Cargando…
Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked
BACKGROUND: Transcranial ultrasound stimulation (TUS) is emerging as a potentially powerful, non-invasive technique for focal brain stimulation. Recent animal work suggests, however, that TUS effects may be confounded by indirect stimulation of early auditory pathways. OBJECTIVE: We aimed to investi...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Elsevier
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7710976/ https://www.ncbi.nlm.nih.gov/pubmed/32891872 http://dx.doi.org/10.1016/j.brs.2020.08.014 |
_version_ | 1783618046310481920 |
---|---|
author | Braun, Verena Blackmore, Joseph Cleveland, Robin O. Butler, Christopher R. |
author_facet | Braun, Verena Blackmore, Joseph Cleveland, Robin O. Butler, Christopher R. |
author_sort | Braun, Verena |
collection | PubMed |
description | BACKGROUND: Transcranial ultrasound stimulation (TUS) is emerging as a potentially powerful, non-invasive technique for focal brain stimulation. Recent animal work suggests, however, that TUS effects may be confounded by indirect stimulation of early auditory pathways. OBJECTIVE: We aimed to investigate in human participants whether TUS elicits audible sounds and if these can be masked by an audio signal. METHODS: In 18 healthy participants, T1-weighted magnetic resonance brain imaging was acquired for 3D ultrasound simulations to determine optimal transducer placements and source amplitudes. Thermal simulations ensured that temperature rises were <0.5 °C at the target and <3 °C in the skull. To test for non-specific auditory activation, TUS (500 kHz, 300 ms burst, modulated at 1 kHz with 50% duty cycle) was applied to primary visual cortex and participants were asked to distinguish stimulation from non-stimulation trials. EEG was recorded throughout the task. Furthermore, ex-vivo skull experiments tested for the presence of skull vibrations during TUS. RESULTS: We found that participants can hear sound during TUS and can distinguish between stimulation and non-stimulation trials. This was corroborated by EEG recordings indicating auditory activation associated with TUS. Delivering an audio waveform to participants through earphones while TUS was applied reduced detection rates to chance level and abolished the TUS-induced auditory EEG signal. Ex vivo skull experiments demonstrated that sound is conducted through the skull at the pulse repetition frequency of the ultrasound. CONCLUSION: Future studies using TUS in humans need to take this auditory confound into account and mask stimulation appropriately. |
format | Online Article Text |
id | pubmed-7710976 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Elsevier |
record_format | MEDLINE/PubMed |
spelling | pubmed-77109762020-12-09 Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked Braun, Verena Blackmore, Joseph Cleveland, Robin O. Butler, Christopher R. Brain Stimul Article BACKGROUND: Transcranial ultrasound stimulation (TUS) is emerging as a potentially powerful, non-invasive technique for focal brain stimulation. Recent animal work suggests, however, that TUS effects may be confounded by indirect stimulation of early auditory pathways. OBJECTIVE: We aimed to investigate in human participants whether TUS elicits audible sounds and if these can be masked by an audio signal. METHODS: In 18 healthy participants, T1-weighted magnetic resonance brain imaging was acquired for 3D ultrasound simulations to determine optimal transducer placements and source amplitudes. Thermal simulations ensured that temperature rises were <0.5 °C at the target and <3 °C in the skull. To test for non-specific auditory activation, TUS (500 kHz, 300 ms burst, modulated at 1 kHz with 50% duty cycle) was applied to primary visual cortex and participants were asked to distinguish stimulation from non-stimulation trials. EEG was recorded throughout the task. Furthermore, ex-vivo skull experiments tested for the presence of skull vibrations during TUS. RESULTS: We found that participants can hear sound during TUS and can distinguish between stimulation and non-stimulation trials. This was corroborated by EEG recordings indicating auditory activation associated with TUS. Delivering an audio waveform to participants through earphones while TUS was applied reduced detection rates to chance level and abolished the TUS-induced auditory EEG signal. Ex vivo skull experiments demonstrated that sound is conducted through the skull at the pulse repetition frequency of the ultrasound. CONCLUSION: Future studies using TUS in humans need to take this auditory confound into account and mask stimulation appropriately. Elsevier 2020 /pmc/articles/PMC7710976/ /pubmed/32891872 http://dx.doi.org/10.1016/j.brs.2020.08.014 Text en © 2020 The Authors http://creativecommons.org/licenses/by/4.0/ This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Braun, Verena Blackmore, Joseph Cleveland, Robin O. Butler, Christopher R. Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title | Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title_full | Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title_fullStr | Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title_full_unstemmed | Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title_short | Transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
title_sort | transcranial ultrasound stimulation in humans is associated with an auditory confound that can be effectively masked |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7710976/ https://www.ncbi.nlm.nih.gov/pubmed/32891872 http://dx.doi.org/10.1016/j.brs.2020.08.014 |
work_keys_str_mv | AT braunverena transcranialultrasoundstimulationinhumansisassociatedwithanauditoryconfoundthatcanbeeffectivelymasked AT blackmorejoseph transcranialultrasoundstimulationinhumansisassociatedwithanauditoryconfoundthatcanbeeffectivelymasked AT clevelandrobino transcranialultrasoundstimulationinhumansisassociatedwithanauditoryconfoundthatcanbeeffectivelymasked AT butlerchristopherr transcranialultrasoundstimulationinhumansisassociatedwithanauditoryconfoundthatcanbeeffectivelymasked |