Moreover, facial EMG responses are consistent across stimulus modalities, e.g. tactile (experienced touch) and visual (observed touch). Finally, the temporal resolution of facial EMG can detect responses on timescales that supersede that of verbal reporting. Together, our data suggest that facial EMG is a suitable methodology for use in affective tactile research that can be used to supplement, or in some cases, supplant, existing measures.

We describe a protocol to assess facial muscle activity in response to experienced and observed tactile stimulation using facial electromyography.

Usando l'elettromiografia facciale per valutare le reazioni del muscolo facciale tatto affettiva esperto e osservati in esseri umani

"Affective" touch is believed to be processed in a manner distinct from discriminatory touch and to involve activation of C-tactile (CT) afferent fibers. ...

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.

Applicazione di stimoli visivi e tattili incongruenti durante il trasferimento di oggetti con feedback vibro-tattile

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

A Tactile Automated Passive-Finger Stimulator (TAPS)

Although tactile spatial acuity tests are used in both neuroscience research and clinical assessment, few automated devices exist for delivering controlled spatially structured stimuli to the skin. Consequently, investigators often apply tactile stimuli manually. Manual stimulus application is time consuming, requires great care and concentration on the part of the investigator, and leaves many stimulus parameters uncontrolled. We describe here a computer-controlled tactile stimulus system, the Tactile Automated Passive-finger Stimulator (TAPS), that applies spatially structured stimuli to the skin, controlling for onset velocity, contact force, and contact duration. TAPS is a versatile, programmable system, capable of efficiently conducting a variety of psychophysical procedures. We describe the components of TAPS, and show how TAPS is used to administer a two-interval forced-choice tactile grating orientation test.
Corresponding Author: Daniel Goldreich

A Tactile Automated Passive-Finger Stimulator TAPS

We describe a computer-controlled device for investigating the sense of touch: the Tactile Automated Passive-finger Stimulator (TAPS). We describe the components of TAPS, and show how TAPS is used to administer a two-interval forced-choice tactile grating orientation test.

Un tattile automatica Passive-Finger stimolatore (TAPS)

Although tactile spatial acuity tests are used in both neuroscience research and clinical assessment, few automated devices exist for delivering ...

Biologia

A Standardized Method for Measurement of Elbow Kinesthesia

Proprioception is an important component of controlled movement. The threshold to detection of passive movement (TDPM) is a commonly used method for quantifying the proprioceptive submodality of kinesthesia in research settings. The TDPM paradigm has been found to be valid and reliable; however, the equipment and methods used for TDPM vary between studies. In particular, the research laboratory apparatuses for producing passive movement of an extremity are often custom designed by individual laboratories or inaccessible due to high cost. There is a need for a standardized, valid, and reliable method for measuring TDPM using readily available equipment. The purpose of this protocol is to provide a standardized method for measurement of TDPM at the elbow that is economical, easy to administer, and that produces quantitative results for measurement purposes in research-based settings. This method was tested on 20 healthy adults without neurological impairment, and eight adults with chronic stroke. The results obtained suggest this method is a reliable way to quantify elbow TDPM in healthy adults, and provides initial support for validity. Researchers seeking a balance between equipment affordability and measurement precision are most likely to find this protocol of benefit.

Here, we present a standardized method for measurement of elbow passive kinesthesia using the threshold to detection of passive movement (TDPM) that is appropriate for a research setting.

Un metodo standardizzato per la misurazione della kinestesia dell'gomito

Proprioception is an important component of controlled movement. The threshold to detection of passive movement (TDPM) is a commonly used method for ...

Non-Invasive Modulation and Robotic Mapping of Motor Cortex in the Developing Brain

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries unique challenges in children. Similarly, transcranial direct current stimulation (tDCS) can improve motor learning in adults but has only recently been applied to children. The use of tDCS and emerging techniques like high&#8211;definition tDCS (HD-tDCS) require special methodological considerations in the developing brain. Robotic TMS motor mapping may confer unique advantages for mapping, particularly in the developing brain. Here, we aim to provide a practical, standardized approach for two integrated methods capable of simultaneously exploring motor cortex modulation and motor maps in children. First, we describe a protocol for robotic TMS motor mapping. Individualized, MRI-navigated 12x12 grids centered on the motor cortex guide a robot to administer single-pulse TMS. Mean motor evoked potential (MEP) amplitudes per grid point are used to generate 3D motor maps of individual hand muscles with outcomes including map area, volume, and center of gravity. Tools to measure safety and tolerability of both methods are also included. Second, we describe the application of both tDCS and HD-tDCS to modulate the motor cortex and motor learning. An experimental training paradigm and sample results are described. These methods will advance the application of non-invasive brain stimulation in children.

We demonstrate protocols for the modulation (tDCS, HD-tDCS) and mapping (robotic TMS) of the motor cortex in children.

Modulazione non invasiva e mappatura robotica della Corteccia motoria nel cervello in via di sviluppo

Mapping the motor cortex with transcranial magnetic stimulation (TMS) has potential to interrogate motor cortex physiology and plasticity but carries ...

Neuroscienze

Capturing Dynamic Finger Gesturing with High-resolution Surface Electromyography and Computer Vision

Finger gestures are a critical element in human communication, and as such, finger gesture recognition is widely studied as a human-computer interface for state-of-the-art prosthetics and optimized rehabilitation. Surface electromyography (sEMG), in conjunction with deep learning methods, is considered a promising method in this domain. However, current methods often rely on cumbersome recording setups and the identification of static hand positions, limiting their effectiveness in real-world applications. The protocol we report here presents an advanced approach combining a wearable surface EMG and finger&#160;tracking system to capture comprehensive data during dynamic hand movements. The method records muscle activity from soft printed electrode arrays (16 electrodes) placed on the forearm as subjects perform gestures in different hand positions and during movement. Visual instructions prompt subjects to perform specific gestures while EMG and finger positions are recorded. The integration of synchronized EMG recordings and finger tracking data enables comprehensive analysis of muscle activity patterns and corresponding gestures. The reported approach demonstrates the potential of combining EMG and visual tracking technologies as an important resource for developing intuitive and responsive gesture recognition systems with applications in prosthetics, rehabilitation, and interactive technologies. This protocol aims to guide researchers and practitioners, fostering further innovation and application of gesture recognition in dynamic and real-world scenarios.

The paper presents a comprehensive protocol for simultaneously recording hand-electromyography (EMG) and visual finger tracking during natural finger gesturing. The visual data is designed to serve as the ground truth for the development of accurate EMG-based computational models for finger gesture recognition.

Acquisizione di gesti dinamici delle dita con l'elettromiografia di superficie ad alta risoluzione e la visione artificiale

Finger gestures are a critical element in human communication, and as such, finger gesture recognition is widely studied as a human-computer interface for ...

Bioingegneria

Assessing Corticospinal Excitability During Goal-Directed Reaching Behavior

Reaching is a widely studied behavior in motor physiology and neuroscience research. While reaching has been examined using a variety of behavioral manipulations, there remain significant gaps in the understanding of the neural processes involved in reach planning, execution, and control. The novel approach described here combines a two-dimensional reaching task with transcranial magnetic stimulation (TMS) and concurrent electromyography (EMG) recording from multiple muscles. This method allows for the noninvasive detection of corticospinal activity at precise time points during the unfolding of reaching movements. The example task code includes a delayed response reaching task with two possible targets displayed &#177; 45&#176; off the midline. Single pulse TMS is delivered on the majority of task trials, either at the onset of the preparatory cue (baseline) or 100 ms prior to the imperative cue (delay). This sample design is suitable for investigating changes in corticospinal excitability during reach preparation. The sample code also includes a visuomotor perturbation (i.e., cursor rotation of &#177; 20&#176;) to investigate the effects of adaptation on corticospinal excitability during reach preparation. The task parameters and TMS delivery can be adjusted to address specific hypotheses about the state of the motor system during reaching behavior. In the initial implementation, motor evoked potentials (MEPs) were successfully elicited on 83% of TMS trials, and reach trajectories were recorded on all trials.

Reaching is a fundamental skill that allows humans to interact with the environment. Several studies have aimed to characterize reaching behavior using a variety of methodologies. This paper offers an open-source application of transcranial magnetic stimulation to assess the state of corticospinal excitability in humans during reaching task performance.

Valutazione dell'eccitabilità corticospinale durante il comportamento di raggiungimento diretto all'obiettivo

Reaching is a widely studied behavior in motor physiology and neuroscience research. While reaching has been examined using a variety of behavioral ...