Assessing the Effects of Continuous Theta Burst Stimulation Over the Dorsolateral Prefrontal Cortex on Human Cognition: A Systematic Review

Abstract

Theta burst stimulation is increasingly growing in popularity as a non-invasive method of moderating corticospinal networks. Theta burst stimulation uses gamma frequency trains applied at the rhythm of theta, thus, mimicking theta–gamma coupling involved in cognitive processes. The dorsolateral prefrontal cortex has been found to play a crucial role in numerous cognitive processes. Here, we include 25 studies for review to determine the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex; 20 of these studies are healthy participant and five are patient (pharmacotherapy-resistant depression) studies. Due to the heterogeneous nature of the included studies, only a descriptive approach is used and meta-analytics ruled out. The cognitive effect is measured on various cognitive domains: attention, working memory, planning, language, decision making, executive function, and inhibitory and cognitive control. We conclude that continuous theta burst stimulation over the dorsolateral prefrontal cortex mainly inhibits cognitive performance. However, in some instances, it can lead to improved performance by inhibiting the effect of distractors or other competing irrelevant cognitive processes. To be precise, continuous theta burst stimulation over the right dorsolateral prefrontal cortex impaired attention, inhibitory control, planning, and goal-directed behavior in decision making but also improved decision making by reducing impulsivity. Conversely, continuous theta burst stimulation over the left dorsolateral prefrontal cortex impaired executive function, working, auditory feedback regulation, and cognitive control but accelerated the planning, decision-making process. These findings constitute a useful contribution to the literature on the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex.

Local Prefrontal Cortex TMS-Induced Reactivity Is Related to Working Memory and Reasoning in Middle-Aged Adults

“…In particular, whereas PFC has been more related to executive function and cognitive control (Friedman and Robbins, 2021 ), IPL has been associated with language and social cognition (Numssen et al, 2021 ). In line with our results, Ngetich et al ( 2020 ) showed that after a continuous theta burst stimulation over L-PFC, there was a change in executive functions like working memory and decision making (Ngetich et al, 2020 ). Similarly, it has been shown that abnormal higher cortical excitability in the PFC in patients with AD than healthy controls was inversely associated with global cognition/executive functions (Joseph et al, 2021 ), confirming the relation between cognitive functions performance and PFC evoked activity.…”

The Role of the Dorsolateral Prefrontal Cortex for Speech and Language Processing

“…To some extent, executive control functions of the DLPFC seem to be lateralized (Seikel, 2018;Ngetich et al, 2020). Left hemispheric functions seem to be associated with target-directed perception, attention, memory management, and decision making, whereas the working characteristics of right DLPFC are more reflective and related to superordinate attentional functions in terms of alertness.…”

Enhancing Visuospatial Working Memory Performance Using Intermittent Theta-Burst Stimulation Over the Right Dorsolateral Prefrontal Cortex

“…It is worth noting that theta-burst stimulation (TBS) is a variant of TMS that uses gamma frequency trains applied in the rhythm of theta (thus mimicking theta-gamma coupling involved in the working and the long-term memory processes) ( Chung et al, 2018b ; Ngetich et al, 2020 ). The original study by Huang et al (2005) indicates that TBS consist of a 50 Hz triplet of pulses interspersed at 5 Hz (repeated every 200 ms), and categorizes TBS into three types based on their stimulation patterns.…”