The investigators aimed to divide the healthy individuals aged between 18-45 years, included in our study, into three groups as bilateral, unilateral-right and unilateral-left Auricular Vagus Nerve Stimulation (VNS). The investigators planned to examine the effects of vagal nerve stimulation applied to each group with superficial EMG and EEG measurements before and after.

Auricular vagus nerve stimulation has effects on cerebral activity. Therefore, this effect will be evaluated with EEG. In addition, whether there is a secondary peripheral effect will be examined by EMG method.

Changes to be detected in EEG and EMG in healthy individuals may give an idea about the use of auricular vagus nerve stimulation in patients.

In this study, healthy individuals between the ages of 18-45, who do not have any chronic diseases and who do not have to use any medication regularly will be included in all three groups. Due to the superficial EMG measurement method the investigators used, those who have orthopedic problems in the upper extremity (shoulder, elbow, wrist and fingers) or have a history of surgical operation in the upper extremity, however, any systemic disease such as diabetes, gout, chronic kidney failure, rheumatoid arthritis, thyroid diseases individuals will be excluded from the study in all three groups.

Superficial EMG measurement will be made with BIOPAC EMG (Biopac systems, Santa Barbara, CA, USA). Dominant and non-dominant wrist extensor muscle electromyography will be performed with the BIOPAC (Biopac Systems, Santa Barbara, CA, USA) electromyography device and hand grip strength wiil be measured simultaneously with the hand dynamometer of the same device.

A single channel will be used for electromyography measurement , which was taken via surface electrodes (Ag-Cl) over the extensor wrist muscle; the ulnar styloid process will be selected for the ground electrode. Electrodes on the muscle will be placed about 0.5 cm apart. The measurement will be taken in the standard measurement position of the hand dynamometer, with 0° shoulder flexion, 0° shoulder abduction, 90° elbow flexion and forearm in the midline position, in the sitting position, during for 5 seconds of maximum grip.The measurement will be repeated 3 times and root mean square (RMS) calculations will be made with the MATLAB software.

The bioelectrical activity of the brain will be measured with the EMOTIV EPOC+ EEG device.

Auricular Vagus Nerve Stimulation will be performed with a device called VAGUSTIM. Auricular Vagus Nerve Stimulation will be performed for 20 minutes with a frequency of 10 Hz and a pulse width of 300 µs.

The investigators are planning to examine the effects of vagal nerve stimulation, which the investigators will apply to each group using different methods, by examining the effects of vagal nerve stimulation before and after the superficial EMG and EEG measurements as well as the first test and post test measurement in each group, and at the same time, the investigators are planning to evaluate the results the investigators obtained by comparing the results between the groups in all three groups.

Inclusion Criteria:

• Between the ages of 18-45,
• Who do not have any chronic diseases
• Who do not have to use any medication regularly

Exclusion Criteria:

• Due to the superficial EMG measurement method we used,
• Those who have orthopedic problems in the upper extremity (shoulder, elbow, wrist and fingers) or have a history of surgical operation in the upper extremity,
• Systemic disease such as diabetes, gout, chronic kidney failure, rheumatoid arthritis, thyroid diseases individuals .