To evaluate the effects of tDCS on modulating and stydying frontal brain asymmetry.
ID
Source
Brief title
Condition
- Neurological disorders NEC
- Psychiatric and behavioural symptoms NEC
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
1. Cerebral physiology: Transcranial magnetic stimulation (TMS) will be used to
examine brain asymmetry by measuring cortical excitability of the left and
right hemisphere, and left-to-right and right-to-left inter-hemispheric
connectivity (see also Protocol 07-044/O) (page 5-7 of the protocol).
2. Background electroencephalogram: To monitor changes in electric activity an
background electroencephalogram (EEG) will be recorded from 32 scalp locations
according to the International 10-20 EEG System using Ag*AgCl-tipped electrodes
(sampling rate: 256 Hz) before and immediately after tDCS (page 7-8 of the
protocol).
3. Mood will be monitored using the 20-item Profile of Mood States
questionnaire (Shacham, 1983) (duration: 10 min). Selective attention for
emotional faces will be indexed using an emotional Stroop task comparing
colour-naming latencies for neutral, angry, fearful and happy faces (page 8 of
the protocol).
Secondary outcome
not applicable.
Background summary
Repetitive transcranial magnetic stimulation (rTMS) is a valuable non-invasive
method that employs magnetic fields to induce current densities of ~20 mA/cm2
to investigate frontal brain asymmetries. Alternatively, transcranial direct
current stimulation (tDCS) applies weak electrical currents 0.029 mA/cm2
directly to the scalp and is suggested to sort effects similar to rTMS.
Importantly, tDCS has several advantages over rTMS which include exposure to
weak currents, no physical discomfort, and placebo controlled designs.
Study objective
To evaluate the effects of tDCS on modulating and stydying frontal brain
asymmetry.
Study design
Placebo controlled double-blind cross-over design.
The experiment will consist of four sessions of one hour.
Procedure
Session 1: intake: screening, questionnaire, EEG recording, cortical
excitability measurement (TMS), attention task
Session 2: test1: questionnaire, tDCS1, questionnaire, EEG recording, cortical
excitability measurement (TMS), attention task
Session 3: test2: questionnaire, tDCS2, questionnaire, EEG recording, cortical
excitability measurement (TMS), attention task
Session 4: test3: questionnaire, tDCS3, questionnaire, EEG recording, cortical
excitability measurement (TMS), attention task
Intervention
Transcranial direct current stimulation (tDCS) will be delivered by a
battery-driven constant DC current stimulator (Eldith DC Stimulator (CE 0118),
Ilmenau) using a pair of electrodes in a 5-7 cm (35 cm2) saline-soaked
synthetic sponge at a current intensity of 1 mA for 15 minutes on three
separate sessions.
1- Cl-Ar tDCS: Cathodal electrode left frontal cortex * anodal electrode right
frontal cortex (1 mA/ 35 cm2, 15 min)
2- Al-Cr tDCS: Anodal electrode left frontal cortex * anodal electrode right
frontal cortex (1 mA/ 35 cm2, 15 min)
3- Placebo tDCS: Random montage (0 mA/ 35 cm2, 15 min)
Study burden and risks
Transcranial direct current stimulation (tDCS) is a painless method that
applies weak electric currents to the scalp which are able to temporarily
modulate brain activity. This technique does not carry any known risk.
Transcranial magnetic stimulation (TMS) is a method that applies magnetic
pulses to scalp to excite neurons in the motor cortex. This neural excitation
causes small hand movements of the muscles that can be recorded using
electrodes attached to the hand. The main concern when using TMS is its
potential to induce a seizure. Safety guidelines, including the limits of
stimulation intensity, monitoring of subjects, medical management of induced
seizures and contraindications to rTMS as described by the International
Federation of Clinical Neurophysiology (Wassermann, 1998) will be followed
strictly, to minimize seizure risk. Other potential adverse effects of rTMS
include induction of a muscle tension headache. These are generally mild
discomforts that respond promptly to common analgesics.
With EEG electric brain activity can be recorded from the scalp using a cap
containing electrodes. EEG technique is safe and utilizes gel (salt solution)
to make contacts between the scalp en electrode. Some people may experience the
cap and gel as a little bit uncomfortable.
Questionnaires an a short attention task will administered to monitor mood and
cognitive performance. Neither of these measures carry any significant risk
Procedure will be identical across test sessions (only the applied tDCS varies)
and each session will last for maximal 1 hour. Duration of total study is 4
hours.
Notably, volunteers can withdraw from the study at any given time for any given
reason or for no reason at all.
Heidelberglaan 2
3584CS Utrecht
Nederland
Heidelberglaan 2
3584CS Utrecht
Nederland
Listed location countries
Age
Inclusion criteria
Non-smoking, right-handed, 18-35 years
Exclusion criteria
Skin disease, metal in cranium, use of psychotropic drugs, including cannabis, XTC, amphetamines and cocaine, epilepsy or family history of epilepsy, history of closed-head injury, history of neurological or psychiatric disorders, medication use (i.e., benzodiazepines, antidepressants and neuroleptica), cardiac pacemaker, pregancy, of electronic hearing devices.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL25351.041.08 |