scholarly journals Researching Hemispheric Specialization in the Control of Final Position Accuracy Using the Transcranial Direct Current Stimulation

2017 ◽  
Vol 9 (7) ◽  
pp. 138 ◽  
Author(s):  
Mostafa Teymuri Kheravi ◽  
Alireza Saberi Kakhki ◽  
Hamidreza Taheri ◽  
Ali Ghanaie Chamanabad ◽  
Mohammad Darainy
Keyword(s):  
Direct Current ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Final Position ◽  
Brain Functions ◽  
Position Accuracy ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
Male University Students

Transcranial Direct Current Simulation (tDCS) can improve or disrupt brain functions and can therefore be used to investigate hemispheric specialization. Accordingly, this study was designed to research hemispheric specialization in the control of final position accuracy by comparing the effects of tDCS on dorsolateral prefrontal cortex (DLPFC) in the right and left hemispheres. Forty-three right-handed male university students (aged 21.34±1.61) volunteered to participate in this study. They were divided into the right DLPFC, left DLPFC, sham, and practice groups, including 12, 11, 9, and 11 participants, respectively. After learning motor skills in two days, the participants practiced final position accuracy in one day. They were asked to move the cursor toward the centers of targets appearing randomly at the top, middle, and bottom on the right side of a monitor as accurately and quickly as they could. At the time of practice, the participants received anodic stimulation in one hemisphere and cathodic stimulation in the other. The results indicated that the left anodic/right cathodic group (left DLPFC) showed the worst performance, which may be caused by the inhibitory effects of cathodic stimulations in the right DLPFC. Therefore, it is predicted that the right hemisphere may have greater specialization in final position accuracy of movement.

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.

An Exploratory TMS Study on Prefrontal Lateralization in Valence Categorization of Facial Expressions

2017 ◽  
Vol 64 (4) ◽  
pp. 282-289 ◽  
Author(s):  
Chiara Ferrari ◽  
Lucile Gamond ◽  
Marcello Gallucci ◽  
Tomaso Vecchi ◽  
Zaira Cattaneo
Keyword(s):  
Facial Expressions ◽  
Emotional Processing ◽  
Right Hemisphere ◽  
Control Site ◽  
Emotional Facial Expressions ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal ◽  
Left And Right ◽  
The Right

Abstract. Converging neuroimaging and patient data suggest that the dorsolateral prefrontal cortex (DLPFC) is involved in emotional processing. However, it is still not clear whether the DLPFC in the left and right hemisphere is differentially involved in emotion recognition depending on the emotion considered. Here we used transcranial magnetic stimulation (TMS) to shed light on the possible causal role of the left and right DLPFC in encoding valence of positive and negative emotional facial expressions. Participants were required to indicate whether a series of faces displayed a positive or negative expression, while TMS was delivered over the right DLPFC, the left DLPFC, and a control site (vertex). Interfering with activity in both the left and right DLPFC delayed valence categorization (compared to control stimulation) to a similar extent irrespective of emotion type. Overall, we failed to demonstrate any valence-related lateralization in the DLPFC by using TMS. Possible methodological limitations are discussed.

Electroencephalographic Activity in a Flanker Interference Task Using Japanese Orthography

2002 ◽  
Vol 14 (7) ◽  
pp. 971-979 ◽  
Author(s):  
Shuhei Yamaguchi ◽  
Genya Toyoda ◽  
Jiang Xu ◽  
Shotai Kobayashi ◽  
Avishai Henik
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Late Phase ◽  
Right Visual Field ◽  
Interference Effects ◽  
Interference Task ◽  
Dorsolateral Prefrontal ◽  
The Right

The neural activities for color word interference effects were investigated using event-related brain potentials (ERPs) recorded in a flanker-type interference task. Kanji words (Japanese morphograms) and kana words (Japanese phono-grams) were used as the flanker stimuli to obtain insights about hemispheric specialization for processing two types of Japanese orthographies. Interference effects in reaction time were larger when kanji words were presented in the left visual field and when kana words were in the right visual field. ERPs were modulated by the incongruent flankers, which generated a negative ERP component with the different onset and offset depending on flanker attributes. Consistent with the behavioral data, the interference-related negativity was observed for kanji words presented in the left visual field and for kana words in the right visual field. The negativity distributed maximally over the fronto-central site. The early part of the negativity distributed strongly over the frontal midline area, whereas it extended bilaterally over the frontal area in the late phase. The present results support the view of preferential processing of kanji in the right hemisphere and that of kana in the left hemisphere. The temporal profile of scalp topographies for the interference-related neural activity suggests that the medial and dorsolateral prefrontal regions may be involved in maintaining attentional set and conflict resolution.

scholarly journals Gene expression profiling of the dorsolateral and medial orbitofrontal cortex in schizophrenia

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Mihovil Mladinov ◽  
Goran Sedmak ◽  
Heidi R. Fuller ◽  
Mirjana Babić Leko ◽  
Davor Mayer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prefrontal Cortex ◽  
Cognitive Processing ◽  
Orbitofrontal Cortex ◽  
Right Hemisphere ◽  
Transcriptome Profiling ◽  
Differentially Expressed ◽  
Unknown Etiology ◽  
Dorsolateral Prefrontal ◽  
The Right

AbstractSchizophrenia is a complex polygenic disorder of unknown etiology. Over 3,000 candidate genes associated with schizophrenia have been reported, most of which being mentioned only once. Alterations in cognitive processing - working memory, metacognition and mentalization - represent a core feature of schizophrenia, which indicates the involvement of the prefrontal cortex in the pathophysiology of this disorder. Hence we compared the gene expression in postmortem tissue from the left and right dorsolateral prefrontal cortex (DLPFC, Brodmann's area 46), and the medial part of the orbitofrontal cortex (MOFC, Brodmann's area 11/12), in six patients with schizophrenia and six control brains. Although in the past decade several studies performed transcriptome profiling in schizophrenia, this is the first study to investigate both hemispheres, providing new knowledge about possible brain asymmetry at the level of gene expression and its relation to schizophrenia. We found that in the left hemisphere, twelve genes from the DLPFC and eight genes from the MOFC were differentially expressed in patients with schizophrenia compared to controls. In the right hemisphere there was only one gene differentially expressed in the MOFC. We reproduce the involvement of previously reported genes TARDBP and HNRNPC in the pathogenesis of schizophrenia, and report seven novel genes:

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.

Hemispheric Specialization and Cognitive Development: Implications for Mathematics Education

1978 ◽  
Vol 9 (1) ◽  
pp. 20-32
Author(s):  
Grayson H. Wheatley ◽  
Robert Mitchell ◽  
Robert L. Frankland ◽  
Rosemarie Kraft
Keyword(s):  
Left Hemisphere ◽  
Hemispheric Asymmetry ◽  
Right Hemisphere ◽  
Mathematics Curriculum ◽  
Hemispheric Specialization ◽  
Brain Hemispheres ◽  
Spatial Tasks ◽  
Concrete Operational ◽  
The Right ◽  
Hemisphere Specialization

Evidence is presented for hemisphere specialization of the two brain hemispheres: the left hemisphere specialized for logico-analytic tasks and the right hemisphere, visuo-spatial tasks. A hypothesis is put forth for the emergence of the specialization that suggests a shift from predominant right hemisphere processing in infancy to predominant left hemisphere processing in adulthood. Results of the studies reviewed suggest the emergence of concrete-operational thought as the left hemisphere becomes capable of processing logical tasks. Electroencephalography seems particularly useful in determining specialization and mapping changes in hemispheric asymmetry. Implications for school mathematics curriculum are presented.

scholarly journals Effects of rTMS Conditioning over the Fronto-parietal Network on Motor versus Visual Attention

2007 ◽  
Vol 19 (3) ◽  
pp. 513-524 ◽  
Author(s):  
Elisabeth Rounis ◽  
Kielan Yarrow ◽  
John C. Rothwell
Keyword(s):  
Visual Attention ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Right Hemisphere ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Motor Preparation ◽  
Attention Task ◽  
Spatial Orienting ◽  
Left Dlpfc ◽  
The Right

Many studies have shown that visuospatial orienting attention depends on a network of frontal and parietal areas in the right hemisphere. Rushworth et al. [Rushworth, M. F., Krams, M., & Passingham, R. E. The attentional role of the left parietal cortex: The distinct lateralization and localization of motor attention in the human brain. Journal of Cognitive Neuroscience, 13, 698–710, 2001] have recently provided evidence for a left-lateralized network of parietal areas involved in motor attention. Using two variants of a cued reaction time (RT) task, we set out to investigate whether high-frequency repetitive transcranial magnetic stimulation (rTMS; 5 Hz) delivered “off-line” in a virtual lesion paradigm over the right or left dorsolateral prefrontal cortex (DLPFC) or the posterior parietal cortex (PPC) would affect performance in a motor versus a visual attention task. Although rTMS over the DLPFC on either side did not affect RT performance on a spatial orienting task, it did lead to an increase in the RTs of invalidly cued trials in a motor attention task when delivered to the left DLPFC. The opposite effect was found when rTMS was delivered to the PPC: In this case, conditioning the right PPC led to increased RTs in invalidly cued trials located in the left hemispace, in the spatial orienting task. rTMS over the PPC on either side did not affect performance in the motor attention task. This double dissociation was evident in the first 10 min after rTMS conditioning. These results enhance our understanding of the networks associated with attention. They provide evidence of a role for the left DLPFC in the mechanisms of motor preparation, and confirm Mesulam's original proposal for a right PPC dominance in spatial attention [Mesulam, M. M. A cortical network for directed attention and unilateral neglect. Annals of Neurology, 10, 309–325, 1981].

Tactile Discrimination of Direction of Lines in Relation to Hemispheric Specialization

1982 ◽  
Vol 54 (2) ◽  
pp. 655-660 ◽  
Author(s):  
Daniela Brizzolara ◽  
Gianni L. De Nobili ◽  
Giovanni Ferretti
Keyword(s):  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Line Orientation ◽  
Contralateral Hemisphere ◽  
Tactile Discrimination ◽  
Experimental Procedure ◽  
Left Hand ◽  
The Right ◽  
Exploratory Movements

The role of the right hemisphere in a task of haptic discrimination of line orientation was studied in 16 children aged 7–6 and 16 adults aged 25 yr. The exploratory movements were limited to hand and wrist, since it has been shown that distal movements are mediated by the contralateral hemisphere. A comparison of the performance of the two hands shows a clear superiority of the left hand and inferred right hemisphere in both children and adults. An especial emphasis in the discussion is given to the role of the experimental procedure in enhancing the effect of the hemispheric functional asymmetries.

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