scholarly journals Causal Evidence for Lateral Prefrontal Cortex Dynamics Supporting Cognitive Control

2017 ◽  
Author(s):  
Derek Evan Nee ◽  
Mark D’Esposito
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Cognitive Control ◽  
Magnetic Stimulation ◽  
Control Site ◽  
Causal Modeling ◽  
Fmri Data ◽  
Dynamic Causal Modeling ◽  
Lateral Prefrontal Cortex ◽  
Theta Burst

AbstractThe lateral prefrontal cortex (LPFC) is essential for higher-level cognition, but how interactions among LPFC areas support cognitive control has remained elusive. In previous work, dynamic causal modeling (DCM) of fMRI data revealed that demands on cognitive control elicited a convergence of influences towards mid LPFC. We proposed that these findings reflect the integration of abstract, rostral and concrete, caudal influences to inform context-appropriate action. Here, we provide a causal test of this model using continuous theta-burst transcranial magnetic stimulation (cTBS). cTBS was applied to caudal, mid, or rostral LPFC, as well as a control site in counterbalanced sessions. In most cases, behavioral modulations resulting from cTBS could be predicted based upon the direction of influences within the previously estimated DCM. However, inconsistent with our DCM, we found that cTBS to caudal LPFC impaired cognitive control processes presumed to involve rostral LPFC. Revising the original DCM with a pathway from caudal LPFC to rostral LPFC significantly improved the fitted DCM and accounted for the observed behavioral findings. These data provide causal evidence for LPFC dynamics supporting cognitive control and demonstrate the utility of combining DCM with causal manipulations to create, test, and refine models of cognition.

scholarly journals Causal evidence for lateral prefrontal cortex dynamics supporting cognitive control

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Derek Evan Nee ◽  
Mark D'Esposito
Keyword(s):  
Prefrontal Cortex ◽  
Cognitive Control ◽  
Information Flow ◽  
Magnetic Stimulation ◽  
Control Site ◽  
Causal Modeling ◽  
Model Fit ◽  
Dynamic Causal Modeling ◽  
Lateral Prefrontal Cortex ◽  
Theta Burst

The lateral prefrontal cortex (LPFC) is essential for higher-level cognition, but the nature of its interactions in supporting cognitive control remains elusive. Previously (Nee and D'Esposito, 2016), dynamic causal modeling (DCM) indicated that mid LPFC integrates abstract, rostral and concrete, caudal influences to inform context-appropriate action. Here, we use continuous theta-burst transcranial magnetic stimulation (cTBS) to test this model causally. cTBS was applied to three LPFC sites and a control site in counterbalanced sessions. Behavioral modulations resulting from cTBS were largely predicted by information flow within the previously estimated DCM. However, cTBS to caudal LPFC unexpectedly impaired processes that are presumed to involve rostral LPFC. Adding a pathway from caudal to mid-rostral LPFC significantly improved the model fit and accounted for the observed behavioral findings. These data provide causal evidence for LPFC dynamics supporting cognitive control and demonstrate the utility of combining DCM with causal manipulations to test and refine models of cognition.

scholarly journals Medial prefrontal cortex has a causal role in selectively enhanced consolidation of emotional memories after a 24-hour delay: An iTBS study

2020 ◽  
Author(s):  
Nicholas Yeh ◽  
Jessica D. Payne ◽  
Sara Y. Kim ◽  
Elizabeth A. Kensinger ◽  
Joshua D. Koen ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Medial Prefrontal Cortex ◽  
Magnetic Stimulation ◽  
Emotional Memory ◽  
Control Site ◽  
Delay Test ◽  
Emotional Information ◽  
Short Delay ◽  
Phase Recognition

AbstractPrevious research points to an association between retrieval-related activity in the medial prefrontal cortex (mPFC) and preservation of emotional information compared to co-occurring neutral information following sleep. Although the role of the mPFC in emotional memory likely begins at encoding, little research has examined how mPFC activity during encoding interacts with consolidation processes to enhance emotional memory. This issue was addressed in the present study using transcranial magnetic stimulation in conjunction with an emotional memory paradigm. Healthy males and females encoded negative and neutral scenes while undergoing concurrent TMS with an intermittent theta burst stimulation (iTBS) protocol. Participants received stimulation to either the mPFC or an active control site (motor cortex) during the encoding phase. Recognition memory for scene components (objects and backgrounds) was assessed after a short (30 minutes) and a long delay (24-hours including a night of sleep) to obtain measures of specific and gist-based memory processes. The results demonstrated that, relative to control stimulation, iTBS to the mPFC enhanced gist, but not specific, memory for negative objects on the long delay test. mPFC stimulation had no discernable effect on gist memory for objects on the short delay test nor on the background images at either test. These results suggest that mPFC activity occurring during encoding interacts with consolidation processes to selectively preserve the gist of negatively salient information.Significance StatementUnderstanding how emotional information is remembered over long delays is critical to understanding memory in the real world. The present study uses transcranial magnetic stimulation (TMS) to investigate the interplay between mPFC activity that occurs during memory encoding and its subsequent interactions with post-encoding consolidation processes. Excitatory TMS delivered to the mPFC during encoding enhanced gist-based memory for negatively valenced pictures on a test following a 24-hr delay, with no such effect on a test occurring shortly after the encoding phase. These results are consistent with the hypothesis that emotional aspects of memories are differentially subjected to consolidation processes, and that the mPFC might contribute to this “tag-and-capture” mechanism during the initial formation of such memories.

scholarly journals Transcranial magnetic stimulation of the dorsal lateral prefrontal cortex inhibits medial orbitofrontal activity in smokers

2017 ◽  
Vol 26 (8) ◽  
pp. 788-794 ◽  
Author(s):  
Xingbao Li ◽  
Gregory L. Sahlem ◽  
Bashar W. Badran ◽  
Lisa M. McTeague ◽  
Colleen A. Hanlon ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Lateral Prefrontal Cortex ◽  
Stimulation Of

scholarly journals Reliability of transcranial magnetic stimulation evoked potentials to detect the effects of theta-burst stimulation of the prefrontal cortex

2021 ◽  
Author(s):  
Adriano Henrique de Matos Moffa ◽  
Stevan Nikolin ◽  
Donel Martin ◽  
Colleen Loo ◽  
Tjeerd W. Boonstra
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Evoked Potentials ◽  
Magnetic Stimulation ◽  
Cortical Excitability ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Neural Excitability ◽  
Dorsolateral Prefrontal ◽  
Theta Burst

Background: Transcranial magnetic stimulation (TMS) with simultaneous electroencephalography (EEG) is a novel method for assessing cortical properties outside the motor region. Theta burst stimulation (TBS), a form of repetitive TMS, can non-invasively modulate cortical excitability and has been increasingly used to treat psychiatric disorders by targetting the dorsolateral prefrontal cortex (DLPFC). The TMS-evoked potentials (TEPs) analysis has been used to evaluate cortical excitability changes after TBS. However, it remains unclear whether TEPs can detect the neuromodulatory effects of TBS. Objectives: To confirm the reliability of TEP components within and between sessions and to measure changes in neural excitability induced by intermittent (iTBS) and continuous TBS (cTBS) applied to the left DLPFC. Methods: Test-retest reliability of TEPs and TBS-induced changes in cortical excitability were assessed in twenty-four healthy participants by stimulating the DLPFC in five separate sessions, once with sham and twice with iTBS and cTBS. EEG responses were recorded of 100 single TMS pulses before and after TBS, and the reproducibility measures were quantified with the concordance correlation coefficient (CCC). Results: The N100 and P200 components presented substantial reliability within the baseline block (CCCs>0.8) and moderate concordance between sessions (CCCmax≈0.7). Both N40 and P60 TEP amplitudes showed little concordance between sessions. Changes in TEP amplitudes after iTBS were marginally reliable for N100 (CCCmax=0.52), P200 (CCCmax=0.47) and P60 (CCCmax=0.40), presenting only fair levels of concordance at specific time points. Conclusions: The present findings show that only the N100 and P200 components had good concordance between sessions. The reliability of earlier components may have been affected by TMS-evoked artefacts. The poor reliability to detect changes in neural excitability induced by TBS indicates that TEPs do not provide a precise estimate of the changes in excitability in the DLPFC or, alternatively, that TBS did not induce consistent changes in neural excitability.

scholarly journals Assessing neuromodulation effects of theta burst stimulation to the prefrontal cortex using TMS-evoked potentials

2021 ◽  
Author(s):  
Adriano Henrique de Matos Moffa ◽  
Stevan Nikolin ◽  
Donel Martin ◽  
Colleen Loo ◽  
Tjeerd W. Boonstra
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Evoked Potentials ◽  
Effect Size ◽  
Repeated Measures ◽  
Magnetic Stimulation ◽  
Cortical Excitability ◽  
Theta Burst Stimulation ◽  
Burst Stimulation ◽  
Theta Burst

Theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation (TMS), is capable of non-invasively modulating cortical excitability. TBS is gaining popularity as a therapeutic tool for psychiatric disorders such as depression, in which the dorsolateral prefrontal cortex (DLPFC) is the main therapeutic target. However, the neuromodulatory effects of TBS on prefrontal regions remain unclear. An emerging tool to assess neuromodulation in non-motor regions is concurrent transcranial magnetic stimulation and electroencephalography (TMS-EEG) to measure TMS-evoked potentials (TEPs). We assessed twenty-four healthy participants (13 males, mean age 25.2±9.9 years) following intermittent TBS, continuous TBS, and sham applied to the left DLPFC using a double-blinded crossover design. TEPs were obtained at baseline and 2-, 15-, and 30-min post-stimulation. Four TEP components (N40, P60, N100 and P200) were analysed using mixed effects repeated measures models (MRMM). Results indicate no significant effects for any assessed components (all p>.05). The largest effect size (Cohens d = -0.5) comparing iTBS and sham was obtained for the N100 component at 15 minutes post-stimulation. This result was in the same direction but smaller than found in previous studies, suggesting that the true effect size may be lower than previously reported. Accurate estimates of the effects sizes and inter-individual heterogeneity will critically inform clinical applications using TEPs to assess the neuromodulatory effects of TBS.

scholarly journals Augmentation of fear extinction by theta-burst transcranial magnetic stimulation of the prefrontal cortex in humans

2021 ◽  
Vol 46 (2) ◽  
pp. E292-E302
Author(s):  
Jiahui Deng ◽  
Wenmei Fang ◽  
Yimiao Gong ◽  
Yanping Bao ◽  
Hui Li ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Memory Performance ◽  
Fear Memory ◽  
Fear Extinction ◽  
Fear Response ◽  
Left Dlpfc ◽  
Before And After ◽  
Theta Burst

Background: Fear extinction alone does not erase the original fear memory. Interventions that enhance extinction can be beneficial for the treatment of fear-related disorders. Repetitive transcranial magnetic stimulation has been shown to improve memory performance. The present study examined the effects of intermittent theta-burst stimulation (iTBS) on fear extinction and the return of fear memory in humans. Methods: Ninety-one young healthy volunteers underwent 3 experiments using a randomized controlled experimental design. Participants first acquired fear conditioning, after which they received 30 Hz iTBS before and after extinction training. The iTBS was applied to 1 of 2 targets: the left dorsolateral prefrontal cortex (dlPFC) and the vertex (control). Fear responses were measured 24 hours later and 1 month later. Results: During the spontaneous recovery and reinstatement tests, iTBS of the left dlPFC before and after extinction significantly reduced fear response, whereas iTBS of the vertex had no effect on fear memory performance. This combined approach had a relatively long-lasting effect (i.e., at least 1 month). Limitations: We did not explore the effect of iTBS of the dlPFC on the expression of fear without extinction training. The neural mechanisms of iTBS with fear extinction to inhibit the fear response are unclear. Our results are preliminary and should be interpreted with caution. Conclusion: The present results showed that 30 Hz iTBS of the left dlPFC enhanced retention of fear extinction. Our study introduces a new intervention for fear memory and suggests that the left dlPFC may be a treatment target for fear-related disorders.

Sign in / Sign up

Export Citation Format

Share Document