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.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Device: Theta-burst stimulation

• Study Type: Interventional
• Enrollment (Actual): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • The Hong Kong Polytechnic University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intermittent theta-burst stimulation; iTBS will be performed on the left lateral parietal cortex	Device: Theta-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); Other Names: Transcranial Magnetic Stimulation
Active Comparator: Control stimulation; iTBS will be performed on the vertex	Device: Theta-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); Other Names: Transcranial Magnetic Stimulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in recall capacity	Change in the number of correct associations of a face-word association memory test	Change from baseline to directly after stimulation (~6 min after baseline)

Collaborators and Investigators

• Sponsor: Dr Georg Kranz
• Investigators: Principal Investigator: Georg S Kranz, PhD, Department of Rehabilitation Sciences

Study record dates

Study Major Dates

• Study Start (Actual): March 3, 2019
• Primary Completion (Actual): December 3, 2020
• Study Completion (Actual): December 3, 2020

Study Registration Dates

• First Submitted: November 22, 2018
• First Submitted That Met QC Criteria: November 26, 2018
• First Posted (Actual): November 28, 2018

Study Record Updates

• Last Update Posted (Actual): August 17, 2021
• Last Update Submitted That Met QC Criteria: August 16, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: 1-ZVN9

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Behavioral data may be shared with other researchers

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No