scholarly journals Effective connectivity during autobiographical memory search

2019 ◽  
Author(s):  
Norberto Eiji Nawa ◽  
Hiroshi Ando
Keyword(s):  
Autobiographical Memory ◽  
Effective Connectivity ◽  
Memory Search ◽  
Brain Regions ◽  
Inhibitory Effect ◽  
Causal Modeling ◽  
Angular Gyrus ◽  
Large Network ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions

AbstractAutobiographical memory (AM) retrieval is known to recruit a widely distributed network of brain regions but much less is known regarding how these regions interact during the various phases that presumably take place during episodic memory retrieval in general and AM retrieval in particular. Here, we used dynamic causal modeling (DCM) to examine effective connectivity during cued AM search in a sub-network consisting of six major regions within this large network. Functional MRI data was acquired while participants were visually presented verbal cues describing common life events and requested to search for a personal memory that could be associated with each cue. We examined directed couplings between the ventromedial (vmPFC), dorsomedial (dmPFC) and dorsolateral prefrontal cortices (dlPFC), hippocampus, angular gyrus and a region in the posterior midline cortex (RSC/PCC/Prec), all located in the left hemisphere. Results indicated that during AM search, the vmPFC, dlPFC and RSC/PCC/Prec acted as primary drivers of activity in the rest of the network. Moreover, when AM search was completed successfully (Hits), an up-modulation of the effective connectivity of the hippocampus in the vmPFC and angular gyrus was observed. In the same way, there was an increase in the influence of the RSC/PCC/Prec in the activity of the dlPFC and dmPFC. Furthermore, during Hits the angular gyrus showed to have an inhibitory effect in all other nodes of the network. These results are consistent with the notion that midline cortical regions are crucial in supporting the retrieval of AMs, and highlight the interplay between the vmPFC and the RSC/PCC/Prec and the dlPFC during AM search.

scholarly journals Alternation in Effective Connectivity With Cognitive Aging: A Longitudinal Study of Elderly Populations

2021 ◽  
Vol 13 ◽  
Author(s):  
Xingxing Cao ◽  
Tao Liu ◽  
Jiyang Jiang ◽  
Hao Liu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Elderly People ◽  
Cognitive Aging ◽  
Aging Process ◽  
Effective Connectivity ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Causal Modeling ◽  
Angular Gyrus ◽  
Time Points

In this research, we investigated the alterations in the directionality and strength of regional interactions within functionally changed brain networks and their relationship to cognitive decline during the aging process in normal elderly individuals. Thirty-seven cognitively normal elderly people received resting-state fMRI scans and cognitive assessments at baseline (age = 78.65 ± 3.56 years) and at 4-year follow-up. Functional connectivity analyses were used to identify networks containing brain regions whose functions changed with age as regions of interest. The spectral dynamic causal modeling (spDCM) method was used to estimate the causal interactions within networks in subjects at different time points and in subjects with different cognitive levels to explore the alterations with cognitive aging. The results showed that, at both time points, all the networks, except the frontal-parietal network (FPN) at baseline, had mutual interactions between each pair of nodes. Furthermore, when the subjects were divided with global cognition level, lost connections were only found in the subgroup with better performance. These indicated that elderly people appeared to need more interaction pathways between brain areas with cognitive decline. We also observed that the strength of the flow of information from the left angular gyrus to the precuneus, which is associated with activation of memory retrieval and the functional hub involved in various cognitive domains, was predictive of declines in executive function with the aging process, making it a potential predictor of such situation.

scholarly journals Diagnostic Task Specific Activations in Functional MRI and Aberrant Connectivity of Insula with Middle Frontal Gyrus Can Inform the Differential Diagnosis of Psychosis

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 95
Author(s):  
Drozdstoy Stoyanov ◽  
Katrin Aryutova ◽  
Sevdalina Kandilarova ◽  
Rositsa Paunova ◽  
Zlatoslav Arabadzhiev ◽  
...  
Keyword(s):  
Effective Connectivity ◽  
Paranoid Schizophrenia ◽  
Indirect Evidence ◽  
Inhibitory Effect ◽  
Posterior Cingulate Cortex ◽  
Anterior Insula ◽  
Middle Frontal Gyrus ◽  
Angular Gyrus ◽  
Inhibitory Connection ◽  
Significant Difference

We constructed a novel design integrating the administration of a clinical self-assessment scale with simultaneous acquisition of functional Magnetic Resonance Imaging (fMRI), aiming at cross-validation between psychopathology evaluation and neuroimaging techniques. We hypothesized that areas demonstrating differential activation in two groups of patients (the first group exhibiting paranoid delusions in the context of paranoid schizophrenia—SCH—and second group with a depressive episode in the context of major depressive disorder or bipolar disorder—DEP) will have distinct connectivity patterns and structural differences. Fifty-one patients with SCH (n = 25) or DEP (n = 26) were scanned with three different MRI sequences: a structural and two functional sequences—resting-state and task-related fMRI (the stimuli represent items from a paranoid-depressive self-evaluation scale). While no significant differences were found in gray matter volumes, we were able to discriminate between the two clinical entities by identifying two significant clusters of activations in the SCH group—the left Precuneus (PreCu) extending to the left Posterior Cingulate Cortex (PCC) and the right Angular Gyrus (AG). Additionally, the effective connectivity of the middle frontal gyrus (MFG), a part of the Dorsolateral Prefrontal Cortex (DLPFC) to the Anterior Insula (AI), demonstrated a significant difference between the two groups with inhibitory connection demonstrated only in SCH. The observed activations of PreCu, PCC, and AG (involved in the Default Mode Network DMN) might be indirect evidence of the inhibitory connection from the DLPFC to AI, interfering with the balancing function of the insula as the dynamic switch in the DMN. The findings of our current study might suggest that the connectivity from DLPFC to the anterior insula can be interpreted as evidence for the presence of an aberrant network that leads to behavioral abnormalities, the manifestation of which depends on the direction of influence. The reduced effective connectivity from the AI to the DLPFC is manifested as depressive symptoms, and the inhibitory effect from the DLPFC to the AI is reflected in the paranoid symptoms of schizophrenia.

scholarly journals Effective connectivity during autobiographical memory search

2020 ◽  
Vol 10 (8) ◽  
Author(s):  
Norberto Eiji Nawa ◽  
Hiroshi Ando
Keyword(s):  
Autobiographical Memory ◽  
Effective Connectivity ◽  
Memory Search

scholarly journals Altered Prefrontal–Basal Ganglia Effective Connectivity in Patients With Poststroke Cognitive Impairment

2020 ◽  
Vol 11 ◽  
Author(s):  
Jing Zhang ◽  
Zixiao Li ◽  
Xingxing Cao ◽  
Lijun Zuo ◽  
Wei Wen ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Basal Ganglia ◽  
Cognitive Decline ◽  
Effective Connectivity ◽  
Network Connectivity ◽  
Brain Regions ◽  
Neuronal Model ◽  
Causal Modeling ◽  
Healthy Controls

We investigated the association between poststroke cognitive impairment and a specific effective network connectivity in the prefrontal–basal ganglia circuit. The resting-state effective connectivity of this circuit was modeled by employing spectral dynamic causal modeling in 11 poststroke patients with cognitive impairment (PSCI), 8 poststroke patients without cognitive impairment (non-PSCI) at baseline and 3-month follow-up, and 28 healthy controls. Our results showed that different neuronal models of effective connectivity in the prefrontal–basal ganglia circuit were observed among healthy controls, non-PSCI, and PSCI patients. Additional connected paths (extra paths) appeared in the neuronal models of stroke patients compared with healthy controls. Moreover, changes were detected in the extra paths of non-PSCI between baseline and 3-month follow-up poststroke, indicating reorganization in the ipsilesional hemisphere and suggesting potential compensatory changes in the contralesional hemisphere. Furthermore, the connectivity strengths of the extra paths from the contralesional ventral anterior nucleus of thalamus to caudate correlated significantly with cognitive scores in non-PSCI and PSCI patients. These suggest that the neuronal model of effective connectivity of the prefrontal–basal ganglia circuit may be sensitive to stroke-induced cognitive decline, and it could be a biomarker for poststroke cognitive impairment 3 months poststroke. Importantly, contralesional brain regions may play an important role in functional compensation of cognitive decline.

Individual Differences in Mental Imagery Modulate Effective Connectivity of Scene-Selective Regions During Resting State

2021 ◽  
Author(s):  
Maria Giulia Tullo ◽  
Hannes Almgren ◽  
Frederik Van de Steen ◽  
Valentina Sulpizio ◽  
Daniele Marinazzo ◽  
...  
Keyword(s):  
Individual Differences ◽  
Mental Imagery ◽  
Resting State ◽  
Effective Connectivity ◽  
Relevant Information ◽  
Brain Regions ◽  
Intrinsic Activity ◽  
Inhibitory Influence ◽  
Cortical Regions ◽  
Intrinsic Fluctuation

Abstract Successful navigation relies on the ability to identify, perceive, and correctly process the spatial structure of a scene. It is well known that visual mental imagery plays a crucial role in navigation. Indeed, cortical regions encoding navigationally relevant information are also active during mental imagery of navigational scenes. However, it remains unknown whether their intrinsic activity and connectivity reflect the individuals’ ability to imagine a scene. Here, we primarily investigated the intrinsic causal interactions among scene-selective brain regions such as Parahipoccampal Place Area (PPA), Retrosplenial Complex (RSC), and Occipital Place Area (OPA) using Dynamic Causal Modelling (DCM) for resting-state functional magnetic resonance (rs-fMRI) data. Second, we tested whether resting-state effective connectivity parameters among scene-selective regions could reflect individual differences in mental imagery in our sample, as assessed by the self-reported Vividness of Visual Imagery Questionnaire (VVIQ). We found an inhibitory influence of occipito-medial on temporal regions, and an excitatory influence of more anterior on more medial and posterior brain regions. Moreover, we found that a key role in imagery is played by the connection strength from OPA to PPA, especially in the left hemisphere, since the influence of the signal between these scene-selective regions positively correlated with good mental imagery ability. Our investigation contributes to the understanding of the complexity of the causal interaction among brain regions involved in navigation and provides new insight in understanding how an essential ability, such as mental imagery, can be explained by the intrinsic fluctuation of brain signal.

scholarly journals Altered neural activity in brain cough suppression networks in cigarette smokers

2019 ◽  
Vol 54 (3) ◽  
pp. 1900362 ◽  
Author(s):  
Ayaka Ando ◽  
Stuart B. Mazzone ◽  
Michael J. Farrell
Keyword(s):  
Prefrontal Cortex ◽  
Neural Circuits ◽  
Brain Regions ◽  
Smoking Behaviour ◽  
Brain Network ◽  
Functional Brain Imaging ◽  
Cigarette Smokers ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Airway Irritation

Cough is important for airway defence, and studies in healthy animals and humans have revealed multiple brain networks intimately involved in the perception of airway irritation, cough induction and cough suppression. Changes in cough sensitivity and/or the ability to suppress cough accompany pulmonary pathologies, suggesting a level of plasticity is possible in these central neural circuits. However, little is known about how persistent inputs from the lung might modify the brain processes regulating cough.In the present study, we used human functional brain imaging to investigate the central neural responses that accompany an altered cough sensitivity in cigarette smokers.In nonsmokers, inhalation of the airway irritant capsaicin induced a transient urge-to-cough associated with the activation of a distributed brain network that included sensory, prefrontal and motor cortical regions. Cigarette smokers demonstrated significantly higher thresholds for capsaicin-induced urge-to-cough, consistent with a reduced sensitivity to airway irritation. Intriguingly, this was accompanied by increased activation in brain regions known to be involved in both cough sensory processing (primary sensorimotor cortex) and cough suppression (dorsolateral prefrontal cortex and the midbrain nucleus cuneiformis). Activations in the prefrontal cortex were highest among participants with the least severe smoking behaviour, whereas those in the midbrain correlated with more severe smoking behaviour.These outcomes suggest that smoking-induced sensitisation of central cough neural circuits is offset by concurrently enhanced central suppression. Furthermore, central suppression mechanisms may evolve with the severity of smoke exposure, changing from initial prefrontal inhibition to more primitive midbrain processes as exposure increases.

scholarly journals Multivariate Granger Causality Analysis of Acupuncture Effects in Mild Cognitive Impairment Patients: An fMRI Study

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Shangjie Chen ◽  
Lijun Bai ◽  
Maosheng Xu ◽  
Fang Wang ◽  
Liang Yin ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Granger Causality ◽  
Effective Connectivity ◽  
Brain Networks ◽  
Brain Regions ◽  
Causality Analysis ◽  
Granger Causality Analysis ◽  
Cognitive States ◽  
Dorsolateral Prefrontal

Evidence from clinical reports has indicated that acupuncture has a promising effect on mild cognitive impairment (MCI). However, it is still unknown that by what way acupuncture can modulate brain networks involving the MCI. In the current study, multivariate Granger causality analysis (mGCA) was adopted to compare the interregional effective connectivity of brain networks by varying needling depths (deep acupuncture, DA; superficial acupuncture, SA) and at different cognitive states, which were the MCI and healthy control (HC). Results from DA at KI3 in MCI showed that the dorsolateral prefrontal cortex and hippocampus emerged as central hubs and had significant causal influences with each other, but significant in HC for DA. Moreover, only several brain regions had remarkable causal interactions following SA in MCI and even few brain regions following SA in HC. Our results indicated that acupuncture at KI3 at different cognitive states and with varying needling depths may induce distinct reorganizations of effective connectivities of brain networks, and DA at KI3 in MCI can induce the strongest and more extensive effective connectivities related to the therapeutic effect of acupuncture in MCI. The study demonstrated the relatively functional specificity of acupuncture at KI3 in MCI, and needling depths play an important role in acupuncture treatments.

scholarly journals Neural correlates of newsvendor-based decision making in the human brain: An exploratory study to link neuroeconomics with neuroimaging using fNIRS

2020 ◽  
Author(s):  
Hashini Wanniarachchi ◽  
Yan Lang ◽  
Xinlong Wang ◽  
Sridhar Nerur ◽  
Kay-Yut Chen ◽  
...  
Keyword(s):  
Decision Making ◽  
Near Infrared ◽  
Human Subjects ◽  
Brain Regions ◽  
Profit Margin ◽  
Risky Decision ◽  
Functional Near Infrared Spectroscopy ◽  
Novel Approach ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions

AbstractNeuroeconomics with neuroimaging is a novel approach involving economics and neuroscience. The newsvendor problem (NP) is a prevalent economics concept that may be used to map brain activations during NP-evoked risky decision making. In this study, we hypothesized that key brain regions responsible for NP are dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC). Twenty-seven human subjects participated in the study using 40 NP trials; the participants were randomly assigned to a group with a low-profit margin (LM) or high-profit margin (HM) treatment. Cerebral hemodynamic responses were recorded simultaneously during the NP experiments from all participants with a 77-channel functional Near-infrared Spectroscopy (fNIRS) system. After data preprocessing, general linear model was applied to generate brain activation maps, followed by statistical t-tests. The results showed that: (a) DLPFC and OFC were significantly evoked by NP versus baseline regardless of treatment types; (b) DLPFC and OFC were activated by HM versus baseline; and (c) DLPFC was activated during LM versus baseline. Furthermore, significant deactivation in right DLPFC was shown due to LM with respect to HM. This study affirms that DLPFC and OFC are two key cortical regions when solving NP. In particular, right DLPFC was found to be more deactivated under challenging risk decision making.

Sign in / Sign up

Export Citation Format

Share Document