UNBIASING THE BRAIN: THE EFFECTS OF MEDITATION UPON THE CEREBRAL HEMISPHERES

1983 ◽  
Vol 11 (1) ◽  
pp. 65-76 ◽  
Author(s):  
John Meissner ◽  
Michael Pirot
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Transcendental Meditation ◽  
Hand Preference ◽  
Control Group ◽  
Control Groups ◽  
Clinical Method ◽  
The Right ◽  
The Brain

Twenty males with a strong right hand preference underwent 120 simple reaction time trials to a 500 hz auditory stimulus presented to right, left and both ears. Ten Transcendental Meditators served as their own controls in twenty minute meditation and relaxation conditions and were also compared to a ten Non-Meditator control group who relaxed only in two 20-minute conditions. The reaction time trials were administered after the conditions. When the ears were compared to each other a significant right-ear (left hemisphere) advantage (REA) occurred in all relaxation conditions of the Meditator and Non-Meditator control groups. However, no REA emerged after meditation conditions of the Meditator group. The Meditator group after meditation compared to their own baseline relaxation condition showed a significant suppression of reaction time latencies to stimulation delivered to the left hemisphere and a significant facilitation to stimulation delivered to the right hemisphere. The meaning of these findings suggest Transcendental Meditation is an attentional strategy that disrupts the usual biases of the brain which also has implications as a clinical method. A neuropsychological explanation of the results suggest a comprehensive theory of Transcendental Meditation.

scholarly journals The appropriacy of fluency tests in assessing epileptic seizure lateralization in children with partial epilepsy

Psihologija ◽  
2008 ◽  
Vol 41 (2) ◽  
pp. 195-211
Author(s):  
Jasmina Vuksanovic ◽  
Milena Djuric
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Partial Epilepsy ◽  
Quantitative Comparison ◽  
Control Group ◽  
Healthy Children ◽  
Healthy Controls ◽  
Seizure Focus ◽  
Qualitative And Quantitative ◽  
The Right

Fluency tests are frequently used in clinical practice to asses executive functions. The literature data are not unequivocal although in a great number of papers is pointed out the importance of the left hemisphere, specially of the left frontal lobes in the mediation of phonological fluency and the right hemisphere in the mediation of nonverbal fluency. This paper considers the suitability of fluency tests for the detection of left versus right seizure laterality. The sample consisted of thirty-two epilepsy patients divided into two groups: LHF-participants with the seizure focus in the left hemisphere (n=16), and DHF-participants with the seizure focus in the right hemisphere (n=16), and K-the control group of t age-matched healthy children (n=50) aged 7-11 years. The qualitative and quantitative comparison of the phonological and nonverbal fluency performance was carried out in consideration of the seizure laterality as well as compared to the healthy controls. The results of phonological fluency performance revealed that the performance of the LHF group was significantly reduced as compared to both DHF and K group. The analysis of nonverbal fluency performance revealed that the performance of the DHF group was significantly reduced as compared to both LHF and K group The qualitative analysis obtained valuable data, which could additionally contribute to the neuropsychological evaluation of the left versus right seizure laterality.

Asymmetrical Inhibitory Effects of the First Stimulus on Reaction Time to the Second Stimulus in Double-Stimulation Situations

1980 ◽  
Vol 51 (1) ◽  
pp. 239-244 ◽  
Author(s):  
Hitoshi Honda
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Stimulation ◽  
Output Coupling ◽  
Input Output ◽  
Inhibitory Effects ◽  
Right Hand ◽  
The Right ◽  
Double Stimulation

Inhibitory effects of S1 on the RT to S2 in double (visual-visual) stimulation situations were examined using 10 right-handed subjects, especially from the viewpoint of hemispheric input/output coupling. It was shown that the RT of the left hemisphere (right hand) to S2 after the projection of S1 into the right hemisphere was slower than the RTs under other conditions. The results were interpreted as showing an asymmetrical interhemispheric interfering effect in situations of double stimulation.

Asymmetries of Sensory Functions (Spatial and Temporal Discrimination) in Normal Persons

1947 ◽  
Vol 93 (391) ◽  
pp. 318-332 ◽  
Author(s):  
H. H. Fleischhacker
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Temporal Discrimination ◽  
Mental Symptoms ◽  
The Right ◽  
The Brain ◽  
Sensory Functions

Commenting on the different symptoms produced by disturbances of the left hemisphere (aphasia, apraxia, etc.) and of the right (dreamy states, hallucinations, etc.), Hughlings Jackson on many occasions pointed out that there exists a “duality” of the brain; the anterior parts of the left hemisphere serving more controlled and objective purposes, the posterior parts of the right more subjective† and the anterior parts of the right serving more automatic purposes. Consequently, quoting Bastian and Rosenthal to support him, he tendered the suggestion that “mental” symptoms might be indicative of a disturbance particularly of the posterior parts of the right hemisphere (in right-handed people).

Effect of Visual Complexity in Identification of Tachistoscopic Images

1994 ◽  
Vol 78 (3) ◽  
pp. 971-978 ◽  
Author(s):  
Robert Geheb ◽  
Keith E. Whitfield ◽  
Linda Brannon
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Complexity ◽  
Reaction Times ◽  
Right Cerebral Hemisphere ◽  
The Mean ◽  
The Times ◽  
The Right ◽  
Mean Reaction Time

The present study of gender differences in hemispheric processing involved identification of tachistoscopically presented images of varying complexity. A computerized tachistoscopic program was administered to 24 men and 34 women. Time to identify contour and detailed pictures presented to the left or right cerebral hemisphere was recorded. Mean reaction time for contour pictures was significantly faster than for detailed pictures, and mean reaction time to the right hemisphere was significantly faster than that to the left hemisphere. The mean reaction time for men to identify pictures exposed to the left hemisphere was significantly slower than that for exposure to the right hemisphere for women. The mean reaction time for both men and women to identify contour pictures exposed to the right hemisphere was significantly faster than the mean time to identify detailed pictures presented to the left hemisphere. The interaction of gender, hemisphere, and complexity was also significant in that mean reaction times for men to identify detailed pictures presented to the left hemisphere were slower than the times for women to identify contour pictures presented to the right hemisphere. The results are discussed in relation to theories about hemispheres, gender, and differences in picture features.

Relations between White Matter Maturation and Reaction Time in Childhood

2013 ◽  
Vol 20 (1) ◽  
pp. 99-112 ◽  
Author(s):  
Nadia Scantlebury ◽  
Todd Cunningham ◽  
Colleen Dockstader ◽  
Suzanne Laughlin ◽  
William Gaetz ◽  
...  
Keyword(s):  
Information Processing ◽  
Reaction Time ◽  
White Matter ◽  
Left Hemisphere ◽  
Processing Speed ◽  
Right Hemisphere ◽  
Optic Radiation ◽  
Information Processing Speed ◽  
White Matter Maturation ◽  
The Right

AbstractWhite matter matures with age and is important for the efficient transmission of neuronal signals. Consequently, white matter growth may underlie the development of cognitive processes important for learning, including the speed of information processing. To dissect the relationship between white matter structure and information processing speed, we administered a reaction time task (finger abduction in response to visual cue) to 27 typically developing, right-handed children aged 4 to 13. Magnetoencephalography and Diffusion Tensor Imaging were used to delineate white matter connections implicated in visual-motor information processing. Fractional anisotropy (FA) and radial diffusivity (RD) of the optic radiation in the left hemisphere, and FA and mean diffusivity (MD) of the optic radiation in the right hemisphere changed significantly with age. MD and RD decreased with age in the right inferior fronto-occipital fasciculus, and bilaterally in the cortico-spinal tracts. No age-related changes were evident in the inferior longitudinal fasciculus. FA of the cortico-spinal tract in the left hemisphere and MD of the inferior fronto-occipital fasciculus of the right hemisphere contributed uniquely beyond the effect of age in accounting for reaction time performance of the right hand. Our findings support the role of white matter maturation in the development of information processing speed. (JINS, 2013, 19, 1–14)

scholarly journals Artificial Intelligence to Analyze the Cortical Thickness Through Age

2021 ◽  
Vol 4 ◽  
Author(s):  
Sergio Ledesma ◽  
Mario-Alberto Ibarra-Manzano ◽  
Dora-Luz Almanza-Ojeda ◽  
Pascal Fallavollita ◽  
Jason Steffener
Keyword(s):  
Artificial Intelligence ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Left Hemisphere ◽  
Cortical Thickness ◽  
Right Hemisphere ◽  
Unseen Data ◽  
Artificial Neural ◽  
The Right ◽  
The Brain

In this study, Artificial Intelligence was used to analyze a dataset containing the cortical thickness from 1,100 healthy individuals. This dataset had the cortical thickness from 31 regions in the left hemisphere of the brain as well as from 31 regions in the right hemisphere. Then, 62 artificial neural networks were trained and validated to estimate the number of neurons in the hidden layer. These neural networks were used to create a model for the cortical thickness through age for each region in the brain. Using the artificial neural networks and kernels with seven points, numerical differentiation was used to compute the derivative of the cortical thickness with respect to age. The derivative was computed to estimate the cortical thickness speed. Finally, color bands were created for each region in the brain to identify a positive derivative, that is, a part of life with an increase in cortical thickness. Likewise, the color bands were used to identify a negative derivative, that is, a lifetime period with a cortical thickness reduction. Regions of the brain with similar derivatives were organized and displayed in clusters. Computer simulations showed that some regions exhibit abrupt changes in cortical thickness at specific periods of life. The simulations also illustrated that some regions in the left hemisphere do not follow the pattern of the same region in the right hemisphere. Finally, it was concluded that each region in the brain must be dynamically modeled. One advantage of using artificial neural networks is that they can learn and model non-linear and complex relationships. Also, artificial neural networks are immune to noise in the samples and can handle unseen data. That is, the models based on artificial neural networks can predict the behavior of samples that were not used for training. Furthermore, several studies have shown that artificial neural networks are capable of deriving information from imprecise data. Because of these advantages, the results obtained in this study by the artificial neural networks provide valuable information to analyze and model the cortical thickness.

scholarly journals EEG Asymmetries in Depressive Female Adolescents with Different Kinds of Auto-Aggressive Behavior

Psychiatry ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 14-21
Author(s):  
E. V. Iznak ◽  
E. V. Damyanovich ◽  
N. S. Levchenko ◽  
I. V. Oleichik ◽  
A. F. Iznak
Keyword(s):  
Aggressive Behavior ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Spectral Power ◽  
Quantitative Eeg ◽  
Female Adolescents ◽  
Self Injury ◽  
Increased Risk ◽  
The Right ◽  
The Brain

Background: non-suicidal self-injury (NSSI) in adolescence is a significant risk factor for suicide, and therefore, the search for neurobiological markers and predictors of risk for suicidal intentions and actions seems to be an urgent task. In particular, quantitative EEG parameters can be such predictors.Objective: to identify the features of EEG in female adolescents with endogenous depressive conditions, manifested only by NSSI without suicidal intentions, in comparison with the EEG of patients who had suicidal auto-aggressive behavior (SAB) in the structure of depression.Patients and methods: the study was conducted as a comparative clinical and neurophysiological. The study included 45 female patients aged 16–25 years with endogenous depressive conditions, divided into 2 subgroups: those who showed only NSSI (NSSI subgroup, 21 patients), or who had a history of SAB (SAB subgroup, 24 patients). Clinical-psychopathological, psychometric, neurophysiological and statistical methods were used.Results and its discussion: intergroup differences were revealed in relation to the ratio and hemispheric asymmetry of the EEG spectral power of narrow frequency sub-bands of the parietal-occipital alpha rhythm. In the SAB subgroup alpha-2 (9–11 Hz) rhythm spectral power is higher than in the NSSI subgroup, the focus of alpha-2 spectral power is located in the right hemisphere, and alpha-3 sub-band (11–13 Hz) spectral power is higher than of alpha-1 (8–9 Hz). In the NSSI subgroup, alpha-1 (8–9 Hz) sub-band spectral power are higher than of alpha-3 (11–13 Hz), and focuses of alpha-2 (9–11 Hz) and alpha-3 (11–13 Hz) rhythms are localized in the left hemisphere. The results are discussed in terms of functional specialization of the brain hemispheres in relation to the regulation of emotions and control of behavior.Conclusions: the spatial distribution of the EEG frequency components in the SAB subgroup reflects the greater activation of the brain left hemisphere that is more typical for the EEG of individuals with an increased risk of suicide. In the NSSI subgroup, the right hemisphere is relatively more activated that is more typical for EEG in depressive disorders.The results obtained allow the use of quantitative EEG data to clarify the degree of suicidal risk in depressed female adolescents with non-suicidal self-injury.

scholarly journals The Up-Regulation of CXCL12-CXCR4 Axis By Radiotherapy Could Accelerate Glioma Progression

2021 ◽  
Author(s):  
Yuichiro Tsuji ◽  
Naosuke Nonoguchi ◽  
Daisuke Okuzaki ◽  
Yusuke Wada ◽  
Daisuke Motooka ◽  
...  
Keyword(s):  
Survival Time ◽  
Brain Tissue ◽  
Left Hemisphere ◽  
Median Survival Time ◽  
Glioma Cell ◽  
Right Hemisphere ◽  
X Ray ◽  
The Right ◽  
The Brain ◽  
Cxcr4 Axis

Abstract Background: This study investigated whether the effect of changes in the microenvironment of parenchymal brain tissue caused by radiotherapy for malignant brain tumors affect the recurrence and progression of glioma. Methods: 3 months after the same 65-Gy irradiation had been applied to the right hemisphere. Irradiated Fisher rats were divided into three groups for in vitro assay as follows. IR/Ipsi-brain; the right-hemisphere tissue was used for experiments. IR/Contra-brain; the left-hemisphere tissue was used. Sham-IR/Brain; sham-irradiation was applied to the brain, and the right-hemisphere tissue was used. The effects of proteins extracted from the brains directly or indirectly affected by irradiation on the growth of F98 cells, the effect on tube formation, the influence on tumor biology, and the influence on cytokine production were investigated. Additionally, irradiated animals were divided into three groups for in vivo assay as follows. IR/Ipis-tumor; F98 cells (a glioma cell line) were transplanted to the right hemisphere. IR/Contra-tumor; F98 cells were transplanted to the left hemisphere. Sham-IR/Tumor; F98 cells were transplanted to the right hemisphere without irradiation. The median survival time of F98 transplanted rats was also examined. Results: X-ray irradiation promoted the secretion of cytokines such as TNFα, TGF-β1, VEGF-A, and CXCL12 from the irradiated brain. F98 glioma cells implanted in the irradiated brains showed significantly high proliferation and angiogenesis ability, and the post-irradiation F98 tumor-implanted rats showed a shorter median survival time compared to the Sham-irradiation group.Conclusions: These results indicate that the up-regulation of CXCL12-CXCR4 axis by radiotherapy could promote tumor proliferation. Radiation therapy is a standard treatment for malignant gliomas including glioblastoma multiforme, but the current study suggests that the microenvironment around the brain tissue in the chronic phase after exposure to X-ray radiation becomes suitable for glioma cell growth and invasion.

EFFECT OF AMINOTHIOL ANTIHyPOXANTS ON INTERHEMISPHERIC ASyMMETRy OF THE bRAIN

2012 ◽  
Vol 10 (1) ◽  
pp. 51-53
Author(s):  
Vladimir Vladimirovich Mihkeev ◽  
Vera Vasilievna Marysheva ◽  
Boris Nikolaevich Bogomolov ◽  
Lubov Vladislavovna Zhukova-Williams
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Acute Hypoxia ◽  
Life Time ◽  
Antihypoxic Activity ◽  
Interhemispheric Relations ◽  
Hypoxia With Hypercapnia ◽  
Antihypoxic Effect ◽  
The Right ◽  
The Brain

The effect of aminothiol antihipoxants amthizol and its analogue VM-606 on the resistance of the SHR mice males to an acute hypoxia with hypercapnia under conditions of isolated functioning of one of the hemispheres of the brain was studied. Antihypoxic agent amthizol 25 mg/kg increases life time of naïve mice by 46.2%. The drug acted on the sham-operated mice more slightly, increasing of their life only on 28.1% (p<0.01). Administration of amthizol under conditions of functioning of the right hemisphere significantly enhanced (+64.8%) the life time of mice. No antihypoxic effect was registered after administration of amthizol to mice with active left hemisphere: the result was the same as in mice without amthizol. Therefore, antihypoxic effect of amthizol was due to its action on the right (but not the left) hemisphere of the brain. VM-606 possessed more antihypoxic activity in comparison with amthizol. After unilateral cortical inactivation, VM-606 increased life time of mice both in active right and active left hemispheres, but in more degree in active right hemisphere. Thus, interhemispheric differences in resistance of mice to hypoxia with hypercapnia were diminished. Therefore, the differences between amthizol and VM-606 are the followings: amthizol inverts interhemispheric relations in hypoxia whereas VM-606 diminishes them.

scholarly journals Processing of metaphors in transcortical motor aphasia

2008 ◽  
Vol 2 (4) ◽  
pp. 339-348 ◽  
Author(s):  
Renata Mancopes ◽  
Fernanda Schultz
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Great Emphasis ◽  
Clinical Aspects ◽  
Metaphor Comprehension ◽  
Motor Aphasia ◽  
The Right ◽  
Left Hemisphere Stroke ◽  
Comprehension Tests ◽  
The Brain

Abstract Great emphasis has been placed on the right hemisphere, due to its possible selective contribution, in the processing of metaphorical statements. Objectives: To describe the processing of metaphors in the case of a patient with transcortical motor aphasia, using specific tests for patients with encephalic injuries of the right hemisphere, and to contribute to the discussion on the inter-hemispheric relationships associated with this function. Methods: A 54 year-old man with transcortical motor aphasia was evaluated three years after a left hemisphere stroke. The tasks of comprehension of metaphors were based on the subtest Metaphor Comprehension Task of the Montreal Evaluation of Communications Scale (MEC). Two metaphor comprehension tests were applied, in 45-minute sessions with a 48 hour interval between each. Test 1 involved comprehension of the metaphors according to the options offered, and Test 2 the comprehension of metaphors measured by response time and visual field. Results: Although the right hemisphere was not affected by the stroke in this case, difficulties were observed in the processing of metaphors. Conclusions: This study suggests that the left hemisphere participates in the processing of figurative meanings. The adaptability of the brain can also re-accommodate the uninjured areas of the brain, causing the dynamic of the brain to be modified. As a result, deducing cerebral functions based on clinical data can be problematic. The value of this study is that it can contribute to clinical aspects of language rehabilitation.

Sign in / Sign up

Export Citation Format

Share Document