Interaction of Perceived Frequency and Intensity in Fingertip Electrotactile Stimulation: Dissimilarity Ratings and Multidimensional Scaling

Abstract

Sensations elicited by electrical stimulation of touch are multidimensional, varying in perceived intensity and quality in response to changes in stimulus current or waveform timing. This study manipulated both current and frequency while volunteer participants estimated the dissimilarity of all non-identical pairs of 16 stimulus conditions. Multidimensional scaling analysis revealed that a model having two perceptual dimensions was adequate in representing the electrotactile (electrocutaneous) sensations. The two dimensions were identified as perceptual frequency and intensity, and were strongly correlated with the two stimulus variables, frequency and current, although not in a 1:1 correspondence. Perception of frequency differences increased monotonically with stimulus intensity, which is consistent with other human sensory systems such as hearing and vision. Our results are consistent with previously-reported research using different methodology and cutaneous locus. Congruence across different methods and laboratories suggests similar underlying perceptual mechanisms.

Electrically-Evoked Proximity Sensation Can Enhance Fine Finger Control in Telerobotic Pinch

“…Therefore, we expect that the frequency modulation, within the frequency range for pulsing sensation, can be used to deliver analog information. It agrees with previous studies regarding the immense potential of electrotactile feedback on the fingertip in sending multi-bit digital information via frequency modulation [52][53][54][55] . Based on the questionnaire results, subjects could distinguish the pulsing sensation from the buzzing sensation and the pulsing sensation can be discretely changed to the buzzing sensation by a leap of 10 Hz from (f max − 5) Hz to (f max + 5) Hz.…”

Temporal patterns in electrical nerve stimulation: Burst gap code shapes tactile frequency perception

“…Previous studies have varied the width of the electrical pulse, which varies the charge delivered and changes the number of afferents recruited, in turn modulating perceived intensity [37]. However, altering the charge delivered by a pulse risks generating discomfort in the subject, so a method which can extend the range of intensity sensation without changing individual electrical impulses may be of value [57]. Whilst modulating the pulse rate at a fixed pulse width can influence perceived intensity [37], it would also change perceived frequency [57].…”

“…However, altering the charge delivered by a pulse risks generating discomfort in the subject, so a method which can extend the range of intensity sensation without changing individual electrical impulses may be of value [57]. Whilst modulating the pulse rate at a fixed pulse width can influence perceived intensity [37], it would also change perceived frequency [57]. The benefit of the burst stimulation method we describe here is that we can control perceived frequency, which is determined by the burst gap, regardless of burst features such as the number of pulses within a burst [5].…”

Electrotactile feedback applications for hand and arm interactions: A systematic review, meta-analysis, and future directions

“…Most haptic interfaces are therefore designed and developed for the fingers and the hands [6], [8]. In this respect, Kaczmarek et al, (2017) found that users Acceptability/Suitability [17], [24], [25], [26], [27], [28] [22], [29], [30], [31], [32], [33], [34] 1 -21 [35], [36], [37], [38], [39] [22], [33], [34], [40] 1 -21 Free Electrodes; Touchpad; Armband None; Prosthetic hand Index & Middle Fingertip; Forearm; Palm Touch Rendering [20], [24], [41], [42], [43], [44] [45], [46], [47], [48], [49], [50] [19], [51], [52], [53], [54], [ Texture Rendering [19], [54], [56], [57], [58], [59], [60], [61] [14], [...…”

“…The electrotactile feedback on the palm was mainly examined in psychophysic studies (e.g., [11], [34]). Equally, the rest of the fingertips were stimulated only in psychophysical studies (e.g., [27]) or in teleoperation studies (e.g., [18], [85]). In summary, as the Fig.…”