LinkGlide: A Wearable Haptic Display with Inverted Five-Bar Linkages for Delivering Multi-contact and Multi-modal Tactile Stimuli

Individuals with autism spectrum disorders (ASDs) commonly experience problems with the processing of tactile stimuli and poor quality of sleep. The aim of the present study was to analyze whether tactile stimuli modulation (TSM) disorders might be linked to insomnia prevalence in ASD individuals. We hypothesized that sleep disorders in children with ASD may result from improper tactile under/over responsivity. The study included 27 children diagnosed with ASD, aged 6.8 (±2.9 years) with male dominance (n = 22, 81.5%). To evaluate the pattern of TSM we used a clinical interview with a parent, and guided and spontaneous observation of the patients. Sleep disorders were diagnosed using the Athens Insomnia Scale. Of all the children diagnosed with TSM, 20 patients (74.1%) had an over-responsivity pattern and 7 children (25.9%) had an under-responsivity pattern. Of the patients, 11 children (40.7%) met the diagnostic criteria for insomnia. The data indicated a statistical tendency for higher prevalence of insomnia in individuals diagnosed with tactile under-responsivity (p = 0.051). We concluded that under-responsivity toward tactile stimuli may be partly responsible for poor sleep quality in ASD. There is an urgent need to treat sleep and sensory disruptions which may intensify behavioral difficulties in ASD.

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Temporal coherency of mechanical stimuli modulates tactile form perception

Scientific Reports ◽

10.1038/s41598-021-90661-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Masashi Nakatani ◽

Yasuaki Kobayashi ◽

Kota Ohno ◽

Masaaki Uesaka ◽

Sayako Mogami ◽

...

Keyword(s):

Sensory Neuron ◽

Sensory Neurons ◽

Contact Surface ◽

Relative Magnitude ◽

Form Perception ◽

Tangential Displacement ◽

Surface Geometry ◽

Tactile Stimuli ◽

Surface Patterns ◽

Temporal Coherency

AbstractThe human hand can detect both form and texture information of a contact surface. The detection of skin displacement (sustained stimulus) and changes in skin displacement (transient stimulus) are thought to be mediated in different tactile channels; however, tactile form perception may use both types of information. Here, we studied whether both the temporal frequency and the temporal coherency information of tactile stimuli encoded in sensory neurons could be used to recognize the form of contact surfaces. We used the fishbone tactile illusion (FTI), a known tactile phenomenon, as a probe for tactile form perception in humans. This illusion typically occurs with a surface geometry that has a smooth bar and coarse textures in its adjacent areas. When stroking the central bar back and forth with a fingertip, a human observer perceives a hollow surface geometry even though the bar is physically flat. We used a passive high-density pin matrix to extract only the vertical information of the contact surface, suppressing tangential displacement from surface rubbing. Participants in the psychological experiment reported indented surface geometry by tracing over the FTI textures with pin matrices of the different spatial densities (1.0 and 2.0 mm pin intervals). Human participants reported that the relative magnitude of perceived surface indentation steeply decreased when pins in the adjacent areas vibrated in synchrony. To address possible mechanisms for tactile form perception in the FTI, we developed a computational model of sensory neurons to estimate temporal patterns of action potentials from tactile receptive fields. Our computational data suggest that (1) the temporal asynchrony of sensory neuron responses is correlated with the relative magnitude of perceived surface indentation and (2) the spatiotemporal change of displacements in tactile stimuli are correlated with the asynchrony of simulated sensory neuron responses for the fishbone surface patterns. Based on these results, we propose that both the frequency and the asynchrony of temporal activity in sensory neurons could produce tactile form perception.

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Stimulus Generalization Using Nonvisual Stimuli with a Student Who Has Autism Spectrum Disorder and Visual Impairment

Journal of Visual Impairment & Blindness ◽

10.1177/0145482x21999503 ◽

2021 ◽

Vol 115 (2) ◽

pp. 121-133

Author(s):

Robin Arnall ◽

Yors Garcia ◽

Annette K. Griffith ◽

Jack Spear

Keyword(s):

Visual Impairment ◽

Private School ◽

Sensory Input ◽

Language Skills ◽

Autism Spectrum ◽

Multiple Baseline ◽

Stimulus Generalization ◽

Baseline Design ◽

Tactile Stimuli ◽

Low Levels

Introduction: The main objective of this study was to determine whether stimulus symmetry, or untaught generalized relations among stimuli, could be demonstrated using audio and tactile stimuli (i.e., nonvisual). Methods: A modified alternating treatment within a concurrent multiple baseline design across nonvisual stimulus sets (i.e., tactile and audio) was implemented with Zach, an 11-year-old male diagnosed with autism and visual impairment, to teach two relations (sound–touch and sound–label) among stimuli. Following training, the researcher tested whether Zach could identify stimuli through an untaught relation (touch–label). The study presented here required a week to complete and was conducted at a private school for individuals with behavioral concerns. Results: During baseline, Zach demonstrated low levels of correct responses (average of 7% across all relations) for all skills. In the training phase (for only two of the three targeted skills, sound–touch and sound–label relations), Zach demonstrated proficiency for most stimuli used in the sets (average of 61% across relations). Finally, in the testing phase (the untaught touch–label relation), Zach demonstrated high levels of generalized acquisition (89%). Discussion: Results indicated that the procedure used in this study could be generalized to novel populations, including those with visual impairments, and that different forms of sensory input could be used, including auditory and tactile-based teaching. Implications for practitioners: Individuals working with learners with differing levels of visual impairment could utilize the demonstrated procedure to associate types of stimuli, using methods other than visual input. The procedure outlined would benefit a population that may require assistance with developing language skills but who also may have difficulties using common visual stimuli.

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