Prefrontal iTBS on Working Memory

Exploring the Effects of Prefrontal iTBS on Working Memory in Healthy Participants: a Concurrent TMS/fNIRS Study

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT05774223

Enrollment

Registered

2023-03-17

Start date

2023-03-01

Completion date

2023-06-15

Last updated

2023-06-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

Theta-Burst stimulation (iTBS), Functional near-infrared spectroscopy (fNIRS), Concurrent TMS/fNIRS, Working memory

Brief summary

The investigators previous pilot study showed that the brain remained activated after 3 minutes of intermittent theta burst stimulation (iTBS). Therefore, an open question remains that how long the effects will last and when the maximum effects will be achieved. In addition, many pioneering works showed the positive effects of repetitive transcranial magnetic stimulation (rTMS) on working memory. Intermittent theta burst stimulation (iTBS) is a patterned form of rTMS, it has shown a non-inferior efficacy in depression but with a much shorter time (approximately 3 mins) than traditional rTMS (approximately 40 mins). As discussed above, this study aims to investigate the effects of prefrontal iTBS on working memory using concurrent iTBS/fNIRS and to explore the duration of the effects.

Interventions

DEVICETranscranial magnetic stimulation (TMS)-active

Active intermittent TBS (iTBS) will be applied to the left DLPFC at 80% of the resting motor threshold (rMT) (Hoy et al., 2016). A stimulation, where 3-pulse at 50 Hz will be given, will repeat every 10 s for a total of 190 s (600 pulses in total) (Huang et al., 2005). The left DLPFC stimulation site will be determined using the neuronavigator system (lDLPFC, x-38, y+44, z+26).

DEVICETranscranial magnetic stimulation (TMS)-sham

Sham intermittent TBS (iTBS) will be applied to the left DLPFC at 80% of the resting motor threshold (rMT) (Hoy et al., 2016). The coil will be placed perpendicular to the left DLPFC. A stimulation, where 3-pulse at 50 Hz will be given, will repeat every 10 s for a total of 190 s (600 pulses in total) (Huang et al., 2005). The left DLPFC stimulation site will be determined using the neuronavigator system (lDLPFC, x-38, y+44, z+26).

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

BASIC_SCIENCE

Masking

SINGLE (Subject)

Masking description

Participants will not be informed of the type of stimulation

Intervention model description

Healthy volunteers will receive iTBS two times with active or sham stimulation separated by one week to investigate the effect duration of iTBS on working memory

Eligibility

Sex/Gender

ALL

Age

18 Years to 35 Years

Healthy volunteers

Yes

Inclusion criteria

* right-handed participants * normal or corrected-to-normal vision

Exclusion criteria

* a current or past diagnosis of any neurological or psychiatric disorder * any severe medical conditions, seizure, and pregnancy * contraindication to TMS (e.g., with mental implants)

Design outcomes

Primary

Measure	Time frame	Description
N-back	before and post iTBS, up to 3 months	The accuracy number of each n-back task

Secondary

Measure	Time frame	Description
Hemoglobin change	before and post iTBS, up to 3 months	The hemoglobin change throughout whole procedure.

Countries

Hong Kong

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026