An increasing number of studies have used the intermittent theta-burst stimulation (iTBS) protocol to investigate neural plasticity non-invasively in the prefontal cortex in healthy humans and in patients with psychiatric disorders. However, the variability in the neurophysiological response to iTBS stimulation is high. The cause of this variability is multifactorial and to some degree still unknown. Therefore, the current study explores inter- and intra-individual factors that are potentially moderating iTBS-induced excitability changes. A greater understanding of these determinants would be highly valuable for optimizing the therapeutic application of iTBS.

The investigators will measure the cortical excitability induced by iTBS with concurrent TBS/fNIRS technique in the same healthy individuals on multiple testing days. Meanwhile, several potential inter- (age, gender, etc.) and intra-individual factors (daily mood, daily physical activity levels, etc.) recently identified in non-invasive transcranial brain stimulation studies will be assessed before applying iTBS to the same individual on each testing day.

Inclusion Criteria:

• healthiness based on history and psychiatric assessment
• being able to hear and understand the verbal instructions
• completed at least 6 years of formal education

Exclusion Criteria:

• a current or past diagnosis of psychiatric, neurological disorders, or severe internal illness
• any conditions that will contraindicate to iTBS or fNIRS
• psychiatric disorders in their first-degree relatives
• pregnancy

IPD may be shared upon request

Upon request

Upon request