GAMMAtACS: Effects of Gamma-tACS on EEG Periodic Activity
Study Details
Study Description
Brief Summary
In this study on healthy subjects, the effect of transcranial alternating current stimulation (tACS) will be investigated. In particular, the distinction between periodic and aperiodic electroencephalogram (EEG) activity will be considered, as well as the state-dependency phenomenon. Participants will take part in two experimental sessions that will include tACS stimulation (one real, one control). Before, during, and after stimulation, subjects will have their EEG recorded during rest or during tasks.
The aim of this study is to investigate how the modulatory effects of gamma-tACS interact with intrinsic neural activity, measured in terms of periodic and aperiodic activity, as well as neurophysiological and behavioral modulation, taking into consideration the state-dependency phenomenon, which refers to the brain's activation state prior to stimulation.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: real tACS
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Device: real tACS
tACS is a non-invasive method to induce brain modulation. It will be applied at a frequency of 40 Hz (gamma-tACS) with a peak-to-peak intensity of 2 mA. During the real tACS condition, the alternating current will be administered for 20 minutes.
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| Sham Comparator: sham tACS
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Device: sham tACS
In the sham tACS condition, the current will be delivered only for the first 30 seconds and then stopped, in order to simulate the same somatosensory sensations as real tACS, but without inducing modulation.
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Outcome Measures
Primary Outcome Measures
- resting-state electroencephalography (EEG) signal [baseline]
The periodic and aperiodic activity of the EEG signal will be estimated through Brainstorm (i.e., EEG analysis software) and quantified in terms of numerical values representing the periodic/aperiodic component of the EEG signal. The periodic and aperiodic activity of the EEG signal will be assessed during three time frames: baseline, during the intervention, and immediately after the intervention (real or sham tACS)
- resting-state electroencephalography (EEG) signal [during the intervension]
The periodic and aperiodic activity of the EEG signal will be estimated through Brainstorm (i.e., EEG analysis software) and quantified in terms of numerical values representing the periodic/aperiodic component of the EEG signal. The periodic and aperiodic activity of the EEG signal will be assessed during three time frames: baseline, during the intervention, and immediately after the intervention (real or sham tACS)
- resting-state electroencephalography (EEG) signal [immediately after the intervention]
The periodic and aperiodic activity of the EEG signal will be estimated through Brainstorm (i.e., EEG analysis software) and quantified in terms of numerical values representing the periodic/aperiodic component of the EEG signal. The periodic and aperiodic activity of the EEG signal will be assessed during three time frames: baseline, during the intervention, and immediately after the intervention (real or sham tACS)
Secondary Outcome Measures
- behavioral performance (response times) [baseline]
Participants' motor performance at a computerized task will be measured in terms of response times (how fast the participants press a computer button, according to the task's instructions). The participants' motor performance will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
- behavioral performance (response times) [immediately after the intervention]
Participants' motor performance at a computerized task will be measured in terms of response times (how fast the participants press a computer button, according to the task's instructions). The participants' motor performance will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
- behavioral performance (accuracy) [baseline]
Participants' motor performance at a computerized task will be measured in terms of accuracy (% of correct responses at the computerized task, according to the task's instructions). The participants' motor performance will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
- behavioral performance (accuracy) [immediately after the intervention]
Participants' motor performance at a computerized task will be measured in terms of accuracy (% of correct responses at the computerized task, according to the task's instructions). The participants' motor performance will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
- auditory steady state response (ASSR) [baseline]
The auditory steady state response will be measured via EEG during entrainment through exposure to amplitude-modulated 40Hz sounds (5 min, sequence of amplitude-modulated tones at 40 Hz, delivered via earplug binaurally). The auditory steady state response will be measured as power of the EEG gamma band. The auditory steady state response will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
- auditory steady state response (ASSR) [immediately after the intervention]
The auditory steady state response will be measured via EEG during entrainment through exposure to amplitude-modulated 40Hz sounds (5 min, sequence of amplitude-modulated tones at 40 Hz, delivered via earplug binaurally). The auditory steady state response will be measured as power of the EEG gamma band. The auditory steady state response will be assessed during two time frames: baseline and immediately after the intervention (real or sham tACS)
Eligibility Criteria
Criteria
Inclusion Criteria:
- Healthy adults
Exclusion Criteria:
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Common exclusion criteria
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Left-handedness (assessed through the Oldfield test)
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Diagnosis of neurological or psychiatric disorders
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Vision problems that prevent reading, not correctable with lenses
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Diagnosis of substance dependence on drugs or alcohol
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Presence of hearing aids/prostheses
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Diagnosis of epilepsy or family history up to the second degree with it
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Episodes of febrile convulsions or recurrent fainting
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Head trauma
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Presence of surgical clips or metal implants in the head
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Diagnosis of heart disease
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Presence of a cardiac pacemaker or artificial heart valve
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Presence of hearing aids/prostheses
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Hearing problems or tinnitus
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Vision problems not corrected with lenses (such as color blindness)
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Taking tricyclic antidepressant medications
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Taking neuroleptic medications
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Diagnosis of headache or migraine
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Taking more than 3 alcoholic units in the last 24 hours
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Taking 2 or more cups of coffee or caffeine from other sources in the last 2 hours
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | IRCCS San Camillo Hospital | Venice | Italy |
Sponsors and Collaborators
- IRCCS San Camillo, Venezia, Italy
Investigators
- Principal Investigator: Arcara, IRCCS San Camillo Hospital
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 2021.18