Transcranial Alternating Current Stimulation to Modulate Alpha Activity: A Systematic Review

Neuromodulation Technology at the Neural Interface, Journal Year: 2023, Volume and Issue: 26(8), P. 1549 - 1584

Published: Jan. 31, 2023

Transcranial alternating current stimulation (tACS) has been one of numerous investigation methods used for their potential to modulate brain oscillations; however, such investigations have given contradictory results and a lack standardization.In this systematic review, we aimed assess the tACS alpha spectral power. The secondary outcome was identification methodologic key parameters, adverse effects, sensations.Studies in healthy adults who were receiving active sham intervention or any differential condition included. main assessed increase/decrease power through either electroencephalography magnetoencephalography. Secondary outcomes sensation reporting, effects. Risks bias study quality with Cochrane assessment tool.We obtained 1429 references, 20 met selection criteria. A statistically significant alpha-power increase observed nine studies using continuous two intermittent set at frequency within range. three more outside Heterogeneity among parameters recognized. Reported effects mild. implementation double blind identified as challenging tACS, part owing electrical artifacts generated by on recorded signal.Most reported that optimization noninvasive method is interest mostly its clinical applications neurological conditions associated perturbations activity. However, research efforts are needed standardize optimal achieve lasting modulation develop alternatives reduce experimental bias, improve

Language: Английский

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Improved tactile speech perception using audio-to-tactile sensory substitution with formant frequency focusing

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Feb. 28, 2024

Abstract Haptic hearing aids, which provide speech information through tactile stimulation, could substantially improve outcomes for both cochlear implant users and those unable to access implants. Recent advances in wide-band haptic actuator technology have made new audio-to-tactile conversion strategies viable wearable devices. One such strategy filters the audio into eight frequency bands, are evenly distributed across range. The amplitude envelopes from bands modulate amplitudes of low-frequency tones, delivered vibration a single site on wrist. This vocoder effectively transfers some phonemic information, but vowels obstruent consonants poorly portrayed. In 20 participants with normal touch perception, we tested (1) whether focusing more densely around first second formant frequencies improved vowel discrimination, (2) at mid-to-high consonant discrimination. obstruent-focused approach was found be ineffective. However, formant-focused discrimination by 8%, without changing overall strategy, can readily implemented real time compact device, perception aid users.

Language: Английский

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Alpha‐Band Brain Activity Shapes Online Perceptual Learning of Concurrent Speech Differentially in Musicians vs. Nonmusicians

European Journal of Neuroscience, Journal Year: 2025, Volume and Issue: 61(9)

Published: April 28, 2025

ABSTRACT Plasticity from auditory experience shapes the brain's encoding and perception of sound. Though stronger neural entrainment (i.e., brain‐to‐acoustic synchronization) aids speech perception, underlying oscillatory activity may uniquely interact with long‐term experiences music training) short‐term plasticity during concurrent perception. Here, we explored rapid perceptual learning sounds in normal‐hearing young adults who differed their amount self‐reported training (defined as “musicians” “nonmusicians”). Participants learned to identify double‐vowel mixtures ~45 min sessions high‐density EEG recordings. We analyzed alpha‐band power (7–12 Hz) following a rhythmic speech‐stimulus train (~9 preceding behavioral identification determine whether increased (brain‐to‐speech entrainment) or decreased alpha (alpha‐band suppression) corresponded task success. Source directed functional connectivity analyses data probed behavior was driven by group differences auditory‐motor coupling. Both groups improved training. Listeners' prior target predicted performance; surprisingly, oscillations were observed incorrect compared correct trial responses. also found stark hemispheric biases coupling, greater right left hemisphere for musicians (R > L) but not nonmusicians = L). Stronger responses supports notion that (~10 suppression is an important modulator trial‐by‐trial success processing. Our findings suggest impact

Language: Английский

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Neuronal basis of audio-tactile speech perception

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 19, 2024

Abstract Since childhood, we experience speech as a combination of audio and visual signals, with cues particularly beneficial in difficult auditory conditions. This study investigates an alternative multisensory context speech, namely audio-tactile, which could prove for rehabilitation the hearing impaired population. We show improved understanding distorted background noise, when combined low-frequency speech-extracted vibrotactile stimulation delivered on fingertips. The quick effect might be related to fact that both tactile signals contain same type information. Changes functional connectivity due audio-tactile training are primarily observed system, including early regions, lateral occipital cortex, middle temporal motion area, extrastriate body area. These effects, despite lack input during task, possibly reflect automatic involvement areas supporting lip-reading spatial aspects language, such gesture observation, acoustic For integration increased sensorimotor hub representing entire body, parietal system motor planning based inputs, along several areas. After training, increases high-order language-related frontal regions. Overall, results suggest new task activates regions partially overlap established brain network audio-visual processing. further indicates neuronal plasticity perceptual learning is first built upon existing structural blueprint connectivity. Further effects task-specific behaviour perception, well signal Possibly, longer regime required strengthen direct pathways between

Language: Английский

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Improved speech intelligibility in the presence of congruent vibrotactile speech input

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: Dec. 19, 2023

Vibrotactile stimulation is believed to enhance auditory speech perception, offering potential benefits for cochlear implant (CI) users who may utilize compensatory sensory strategies. Our study advances previous research by directly comparing tactile intelligibility enhancements in normal-hearing (NH) and CI participants, using the same paradigm. Moreover, we assessed enhancement considering stimulus non-specific, excitatory effects through an incongruent audio-tactile control condition that did not contain any speech-relevant information. In addition this condition, presented sentences only a congruent with providing low-frequency envelope information via vibrating probe on index fingertip. The involved 23 NH listeners 14 users. both groups, significant were observed stimuli (5.3% 5.4% participants), but stimulation. These findings replicate previously effects. Juxtaposing our research, informational content of emerges as modulator intelligibility: Generally, enhanced, non-matching reduced, neutral change test outcomes. We conclude temporal cues provided vibrotactile aid parsing continuous signals into syllables words, consequently leading improvements intelligibility.

Language: Английский

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Effects of continuous tactile stimulation on auditory-evoked cortical responses depend on the audio-tactile phase

NeuroImage, Journal Year: 2023, Volume and Issue: 274, P. 120140 - 120140

Published: April 28, 2023

Auditory perception can benefit from stimuli in non-auditory sensory modalities, as for example lip-reading. Compared with such visual influences, tactile influences are still poorly understood. It has been shown that single pulses enhance the of auditory depending on their relative timing, but whether and how brief enhancements be stretched time more sustained, phase-specific periodic stimulation is unclear. To address this question, we presented fluctuated coherently continuously at 4 Hz an noise (either in-phase or anti-phase) assessed its effect cortical processing signal embedded noise. Scalp-electroencephalography recordings revealed enhancing responses phase-locked to a suppressive anti-phase evoked by signal. Although these effects appeared follow well-known principles multisensory integration discrete audio-tactile events, they were not accompanied corresponding behavioral measures perception. Our results indicate continuous acoustically-induced fluctuations mask ongoing They further suggest sustained insufficient inducing bottom-up benefits.

Language: Английский

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Speech-derived haptic stimulation enhances speech recognition in a multi-talker background

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: Oct. 3, 2023

Speech understanding, while effortless in quiet conditions, is challenging noisy environments. Previous studies have revealed that a feasible approach to supplement speech-in-noise (SiN) perception consists presenting speech-derived signals as haptic input. In the current study, we investigated whether presentation of vibrotactile signal derived from speech temporal envelope can improve SiN intelligibility multi-talker background for untrained, normal-hearing listeners. We also determined if sensitivity, evaluated using detection thresholds, modulates extent audio-tactile improvement. practice, measured participants' recognition noise without (audio-only) and with (audio-tactile) concurrent stimulation delivered three schemes: left or right palm, both. Averaged across delivery schemes, led significant improvement 0.41 dB when compared audio-only condition. Notably, there were no differences observed between improvements these schemes. addition, benefit was significantly predicted by threshold levels unimodal performance. The afforded speech-envelope-derived line previously uncovered enhancements untrained listeners known hearing impairment. Overall, results highlight potential recognition, especially individuals poor abilities, tentatively more so increasing tactile sensitivity. Moreover, they lend support multimodal accounts research on aid devices.

Language: Английский

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Touch Helps Hearing: Evidence From Continuous Audio-Tactile Stimulation

Ear and Hearing, Journal Year: 2024, Volume and Issue: 46(1), P. 184 - 195

Published: July 24, 2024

Objectives: Identifying target sounds in challenging environments is crucial for daily experiences. It important to note that it can be enhanced by nonauditory stimuli, example, through lip-reading an ongoing conversation. However, how tactile stimuli affect auditory processing still relatively unclear. Recent studies have shown brief reliably facilitate perception, while using longer-lasting audio-tactile stimulation yielded conflicting results. This study aimed investigate the impact of pulsating on basic processing. Design: In experiment 1, electroencephalogram (EEG) was recorded 24 participants performed a loudness-discrimination task 4-Hz modulated tone-in-noise and received either in-phase, anti-phase, or no electrotactile above median nerve. 2, another were presented with same as before, but detection their selective attention manipulated. Results: We found in-phase EEG responses tone, whereas anti-phase suppressed these responses. No corresponding effects performance observed 1. Using yes/no paradigm we stimulation, not improved thresholds. Selective also thresholds did modulate benefit from stimulation. Conclusions: Our highlights input enhance reflected scalp might implications development hearing enhancement technologies interventions.

Language: Английский

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A standardised open science framework for sharing and re-analysing neural data acquired to continuous stimuli

Neurons Behavior Data analysis and Theory, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 16, 2024

Neurophysiology research has demonstrated that it is possible and valuable to investigate sensory processing in scenarios involving continuous streams, such as speech music. Over the past 10 years or so, novel analytic frameworks combined with growing participation data sharing led a surge of publicly available datasets experiments. However, open science efforts this domain remain scattered, lacking cohesive set guidelines. This paper presents an end-to-end framework for storage, analysis, sharing, re-analysis neural recorded during We propose structure builds on existing custom structures (Continuous-event Neural Data CND), providing precise naming conventions types, well workflow storing loading general-purpose BIDS structure. The been designed interface EEG/MEG analysis toolboxes, Eelbrain, NAPLib, MNE, mTRF-Toolbox. present guidelines by taking both user view (rapidly re-analyse data) experimenter (store, analyse, share), making process straightforward accessible. Additionally, we introduce web-based browser enables effortless replication published results re-analysis.

Language: Английский

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AVbook, a high-frame-rate corpus of narrative audiovisual speech for investigating multimodal speech perception

The Journal of the Acoustical Society of America, Journal Year: 2023, Volume and Issue: 153(5), P. 3130 - 3130

Published: May 1, 2023

Seeing a speaker's face can help substantially with understanding their speech, particularly in challenging listening conditions. Research into the neurobiological mechanisms behind audiovisual integration has recently begun to employ continuous natural speech. However, these efforts are impeded by lack of high-quality recordings speaker narrating longer text. Here, we seek close this gap developing AVbook, an speech corpus designed for cognitive neuroscience studies and recognition. The consists 3.6 h two speakers, one male female, each reading 59 passages from narrative English were acquired at high frame rate 119.88 frames/s. includes phone-level alignment files set multiple-choice questions test attention different passages. We verified efficacy pilot study. A short written summary is also provided recording. To enable synchronization when presenting stimuli, four videos electronic clapperboard recorded corpus. publicly available support research neurobiology processing as well development computer algorithms

Language: Английский

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