@article{rustamov2025cortical,

title = {Cortical Spectral Dynamics of Vibrotactile Frequency Processing},

author = {Nabi Rustamov and Phillip Demarest and Zhuangyu Han and Safia Mohamud and Simon Haroutounian and Eric C Leuthardt},

doi = {https://doi.org/10.21203/rs.3.rs-6043161/v1},

year  = {2025},

date = {2025-02-21},

urldate = {2025-01-01},

journal = {Scientific Reports},

abstract = {While scientific research has extensively explored how the brain integrates touch and pain signals, the cerebral processing of specific vibrotactile frequencies remains poorly understood. This gap is particularly significant given clinical evidence that vibrotactile stimulation can reduce pain in both chronic pain patients and experimental settings. Our study investigated the cortical electrophysiological correlates of peripheral vibrotactile stimulation across different frequencies in healthy volunteers, with a focus on frequency-dependent patterns of neuronal activation. While electroencephalogram (EEG) was recorded, healthy participants received vibrotactile stimulation to the left index fingertip at frequencies corresponding to established neural rhythms: delta (2 Hz), theta (6 Hz), alpha (12 Hz), beta (20 Hz), and gamma (40 Hz). We compared the EEG bandwidth activity between vibrotactile stimulation conditions relative to resting baseline. Our findings demonstrated that vibrotactile stimulation produces distinct frequency-dependent patterns of cortical activation. A key finding was that 6 Hz stimulation selectively enhanced theta power in the left prefrontal cortex - an electrophysiological signature previously linked to successful pain relief. These findings advance the understanding of the "spectrotopic" nature of vibrotactile frequency processing in the cortex and provide a mechanistic foundation for developing novel vibration-based therapies in the future.},

keywords = {DSI-24, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{calvo2025deep,

title = {Deep Learning-Driven EEG Analysis for Personalized Deep Brain Stimulation Programming in Parkinson's Disease},

author = {Nicolas Calvo Peiro and Mathias Ramm Haugland and Alena Kutuzova and Cosima Graef and Aminata Bocum and Yen Foung Tai and Anastasia Borovykh and Shlomi Haar},

doi = {https://doi.org/10.1101/2025.02.11.25321886},

year  = {2025},

date = {2025-02-13},

urldate = {2025-01-01},

journal = {medRxiv},

pages = {2025–02},

publisher = {Cold Spring Harbor Laboratory Press},

abstract = {Deep Brain Stimulation (DBS) is an invasive procedure used to alleviate motor symptoms in Parkinson’s Disease (PD) patients. While brain activity can be used to optimise DBS parameters, the impact of DBS parameters on brain activity remains unclear. We aimed to identify the cortical neural response to changes in DBS parameters, which are sensitive to the effect of small changes in the stimulation parameters and could be used as neural biomarkers. We recorded in-clinic EEG data from seven hemispheres of PD patients during DBS programming sessions.



Here we developed a siamese adaptation of the EEGNet deep learning architecture and trained it to distinguish whether two short (1-sec-long) segments of brain activity were taken with the same stimulation parameters, or if either the strength or location of the stimulation had changed. 13 independent models were trained independently in each hemisphere for stimulation amplitude or contact, and all achieved high accuracy with an average of 78%. Our models are sensitive to changes in brain activity recorded at the scalp of the patients following changes as small as 0.3mA in the DBS parameters.



Next, we interpreted what our black-box AI models learned with an ablation-based explainability method, that extracts frequency bands learned by the models through a perturbation of the input’s frequency spectrum. We found that fast Narrow-Band Gamma oscillations (60-90Hz), contributed most to the models across all 7 hemispheres.



This work, using a data-driven approach, joins a recent body of evidence suggesting cortical Narrow-Band Gamma activity as the potential range for digital biomarkers for DBS optimization.},

keywords = {Biomarker, DSI-7, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{jeong2024attentional,

title = {Attentional state-synchronous peripheral electrical stimulation during action observation induced distinct modulation of corticospinal plasticity after stroke},

author = {Chang Hyeon Jeong and Hyunmi Lim and Jiye Lee and Hye Sun Lee and Jeonghun Ku and Youn Joo Kang},

doi = {10.3389/fnins.2024.1373589},

year  = {2024},

date = {2024-03-18},

urldate = {2024-03-18},

journal = {Frontiers in Neuroscience},

volume = {18},

pages = {1373589},

publisher = {Frontiers},

abstract = {Introduction: Brain computer interface-based action observation (BCI-AO) is a promising technique in detecting the user's cortical state of visual attention and providing feedback to assist rehabilitation. Peripheral nerve electrical stimulation (PES) is a conventional method used to enhance outcomes in upper extremity function by increasing activation in the motor cortex. In this study, we examined the effects of different pairings of peripheral nerve electrical stimulation (PES) during BCI-AO tasks and their impact on corticospinal plasticity. Materials and methods: Our innovative BCI-AO interventions decoded user's attentive watching during task completion. This process involved providing rewarding visual cues while simultaneously activating afferent pathways through PES. Fifteen stroke patients were included in the analysis. All patients underwent a 15 min BCI-AO program under four different experimental conditions: BCI-AO without PES, BCI-AO with continuous PES, BCI-AO with triggered PES, and BCI-AO with reverse PES application. PES was applied at the ulnar nerve of the wrist at an intensity equivalent to 120% of the sensory threshold and a frequency of 50 Hz. The experiment was conducted randomly at least 3 days apart. To assess corticospinal and peripheral nerve excitability, we compared pre and post-task (post 0, post 20 min) parameters of motor evoked potential and F waves under the four conditions in the muscle of the affected hand.The findings indicated that corticospinal excitability in the affected hemisphere was higher when PES was synchronously applied with AO training, using BCI during a state of attentive watching. In contrast, there was no effect on corticospinal activation when PES was applied continuously or in the reverse manner. This paradigm promoted corticospinal plasticity for up to 20 min after task completion. Importantly, the effect was more evident in patients over 65 years of age.The results showed that task-driven corticospinal plasticity was higher when PES was applied synchronously with a highly attentive brain state during the action observation task, compared to continuous or asynchronous application. This study provides insight into how optimized BCI technologies dependent on brain state used in conjunction with other rehabilitation training could enhance treatment-induced neural plasticity.},

keywords = {BCI, DSI-24, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{chan2023effects,

title = {Effects of multisession cathodal transcranial direct current stimulation with cognitive training on sociocognitive functioning and brain dynamics in ASD: A double-blind, sham-controlled, randomized EEG study},

author = {Melody MY Chan and Coco XT Choi and Tom CW Tsoi and Caroline KS Shea and Klaire WK Yiu and Yvonne MY Han},

doi = {https://doi.org/10.1016/j.brs.2023.10.012},

year  = {2023},

date = {2023-10-31},

urldate = {2023-01-01},

journal = {Brain Stimulation},

volume = {16},

issue = {8},

pages = {P1604-1616},

publisher = {Elsevier},

abstract = {Background

Few treatment options are available for targeting core symptoms of autism spectrum disorder (ASD). The development of treatments that target common neural circuit dysfunctions caused by known genetic defects, namely, disruption of the excitation/inhibition (E/I) balance, is promising. Transcranial direct current stimulation (tDCS) is capable of modulating the E/I balance in healthy individuals, yet its clinical and neurobiological effects in ASD remain elusive.



Objective

This double-blind, randomized, sham-controlled trial investigated the effects of multisession cathodal prefrontal tDCS coupled with online cognitive remediation on social functioning, information processing efficiency and the E/I balance in ASD patients aged 14–21 years.



Methods

Sixty individuals were randomly assigned to receive either active or sham tDCS (10 sessions in total, 20 min/session, stimulation intensity: 1.5 mA, cathode: F3, anode: Fp2, size of electrodes: 25 cm2) combined with 20 min of online cognitive remediation. Social functioning, information processing efficiency during cognitive tasks, and theta- and gamma-band E/I balance were measured one day before and after the treatment.



Results

Compared to sham tDCS, active cathodal tDCS was effective in enhancing overall social functioning [F(1, 58) = 6.79, p = .012, ηp2 = 0.105, 90% CI: (0.013, 0.234)] and information processing efficiency during cognitive tasks [F(1, 58) = 10.07, p = .002, ηp2 = 0.148, 90% CI: (0.034, 0.284)] in these individuals. Electroencephalography data showed that this cathodal tDCS protocol was effective in reducing the theta-band E/I ratio of the cortical midline structures [F(1, 58) = 4.65, p = .035, ηp2 = 0.074, 90% CI: (0.010, 0.150)] and that this reduction significantly predicted information processing efficiency enhancement (b = −2.546, 95% BCa CI: [-4.979, −0.113], p = .041).



Conclusion

Our results support the use of multisession cathodal tDCS over the left dorsolateral prefrontal cortex combined with online cognitive remediation for reducing the elevated theta-band E/I ratio in sociocognitive information processing circuits in ASD patients, resulting in more adaptive regulation of global brain dynamics that is associated with enhanced information processing efficiency after the intervention.},

keywords = {Biomarker, DSI-24, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{dhaliwal2022changes,

title = {Changes in Electroencephalogram (EEG) After Foot Stimulation with Embedded Haptic Vibrotactile Trigger Technology: Neuromatrix and Pain Modulation Considerations. Anesth Pain Res. 2022; 6 (2): 1-11},

author = {BS Dhaliwal and J Haddad and M Debrincat and others},

url = {https://www.scivisionpub.com/pdfs/improvement-in-balance-and-stability-using-a-novel-sensory-application-haptic-vibrotactile-trigger-technology-2537.pdf},

year  = {2022},

date = {2022-12-16},

urldate = {2022-01-01},

journal = {Correspondence: Peter Hurwitz, Clarity Science LLC},

volume = {750},

abstract = {Background: Globally, pain and pain-related diseases are the leading causes of disability and disease burden. In the United States, pain is the most common reason patients consult primary care providers. An estimated 100 million people live with chronic or recurrent pain. Existing pharmacological treatments for pain include anti-inflammatory agents, opioids, and other oral and topical analgesics. Many of these have been associated with troublesome and potentially harmful adverse effects. Understanding the complex pain neuromatrix may help in identifying alternative, non-invasive strategies and treatment approaches to address pain severity, interference, and improve patient outcomes. The neuromatrix of pain is a network of neuronal pathways and circuits responding to sensory (nociceptive) stimulation. Research has suggested that the output patterns of the body-self neuromatrix are responsible for causing or triggering perceptual, homeostatic, and behavioral programs following traumatic injury, other pathology, or chronic stress. As such, pain can be considered a product of the output of a widely distributed neural network within the brain instead of a sequential result of sensory inputs triggered by injury, inflammation, or other pathology. For over a century, the Brodmann Areas remain the most widely known and frequently cited cytoarchitectural organization of the human cortex. Certain Brodmann areas of the brain have been associated with the current understanding of the neuromatrix of pain. The areas expands well beyond the thalamus and anterior cingulate, and primary (S1) and secondary (S2) somatosensory cortices to include the midbrain region of the periaqueductal gray (PAG) and the lenticular complex as well as the insula, orbitofrontal (Brodmann's area [BA] 11, 47), prefrontal (BA 9, 10, 44-46), motor (BA 6, Supplementary motor area, and M1), inferior parietal (BA 39, 40), and anterior cingulate (BA 24, 25) cortices (ACCs). Treatments that are non-invasive and non-pharmacological and target both central and peripheral nociceptive mechanisms that are identified as having an impact on the Brodmann areas associated with the neuromatrix of pain may potentially be considered a beneficial pain management option for patients. Haptic vibrotactile trigger technology targets the nociceptive pathways and is theorized to disrupt the neuromatrix of pain. The technology has been incorporated into non-pharmacological patches and other non-invasive routes of delivery such as apparel (socks), braces, wristbands, and compression sleeves. The purpose of this minimal risk study was to compare electroencephalogram (EEG) patterns in areas of the brain that have been associated with the neuromatrix for pain in subjects wearing socks that were embedded with haptic vibrotactile trigger technology with those patients that wore socks that were not embedded with the technology.



Methods: This IRB-approved study compared electroencephalogram (EEG) patterns in subjects wearing cloth socks embedded with haptic vibrotactile trigger technology (Superneuro VTT Enhanced Socks (Srysty Holding Co., Toronto, Canada) with those patients that wore cloth socks that were not embedded with the technology. Baseline EEG data from 19 scalp locations were recorded in sixty (60) adult subjects (36 females and 24 males) ranging from ages 14 to 83 wearing standard store-purchased cloth socks on their feet. The subject’s standard socks were then removed and replaced with the Superneuro VTT enhanced socks on the subject’s feet. A second EEG recording was then obtained. Both eyes-closed and eyes-open data were recorded.



Results: The results showed statistically significant t-test differences (P < .01) in 59 out of 60 subjects in absolute power and 60 out of 60 subjects showed statistically significant differences in coherence and phase difference. The largest differences were in the alpha1 and beta2 frequency bands and especially in central scalp locations. Paired t-tests of LORETA current source densities between socks on and socks off demonstrated statistically significant differences in 60 out of 60 subjects. The largest effects of Superneuro VTT enhanced socks on were on the medial bank of the somatosensory cortex as well as in the left frontal lobes in the theta and alpha frequency.



Conclusions: Study results indicate that foot stimulation with embedded haptic vibrotactile trigger technology showed significant modulation in the Brodmann areas that have been shown to be associated with the neuromatrix for pain in the human brain. Further research is suggested to evaluate if this technology has a positive impact on pain severity, pain interference, and quality of life and to be considered as a potentially beneficial pain management strategy and as part of a multi-modal treatment approach. },

keywords = {DSI-24, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{won2022can,

title = {Can Vibrotactile Stimulation and tDCS Help Inefficient BCI Users?},

author = {Kyungho Won and Heegyu Kim and Daeun Gwon and Minkyu Ahn and Chang S Nam and Sung Chan Jun},

doi = {https://doi.org/10.21203/rs.3.rs-1849849/v1},

year  = {2022},

date = {2022-07-22},

urldate = {2022-07-22},

abstract = {Brain-computer interface (BCI) has helped people by enabling them to control a computer or machine through brain activity without actual body movement. Despite this advantage, BCI cannot be used widely because some people cannot achieve controllable performance. To solve this problem, researchers have proposed stimulation methods to modulate relevant brain activity to improve BCI performance. However, multiple studies have reported mixed results following stimulation, and comparative study of different stimulation modalities has been overlooked. Accordingly, this comparative study was designed to investigate vibrotactile stimulation and transcranial direct current stimulation’s (tDCS) effects on brain activity modulation and motor imagery BCI performance among inefficient BCI users. We recruited 44 subjects and divided them into sham, vibrotactile stimulation, and tDCS groups, and low performers were selected from each stimulation group. We found that the BCI performance of low performers in the vibrotactile stimulation group increased significantly by 9.13% (p=0.0053), and while the tDCS group subjects’ performance increased by 5.13%, it was not significant. In contrast, sham group subjects showed no increased performance. In addition to BCI performance, pre-stimulus alpha band power and the phase locking value (PLVs) averaged over sensory motor areas showed significant increases in low performers following stimulation in the vibrotactile stimulation and tDCS groups, while sham stimulation group subjects and high performers across all groups showed no significant stimulation effects. Our findings suggest that stimulation effects may differ depending upon BCI efficiency, and inefficient BCI users have greater plasticity than efficient BCI users.},

keywords = {BCI, DSI-24, Neuromodulation},

pubstate = {published},

tppubtype = {article}

}

@article{lim2020transcranial,

title = {Transcranial Direct Current Stimulation Effect on Virtual Hand Illusion},

author = {Hyunmi Lim and Won-Seok Kim and Jeonghun Ku},

doi = {https://doi.org/10.1089/cyber.2019.0741},

year  = {2020},

date = {2020-08-04},

urldate = {2020-08-04},

journal = {Cyberpsychology, Behavior, and Social Networking},

volume = {23},

number = {8},

pages = {541--549},

publisher = {Mary Ann Liebert, Inc., publishers 140 Huguenot Street, 3rd Floor New~…},

abstract = {Virtual reality (VR) is effectively used to evoke the mirror illusion, and transcranial direct current stimulation (tDCS) synergistically facilitates this illusion. This study investigated whether a mirror virtual hand illusion (MVHI) induced by an immersive, first-person-perspective, virtual mirror system could be modulated by tDCS of the primary motor cortex. Fourteen healthy adults (average age 21.86 years ±0.47, seven men and seven women) participated in this study, and they experienced VR with and without tDCS—the tDCS and sham conditions, each of which takes ∼30 minutes—on separate days to allow the washout of the tDCS effect. While experiencing VR, the movements of the virtual left hand reflected the flexion and extension of the real right hand. Subsequently, electroencephalogram was recorded, the magnitude of the proprioceptive shift was measured, and the participants provided responses to a questionnaire regarding hand ownership. A significant difference in the proprioceptive shift was observed between the tDCS and sham conditions. In addition, there was significant suppression of the mu power in Pz, and augmentation of the beta power in the Pz, P4, O1, and O2 channels. The difference in proprioceptive deviation between the two conditions showed significant negative correlation with mu suppression over the left frontal lobe in the tDCS condition. Finally, the question “I felt that the virtual hand was my own hand” received a significantly higher score under the tDCS condition. In short, applying tDCS over the motor cortex facilitates the MVHI by activating the attentional network over the parietal and frontal lobes such that the MVHI induces more proprioceptive drift, which suggests that the combination of VR and tDCS can enhance the immersive effect in VR. This result provides better support for the use of the MVHI paradigm in combination with tDCS for recovery from illnesses such as stroke.},

keywords = {DSI-24, Neuromodulation, Stroke, VR},

pubstate = {published},

tppubtype = {article}

}

@article{hunter2018change,

title = {Change in quantitative EEG theta cordance as a potential predictor of repetitive transcranial magnetic stimulation clinical outcome in major depressive disorder},

author = {Aimee M Hunter and Thien X Nghiem and Ian A Cook and David E Krantz and Michael J Minzenberg and Andrew F Leuchter},

doi = {https://doi.org/10.1177/1550059417746212},

year  = {2017},

date = {2017-12-10},

urldate = {2017-12-10},

journal = {Clinical EEG and Neuroscience},

volume = {49},

number = {5},

pages = {306--315},

publisher = {Sage Publications Sage CA: Los Angeles, CA},

abstract = {Repetitive transcranial magnetic stimulation (rTMS) has demonstrated efficacy in major depressive disorder (MDD), although clinical outcome is variable. Change in the resting-state quantitative electroencephalogram (qEEG), particularly in theta cordance early in the course of treatment, has been linked to antidepressant medication outcomes but has not been examined extensively in clinical rTMS. This study examined change in theta cordance over the first week of clinical rTMS and sought to identify a biomarker that would predict outcome at the end of 6 weeks of treatment. Clinically stable outpatients (n = 18) received nonblinded rTMS treatment administered to the dorsolateral prefrontal cortex (DLPFC). Treatment parameters (site, intensity, number of pulses) were adjusted on an ongoing basis guided by changes in symptom severity rating scale scores. qEEGs were recorded at pretreatment baseline and after 1 week of left DLPFC (L-DLPFC) rTMS using a 21-channel dry-electrode headset. Analyses examined the association between week 1 regional changes in theta band (4-8 Hz) cordance, and week 6 patient- and physician-rated outcomes. Theta cordance change in the central brain region predicted percent change in Inventory of Depressive Symptomology–Self-Report (IDS-SR) score, and improvement versus nonimprovement on the Clinical Global Impression–Improvement Inventory (CGI-I) (R2 = .38, P = .007; and Nagelkerke R2 = .78, P = .0001, respectively). The cordance biomarker remained significant when controlling for age, gender, and baseline severity. Treatment-emergent change in EEG theta cordance in the first week of rTMS may predict acute (6-week) treatment outcome in MDD. This oscillatory synchrony biomarker merits further study in independent samples.},

keywords = {Biomarker, DSI-24, Neuromodulation, qEEG},

pubstate = {published},

tppubtype = {article}

}