1
|
Biačková N, Adamová A, Klírová M. Transcranial alternating current stimulation in affecting cognitive impairment in psychiatric disorders: a review. Eur Arch Psychiatry Clin Neurosci 2024; 274:803-826. [PMID: 37682331 PMCID: PMC11127835 DOI: 10.1007/s00406-023-01687-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 08/21/2023] [Indexed: 09/09/2023]
Abstract
Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation method that, through its manipulation of endogenous oscillations, can affect cognition in healthy adults. Given the fact that both endogenous oscillations and cognition are impaired in various psychiatric diagnoses, tACS might represent a suitable intervention. We conducted a search of Pubmed and Web of Science databases and reviewed 27 studies where tACS is used in psychiatric diagnoses and cognition change is evaluated. TACS is a safe and well-tolerated intervention method, suitable for multiple-sessions protocols. It can be administered at home, individualized according to the patient''s anatomical and functional characteristics, or used as a marker of disease progression. The results are varying across diagnoses and applied protocols, with some protocols showing a long-term effect. However, the overall number of studies is small with a great variety of diagnoses and tACS parameters, such as electrode montage or used frequency. Precise mechanisms of tACS interaction with pathophysiological processes are only partially described and need further research. Currently, tACS seems to be a feasible method to alleviate cognitive impairment in psychiatric patients; however, a more robust confirmation of efficacy of potential protocols is needed to introduce it into clinical practise.
Collapse
Affiliation(s)
- Nina Biačková
- Neurostimulation Department, National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Andrea Adamová
- Neurostimulation Department, National Institute of Mental Health, Klecany, Czech Republic
- Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Monika Klírová
- Neurostimulation Department, National Institute of Mental Health, Klecany, Czech Republic.
- Third Faculty of Medicine, Charles University, Prague, Czech Republic.
| |
Collapse
|
2
|
de la Salle S, Choueiry J, Payumo M, Devlin M, Noel C, Abozmal A, Hyde M, Baysarowich R, Duncan B, Knott V. Transcranial Alternating Current Stimulation Alters Auditory Steady-State Oscillatory Rhythms and Their Cross-Frequency Couplings. Clin EEG Neurosci 2024; 55:329-339. [PMID: 37306065 PMCID: PMC11020127 DOI: 10.1177/15500594231179679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 05/02/2023] [Indexed: 06/13/2023]
Abstract
Auditory cortical plasticity deficits in schizophrenia are evidenced with electroencephalographic (EEG)-derived biomarkers, including the 40-Hz auditory steady-state response (ASSR). Aiming to understand the underlying oscillatory mechanisms contributing to the 40-Hz ASSR, we examined its response to transcranial alternating current stimulation (tACS) applied bilaterally to the temporal lobe of 23 healthy participants. Although not responding to gamma tACS, the 40-Hz ASSR was modulated by theta tACS (vs sham tACS), with reductions in gamma power and phase locking being accompanied by increases in theta-gamma phase-amplitude cross-frequency coupling. Results reveal that oscillatory changes induced by frequency-tuned tACS may be one approach for targeting and modulating auditory plasticity in normal and diseased brains.
Collapse
Affiliation(s)
- Sara de la Salle
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
- Faculty of Medicine, School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Joëlle Choueiry
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Mark Payumo
- School of Psychology, Carleton University, Ottawa, ON, Canada
| | - Matt Devlin
- Faculty of Medicine, School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Chelsea Noel
- Faculty of Medicine, School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Ali Abozmal
- Faculty of Medicine, School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Molly Hyde
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Renée Baysarowich
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Brittany Duncan
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
| | - Verner Knott
- Clinical Neuroelectrophysiology and Cognitive Research, The Royal's Institute of Mental Health Research, Ottawa, ON, Canada
- Faculty of Medicine, School of Psychology, University of Ottawa, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Psychology, Carleton University, Ottawa, ON, Canada
| |
Collapse
|
3
|
Jones KT, Gallen CL, Ostrand AE, Rojas JC, Wais P, Rini J, Chan B, Lago AL, Boxer A, Zhao M, Gazzaley A, Zanto TP. Gamma neuromodulation improves episodic memory and its associated network in amnestic mild cognitive impairment: a pilot study. Neurobiol Aging 2023; 129:72-88. [PMID: 37276822 PMCID: PMC10583532 DOI: 10.1016/j.neurobiolaging.2023.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 04/10/2023] [Accepted: 04/17/2023] [Indexed: 06/07/2023]
Abstract
Amnestic mild cognitive impairment (aMCI) is a predementia stage of Alzheimer's disease associated with dysfunctional episodic memory and limited treatment options. We aimed to characterize feasibility, clinical, and biomarker effects of noninvasive neurostimulation for aMCI. 13 individuals with aMCI received eight 60-minute sessions of 40-Hz (gamma) transcranial alternating current stimulation (tACS) targeting regions related to episodic memory processing. Feasibility, episodic memory, and plasma Alzheimer's disease biomarkers were assessed. Neuroplastic changes were characterized by resting-state functional connectivity (RSFC) and neuronal excitatory/inhibitory balance. Gamma tACS was feasible and aMCI participants demonstrated improvement in multiple metrics of episodic memory, but no changes in biomarkers. Improvements in episodic memory were most pronounced in participants who had the highest modeled tACS-induced electric fields and exhibited the greatest changes in RSFC. Increased RSFC was also associated with greater hippocampal excitability and higher baseline white matter integrity. This study highlights initial feasibility and the potential of gamma tACS to rescue episodic memory in an aMCI population by modulating connectivity and excitability within an episodic memory network.
Collapse
Affiliation(s)
- Kevin T Jones
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA.
| | - Courtney L Gallen
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA
| | - Avery E Ostrand
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA
| | - Julio C Rojas
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Weill Institute for Neurosciences, Memory and Aging Center, University of California-San Francisco, San Francisco, CA
| | - Peter Wais
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA
| | - James Rini
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA
| | - Brandon Chan
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Weill Institute for Neurosciences, Memory and Aging Center, University of California-San Francisco, San Francisco, CA
| | - Argentina Lario Lago
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Weill Institute for Neurosciences, Memory and Aging Center, University of California-San Francisco, San Francisco, CA
| | - Adam Boxer
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Weill Institute for Neurosciences, Memory and Aging Center, University of California-San Francisco, San Francisco, CA
| | - Min Zhao
- Departments of Ophthalmology and Vision Science and Dermatology, Institute for Regenerative Cures, University of California-Davis, Davis, CA
| | - Adam Gazzaley
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA; Departments of Physiology and Psychiatry, University of California-San Francisco, San Francisco, CA
| | - Theodore P Zanto
- Department of Neurology, University of California-San Francisco, San Francisco, CA; Neuroscape, University of California-San Francisco, San Francisco, CA.
| |
Collapse
|
4
|
Jones KT, Ostrand AE, Gazzaley A, Zanto TP. Enhancing cognitive control in amnestic mild cognitive impairment via at-home non-invasive neuromodulation in a randomized trial. Sci Rep 2023; 13:7435. [PMID: 37156876 PMCID: PMC10167304 DOI: 10.1038/s41598-023-34582-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 05/03/2023] [Indexed: 05/10/2023] Open
Abstract
Individuals with multi-domain amnestic mild cognitive impairment (md-aMCI) have an elevated risk of dementia and need interventions that may retain or remediate cognitive function. In a feasibility pilot study, 30 older adults aged 60-80 years with md-aMCI were randomized to 8 sessions of transcranial alternating current stimulation (tACS) with simultaneous cognitive control training (CCT). The intervention took place within the participant's home without direct researcher assistance. Half of the participants received prefrontal theta tACS during CCT and the other half received control tACS. We observed high tolerability and adherence for at-home tACS + CCT. Within 1-week, only those who received theta tACS exhibited improved attentional abilities. Neuromodulation is feasible for in-home settings, which can be conducted by the patient, thereby enabling treatment in difficult to reach populations. TACS with CCT may facilitate cognitive control abilities in md-aMCI, but research in a larger population is needed to validate efficacy.
Collapse
Affiliation(s)
- Kevin T Jones
- Department of Neurology, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA.
- Neuroscape, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA.
- Sandler Neurosciences Center, 675 Nelson Rising Lane, San Francisco, CA, 94158, USA.
| | - Avery E Ostrand
- Department of Neurology, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
- Neuroscape, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
| | - Adam Gazzaley
- Department of Neurology, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
- Neuroscape, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
- Departments of Physiology and Psychiatry, University of California-San Francisco, 675 18th St, San Francisco, CA, 94143, USA
| | - Theodore P Zanto
- Department of Neurology, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
- Neuroscape, University of California-San Francisco, 675 Nelson Rising Ln, San Francisco, CA, 94158, USA
| |
Collapse
|
5
|
He Y, Liu S, Chen L, Ke Y, Ming D. Neurophysiological mechanisms of transcranial alternating current stimulation. Front Neurosci 2023; 17:1091925. [PMID: 37090788 PMCID: PMC10117687 DOI: 10.3389/fnins.2023.1091925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/20/2023] [Indexed: 04/09/2023] Open
Abstract
Neuronal oscillations are the primary basis for precise temporal coordination of neuronal processing and are linked to different brain functions. Transcranial alternating current stimulation (tACS) has demonstrated promising potential in improving cognition by entraining neural oscillations. Despite positive findings in recent decades, the results obtained are sometimes rife with variance and replicability problems, and the findings translation to humans is quite challenging. A thorough understanding of the mechanisms underlying tACS is necessitated for accurate interpretation of experimental results. Animal models are useful for understanding tACS mechanisms, optimizing parameter administration, and improving rational design for broad horizons of tACS. Here, we review recent electrophysiological advances in tACS from animal models, as well as discuss some critical issues for results coordination and translation. We hope to provide an overview of neurophysiological mechanisms and recommendations for future consideration to improve its validity, specificity, and reproducibility.
Collapse
Affiliation(s)
- Yuchen He
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Shuang Liu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Long Chen
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Yufeng Ke
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Dong Ming
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
- Department of Biomedical Engineering, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
- Tianjin International Joint Research Center for Neural Engineering, Tianjin, China
| |
Collapse
|
6
|
Liu Y, Liu S, Tang C, Tang K, Liu D, Chen M, Mao Z, Xia X. Transcranial alternating current stimulation combined with sound stimulation improves cognitive function in patients with Alzheimer's disease: Study protocol for a randomized controlled trial. Front Aging Neurosci 2023; 14:1068175. [PMID: 36698862 PMCID: PMC9869764 DOI: 10.3389/fnagi.2022.1068175] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
Background The number of patients with Alzheimer's disease (AD) worldwide is increasing yearly, but the existing treatment methods have poor efficacy. Transcranial alternating current stimulation (tACS) is a new treatment for AD, but the offline effect of tACS is insufficient. To prolong the offline effect, we designed to combine tACS with sound stimulation to maintain the long-term post-effect. Materials and methods To explore the safety and effectiveness of tACS combined with sound stimulation and its impact on the cognition of AD patients. This trial will recruit 87 patients with mild to moderate AD. All patients were randomly divided into three groups. The change in Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) scores from the day before treatment to the end of treatment and 3 months after treatment was used as the main evaluation index. We will also explore the changes in the brain structural network, functional network, and metabolic network of AD patients in each group after treatment. Discussion We hope to conclude that tACS combined with sound stimulation is safe and tolerable in 87 patients with mild to moderate AD under three standardized treatment regimens. Compared with tACS alone or sound alone, the combination group had a significant long-term effect on cognitive improvement. To screen out a better treatment plan for AD patients. tACS combined with sound stimulation is a previously unexplored, non-invasive joint intervention to improve patients' cognitive status. This study may also identify the potential mechanism of tACS combined with sound stimulation in treating mild to moderate AD patients. Clinical Trial Registration Clinicaltrials.gov, NCT05251649. Registered on February 22, 2022.
Collapse
Affiliation(s)
- Yang Liu
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | | | - Can Tang
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Keke Tang
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Di Liu
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Meilian Chen
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Zhiqi Mao
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China,*Correspondence: Zhiqi Mao, ; Xuewei Xia,
| | - Xuewei Xia
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China,*Correspondence: Zhiqi Mao, ; Xuewei Xia,
| |
Collapse
|
7
|
Wang Y, Zhang Y, Hou P, Dong G, Shi L, Li W, Wei R, Li X. Excitability changes induced in the human auditory cortex by transcranial alternating current stimulation. Neurosci Lett 2023; 792:136960. [PMID: 36372094 DOI: 10.1016/j.neulet.2022.136960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 10/18/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022]
Abstract
Transcranial alternating current stimulation (tACS) has been widely studied for its ability to regulate motor, perceptual, and cognitive functions. Given the unique frequency specificity of tACS, it is expected to directly target rhythmic activity in the typical electroencephalogram (EEG) range. After tACS stimulation, changes in stimulation-induced and evoked activities can be inspected. Detecting changes in auditory evoked activity after different frequencies of tACS stimulation will be helpful for further revealing the influence of tACS on the excitation/inhibition of γ activity in the auditory cortex. Using a randomized repeated measures design, this study assessed the effects of alpha(α)-tACS and gamma(γ)-tACS on the auditory steady-state response (ASSR) in 11 normal-hearing participants. Participants attended four sessions held at least one week apart, receiving tACS or sham treatment. The results indicated that α-tACS had an inhibitory effect on 40-Hz ASSR compared to both γ-tACS and sham tACS, which occurred 30 min after stimulation. Taken together, these findings contribute to the understanding of tACS-induced excitability changes in the human auditory cortex, helping reveal the neurophysiological changes after tACS.
Collapse
Affiliation(s)
- Yao Wang
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China; School of Precision Instruments and Optoelectronics Engineering Tianjin University, Tianjin University, Tianjin 300072, China
| | - Yue Zhang
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Peiyun Hou
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Gaoyuan Dong
- School of Electrical and Electronic Engineering, Tiangong University, Tianjin 300387, China
| | - Limeng Shi
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Weiming Li
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Ran Wei
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Xiaojie Li
- Department of Biomedical Engineering, School of Life Sciences, Tiangong University, Tianjin 300387, China.
| |
Collapse
|
8
|
Günther A, Hanganu-Opatz IL. Neuronal oscillations: early biomarkers of psychiatric disease? Front Behav Neurosci 2022; 16:1038981. [PMID: 36600993 PMCID: PMC9806131 DOI: 10.3389/fnbeh.2022.1038981] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/09/2022] [Indexed: 12/23/2022] Open
Abstract
Our understanding of the environmental and genetic factors contributing to the wide spectrum of neuropsychiatric disorders has significantly increased in recent years. Impairment of neuronal network activity during early development has been suggested as a contributor to the emergence of neuropsychiatric pathologies later in life. Still, the neurobiological substrates underlying these disorders remain yet to be fully understood and the lack of biomarkers for early diagnosis has impeded research into curative treatment options. Here, we briefly review current knowledge on potential biomarkers for emerging neuropsychiatric disease. Moreover, we summarize recent findings on aberrant activity patterns in the context of psychiatric disease, with a particular focus on their potential as early biomarkers of neuropathologies, an essential step towards pre-symptomatic diagnosis and, thus, early intervention.
Collapse
|
9
|
Rahimi V, Mohammadkhani G, Alaghband Rad J, Mousavi SZ, Khalili ME. Modulation of auditory temporal processing, speech in noise perception, auditory-verbal memory, and reading efficiency by anodal tDCS in children with dyslexia. Neuropsychologia 2022; 177:108427. [PMID: 36410540 DOI: 10.1016/j.neuropsychologia.2022.108427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 10/30/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022]
Abstract
Dyslexia is a neurodevelopmental disorder that is prevalent in children. It is estimated that 30-50% of individuals diagnosed with dyslexia also manifest an auditory perceptual deficit characteristic of auditory processing disorder (APD). Some studies suggest that defects in basic auditory processing can lead to phonological defects as the most prominent cause of dyslexia. Thus, in some cases, there may be interrelationships between dyslexia and some of the aspects of central auditory processing. In recent years, transcranial direct current stimulation (tDCS) has been used as a safe method for the modulation of central auditory processing aspects in healthy adults and reading skills in children with dyslexia. Therefore, the objectives of our study were to investigate the effect of tDCS on the modulation of different aspects of central auditory processing, aspects of reading, and the relationship between these two domains in dyslexic children with APD. A within-subjects design was employed to investigate the effect of two electrode arrays (the anode on the left STG (AC)/cathode on the right shoulder and anode on the left STG/cathode on the right STG) on auditory temporal processing; speech-in-noise perception, short-term auditory memory; and high-frequency word, low-frequency word, pseudoword, and text reading. The results of this clinical trial showed the modulation of the studied variables in central auditory processing and the accuracy and speed of reading variables compared to the control and sham statuses in both electrode arrays. Our results also showed that the improvement of the accuracy and speed of text reading, as well as the accuracy of pseudoword reading were related to the improvement of speech in noise perception and temporal processing. The results of this research can be effective in clarifying the basis of the neurobiology of dyslexia and, in particular, the hypothesis of the role of basic auditory processing and subsequently the role of the auditory cortex in dyslexia. These results might provide a framework to facilitate behavioral rehabilitation in dyslexic children with APD.
Collapse
Affiliation(s)
- Vida Rahimi
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Science, Tehran, Iran
| | - Ghassem Mohammadkhani
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Science, Tehran, Iran.
| | - Javad Alaghband Rad
- Department of Psychiatry, Tehran University of Medical Sciences, Roozbeh Hospital, Tehran, Iran
| | - Seyyedeh Zohre Mousavi
- Department of Speech Therapy, School of Rehabilitation, Iran University of Medical Science, Tehran, Iran
| | - Mohammad Ehsan Khalili
- Department of Audiology, School of Rehabilitation, Tehran University of Medical Science, Tehran, Iran
| |
Collapse
|
10
|
Zhang C, Li Y, Huang S, Yang L, Zhao H. Effects of Different Types of Electric Fields on Mechanical Properties and Microstructure of Ex Vivo Porcine Brain Tissues. ACS Biomater Sci Eng 2022; 8:5349-5360. [PMID: 36346997 DOI: 10.1021/acsbiomaterials.2c00456] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Electrotherapy plays a crucial role in regulating neuronal activity. Nevertheless, the relevant therapeutic mechanisms are still unclear; thus, the effects of electric fields on brain tissue's mechanical properties and microstructure need to be explored. In this study, focusing on the changes in mechanical properties and microstructure of ex vivo porcine brain tissues under different types of electric fields, directional and alternating electric fields (frequencies of 5, 20, 50, and 80 Hz, respectively) integrate with a custom-designed indentation device. The experimental results showed that for the ex vivo brain tissue, the directional electric field (DEF) can reduce the elastic properties of brain tissue. Simultaneously, the DEF can increase the cell spacing and reduce the proteoglycan content. The transmission electron microscope (TEM) analysis observed that the DEF can reduce the integrity of the plasma membrane, the endoplasmic reticulum's stress response, and the myelin lamella's separation. The alternating electric field (AEF) can accelerate the stress relaxation process of brain tissue and change the time-dependent mechanical properties of brain tissue. Meanwhile, with the increase in frequency, the cell spacing decreased, and the proteoglycan content gradually approached the control group without electric fields. TEM analysis observed that with the increase in frequency, the integrity of the plasma membrane increases, and the separation of the myelin lamella gradually disappears. Understanding the changes in the mechanical properties and microstructure of brain tissue under AEF and DEF enables a preliminary exploration of the therapeutic mechanism of electrotherapy. Simultaneously, the essential data was provided to support the development of embedded electrodes. In addition, the ex vivo experiments build a solid foundation for future in vivo experiments.
Collapse
Affiliation(s)
- Chi Zhang
- School of Mechanical & Aerospace Engineering, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China.,Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China
| | - Yiqiang Li
- School of Mechanical & Aerospace Engineering, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China.,Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China
| | - Sai Huang
- School of Mathematics and Statistics, Northeast Normal University, 5268 Renmin Street, Changchun130024, P. R. China
| | - Li Yang
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun130062, P. R. China
| | - Hongwei Zhao
- School of Mechanical & Aerospace Engineering, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China.,Key Laboratory of CNC Equipment Reliability, Ministry of Education, Jilin University, 5988 Renmin Street, Changchun130025, P. R. China
| |
Collapse
|
11
|
Liu Y, Tang C, Wei K, Liu D, Tang K, Chen M, Xia X, Mao Z. Transcranial alternating current stimulation combined with sound stimulation improves the cognitive function of patients with Alzheimer's disease: A case report and literature review. Front Neurol 2022; 13:962684. [PMID: 36212652 PMCID: PMC9539040 DOI: 10.3389/fneur.2022.962684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a relatively new non-invasive brain electrical stimulation method for the treatment of patients with Alzheimer's disease (AD), but it has poor offline effects. Therefore, we applied a new combined stimulation method to observe the offline effect on the cognitive function of patients with AD. Here, we describe the clinical results of a case in which tACS combined with sound stimulation was applied to treat moderate AD. The patient was a 73-year-old woman with a 2-year history of persistent cognitive deterioration despite the administration of Aricept and Sodium Oligomannate. Therefore, the patient received tACS combined with sound stimulation. Her cognitive scale scores improved after 15 sessions and continued to improve at 4 months of follow-up. Although the current report may provide a new alternative therapy for patients with AD, more clinical data are needed to support its efficacy.
Collapse
Affiliation(s)
- Yang Liu
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Can Tang
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Kailun Wei
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Di Liu
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Keke Tang
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Meilian Chen
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Xuewei Xia
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
- *Correspondence: Xuewei Xia
| | - Zhiqi Mao
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
- Zhiqi Mao
| |
Collapse
|
12
|
Wu M, Luo B, Yu Y, Li X, Gao J, Li J, Sorger B, Riecke L. Rhythmic musical-electrical trigeminal nerve stimulation improves impaired consciousness. Neuroimage Clin 2022; 36:103170. [PMID: 36063757 PMCID: PMC9460811 DOI: 10.1016/j.nicl.2022.103170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/27/2022] [Accepted: 08/23/2022] [Indexed: 12/14/2022]
Abstract
Accumulating evidence shows that consciousness is linked to neural oscillations in the thalamocortical system, suggesting that deficits in these oscillations may underlie disorders of consciousness (DOC). However, patient-friendly non-invasive treatments targeting this functional anomaly are still missing and the therapeutic value of oscillation restoration has remained unclear. We propose a novel approach that aims to restore DOC patients' thalamocortical oscillations by combining rhythmic trigeminal-nerve stimulation with comodulated musical stimulation ("musical-electrical TNS"). In a double-blind, placebo-controlled, parallel-group study, we recruited 63 patients with DOC and randomly assigned them to groups receiving gamma, beta, or sham musical-electrical TNS. The stimulation was applied for 40 min on five consecutive days. We measured patients' consciousness before and after the stimulation using behavioral indicators and neural responses to rhythmic auditory speech. We further assessed their outcomes one year later. We found that musical-electrical TNS reliably lead to improvements in consciousness and oscillatory brain activity at the stimulation frequency: 43.5 % of patients in the gamma group and 25 % of patients in the beta group showed an improvement of their diagnosis after being treated with the stimulation. This group of benefitting patients still showed more positive outcomes one year later. Moreover, patients with stronger behavioral benefits showed stronger improvements in oscillatory brain activity. These findings suggest that brain oscillations contribute to consciousness and that musical-electrical TNS may serve as a promising approach to improve consciousness and predict long-term outcomes in patients with DOC.
Collapse
Affiliation(s)
- Min Wu
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China,Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Benyan Luo
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China,Corresponding author.
| | - Yamei Yu
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoxia Li
- Department of Neurology & Brain Medical Centre, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jian Gao
- Hangzhou Mingzhou Brain Rehabilitation Hospital, Hangzhou, China
| | - Jingqi Li
- Hangzhou Mingzhou Brain Rehabilitation Hospital, Hangzhou, China
| | - Bettina Sorger
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Lars Riecke
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| |
Collapse
|
13
|
Structural and functional network mechanisms of rescuing cognitive control in aging. Neuroimage 2022; 262:119547. [DOI: 10.1016/j.neuroimage.2022.119547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 07/13/2022] [Accepted: 08/04/2022] [Indexed: 11/23/2022] Open
|
14
|
Applications of open-source software ROAST in clinical studies: A review. Brain Stimul 2022; 15:1002-1010. [PMID: 35843597 PMCID: PMC9378654 DOI: 10.1016/j.brs.2022.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/09/2022] [Accepted: 07/10/2022] [Indexed: 11/21/2022] Open
Abstract
Background: Transcranial electrical stimulation (TES) is broadly investigated as a therapeutic technique for a wide range of neurological disorders. The electric fields induced by TES in the brain can be estimated by computational models. A realistic and volumetric approach to simulate TES (ROAST) has been recently released as an open-source software package and has been widely used in TES research and its clinical applications. Rigor and reproducibility of TES studies have recently become a concern, especially in the context of computational modeling. Methods: Here we reviewed 94 clinical TES studies that leveraged ROAST for computational modeling. When reviewing each study, we pay attention to details related to the rigor and reproducibility as defined by the locations of stimulation electrodes and the dose of stimulating current. Specifically, we compared across studies the electrode montages, stimulated brain areas, achieved electric field strength, and the relations between modeled electric field and clinical outcomes. Results: We found that over 1800 individual heads have been modeled by ROAST for more than 30 different clinical applications. Similar electric field intensities were found to be reproducible by ROAST across different studies at the same brain area under same or similar stimulation montages. Conclusion: This article reviews the use cases of ROAST and provides an overview of how ROAST has been leveraged to enhance the rigor and reproducibility of TES research and its applications.
Collapse
|
15
|
Johnson EL, Yin Q, O'Hara NB, Tang L, Jeong JW, Asano E, Ofen N. Dissociable oscillatory theta signatures of memory formation in the developing brain. Curr Biol 2022; 32:1457-1469.e4. [PMID: 35172128 PMCID: PMC9007830 DOI: 10.1016/j.cub.2022.01.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/15/2021] [Accepted: 01/19/2022] [Indexed: 11/16/2022]
Abstract
Understanding complex human brain functions is critically informed by studying such functions during development. Here, we addressed a major gap in models of human memory by leveraging rare direct electrophysiological recordings from children and adolescents. Specifically, memory relies on interactions between the medial temporal lobe (MTL) and prefrontal cortex (PFC), and the maturation of these interactions is posited to play a key role in supporting memory development. To understand the nature of MTL-PFC interactions, we examined subdural recordings from MTL and PFC in 21 neurosurgical patients aged 5.9-20.5 years as they performed an established scene memory task. We determined signatures of memory formation by comparing the study of subsequently recognized to forgotten scenes in single trials. Results establish that MTL and PFC interact via two distinct theta mechanisms, an ∼3-Hz oscillation that supports amplitude coupling and slows down with age and an ∼7-Hz oscillation that supports phase coupling and speeds up with age. Slow and fast theta interactions immediately preceding scene onset further explained age-related differences in recognition performance. Last, with additional diffusion imaging data, we linked both functional mechanisms to the structural maturation of the cingulum tract. Our findings establish system-level dynamics of memory formation and suggest that MTL and PFC interact via increasingly dissociable mechanisms as memory improves across development.
Collapse
Affiliation(s)
- Elizabeth L Johnson
- Life-Span Cognitive Neuroscience Program, Institute of Gerontology and Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI 48202, USA; Departments of Medical Social Sciences and Pediatrics, Northwestern University, Chicago, IL 60611, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Qin Yin
- Life-Span Cognitive Neuroscience Program, Institute of Gerontology and Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI 48202, USA; Department of Psychology, Wayne State University, Detroit, MI 48202, USA
| | - Nolan B O'Hara
- Translational Neuroscience Program, Wayne State University, Detroit, MI 48201, USA
| | - Lingfei Tang
- Life-Span Cognitive Neuroscience Program, Institute of Gerontology and Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI 48202, USA; Department of Psychology, Wayne State University, Detroit, MI 48202, USA
| | - Jeong-Won Jeong
- Translational Neuroscience Program, Wayne State University, Detroit, MI 48201, USA; Departments of Pediatrics and Neurology, Children's Hospital of Michigan, Wayne State University, Detroit, MI 48201, USA
| | - Eishi Asano
- Translational Neuroscience Program, Wayne State University, Detroit, MI 48201, USA; Departments of Pediatrics and Neurology, Children's Hospital of Michigan, Wayne State University, Detroit, MI 48201, USA
| | - Noa Ofen
- Life-Span Cognitive Neuroscience Program, Institute of Gerontology and Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI 48202, USA; Department of Psychology, Wayne State University, Detroit, MI 48202, USA; Translational Neuroscience Program, Wayne State University, Detroit, MI 48201, USA.
| |
Collapse
|
16
|
Johnson EL, Arciniega H, Jones KT, Kilgore-Gomez A, Berryhill ME. Individual predictors and electrophysiological signatures of working memory enhancement in aging. Neuroimage 2022; 250:118939. [PMID: 35104647 PMCID: PMC8923157 DOI: 10.1016/j.neuroimage.2022.118939] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 01/25/2022] [Indexed: 12/21/2022] Open
Abstract
A primary goal of translational neuroscience is to identify the neural mechanisms of age-related cognitive decline and develop protocols to maximally improve cognition. Here, we demonstrate how interventions that apply noninvasive neurostimulation to older adults improve working memory (WM). We found that one session of sham-controlled transcranial direct current stimulation (tDCS) selectively improved WM in older adults with more education, extending earlier work and underscoring the importance of identifying individual predictors of tDCS responsivity. Improvements in WM were associated with two distinct electrophysiological signatures. First, a broad enhancement of theta network synchrony tracked improvements in behavioral accuracy, with tDCS effects moderated by education level. Further analysis revealed that accuracy dynamics reflected an anterior-posterior network distribution regardless of cathode placement. Second, specific enhancements of theta-gamma phase-amplitude coupling (PAC) reflecting tDCS current flow tracked improvements in reaction time (RT). RT dynamics further explained inter-individual variability in WM improvement independent of education. These findings illuminate theta network synchrony and theta-gamma PAC as distinct but complementary mechanisms supporting WM in aging. Both mechanisms are amenable to intervention, the effectiveness of which can be predicted by individual demographic factors.
Collapse
Affiliation(s)
- Elizabeth L Johnson
- Northwestern University, Departments of Medical Social Sciences and Pediatrics, Chicago, IL, 60611.
| | - Hector Arciniega
- Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02215
| | - Kevin T Jones
- University of California-San Francisco, Department of Neurology, Neuroscape, San Francisco, CA, 94158
| | - Alexandrea Kilgore-Gomez
- Department of Psychology, Program in Cognitive and Brain Sciences, Program in Integrative Neuroscience, University of Nevada, Reno, 89557
| | - Marian E Berryhill
- Department of Psychology, Program in Cognitive and Brain Sciences, Program in Integrative Neuroscience, University of Nevada, Reno, 89557.
| |
Collapse
|
17
|
Gnanateja GN, Devaraju DS, Heyne M, Quique YM, Sitek KR, Tardif MC, Tessmer R, Dial HR. On the Role of Neural Oscillations Across Timescales in Speech and Music Processing. Front Comput Neurosci 2022; 16:872093. [PMID: 35814348 PMCID: PMC9260496 DOI: 10.3389/fncom.2022.872093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 05/24/2022] [Indexed: 11/25/2022] Open
Abstract
This mini review is aimed at a clinician-scientist seeking to understand the role of oscillations in neural processing and their functional relevance in speech and music perception. We present an overview of neural oscillations, methods used to study them, and their functional relevance with respect to music processing, aging, hearing loss, and disorders affecting speech and language. We first review the oscillatory frequency bands and their associations with speech and music processing. Next we describe commonly used metrics for quantifying neural oscillations, briefly touching upon the still-debated mechanisms underpinning oscillatory alignment. Following this, we highlight key findings from research on neural oscillations in speech and music perception, as well as contributions of this work to our understanding of disordered perception in clinical populations. Finally, we conclude with a look toward the future of oscillatory research in speech and music perception, including promising methods and potential avenues for future work. We note that the intention of this mini review is not to systematically review all literature on cortical tracking of speech and music. Rather, we seek to provide the clinician-scientist with foundational information that can be used to evaluate and design research studies targeting the functional role of oscillations in speech and music processing in typical and clinical populations.
Collapse
Affiliation(s)
- G Nike Gnanateja
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Dhatri S Devaraju
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthias Heyne
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Yina M Quique
- Center for Education in Health Sciences, Northwestern University, Chicago, IL, United States
| | - Kevin R Sitek
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Monique C Tardif
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, United States
| | - Rachel Tessmer
- Department of Speech, Language, and Hearing Sciences, The University of Texas at Austin, Austin, TX, United States
| | - Heather R Dial
- Department of Speech, Language, and Hearing Sciences, The University of Texas at Austin, Austin, TX, United States.,Department of Communication Sciences and Disorders, University of Houston, Houston, TX, United States
| |
Collapse
|
18
|
Nooristani M, Augereau T, Moïn-Darbari K, Bacon BA, Champoux F. Using Transcranial Electrical Stimulation in Audiological Practice: The Gaps to Be Filled. Front Hum Neurosci 2021; 15:735561. [PMID: 34887736 PMCID: PMC8650084 DOI: 10.3389/fnhum.2021.735561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/01/2021] [Indexed: 11/30/2022] Open
Abstract
The effects of transcranial electrical stimulation (tES) approaches have been widely studied for many decades in the motor field, and are well known to have a significant and consistent impact on the rehabilitation of people with motor deficits. Consequently, it can be asked whether tES could also be an effective tool for targeting and modulating plasticity in the sensory field for therapeutic purposes. Specifically, could potentiating sensitivity at the central level with tES help to compensate for sensory loss? The present review examines evidence of the impact of tES on cortical auditory excitability and its corresponding influence on auditory processing, and in particular on hearing rehabilitation. Overall, data strongly suggest that tES approaches can be an effective tool for modulating auditory plasticity. However, its specific impact on auditory processing requires further investigation before it can be considered for therapeutic purposes. Indeed, while it is clear that electrical stimulation has an effect on cortical excitability and overall auditory abilities, the directionality of these effects is puzzling. The knowledge gaps that will need to be filled are discussed.
Collapse
Affiliation(s)
- Mujda Nooristani
- École d'Orthophonie et d'Audiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, QC, Canada
| | - Thomas Augereau
- École d'Orthophonie et d'Audiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, QC, Canada
| | - Karina Moïn-Darbari
- École d'Orthophonie et d'Audiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, QC, Canada
| | | | - François Champoux
- École d'Orthophonie et d'Audiologie, Université de Montréal, Montréal, QC, Canada.,Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montréal, QC, Canada
| |
Collapse
|
19
|
Zanto TP, Jones KT, Ostrand AE, Hsu WY, Campusano R, Gazzaley A. Individual differences in neuroanatomy and neurophysiology predict effects of transcranial alternating current stimulation. Brain Stimul 2021; 14:1317-1329. [PMID: 34481095 DOI: 10.1016/j.brs.2021.08.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Noninvasive transcranial electrical stimulation (tES) research has been plagued with inconsistent effects. Recent work has suggested neuroanatomical and neurophysiological variability may alter tES efficacy. However, direct evidence is limited. OBJECTIVE We have previously replicated effects of transcranial alternating current stimulation (tACS) on improving multitasking ability in young adults. Here, we attempt to assess whether these stimulation parameters have comparable effects in older adults (aged 60-80 years), which is a population known to have greater variability in neuroanatomy and neurophysiology. It is hypothesized that this variability in neuroanatomy and neurophysiology will be predictive of tACS efficacy. METHODS We conducted a pre-registered study where tACS was applied above the prefrontal cortex (between electrodes F3-F4) while participants were engaged in multitasking. Participants were randomized to receive either 6-Hz (theta) tACS for 26.67 min daily for three days (80 min total; Long Exposure Theta group), 6-Hz tACS for 5.33 min daily (16-min total; Short Exposure Theta group), or 1-Hz tACS for 26.67 min (80 min total; Control group). To account for neuroanatomy, magnetic resonance imaging data was used to form individualized models of the tACS-induced electric field (EF) within the brain. To account for neurophysiology, electroencephalography data was used to identify individual peak theta frequency. RESULTS Results indicated that only in the Long Theta group, performance change was correlated with modeled EF and peak theta frequency. Together, modeled EF and peak theta frequency accounted for 54%-65% of the variance in tACS-related performance improvements, which sustained for a month. CONCLUSION These results demonstrate the importance of individual differences in neuroanatomy and neurophysiology in tACS research and help account for inconsistent effects across studies.
Collapse
Affiliation(s)
- Theodore P Zanto
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA.
| | - Kevin T Jones
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Avery E Ostrand
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Wan-Yu Hsu
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA
| | - Richard Campusano
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA
| | - Adam Gazzaley
- Department of Neurology, University of California-San Francisco, San Francisco, CA, USA; Neuroscape, University of California-San Francisco, San Francisco, CA, USA; Departments of Physiology and Psychiatry, University of California-San Francisco, San Francisco, CA, USA
| |
Collapse
|