Individualised Transcranial Magnetic Stimulation Targeting of the Left Dorsolateral Prefrontal Cortex for Enhancing Cognition: A Randomised Controlled Trial

Abstract

Repetitive transcranial magnetic stimulation (rTMS) has been demonstrated to produce cognitive enhancing effects across different neuropsychiatric disorders; however, so far, these effects have been limited. This trial investigated the efficacy of using a novel individualised approach to target the left dorsolateral prefrontal cortex (L-DLPFC) for enhancing cognitive flexibility based on performance on a cognitive task. First, forty healthy participants had their single target site at the L-DLPFC determined based on each individual’s performance on a random letter generation task. Participants then received, in a cross-over single-blinded experimental design, a single session of intermittent theta burst stimulation (iTBS) to their individualised DLPFC target site, an active control site and sham iTBS. Following each treatment condition, participants completed the Task Switching task and Colour–Word Stroop test. There was no significant main effect of treatment condition on the primary outcome measure of switch reaction times from the Task Switching task [F = 1.16 (2, 21.6), p = 0.33] or for any of the secondary cognitive outcome measures. The current results do not support the use of our novel individualised targeting methodology for enhancing cognitive flexibility in healthy participants. Research into alternative methodological targeting approaches is required to further improve rTMS’s cognitive enhancing effects.

Neural dynamics of delayed feedback in robot teleoperation: insights from fNIRS analysis

“…Each selected region plays a crucial role in teleoperation: the APFC is involved in executive functions and complex problem-solving (Euston et al, 2012 ; Carlén, 2017 ), the LDLPFC and RDLPFC in working memory and decision-making processes (Philiastides et al, 2011 ; Kim K. et al, 2021 ; Martin et al, 2024 ), the LM1 and RM1 in movement planning (Hoshi and Tanji, 2000 ; Garbarini et al, 2019 ; Gale et al, 2021 ), and the LPM and RPM are involved in the execution of movements (Schnitzler et al, 1997 ; Solopchuk et al, 2016 ). Notably, the APFC, LDLPFC, and RDLPFC also contribute to the perception of time, a cognitive function that becomes especially important in the context of feedback delays where the brain must reconcile the discrepancy between expected and actual sensory inputs (Wei-Cong et al, 2015 ; Coull et al, 2016 ).…”