Transcranial alternating current stimulation (tACS) at 80 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted.

Transcranial alternating current stimulation (tACS) at 6-80 Hz theta- gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted.

Transcranial alternating current stimulation (tACS) sham will be applied to the the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted.

Transcranial alternating current stimulation (tACS) at 40 Hz gamma frequency will be applied to the bilateral dorsolateral prefrontal cortex (DLPFC). Each session will last 20 minutes. A total of five sessions will be conducted.

In this study, a single 20-minute session of tACS will be administered over the bilateral dorsolateral prefrontal cortex (DLPFC) at various gamma frequencies (80 Hz).The anodal surface electrode will be placed over the left DLPFC (F3 according to the 10-20 system), and the cathodal electrode over the right DLPFC (F4).

Öktem Verbal Memory Test is a test of verbal memory processes, developed and validated by Öktem in 1992. It is designed to measure various variables related to memory.

This test, which is a subtest of the Wechsler Memory Scale, was developed to assess overall attention. It consists of two stages. The first stage evaluates the forward digit span, composed of random sequences ranging from 2 to 8 digits. In the second stage, the backward digit span is assessed using random sequences of 2 to 7 digits. In the first stage, numbers are read aloud with one-second intervals, and participants are expected to repeat the sequences exactly as presented. In the second stage, numbers are again read with one-second intervals, but participants are required to repeat the digits in reverse order. The test is terminated if the participant makes consecutive errors. The forward digit span assesses sustained attention, while the backward span also evaluates working memory performance.

Verbal fluency tests measure the ability to generate words within a specific category over a limited time period. Verbal fluency performance has been associated not only with general language skills and semantic memory functions but also with executive functions such as attention, working memory, and processing speed. In this study, semantic and phonemic fluency tasks will be used.

The EEG recordings of the participants will be conducted using a BrainAmp 64-channel DC system. A 64-channel EasyCap will be used. AFz will serve as the ground electrode, and FCz will be used as the reference electrode. Impedance values will be maintained below 10 kOhm. EEG data will be recorded using the BrainVision Recorder software (Brain Products, Munich, Germany) with a band-pass filter set between 0.01 and 250 Hz.A 4-minute eyes-open and a 4-minute eyes-closed resting-state EEG recording will be conducted. EEG will also be recorded during the 2-back task and the memory task. 2-back Task: A visual n-back task will be administered to assess working memory. The task load will consist of 8-minute sessions. Memory Task: The memory task, which involves both encoding and retrieval of episodic information, will be examined using a visual memory paradigm presented to the participants.

The Self-Reported Attention Deficit Scale is one of the screening tools developed by the World Health Organization (WHO) to identify mental disorders. The scale consists of two subscales: "attention deficit" and "hyperactivity/impulsivity," each comprising nine items. These questions are designed to assess how frequently each symptom has occurred over the past six months. Responses are scored on a scale ranging from 0 to 4, where 0 indicates "never," 1 indicates "rarely," 2 indicates "sometimes," 3 indicates "often," and 4 indicates "very often."