scholarly journals Stimulation of the left dorsolateral prefrontal cortex with slow rTMS enhances verbal memory formation

PLoS Biology ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. e3001363
Author(s):  
Mircea van der Plas ◽  
Verena Braun ◽  
Benjamin Johannes Stauch ◽  
Simon Hanslmayr
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Incidental Finding ◽  
Memory Performance ◽  
Memory Formation ◽  
Control Group ◽  
Specific Information ◽  
Left Dlpfc ◽  
Beta Power ◽  
Dorsolateral Prefrontal

Encoding of episodic memories relies on stimulus-specific information processing and involves the left prefrontal cortex. We here present an incidental finding from a simultaneous EEG-TMS experiment as well as a replication of this unexpected effect. Our results reveal that stimulating the left dorsolateral prefrontal cortex (DLPFC) with slow repetitive transcranial magnetic stimulation (rTMS) leads to enhanced word memory performance. A total of 40 healthy human participants engaged in a list learning paradigm. Half of the participants (N = 20) received 1 Hz rTMS to the left DLPFC, while the other half (N = 20) received 1 Hz rTMS to the vertex and served as a control group. Participants receiving left DLPFC stimulation demonstrated enhanced memory performance compared to the control group. This effect was replicated in a within-subjects experiment where 24 participants received 1 Hz rTMS to the left DLPFC and vertex. In this second experiment, DLPFC stimulation also induced better memory performance compared to vertex stimulation. In addition to these behavioural effects, we found that 1 Hz rTMS to DLPFC induced stronger beta power modulation in posterior areas, a state that is known to be beneficial for memory encoding. Further analysis indicated that beta modulations did not have an oscillatory origin. Instead, the observed beta modulations were a result of a spectral tilt, suggesting inhibition of these parietal regions. These results show that applying 1 Hz rTMS to DLPFC, an area involved in episodic memory formation, improves memory performance via modulating neural activity in parietal regions.

scholarly journals Slow rTMS to the left DLPFC enhances verbal memory formation

2021 ◽  
Author(s):  
Mircea van der Plas ◽  
Verena Braun ◽  
Benjamin Johannes Stauch ◽  
Simon Hanslmayr
Keyword(s):  
Prefrontal Cortex ◽  
Verbal Memory ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Incidental Finding ◽  
Memory Performance ◽  
Memory Formation ◽  
Control Group ◽  
Specific Information ◽  
Left Dlpfc ◽  
Beta Power

AbstractEncoding of episodic memories relies on stimulus-specific information processing and involves the left prefrontal cortex. We here present an incidental finding from a simultaneous EEG-TMS experiment as well as a replication of this unexpected effect. Our results reveal that stimulating the left dorsolateral prefrontal cortex (DLPFC) with slow repetitive transcranial magnetic stimulation (rTMS) leads to enhanced word memory performance. 40 healthy human participants engaged in a list learning paradigm. Half of the subjects (N=20) received 1 Hz rTMS to the left DLPFC while the other half (N=20) received 1 Hz rTMS to the vertex and served as a control group. Subjects receiving left DLPFC stimulation demonstrated enhanced memory performance compared to the control group. This effect was replicated in a double-blind within-subjects experiment where 24 participants received 1 Hz rTMS to the left DLPFC and vertex. In this second experiment, DLPFC stimulation also induced better memory performance compared to vertex stimulation. In addition to these behavioural effects, we found that 1 Hz rTMS to DLPFC induced stronger beta power modulation in posterior areas, a state which is known to be beneficial for memory encoding. Further analysis indicated, that beta modulations did not have an oscillatory origin. Instead, the observed beta modulations were a result of a spectral tilt, suggesting inhibition of these parietal regions. These results show that applying 1 Hz rTMS to DLPFC, an area involved in episodic memory formation, improves memory performance via modulating neural activity in parietal regions.

scholarly journals Disruption of the Dorsolateral Prefrontal Cortex Facilitates the Consolidation of Procedural Skills

2010 ◽  
Vol 22 (6) ◽  
pp. 1158-1164 ◽  
Author(s):  
Joseph M. Galea ◽  
Neil B. Albert ◽  
Thomas Ditye ◽  
R. Chris Miall
Keyword(s):  
Prefrontal Cortex ◽  
Sequence Learning ◽  
Dorsolateral Prefrontal Cortex ◽  
Declarative Memory ◽  
Cognitive Task ◽  
Memory Systems ◽  
Procedural Memory ◽  
Control Group ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal

In explicit sequence learning tasks, an improvement in performance (skill) typically occurs after sleep—leading to the recent literature on sleep-dependent motor consolidation. Consolidation can also be facilitated during wakefulness if declarative knowledge for the sequence is reduced through a secondary cognitive task. Accordingly, declarative and procedural consolidation processes appear to mutually interact. Here we used TMS to test the hypothesis that functions in the dorsolateral prefrontal cortex (DLPFC) that support declarative memory formation indirectly reduce the formation of procedural representations. We hypothesize that disrupting the DLPFC immediately after sequence learning would degrade the retention or the consolidation of the sequence within the declarative memory system and thus facilitate consolidation within procedural memory systems, evident as wakeful off-line skill improvement. Inhibitory theta-burst TMS was applied to the left DLPFC (n = 10), to the right DLPFC (n = 10), or to an occipital cortical control site (n = 10) immediately after training on the serial reaction time task (SRTT). All groups were retested after eight daytime hours without sleep. TMS of either left or right DLPFC lead to skill improvements on the SRTT. Increase in skill was greater following right DLPFC stimulation than left DLPFC stimulation; there was no improvement in skill for the control group. Across all participants, free recall of the sequence was inversely related to the improvements in performance on the SRTT. These results support the hypothesis of interference between declarative and procedural consolidation processes and are discussed in the framework of the interactions between memory systems.

scholarly journals The child brain computes and utilizes internalized maternal choices

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Seung-Lark Lim ◽  
J. Bradley C. Cherry ◽  
Ann M. Davis ◽  
S. N. Balakrishnan ◽  
Oh-Ryeong Ha ◽  
...  
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Self Regulation ◽  
Food Preferences ◽  
Food Choices ◽  
Functional Magnetic Resonance ◽  
Left Dlpfc ◽  
Making Choices ◽  
Dorsolateral Prefrontal

Abstract As children grow, they gradually learn how to make decisions independently. However, decisions like choosing healthy but less-tasty foods can be challenging for children whose self-regulation and executive cognitive functions are still maturing. We propose a computational decision-making process in which children estimate their mother’s choices for them as well as their individual food preferences. By employing functional magnetic resonance imaging during real food choices, we find that the ventromedial prefrontal cortex (vmPFC) encodes children’s own preferences and the left dorsolateral prefrontal cortex (dlPFC) encodes the projected mom’s choices for them at the time of children’s choice. Also, the left dlPFC region shows an inhibitory functional connectivity with the vmPFC at the time of children’s own choice. Our study suggests that in part, children utilize their perceived caregiver’s choices when making choices for themselves, which may serve as an external regulator of decision-making, leading to optimal healthy decisions.

scholarly journals The Contribution of the Dorsolateral Prefrontal Cortex in Full and Divided Encoding: A Paired-Pulse Transcranial Magnetic Stimulation Study

2010 ◽  
Vol 23 (3) ◽  
pp. 107-115 ◽  
Author(s):  
Sophie Blanchet ◽  
Geneviève Gagnon ◽  
Cyril Schneider
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Verbal Material ◽  
Paired Pulse ◽  
Attentional Resources ◽  
Sham Condition ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
Episodic Encoding ◽  
The Right

This research investigated the contribution of the dorsolateral prefrontal cortex (DLPFC) in the attentional resources in episodic encoding for both verbal and non-verbal material. Paired-pulse transcranial magnetic stimulations (TMS) were used to interfere transiently with either the left or right DLPFC during encoding under full attention (FA) or under divided attention (DA) in a recognition paradigm using words and random shapes. Participants recognized fewer items after TMS over the left DLPFC than over the right DLPFC during FA encoding. However, TMS over the left DLPFC did not impair performance when compared to sham condition. Conversely, participants produced fewer items after TMS over the right DLPFC in DA encoding compared to sham condition, but not compared to TMS over the left DLPFC. These effects were found for both words and random shapes. These results suggest that the right DLPFC play an important role in successful encoding with a concomitant task regardless of the type of material.

scholarly journals Verbal Fluency in Mild Alzheimer’s Disease: Transcranial Direct Current Stimulation over the Dorsolateral Prefrontal Cortex

2021 ◽  
pp. 1-11
Author(s):  
Daniela Smirni ◽  
Massimiliano Oliveri ◽  
Eliana Misuraca ◽  
Angela Catania ◽  
Laura Vernuccio ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Verbal Fluency ◽  
Dorsolateral Prefrontal Cortex ◽  
Control Group ◽  
Direct Current Stimulation ◽  
Cathodal Tdcs ◽  
Dorsolateral Prefrontal ◽  
The Right

Background: Recent studies showed that in healthy controls and in aphasic patients, inhibitory trains of repetitive transcranial magnetic stimulation (rTMS) over the right prefrontal cortex can improve phonemic fluency performance, while anodal transcranial direct current stimulation (tDCS) over the left prefrontal cortex can improve performance in naming and semantic fluency tasks. Objective: This study aimed at investigating the effects of cathodal tDCS over the left or the right dorsolateral prefrontal cortex (DLPFC) on verbal fluency tasks (VFT) in patients with mild Alzheimer’s disease (AD). Methods: Forty mild AD patients participated in the study (mean age 73.17±5.61 years). All participants underwent cognitive baseline tasks and a VFT twice. Twenty patients randomly received cathodal tDCS to the left or the right DLPFC, and twenty patients were assigned to a control group in which only the two measures of VFT were taken, without the administration of the tDCS. Results: A significant improvement of performance on the VFT in AD patients was present after tDCS over the right DLPFC (p = 0.001). Instead, no difference was detected between the two VFTs sessions after tDCS over the left DLPFC (p = 0.42). Furthermore, these results cannot be related to task learning effects, since no significant difference was found between the two VFT sessions in the control group (p = 0.73). Conclusion: These data suggest that tDCS over DLPFC can improve VFT performance in AD patients. A hypothesis is that tDCS enhances adaptive patterns of brain activity between functionally connected areas.

Antidepressant efficacy of high-frequency transcranial magnetic stimulation over the left dorsolateral prefrontal cortex in double-blind sham-controlled designs: a meta-analysis

2008 ◽  
Vol 39 (1) ◽  
pp. 65-75 ◽  
Author(s):  
D. J. L. G. Schutter
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Effect Size ◽  
High Frequency ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Meta Analysis ◽  
Double Blind ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal

BackgroundFor more than a decade high-frequency repetitive transcranial magnetic stimulation (rTMS) has been applied to the left dorsolateral prefrontal cortex (DLPFC) in search of an alternative treatment for depression. The aim of this study was to provide an update on its clinical efficacy by performing a meta-analysis involving double-blind sham-controlled studies.MethodA literature search was conducted in the databases PubMed and Web of Science in the period between January 1980 and November 2007 with the search terms ‘depression’ and ‘transcranial magnetic stimulation’. Thirty double-blind sham-controlled parallel studies with 1164 patients comparing the percentage change in depression scores from baseline to endpoint of activeversussham treatment were included. A random effects meta-analysis was performed to investigate the clinical efficacy of fast-frequency rTMS over the left DLPFC in depression.ResultsThe test for heterogeneity was not significant (QT=30.46,p=0.39). A significant overall weighted mean effect size,d=0.39 [95% confidence interval (CI) 0.25–0.54], for active treatment was observed (z=6.52,p<0.0001). Medication resistance and intensity of rTMS did not play a role in the effect size.ConclusionsThese findings show that high-frequency rTMS over the left DLPFC is superior to sham in the treatment of depression. The effect size is robust and comparable to at least a subset of commercially available antidepressant drug agents. Current limitations and future prospects are discussed.

scholarly journals Transcranial Direct Current Stimulation (tDCS) Consequences on Dorsolateral Prefrontal Cortex in Reducing the Symptoms of the Obsessive-Compulsive Disorder

2021 ◽  
Author(s):  
Sina Shafiezadeh ◽  
◽  
Atiyeh Mohammadshirazi ◽  
Mansoureh Eshghi ◽  
Zahra Dokhaei ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Direct Current ◽  
Dorsolateral Prefrontal Cortex ◽  
Sham Group ◽  
P Value ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
The Right

Obsessive-Compulsive Disorder (OCD) is one of the most prevalent debilitating mental disorders that has a general rate of 2 to 3 percent prevalence. Previous studies indicated that there are abnormalities in the dorsolateral prefrontal cortex (DLPFC) of OCD patients, so we decided to use transcranial direct current stimulation (tDCS) to decline the symptoms of these patients. A total number of 24 OCD patients participated in this study with the hope of improvement after the application of tDCS. The subjects were randomly assigned into three groups as Sham, Right DLPFC, and Left DLPFC tDCS, and tDCS were applied for 5 consecutive days as in each session. The protocol was 2 mA current flow for two 15 minutes lasting period following by a 10 minutes rest in between (every session lasts for 40 minutes). Subsequently, the changes in obsessive-compulsive level and depression, anxiety, and stress followed that were evaluated via Yale-Brown and Depression Anxiety Stress Scale 21 (DASS-21) tests by comparing the results of pre-experiment and post-experiment. Ultimately, the results of the Yale-Brown test which evaluates OCD symptoms in Right DLPFC shows significant changes that have occurred after intervention with tDCS (average difference of the Right DLPFC with sham group -6.18 and P-value ≤ 0.01, and for the Left DLPFC with sham group 3.155 and P-value ≥ 0.05). The average DASS scores of pre and post-experiment in the Left DLPFC were -4.63, in the Right DLPFC was -6.62, and in the sham group was -5.13 subsequently. Hereupon, this study demonstrates that tDCS may cause improvements in OCD symptoms.

Stimulation of the dorsolateral-prefrontal cortex improves working memory and planning

2021 ◽  
Vol 25 (1) ◽  
pp. 1-17
Author(s):  
Puladi Farzaneh ◽  
Bagheri Masood ◽  
Ghasem Askarizadeh ◽  
Afsaneh Moradi
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Response Time ◽  
Dorsolateral Prefrontal Cortex ◽  
Control Group ◽  
Response Accuracy ◽  
Significant Difference ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
And Control

The present study aimed to investigate whether working memory (WM) and planning performances can be enhanced using transcranial direct current stimulation (tDCS). A total of 30 healthy individuals were randomly assigned to two groups: active (A)-tDCS and control (S)-tDCS. Anodal stimulation over the left dorsolateral prefrontal cortex (DLPFC) (F3) and cathodal stimulation over the right orbitofrontal cortex (OFC) (FP2) were further implemented at 2 mA in the A-tDCS group, while there was no intervention in the control group. The tools used were software versions of the three-level n-back task and Tower of London (TOL) task, and for each task we measured participants’ response accuracy and response time. The results showed a significant difference between the groups in both cognitive functions, suggesting that tDCS can improve response accuracy in memory and problem-solving ability, but it is less effective in terms of improving response time on planning. Overall, findings suggest that tDCS can enhance WM and planning performances.

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