This project will investigate a novel strategy for enhancing cognitive training (CT). Specifically, the investigators aim to combine a non-invasive form of brain stimulation (tDCS) with CT. This study will examine the optimal time interval - whether tDCS should be administered either before or during CT.

Inclusion Criteria:

• Participants will be healthy right-handed subjects aged 18 to 40 years.

Exclusion Criteria:

• Concurrent medication likely to affect mental performance,
• Current history of drug or alcohol abuse or dependence,
• Any psychiatric or neurological disorder,
• Recent head injury, or history of seizure or stroke.