Participants in this arm will receive anodal transcranial direct current stimulation (tDCS) at 2 mA for 20 minutes per session over 10 consecutive workdays. The anode will be placed over the left dorsolateral prefrontal cortex (F3) and the cathode over the right frontopolar cortex (Fp2) using the 10-20 EEG system. Stimulation will be administered concurrently with cognitive training using the NeuronUP platform, which includes tasks targeting attention, memory, and executive function.

Participants in this arm will undergo the same setup and procedures as the active tDCS group but will receive sham stimulation, which mimics the sensation of tDCS without delivering current beyond the initial ramp-up/down. They will also complete cognitive training with the NeuronUP platform during each session.

This intervention involves non-invasive brain stimulation using transcranial direct current stimulation (tDCS) delivered via saline-soaked sponge electrodes. The anode is placed at F3 (left dorsolateral prefrontal cortex) and the cathode at Fp2 (right frontopolar cortex), according to the international 10-20 EEG system. A 2 mA current is applied for 20 minutes per session, administered once daily on 10 consecutive workdays.

During stimulation, participants engage in cognitive training using the NeuronUP platform, which provides structured, interactive tasks designed to train executive function, attention, and working memory. This combination aims to enhance neural plasticity by pairing neuromodulation with cognitive engagement.

Participants will be monitored for adverse events, side effects (e.g., headache, skin irritation, fatigue), and dropout rates. This will be assessed through participant self-report, clinician observation, and standardized side effect checklists administered during and after each session. The outcome will help determine whether daily tDCS paired with cognitive training is safe and acceptable for adults with ASD and/or ADHD.