Probing TBS-induced Neural Plasticity and Associated Effects on Learning

Probing TBS-induced Neural Plasticity and Associated Effects on Learning

Recent animal research indicates that excitatory brain stimulation opens a time window of increased neural plasticity that permits remodeling of neural representations. Repetitive transcranial magnetic stimulation (rTMS) may thus facilitate learning of new associations by reducing proactive interference but human research is missing. Therefore, it is the aim of this study to investigate the effects of intermittent theta-burst stimulation (iTBS), a potent form of excitatory brain stimulation, on associative memory. Twenty right handed healthy participants will receive 3 minutes of iTBS or sham stimulation of the left lateral parietal cortex after memorizing a set of 20 face-word associations. Recall capacity will be tested directly before and after stimulation. Participants will then learn a new combination of associations using the same set of stimuli, followed by an evaluation of their recall capacity. It is hypothesized that iTBS compared to sham stimulation will reduce recall capacity directly after the stimulation but increase recall capacity of the newly learned associations due to reduced proactive interference. This study may not only pave the way towards a new understanding of the mechanism of action of brain stimulation, but can also help in developing new treatment strategies for neuropsychiatric disorders.

Inclusion Criteria:

• education level of primary six or above
• right-handedness
• normal or corrected-to-normal vision

Exclusion Criteria:

• seizures in medical history
• current or past psychiatric disorders or severe internal or neurological illness
• common TMS exclusion criteria
• substance abuse or dependence
• intake of medication that is known to affect the excitation threshold