scholarly journals Single-Case Neuropsychological Assessment of a Patient with a Posterior Parietal Lesion Using Behavioral Testing and Resting-State fMRI

2021 ◽  
Vol 05 (03) ◽  
pp. 1-1
Author(s):  
Elisa Martín-Arévalo ◽  
◽  
Carole Guedj ◽  
François Cotton ◽  
Gilles Rode ◽  
...  
Keyword(s):  
Visual Field ◽  
Functional Connectivity ◽  
Resting State ◽  
Left Visual Field ◽  
Single Case ◽  
Visual Fields ◽  
Resting State Fmri ◽  
Occipital Area ◽  
Posterior Parietal ◽  
The Right

This study integrated functional connectivity measures using resting-state fMRI and behavioral data from a single-case observation of patient (PER) one year after right-hemispheric hemorrhage in the intraparietal sulcus and superior parietal lobule (IPS/SPL). PER showed no sign of clinical neglect. Her behavioral performance in the visuo-manual pointing task and in the letter discrimination task under conditions of endogenous and exogenous attentional cueing was compared between the left (affected) and right (unaffected/control) peripheral visual fields. The resting-state fMRI demonstrated an imbalance between the right and left hemispheric frontoparietal functional connectivity within the dorsal attentional and motor networks. Although the frontal and occipital cortices were not structurally damaged, specific fronto-occipital functional connectivity was imbalanced, which was strongly associated with the behavioral changes. First, the activity in the right frontal eye field showed weaker correlations with the activity in the right inferior occipital area compared to the correlation with the activity in the left inferior occipital area. This imbalanced fronto-occipital functional connectivity was accompanied by a specific impairment in endogenous covert attention in the left visual field. Second, the activity within M1 in both hemispheres showed weaker correlations with the activity of the right cuneus compared to the correlation with the activity in the left cuneus. The imbalanced fronto-occipital functional connectivity was associated with the impairment of the reaching movement of the left and right hands towards the left visual field (optic ataxia). Altogether, our results showed that a lesion to the posterior parietal cortex affects the relationship between distal regions underlying the sensorimotor and attentional abilities

Visual Field Sensitivity on a Two-Choice Discrimination Task

1981 ◽  
Vol 53 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Paul Salmon ◽  
Albert Rodwan
Keyword(s):  
Visual Field ◽  
Signal Detection ◽  
Left Visual Field ◽  
Discrimination Task ◽  
Visual Fields ◽  
Detection Analysis ◽  
Field Sensitivity ◽  
Signal Detection Analysis ◽  
The Right ◽  
Stimulation Of

A signal-detection analysis was used to evaluate visual-field sensitivity on a two-choice (same/different) discrimination task. Pairs of unfamiliar geometrical forms were presented tachistoscopically to the right or left visual fields of 12 subjects. Of 12 subjects 11 obtained left visual-field values which exceeded those of the right. The data suggested that the superiority of stimulation of the left visual field resulted from greater sensitivity to “same” figure pairs.

Effect of Learning on Hemispheric Dominance and Free Recall in a Single Subject

1972 ◽  
Vol 31 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Lester C. Shine ◽  
Joseph Wiant ◽  
Frank Da Polito
Keyword(s):  
Free Recall ◽  
Visual Field ◽  
Analysis Of Variance ◽  
Field Condition ◽  
Left Visual Field ◽  
Visual Fields ◽  
Hemispheric Dominance ◽  
Right Visual Field ◽  
Single Subject ◽  
The Right

This experiment was designed to investigate the effect of learning on the free recall of letters presented tachistoscopically either to the left visual field, the right visual field, or identically and simultaneously to both visual fields. A modified Shine-Bower analysis of variance was used to analyze S's performance. The results indicate that initially, in accord with previous research, the right visual field is superior to the left visual field in performance, but that this superiority tends to reduce across trials and practically disappears in the later trials. Also, the right visual field condition is not appreciably better in performance than the condition with both visual fields.

scholarly journals Altered Intra- and Interregional Synchronization in Resting-State Cerebral Networks Associated with Chronic Tinnitus

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yu-Chen Chen ◽  
Jian Zhang ◽  
Xiao-Wei Li ◽  
Wenqing Xia ◽  
Xu Feng ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Chronic Tinnitus ◽  
Healthy Controls ◽  
Tinnitus Distress ◽  
The Right

Objective. Subjective tinnitus is hypothesized to arise from aberrant neural activity; however, its neural bases are poorly understood. To identify aberrant neural networks involved in chronic tinnitus, we compared the resting-state functional magnetic resonance imaging (fMRI) patterns of tinnitus patients and healthy controls.Materials and Methods. Resting-state fMRI measurements were obtained from a group of chronic tinnitus patients (n=29) with normal hearing and well-matched healthy controls (n=30). Regional homogeneity (ReHo) analysis and functional connectivity analysis were used to identify abnormal brain activity; these abnormalities were compared to tinnitus distress.Results. Relative to healthy controls, tinnitus patients had significant greater ReHo values in several brain regions including the bilateral anterior insula (AI), left inferior frontal gyrus, and right supramarginal gyrus. Furthermore, the left AI showed enhanced functional connectivity with the left middle frontal gyrus (MFG), while the right AI had enhanced functional connectivity with the right MFG; these measures were positively correlated with Tinnitus Handicap Questionnaires (r=0.459,P=0.012andr=0.479,P=0.009, resp.).Conclusions. Chronic tinnitus patients showed abnormal intra- and interregional synchronization in several resting-state cerebral networks; these abnormalities were correlated with clinical tinnitus distress. These results suggest that tinnitus distress is exacerbated by attention networks that focus on internally generated phantom sounds.

Left Ear Hearing Predicts Functional Activity in the Brains of Patients with Alzheimer’s Disease Dementia

2020 ◽  
pp. 000348942095246
Author(s):  
Alana Aylward ◽  
Susan R. Naidu ◽  
Catherine Mellum ◽  
Jace B. King ◽  
Keith G. Jones ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Speech Processing ◽  
Resting State ◽  
Resting State Fmri ◽  
Auditory Input ◽  
Hearing In Noise ◽  
Processing Ability ◽  
Identification Test ◽  
Global Connectivity ◽  
The Right

Objectives: To determine whether central speech processing ability, as measured by hearing in noise, differs between right and left ears in adults with Alzheimer’s disease related dementia (AD) as well as whether differences in central speech processing ability correlate with an fMRI-based measurement of global functional brain connectivity. Methods: This prospective study was carried out at a tertiary referral center. Patients with an AD diagnosis and pure tone averages 40 dB HL or better were included. They were examined using resting-state fMRI and underwent central audiometric testing using the Dichotic Sentence Identification Test (DSI), the Dichotic Digits Test (DD), and the Synthetic Sentence Identification Test (SS), which test hearing in noise. DSI scores were correlated with resting-state fMRI connectivity between 361 distinct gray matter brain regions of interest (ROIs). Average global connectivity was calculated as mean functional connectivity between an ROI and the other 360 regions, a quantitative marker representing overall functional connectivity in the brain. Results: Sixteen subjects had adequate fMRI and hearing data. The average age was 71.5 years old (±6.0). The average DSI score for the left ear was 40% (±34%) compared to 90% (±10%) in the right ear ( P < .001). No difference between ears was noted on the DD. SS does not differentiate between ears, but worsening scores were noted with increasing background noise. Of the fMRI ROIs, 269 of the 361 had multiple comparison corrected significant correlations between global connectivity and DSI of the left ear ( P = .004, r = .673), and all 269 showed higher functional connectivity for individuals with higher left DSI score. No correlations between DSI of the right ear and functional connectivity were found. Conclusions: Correlation was noted between left sided DSI and functional connectivity in patients with AD. Auditory input from the left ear was more susceptible to impairment, suggesting that side-specific auditory input may influence central auditory processing.

scholarly journals Impaired intrinsic functional connectivity between the thalamus and visual cortex in migraine without aura

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Heng-Le Wei ◽  
Xin Zhou ◽  
Yu-Chen Chen ◽  
Yu-Sheng Yu ◽  
Xi Guo ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Migraine Without Aura ◽  
Network Connectivity ◽  
Resting State Fmri ◽  
Neural Activation ◽  
Scale Scores ◽  
The Right ◽  
Complex Scenario ◽  
Visual Network

Abstract Background Resting-state functional magnetic resonance imaging (fMRI) has confirmed disrupted visual network connectivity in migraine without aura (MwoA). The thalamus plays a pivotal role in a number of pain conditions, including migraine. However, the significance of altered thalamo-visual functional connectivity (FC) in migraine remains unknown. The goal of this study was to explore thalamo-visual FC integrity in patients with MwoA and investigate its clinical significance. Methods Resting-state fMRI data were acquired from 33 patients with MwoA and 22 well-matched healthy controls. After identifying the visual network by independent component analysis, we compared neural activation in the visual network and thalamo-visual FC and assessed whether these changes were linked to clinical characteristics. We used voxel-based morphometry to determine whether functional differences were dependent on structural differences. Results The visual network exhibited significant differences in regions (bilateral cunei, right lingual gyrus and left calcarine sulcus) by inter-group comparison. The patients with MwoA showed significantly increased FC between the left thalami and bilateral cunei and between the right thalamus and the contralateral calcarine sulcus and right cuneus. Furthermore, the neural activation of the left calcarine sulcus was positively correlated with visual analogue scale scores (r = 0.319, p = 0.043), and enhanced FC between the left thalamus and right cuneus in migraine patients was negatively correlated with Generalized Anxiety Disorder scores (r = − 0.617, p = 0.005). Conclusion Our data suggest that migraine distress is exacerbated by aberrant feedback projections to the visual network, playing a crucial role in migraine physiological mechanisms. The current study provides further insights into the complex scenario of migraine mechanisms.

Altered thalamic connectivity during spontaneous attacks of migraine without aura: A resting-state fMRI study

Cephalalgia ◽  
2017 ◽  
Vol 38 (7) ◽  
pp. 1237-1244 ◽  
Author(s):  
Faisal Mohammad Amin ◽  
Anders Hougaard ◽  
Stefano Magon ◽  
Till Sprenger ◽  
Frauke Wolfram ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Migraine Without Aura ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Network Connectivity ◽  
Insular Cortex ◽  
Resting State Fmri ◽  
Brain Regions ◽  
The Right

Background Functional connectivity of brain networks may be altered in migraine without aura patients. Functional magnetic resonance imaging (fMRI) studies have demonstrated changed activity in the thalamus, pons and cerebellum in migraineurs. Here, we investigated the thalamic, pontine and cerebellar network connectivity during spontaneous migraine attacks. Methods Seventeen patients with episodic migraine without aura underwent resting-state fMRI scan during and outside of a spontaneous migraine attack. Primary endpoint was a difference in functional connectivity between the attack and the headache-free days. Functional connectivity was assessed in four different networks using seed-based analysis. The chosen seeds were in the thalamus (MNI coordinates x,y,z: right, 22,–24,0 and left, –22,–28,6), pons (right, 8,–24,–32 and left, –8,–24,–32), cerebellum crus I (right, 46,–58,–30 and left, –46,–58,–30) and cerebellum lobule VI (right, 34,–42,–36 and left, –32,–42,–36). Results We found increased functional connectivity between the right thalamus and several contralateral brain regions (superior parietal lobule, insular cortex, primary motor cortex, supplementary motor area and orbitofrontal cortex). There was decreased functional connectivity between the right thalamus and three ipsilateral brain areas (primary somatosensory cortex and premotor cortex). We found no change in functional connectivity in the pontine or the cerebellar networks. Conclusions The study indicates that network connectivity between thalamus and pain modulating as well as pain encoding cortical areas are affected during spontaneous migraine attacks.

scholarly journals Altered Functional Connectivity of the Insula and Nucleus Accumbens in Internet Gaming Disorder: A Resting State fMRI Study

2016 ◽  
Vol 22 (4) ◽  
pp. 192-200 ◽  
Author(s):  
Chiao-Yun Chen ◽  
Ju-Yu Yen ◽  
Peng-Wei Wang ◽  
Gin-Chung Liu ◽  
Cheng-Fang Yen ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Functional Connectivity ◽  
Frontal Lobe ◽  
Resting State ◽  
Internet Gaming Disorder ◽  
Resting State Fmri ◽  
Gaming Disorder ◽  
Internet Gaming ◽  
Left Dlpfc ◽  
The Right

Aims: A possible addiction mechanism has been represented by altered functional connectivity (FC) in the resting state. The aim of this study was to evaluate the FCs of the insula and nucleus accumbens among subjects with Internet gaming disorder (IGD). Methods: We recruited 30 males with IGD and 30 controls and evaluated their FC using functional magnetic imaging scanning under resting, a state with relaxation, closed eyes, with inducement to think of nothing systematically, become motionless, and instructed not to fall asleep. Results: Subjects with IGD had a lower FC with the left insula over the left dorsolateral prefrontal cortex (DLPFC) and orbital frontal lobe and a higher FC with the insula with the contralateral insula than controls. The inter-hemispheric insula connectivity positively correlated with impulsivity. Further, they had lower FC with the left nucleus accumbens over the left DLPFC and with the right nucleus accumbens over the left DLPFC, and insula and a higher FC with that over the right precuneus. Conclusion: The elevated inter-hemispheric insula FC is found to be associated with impulsivity and might explain why it is involved in IGD. The attenuated frontostriatal suggests that the emotion-driven gaming urge through nucleus accumbens could not be well regulated by the frontal lobe of subjects with IGD.

Inflammation is correlated with abnormal functional connectivity in unmedicated bipolar depression: an independent component analysis study of resting-state fMRI

2021 ◽  
pp. 1-11
Author(s):  
Guixian Tang ◽  
Pan Chen ◽  
Guanmao Chen ◽  
Shuming Zhong ◽  
JiaYing Gong ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Independent Component Analysis ◽  
Resting State ◽  
Bipolar Depression ◽  
Serum Levels ◽  
Resting State Fmri ◽  
Component Analysis ◽  
Independent Component ◽  
Precentral Gyrus ◽  
The Right

Abstract Background Inflammation might play a role in bipolar disorder (BD), but it remains unclear the relationship between inflammation and brain structural and functional abnormalities in patients with BD. In this study, we focused on the alterations of functional connectivity (FC), peripheral pro-inflammatory cytokines and their correlations to investigate the role of inflammation in FC in BD depression. Methods In this study, 42 unmedicated patients with BD II depression and 62 healthy controls (HCs) were enrolled. Resting-state-functional magnetic resonance imaging was performed in all participants and independent component analysis was used. Serum levels of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) were measured in all participants. Correlation between FC values and IL-6 and IL-8 levels in BD was calculated. Results Compared with the HCs, BD II patients showed decreased FC in the left orbitofrontal cortex (OFC) implicating the limbic network and the right precentral gyrus implicating the somatomotor network. BD II showed increased IL-6 (p = 0.039), IL-8 (p = 0.002) levels. Moreover, abnormal FC in the right precentral gyrus were inversely correlated with the IL-8 (r = −0.458, p = 0.004) levels in BD II. No significant correlation was found between FC in the left OFC and cytokines levels. Conclusions Our findings that serum IL-8 levels are associated with impaired FC in the right precentral gyrus in BD II patients suggest that inflammation might play a crucial role in brain functional abnormalities in BD.

Recognition of Alphabetical Arrays Presented in the Right and Left Visual Fields

1969 ◽  
Vol 29 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Robert Fudin
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Visual Fields ◽  
Stimulus Presentation ◽  
Right Visual Field ◽  
Cell Assembly ◽  
A Cell ◽  
Experimental Findings ◽  
The Right ◽  
Central Fixation

Six-letter nonsense arrays were tachistoscopically presented successively in the right visual field (RVF) and left visual field (LVF) at four different displacements from a central fixation point (FP) to 20 Ss. Recognition scores were significantly greater for material exposed in the RVF at each of the first three displacements and for the average of all displacements. In each case the higher recognition score for stimuli in the RVF was limited to letters located in the left-array half (letters 1, 2 and 3). An investigation into the dynamics of scanning indicated that these three letters are more advantageously situated when presented in the RVF. This methodological inconsistency brings into question the use of the results obtained from the successive mode of stimulus presentation as evidence for Hebb's notion of a cell assembly. Several ideas concerning the dynamics of scanning which emerged from the experimental findings were discussed.

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