scholarly journals FUNCTIONAL CONNECTIVITY WITHIN LANGUAGE REGIONS IN APHASIC PATIENTS DURING REAL-TIME fMRI-BASED NEUROFEEDBACK TRAINING

2021 ◽  
Author(s):  
Tapasi Brahma ◽  
Chandrasekharan Kesavadas ◽  
PN Sylaja ◽  
Sujesh Sreedharan
Keyword(s):  
Functional Connectivity ◽  
Real Time ◽  
Polar Region ◽  
Test Group ◽  
Brain Regions ◽  
Control Group ◽  
Neurofeedback Training ◽  
Functional Magnetic Resonance ◽  
Training Systems ◽  
The Brain

Stroke is known to disrupt connectivity in the brain in addition to forming scars. This study analyzed the connectivity changes within the language regions and the adjoining brain regions during real-time Functional Magnetic Resonance Imaging-based neurofeedback training for the rehabilitation of stroke-affected patients with expressive aphasia. The study hypothesizes that with repeated sessions of the training, a rise in functional connectivity within the language regions will be observed for the aphasic patients. The experiment was conducted on three groups of subjects: test patients, control patients, and normal participants. Only the test and the normal groups underwent the training. In the training, the subjects exercised language activity covertly to upregulate the Broca’s area. Neurofeedback of the Broca activity (amplified when it is correlated with the Wernicke activity) is visually presented to the subjects to motivate them to improve their performance and stimulate upregulation of functional connectivity of the Broca’s and Wernicke’s areas. The key observations are as follows: For all the groups, a rise in functional connectivity was noticed mostly among the left hemispheric Regions of Interest (ROIs). While comparing the normal group over the test group, ROIs in the frontal polar region were noticed to have good functional connectivity. While comparing the test group over the control group, ROIs in the supra parietal, and the right central opercular regions were found to have good functional connectivity. This study can contribute to the design of rehabilitative training systems that are tuned to activate the regions that have been observed to show increased functional connectivity.

scholarly journals Brain hubs defined in the group do not overlap with regions of high inter-individual variability

2021 ◽  
Author(s):  
Derek Martin Smith ◽  
Brian T Kraus ◽  
Ally Dworetsky ◽  
Evan M Gordon ◽  
Caterina Gratton
Keyword(s):  
Functional Connectivity ◽  
Brain Function ◽  
Critical Role ◽  
Brain Regions ◽  
Individual Variability ◽  
Spatial Proximity ◽  
Functional Magnetic Resonance ◽  
Multiple Networks ◽  
Human Connectome Project ◽  
The Brain

Connector 'hubs' are brain regions with links to multiple networks. These regions are hypothesized to play a critical role in brain function. While hubs are often identified based on group-average functional magnetic resonance imaging (fMRI) data, there is considerable inter-subject variation in the functional connectivity profiles of the brain, especially in association regions where hubs tend to be located. Here we investigated how group hubs are related to locations of inter-individual variability, to better understand if hubs are (a) relatively conserved across people, (b) locations with malleable connectivity, leading individuals to show variable hub profiles, or (c) artifacts arising from cross-person variation. To answer this question, we compared the locations of hubs and regions of strong idiosyncratic functional connectivity ("variants") in both the Midnight Scan Club and Human Connectome Project datasets. Group hubs defined based on the participation coefficient did not overlap strongly with variants. These hubs have relatively strong similarity across participants and consistent cross-network profiles. Consistency across participants was further improved when participation coefficient hubs were allowed to shift slightly in local position. Thus, our results demonstrate that group hubs defined with the participation coefficient are generally consistent across people, suggesting they may represent conserved cross-network bridges. More caution is warranted with alternative hub measures, such as community density, which are based on spatial proximity and show higher correspondence to locations of individual variability.

scholarly journals Migraine in Multiple Sclerosis Patients Affects Functional Connectivity of the Brain Circuitry Involved in Pain Processing

2021 ◽  
Vol 12 ◽  
Author(s):  
Emanuele Pravatà ◽  
Gianna C. Riccitelli ◽  
Carlo Sestieri ◽  
Rosaria Sacco ◽  
Alessandro Cianfoni ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Functional Connectivity ◽  
Pain Perception ◽  
Brain Regions ◽  
Daily Activities ◽  
Control Group ◽  
Resting State Functional Connectivity ◽  
Brain Circuitry ◽  
Multiple Sclerosis Patients ◽  
The Brain

Migraine is particularly common in patients with multiple sclerosis (MS) and has been linked to the dysfunction of the brain circuitry modulating the peripheral nociceptive stimuli. Using MRI, we explored whether changes in the resting state-functional connectivity (RS-FC) may characterize the occurrence of migraine in patients with MS. The RS-FC characteristics in concerned brain regions were explored in 20 MS patients with migraine (MS+M) during the interictal phase, and compared with 19 MS patients without migraine (MS-M), which served as a control group. Functional differences were correlated to the frequency and severity of previous migraine attacks, and with the resulting impact on daily activities. In MS+M, the loss of periaqueductal gray matter (PAG) positive connectivity with the default mode network and the left posterior cranial pons was associated with an increase of migraine attacks frequency. In contrast, the loss of PAG negative connectivity with sensorimotor and visual network was linked to migraine symptom severity and related daily activities impact. Finally, a PAG negative connection was established with the prefrontal executive control network. Migraine in MS+M patients and its impact on daily activities, underlies RS-FC rearrangements between brain regions involved in pain perception and modulation.

Evaluación de la Conectividad Funcional Relacionada con Procesos Cognitivos en Trabajadores Expuestos a Vapores de Tolueno y Derivados

2021 ◽  
Author(s):  
◽  
A. F. Ponce Martínez
Keyword(s):  
Working Memory ◽  
Functional Connectivity ◽  
Occupational Exposure ◽  
Executive Control ◽  
Chemical Properties ◽  
Brain Regions ◽  
Control Group ◽  
Affective Processes ◽  
Occupationally Exposed ◽  
The Brain

The term “occupational exposure” is used when a person gets in touch with vapors of toluene or its derivatives in their work environment. The occupational exposure to toluene vapors represents a risk for people’s health, because due to its chemical properties, toluene threatens mainly the nervous system. Different studies have reported some alteration of cognitive and affective processes, such as empathy and working memory, due to occupational exposure to toluene. The present work proposes a seed based functional connectivity study of a group of workers occupationally exposed to toluene vapors using resting state functional magnetic resonance imaging (rs-fMRI) in brain regions related to empathy and executive control using the CONN Toolbox. It was found that there are differences in the functional connectivity of the anterior insula and the caudate nucleus with other regions of the brain related to empathy and working memory when compared to a control group, and some possible effects of these differences where explored.

scholarly journals Altered Functional Connectivity of the Primary Visual Cortex in Subjects with Amblyopia

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kun Ding ◽  
Yong Liu ◽  
Xiaohe Yan ◽  
Xiaoming Lin ◽  
Tianzi Jiang
Keyword(s):  
Functional Connectivity ◽  
Activity Patterns ◽  
Brain Regions ◽  
Visual Area ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Blurred Vision ◽  
Visual Areas ◽  
Connectivity Patterns ◽  
The Brain

Amblyopia, which usually occurs during early childhood and results in poor or blurred vision, is a disorder of the visual system that is characterized by a deficiency in an otherwise physically normal eye or by a deficiency that is out of proportion with the structural or functional abnormalities of the eye. Our previous study demonstrated alterations in the spontaneous activity patterns of some brain regions in individuals with anisometropic amblyopia compared to subjects with normal vision. To date, it remains unknown whether patients with amblyopia show characteristic alterations in the functional connectivity patterns in the visual areas of the brain, particularly the primary visual area. In the present study, we investigated the differences in the functional connectivity of the primary visual area between individuals with amblyopia and normal-sighted subjects using resting functional magnetic resonance imaging. Our findings demonstrated that the cerebellum and the inferior parietal lobule showed altered functional connectivity with the primary visual area in individuals with amblyopia, and this finding provides further evidence for the disruption of the dorsal visual pathway in amblyopic subjects.

scholarly journals Aberrant intrinsic functional connectivity within and between corticostriatal and temporal–parietal networks in adults and youth with bipolar disorder

2016 ◽  
Vol 46 (7) ◽  
pp. 1509-1522 ◽  
Author(s):  
J. Stoddard ◽  
S. J. Gotts ◽  
M. A. Brotman ◽  
S. Lever ◽  
D. Hsu ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Functional Connectivity ◽  
Visual Processing ◽  
Age Groups ◽  
Neural Circuitry ◽  
Brain Regions ◽  
Functional Magnetic Resonance ◽  
Intrinsic Functional Connectivity ◽  
Late Stages ◽  
The Brain

BackgroundMajor questions remain regarding the dysfunctional neural circuitry underlying the pathophysiology of bipolar disorder (BD) in both youths and adults. In both age groups, studies implicate abnormal intrinsic functional connectivity among prefrontal, limbic and striatal areas.MethodWe collected resting-state functional magnetic resonance imaging (fMRI) data from youths and adults (ages 10–50 years) with BD (n = 39) and healthy volunteers (HV; n = 78). We identified brain regions with aberrant intrinsic functional connectivity in BD by first comparing voxel-wise mean global connectivity and then conducting correlation analyses. We used k-means clustering and multidimensional scaling to organize all detected regions into networks.ResultsAcross the brain, we detected areas of dysconnectivity in both youths and adults with BD relative to HV. There were no significant age-group × diagnosis interactions. When organized by interregional connectivity, the areas of dysconnectivity in patients with BD comprised two networks: one of temporal and parietal areas involved in late stages of visual processing, and one of corticostriatal areas involved in attention, cognitive control and response generation.ConclusionsThese data suggest that two networks show abnormal intrinsic functional connectivity in BD. Regions in these networks have been implicated previously in BD. We observed similar dysconnectivity in youths and adults with BD. These findings provide guidance for refining models of network-based dysfunction in BD.

scholarly journals Twitches, Blinks, and Fidgets: Important Generators of Ongoing Neural Activity

2018 ◽  
Vol 25 (4) ◽  
pp. 298-313 ◽  
Author(s):  
Patrick J. Drew ◽  
Aaron T. Winder ◽  
Qingguang Zhang
Keyword(s):  
Functional Connectivity ◽  
Neural Activity ◽  
Brain Regions ◽  
Wide Field ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Frequency Range ◽  
Sensory Stimuli ◽  
Motor Actions ◽  
The Brain

Animals and humans continuously engage in small, spontaneous motor actions, such as blinking, whisking, and postural adjustments (“fidgeting”). These movements are accompanied by changes in neural activity in sensory and motor regions of the brain. The frequency of these motions varies in time, is affected by sensory stimuli, arousal levels, and pathology. These fidgeting behaviors can be entrained by sensory stimuli. Fidgeting behaviors will cause distributed, bilateral functional activation in the 0.01 to 0.1 Hz frequency range that will show up in functional magnetic resonance imaging and wide-field calcium neuroimaging studies, and will contribute to the observed functional connectivity among brain regions. However, despite the large potential of these behaviors to drive brain-wide activity, these fidget-like behaviors are rarely monitored. We argue that studies of spontaneous and evoked brain dynamics in awake animals and humans should closely monitor these fidgeting behaviors. Differences in these fidgeting behaviors due to arousal or pathology will “contaminate” ongoing neural activity, and lead to apparent differences in functional connectivity. Monitoring and accounting for the brain-wide activations by these behaviors is essential during experiments to differentiate fidget-driven activity from internally driven neural dynamics.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

scholarly journals Pain Detection and the Privacy of Subjective Experience

2007 ◽  
Vol 33 (2-3) ◽  
pp. 433-456 ◽  
Author(s):  
Adam J. Kolber
Keyword(s):  
Subjective Experience ◽  
Brain Regions ◽  
Physical Pain ◽  
Medical Evidence ◽  
Functional Magnetic Resonance ◽  
Positron Emission ◽  
Pain Symptoms ◽  
The Brain ◽  
Insight Into ◽  
Neuroimaging Techniques

A neurologist with abdominal pain goes to see a gastroenterologist for treatment. The gastroenterologist asks the neurologist where it hurts. The neurologist replies, “In my head, of course.” Indeed, while we can feel pain throughout much of our bodies, pain signals undergo most of their processing in the brain. Using neuroimaging techniques like functional magnetic resonance imaging (“fMRI”) and positron emission tomography (“PET”), researchers have more precisely identified brain regions that enable us to experience physical pain. Certain regions of the brain's cortex, for example, increase in activation when subjects are exposed to painful stimuli. Furthermore, the amount of activation increases with the intensity of the painful stimulus. These findings suggest that we may be able to gain insight into the amount of pain a particular person is experiencing by non-invasively imaging his brain.Such insight could be particularly valuable in the courtroom where we often have no definitive medical evidence to prove or disprove claims about the existence and extent of pain symptoms.

scholarly journals Increased sensitivity to strong perturbations in a whole-brain model of LSD

2021 ◽  
Author(s):  
Beatrice M. Jobst ◽  
Selen Atasoy ◽  
Adrián Ponce-Alvarez ◽  
Ana Sanjuán ◽  
Leor Roseman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
External Perturbation ◽  
Brain Regions ◽  
Lysergic Acid ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Whole Brain ◽  
Response Diversity ◽  
Brain States ◽  
The Brain

AbstractLysergic acid diethylamide (LSD) is a potent psychedelic drug, which has seen a revival in clinical and pharmacological research within recent years. Human neuroimaging studies have shown fundamental changes in brain-wide functional connectivity and an expansion of dynamical brain states, thus raising the question about a mechanistic explanation of the dynamics underlying these alterations. Here, we applied a novel perturbational approach based on a whole-brain computational model, which opens up the possibility to externally perturb different brain regions in silico and investigate differences in dynamical stability of different brain states, i.e. the dynamical response of a certain brain region to an external perturbation. After adjusting the whole-brain model parameters to reflect the dynamics of functional magnetic resonance imaging (fMRI) BOLD signals recorded under the influence of LSD or placebo, perturbations of different brain areas were simulated by either promoting or disrupting synchronization in the regarding brain region. After perturbation offset, we quantified the recovery characteristics of the brain area to its basal dynamical state with the Perturbational Integration Latency Index (PILI) and used this measure to distinguish between the two brain states. We found significant changes in dynamical complexity with consistently higher PILI values after LSD intake on a global level, which indicates a shift of the brain’s global working point further away from a stable equilibrium as compared to normal conditions. On a local level, we found that the largest differences were measured within the limbic network, the visual network and the default mode network. Additionally, we found a higher variability of PILI values across different brain regions after LSD intake, indicating higher response diversity under LSD after an external perturbation. Our results provide important new insights into the brain-wide dynamical changes underlying the psychedelic state - here provoked by LSD intake - and underline possible future clinical applications of psychedelic drugs in particular psychiatric disorders.HighlightsNovel offline perturbational method applied on functional magnetic resonance imaging (fMRI) data under the effect of lysergic acid diethylamide (LSD)Shift of brain’s global working point to more complex dynamics after LSD intakeConsistently longer recovery time after model perturbation under LSD influenceStrongest effects in resting state networks relevant for psychedelic experienceHigher response diversity across brain regions under LSD influence after an external in silico perturbation

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