Healthy
Conditions
Brief summary
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.
Interventions
DEVICETheta-burst stimulation
iTBS comprises 3-pulse 50-Hz bursts, applied every 200 ms (at 5 Hz) as described previously (Huang, Edwards et al. 2005) and consists of 2-second trains with an inter-train-interval of 8 seconds. We will repeat trains (30 pulses; 10 bursts) for 20 times to reach a total number of 600 pulses per session (3x10x20)
Sponsors
Dr Georg Kranz
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)
Intervention model description
single-blind parallel-group crossover design
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in recall capacity | Change from baseline to directly after stimulation (~6 min after baseline) | Change in the number of correct associations of a face-word association memory test |
Countries
Hong Kong
Outcome results
None listed