scholarly journals The Role of Insula-Associated Brain Network in Touch

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Pengxu Wei ◽  
Ruixue Bao
Keyword(s):  
Parietal Cortex ◽  
Superior Temporal Gyrus ◽  
Normal Subjects ◽  
Brain Network ◽  
Seed Region ◽  
Secondary Somatosensory Cortex ◽  
Inferior Parietal Cortex ◽  
Posterior Insula ◽  
The Right ◽  
Post Hoc

The insula is believed to be associated with touch-evoked effects. In this work, functional MRI was applied to investigate the network model of insula function when 20 normal subjects received tactile stimulation over segregated areas. Data analysis was performed with SPM8 and Conn toolbox. Activations in the contralateral posterior insula were consistently revealed for all stimulation areas, with the overlap located in area Ig2. The area Ig2 was then used as the seed to estimate the insula-associated network. The right insula, left superior parietal lobule, left superior temporal gyrus, and left inferior parietal cortex showed significant functional connectivity with the seed region for all stimulation conditions. Connectivity maps of most stimulation conditions were mainly distributed in the bilateral insula, inferior parietal cortex, and secondary somatosensory cortex. Post hoc ROI-to-ROI analysis and graph theoretical analysis showed that there were higher correlations between the left insula and the right insula, left inferior parietal cortex and right OP1 for all networks and that the global efficiency was more sensitive than the local efficiency to detect differences between notes in a network. These results suggest that the posterior insula serves as a hub to functionally connect other regions in the detected network and may integrate information from these regions.

scholarly journals Modulation of the Visual to Auditory Human Inhibitory Brain Network: An EEG Dipole Source Localization Study

2019 ◽  
Vol 9 (9) ◽  
pp. 216 ◽  
Author(s):  
Rupesh Kumar Chikara ◽  
Li-Wei Ko
Keyword(s):  
Human Brain ◽  
Inhibitory Control ◽  
Source Localization ◽  
Visual Stimulation ◽  
Superior Temporal Gyrus ◽  
Brain Network ◽  
Dipole Source ◽  
Beta Band ◽  
Dipole Source Localization ◽  
The Right

Auditory alarms are used to direct people’s attention to critical events in complicated environments. The capacity for identifying the auditory alarms in order to take the right action in our daily life is critical. In this work, we investigate how auditory alarms affect the neural networks of human inhibition. We used a famous stop-signal or go/no-go task to measure the effect of visual stimuli and auditory alarms on the human brain. In this experiment, go-trials used visual stimulation, via a square or circle symbol, and stop trials used auditory stimulation, via an auditory alarm. Electroencephalography (EEG) signals from twelve subjects were acquired and analyzed using an advanced EEG dipole source localization method via independent component analysis (ICA) and EEG-coherence analysis. Behaviorally, the visual stimulus elicited a significantly higher accuracy rate (96.35%) than the auditory stimulus (57.07%) during inhibitory control. EEG theta and beta band power increases in the right middle frontal gyrus (rMFG) were associated with human inhibitory control. In addition, delta, theta, alpha, and beta band increases in the right cingulate gyrus (rCG) and delta band increases in both right superior temporal gyrus (rSTG) and left superior temporal gyrus (lSTG) were associated with the network changes induced by auditory alarms. We further observed that theta-alpha and beta bands between lSTG-rMFG and lSTG-rSTG pathways had higher connectivity magnitudes in the brain network when performing the visual tasks changed to receiving the auditory alarms. These findings could be useful for further understanding the human brain in realistic environments.

scholarly journals Alice in Wonderland syndrome: “Who in the world am I?”

2019 ◽  
Vol 77 (9) ◽  
pp. 672-674 ◽  
Author(s):  
Joseph Bruno Bidin Brooks ◽  
Fabio César Prosdocimi ◽  
Pedro Banho da Rosa ◽  
Yara Dadalti Fragoso
Keyword(s):  
Medical Literature ◽  
Premotor Cortex ◽  
Temporoparietal Junction ◽  
Secondary Somatosensory Cortex ◽  
Alice In Wonderland ◽  
Right Temporoparietal Junction ◽  
Posterior Insula ◽  
Cortical Regions ◽  
The Right ◽  
Visual Cortical

ABSTRACT Alice in Wonderland syndrome (AIWS) is a paroxysmal, perceptual, visual and somesthetic disorder that can be found in patients with migraine, epilepsy, cerebrovascular disease or infections. The condition is relatively rare and unique in its hallucinatory characteristics. Objective: To discuss the potential pathways involved in AIWS. Interest in this subject arose from a patient seen at our service, in which dysmetropsia of body image was reported by the patient, when she saw it in her son. Methods: We reviewed and discussed the medical literature on reported patients with AIWS, possible anatomical pathways involved and functional imaging studies. Results: A complex neural network including the right temporoparietal junction, secondary somatosensory cortex, premotor cortex, right posterior insula, and primary and extrastriate visual cortical regions seem to be involved in AIWS to varying degrees. Conclusions: AIWS is a very complex condition that typically has been described as isolated cases or series of cases.

Influence of Vocabulary-Age on Unilateral Picture-Naming Reaction Times of Normal Subjects

1991 ◽  
Vol 73 (3) ◽  
pp. 1047-1054 ◽  
Author(s):  
Michael P. Rastatter ◽  
Richard McGuire ◽  
Gail Scukanec
Keyword(s):  
Picture Naming ◽  
Significant Interaction ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Reaction Times ◽  
Normal Subjects ◽  
Clinical Literature ◽  
The Right ◽  
Post Hoc ◽  
Developmental Hierarchy

The present study measured naming reaction times of normal subjects to unilaterally presented pictures corresponding to vocabulary levels of < 5.5, 9.5–10.5, and >18.0 years of age. An analysis of variance of latencies showed a significant interaction between visual fields and stimuli. Post hoc tests were interpreted to suggest that the normal right hemisphere was capable of performing certain differential picture encoding operations up to 10.5 years of age and not beyond. Also, unlike the left hemisphere, the right hemisphere does not appear to be organized on a developmental hierarchy, which corresponds with the clinical literature.

scholarly journals Altered brain network centrality in patients with adult comitant exotropia strabismus: A resting-state fMRI study

2017 ◽  
Vol 46 (1) ◽  
pp. 392-402 ◽  
Author(s):  
Gang Tan ◽  
Zeng-Renqing Dan ◽  
Ying Zhang ◽  
Xin Huang ◽  
Yu-Lin Zhong ◽  
...  
Keyword(s):  
Brain Activity ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
Brain Network ◽  
Network Activity ◽  
Ocular Motility ◽  
Behavioral Performance ◽  
Parietal Lobule ◽  
The Right ◽  
The Relationship

Objective To investigate the underlying functional network brain-activity changes in patients with adult comitant exotropia strabismus (CES) and the relationship with clinical features using the voxel-wise degree centrality (DC) method. Methods A total of 30 patients with CES (17 men, 13 women), and 30 healthy controls (HCs; 17 men, 13 women) matched in age, sex, and education level participated in the study. DC was used to evaluate spontaneous brain activity. Receiver operating characteristic (ROC) curve analysis was conducted to distinguish CESs from HCs. The relationship between mean DC values in various brain regions and behavioral performance was examined with correlation analysis. Results Compared with HCs, CES patients exhibited decreased DC values in the right cerebellum posterior lobe, right inferior frontal gyrus, right middle frontal gyrus and right superior parietal lobule/primary somatosensory cortex (S1), and increased DC values in the right superior temporal gyrus, bilateral anterior cingulate, right superior temporal gyrus, and left inferior parietal lobule. However, there was no correlation between mean DC values and behavioral performance in any brain regions. Conclusions Adult comitant exotropia strabismus is associated with abnormal brain network activity in various brain regions, possibly reflecting the pathological mechanisms of ocular motility disorders in CES.

scholarly journals Altered Effective Connectivity of Hippocampus-Dependent Episodic Memory Network in mTBI Survivors

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Hao Yan ◽  
Yanqin Feng ◽  
Qian Wang
Keyword(s):  
Episodic Memory ◽  
Brain Injuries ◽  
Effective Connectivity ◽  
Superior Temporal Gyrus ◽  
Brain Structures ◽  
Brain Network ◽  
Parahippocampal Gyrus ◽  
Memory Network ◽  
Anterior Prefrontal Cortex ◽  
The Right

Traumatic brain injuries (TBIs) are generally recognized to affect episodic memory. However, less is known regarding how external force altered the way functionally connected brain structures of the episodic memory system interact. To address this issue, we adopted an effective connectivity based analysis, namely, multivariate Granger causality approach, to explore causal interactions within the brain network of interest. Results presented that TBI induced increased bilateral and decreased ipsilateral effective connectivity in the episodic memory network in comparison with that of normal controls. Moreover, the left anterior superior temporal gyrus (aSTG, the concept forming hub), left hippocampus (the personal experience binding hub), and left parahippocampal gyrus (the contextual association hub) were no longer network hubs in TBI survivors, who compensated for hippocampal deficits by relying more on the right hippocampus (underlying perceptual memory) and the right medial frontal gyrus (MeFG) in the anterior prefrontal cortex (PFC). We postulated that the overrecruitment of the right anterior PFC caused dysfunction of the strategic component of episodic memory, which caused deteriorating episodic memory in mTBI survivors. Our findings also suggested that the pattern of brain network changes in TBI survivors presented similar functional consequences to normal aging.

scholarly journals Somatosensory responses to nothing: an MEG study of expectations during omission of tactile stimulations

2018 ◽  
Author(s):  
Lau M. Andersen ◽  
Daniel Lundqvist
Keyword(s):  
Index Finger ◽  
Beta Band ◽  
Secondary Somatosensory Cortex ◽  
Inferior Parietal Cortex ◽  
Future Events ◽  
Somatosensory Responses ◽  
The Right ◽  
Gamma Band Activity ◽  
The Brain ◽  
Band Activity

AbstractThe brain builds up expectations to future events based on the patterns of past events. This function has been studied extensively in the auditory and visual domains using various oddball paradigms, but only little exploration of this phenomenon has been done in the somatosensory domain. In this study, we explore how expectations of somatosensory stimulations are established and expressed in neural activity as measured with magnetoencephalography. Using tactile stimulations to the index finger, we compared conditions with actual stimulation to conditions with omitted stimulations, both of which were either expected or unexpected.Our results show that when a stimulation is expected but omitted, a time-locked response occurs ∼135 ms subsequent to the expected stimulation. This somatosensory response to “nothing” was source localized to the secondary somatosensory cortex and to the insula. This provides novel evidence of the capability of the brain of millisecond time-keeping of somatosensory patterns across intervals of 3000 ms.Our results also show that when stimuli are repeated and expectations are established, there is associated activity in the theta and beta bands. These theta and beta band expressions of expectation were localized to the primary somatosensory area, inferior parietal cortex and cerebellum. Furthermore, there was gamma band activity in the right insula for the first stimulation after an omission, which indicates the detection of a new stimulation event after an expected pattern has been broken.Finally, our results show that cerebellum play a crucial role in predicting upcoming stimulation and in predicting when stimulation may begin again.

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