scholarly journals Decreased activity of piriform cortex and orbitofrontal hyperactivation in Usher Syndrome, a human disorder of ciliary dysfunction

2021 ◽  
Author(s):  
Sónia Ferreira ◽  
Isabel Catarina Duarte ◽  
André Paula ◽  
Andreia C. Pereira ◽  
João Carlos Ribeiro ◽  
...  
Keyword(s):  
Orbitofrontal Cortex ◽  
Functional Neuroimaging ◽  
Research Question ◽  
Usher Syndrome ◽  
Piriform Cortex ◽  
Brain Regions ◽  
Compensatory Mechanism ◽  
Vestibular Loss ◽  
Whole Brain ◽  
Main Research

AbstractUsher syndrome (USH) is a condition characterized by ciliary dysfunction leading to retinal degeneration and hearing/vestibular loss. Putative olfactory deficits in humans have been documented at the psychophysical level and remain to be proven at the neurophysiological level. Thus, we aimed to study USH olfactory impairment using functional magnetic resonance imaging. We analyzed differences in whole-brain responses between 27 USH patients and 26 healthy participants during an olfactory detection task with a bimodal odorant (n-butanol). The main research question was whether between-group differences could be identified using a conservative whole-brain approach and in a ROI-based approach in key olfactory brain regions. Results indicated higher olfactory thresholds in USH patients, thereby confirming the hypothesis of reduced olfactory acuity. Importantly, we found decreased BOLD activity for USH patients in response to odorant stimulation in the right piriform cortex, while right orbitofrontal cortex showed increased activity. We also found decreased activity in other higher-level regions in a whole brain approach. We suggest that the hyper activation in the orbitofrontal cortex possibly occurs as a compensatory mechanism after the under-recruitment of the piriform cortex. This study suggests that olfactory deficits in USH can be objectively assessed using functional neuroimaging which reveals differential patterns of activity both in low- and high-level regions of the olfactory network.

scholarly journals A Whole-Brain Computational Modeling Approach to Explain the Alterations in Resting-State Functional Connectivity during Progression of Alzheimer’s Disease

2016 ◽  
Author(s):  
Murat Demirtaş ◽  
Carles Falcon ◽  
Alan Tucholka ◽  
Juan Domingo Gispert ◽  
José Luis Molinuevo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Functional Connectivity ◽  
Computational Modeling ◽  
Resting State ◽  
Functional Neuroimaging ◽  
Brain Regions ◽  
Resting State Functional Connectivity ◽  
Whole Brain ◽  
Modeling Approach

AbstractUnderstanding the mechanisms behind Alzheimer’s disease (AD) is one of the most challenging problems in neuroscience. Recent efforts provided valuable insights on the genetic, biochemical and neuronal correlates of AD. The advances in structural and functional neuroimaging provided massive evidence for the AD related alterations in brain connectivity. In this study, we investigated the whole-brain resting state functional connectivity (FC) and variability in dynamic functional connectivity (v-FC) of the subjects with preclinical condition (PC), mild cognitive impairment (MCI) and Alzheimer’s disease (AD). The synchronization in the whole-brain was monotonously decreasing during the course of the progression. However, only in the AD group the reduced synchronization produced significant widespread effects in FC. Furthermore, we found elevated variability of FC in PC group, which was reversed in AD group. We proposed a whole-brain computational modeling approach to study the mechanisms behind these alterations. We estimated the effective connectivity (EC) between brain regions in the model to reproduce observed FC of each subject. First, we compared ECs between groups to identify the changes in underlying connectivity structure. We found that the significant EC changes were restricted to temporal lobe. Then, based on healthy control subjects we systematically manipulated the dynamics in the model to investigate its effect on FC. The model showed FC alterations similar to those observed in clinical groups providing a mechanistic explanation to AD progression.

Conceptual disorganization and redistribution of resting state cortical hubs in untreated first episode psychosis: A 7T MRI study

2020 ◽  
Author(s):  
Avyarthana Dey ◽  
Kara Dempster ◽  
Michael Mackinley ◽  
Peter Jeon ◽  
Tushar Das ◽  
...  
Keyword(s):  
Negative Symptoms ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
First Episode Psychosis ◽  
Cortical Reorganization ◽  
First Episode ◽  
Formal Thought Disorder ◽  
Whole Brain ◽  
Episode Psychosis ◽  
Positive And Negative Symptoms

Background:Network level dysconnectivity has been studied in positive and negative symptoms of schizophrenia. Conceptual disorganization (CD) is a symptom subtype which predicts impaired real-world functioning in psychosis. Systematic reviews have reported aberrant connectivity in formal thought disorder, a construct related to CD. However, no studies have investigated whole-brain functional correlates of CD in psychosis. We sought to investigate brain regions explaining the severity of CD in patients with first-episode psychosis (FEPs) compared with healthy controls (HCs).Methods:We computed whole-brain binarized degree centrality maps of 31 FEPs, 25 HCs and characterized the patterns of network connectivity in the two groups. In FEPs, we related these findings to the severity of CD. We also studied the effect of positive and negative symptoms on altered network connectivity.Results:Compared to HCs, reduced hubness of a right superior temporal gyrus (rSTG) cluster was observed in the FEPs. In patients exhibiting high CD, increased hubness of a medial superior parietal (mSPL) cluster was observed, compared to patients exhibiting low CD. These two regions were strongly correlated with CD scores but not with other symptom scores.Discussion:Our observations are congruent with previous findings of reduced but not increased hubness. We observed increased hubness of mSPL suggesting that cortical reorganization occurs to provide alternate routes for information transfer.Conclusion:These findings provide insight into the underlying neural processes mediating the presentation of symptoms in untreated FEP. A longitudinal tracking of the symptom course will be useful to assess the mechanisms underlying these compensatory changes.

INITIAL STEP OF SPECIALIZED CORPORA BUILDING: CLEANING PROCEDURES

2020 ◽  
Author(s):  
Vera Yakubson ◽  
Victor Zakharov
Keyword(s):  
Text Processing ◽  
Research Question ◽  
Initial Step ◽  
Main Research ◽  
Academic Texts ◽  
Linguistic Annotation ◽  
Significant Difference ◽  
Cleaning Procedures ◽  
Unique Source ◽  
Future Work

This paper deals with the specialized corpora building, specifically academic language corpus in the biotechnology field. Being a part of larger research devoted to creation and usage of specialized parallel corpus, this piece aims to analyze the initial step of corpus building. Our main research question was what procedures we need to implement to the texts before using them to develop the corpus. Analysis of previous research showed the significant quantity of papers devoted to corpora creation, including academic specialized corpora. Different sides of the process were analyzed in these researches, including the types of texts used, the principles of crawling, the recommended length of texts etc. As to the text processing for the needs of corpora creation, only the linguistic annotation issues were examined earlier. At the same time, the preliminary cleaning of texts before their usage in corpora may have significant influence on the corpus quality and its utility for the linguistic research. In this paper, we considered three small corpora derived from the same set of academic texts in the biotechnology field: “raw” corpus without any preliminary cleaning and two corpora with different level of cleaning. Using different Sketch Engine tools, we analyzed these corpora from the position of their future users, predominantly as sources for academic wordlists and specialized multi-word units. The conducted research showed very little difference between two cleaned corpora, meaning that only basic cleaning procedures such as removal of reference lists are can be useful in corpora design. At the same time, we found a significant difference between raw and cleaned corpora and argue that this difference can affect the quality of wordlists and multi-word terms extraction, therefore these cleaning procedures are meaningful. The main limitation of the study is that all texts were taken from the unique source, so the conclusions could be affected by this specific journal’s peculiarities. Therefore, the future work should be the verification of results on different text collections

THE TRUMP ADMINISTRATION’S APPROACH TO ENERGY SECURITY IN POLAND AND THE BALTIC STATES

2020 ◽  
Vol 18 (1/2020) ◽  
pp. 33-67
Author(s):  
Olga Stevanovic
Keyword(s):  
Energy Security ◽  
Research Question ◽  
Energy Resources ◽  
Baltic States ◽  
Realist Theory ◽  
Main Research ◽  
Security Challenges ◽  
The Us ◽  
The Subject ◽  
The Baltic

The subject of this paper encompasses US policy towards Poland and the Baltic States regarding energy security during Donald Trump’s presidency. It is discernible that vast domestic energy resources have created an opportunity for the US to project more power to these countries, and the surrounding region. We argue that Trump and his administration’s perceptions have served as an intervening variable in that opportunity assessment, in accordance with the neoclassical realist theory. The main research question addressed in this paper is whether US has used that opportunity to contribute to energy security in countries it has traditionally deemed as allies. Two aspects of US approach to energy security of the designated countries are taken into consideration: liquified natural gas exports and support for the Three Seas Initiative. The way Trump presented his policy and its results in his public statements has also been considered in this paper. The article will proceed as follows. The first subsection of the paper represents a summary of energy security challenges in Poland and the Baltic States. The second subsection is dedicated to the opportunity for the US to project energy power and to Trump’s perceptions relevant for the opportunity assessment. The third subsection deals with American LNG exports to these countries as a possible way for contributing to energy security in Poland and the Baltic States. The last part of the paper addresses the Three Seas Initiative and US approach to this platform.

Growth of prefrontal and limbic brain regions and anxiety disorders in children born very preterm

2021 ◽  
pp. 1-12
Author(s):  
Courtney P. Gilchrist ◽  
Deanne K. Thompson ◽  
Bonnie Alexander ◽  
Claire E. Kelly ◽  
Karli Treyvaud ◽  
...  
Keyword(s):  
Anxiety Disorder ◽  
Anxiety Disorders ◽  
Orbitofrontal Cortex ◽  
Developmental Trajectories ◽  
Brain Regions ◽  
Social Risk ◽  
Intracranial Volume ◽  
Total Brain Volume ◽  
Very Preterm ◽  
The Right

Abstract Background Children born very preterm (VP) display altered growth in corticolimbic structures compared with full-term peers. Given the association between the cortiocolimbic system and anxiety, this study aimed to compare developmental trajectories of corticolimbic regions in VP children with and without anxiety diagnosis at 13 years. Methods MRI data from 124 VP children were used to calculate whole brain and corticolimbic region volumes at term-equivalent age (TEA), 7 and 13 years. The presence of an anxiety disorder was assessed at 13 years using a structured clinical interview. Results VP children who met criteria for an anxiety disorder at 13 years (n = 16) displayed altered trajectories for intracranial volume (ICV, p < 0.0001), total brain volume (TBV, p = 0.029), the right amygdala (p = 0.0009) and left hippocampus (p = 0.029) compared with VP children without anxiety (n = 108), with trends in the right hippocampus (p = 0.062) and left medial orbitofrontal cortex (p = 0.079). Altered trajectories predominantly reflected slower growth in early childhood (0–7 years) for ICV (β = −0.461, p = 0.020), TBV (β = −0.503, p = 0.021), left (β = −0.518, p = 0.020) and right hippocampi (β = −0.469, p = 0.020) and left medial orbitofrontal cortex (β = −0.761, p = 0.020) and did not persist after adjusting for TBV and social risk. Conclusions Region- and time-specific alterations in the development of the corticolimbic system in children born VP may help to explain an increase in anxiety disorders observed in this population.

scholarly journals Effects of exposure to immersive videos and photo slideshows of forest and urban environments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fariba Mostajeran ◽  
Jessica Krzikawski ◽  
Frank Steinicke ◽  
Simone Kühn
Keyword(s):  
Research Question ◽  
Well Being ◽  
Urban Environments ◽  
Natural Environments ◽  
Jail Inmates ◽  
Forest Environment ◽  
Main Research ◽  
Head Mounted Display ◽  
Sense Of Presence ◽  
Hospital Patients

AbstractA large number of studies have demonstrated the benefits of natural environments on people’s health and well-being. For people who have limited access to nature (e.g., elderly in nursing homes, hospital patients, or jail inmates), virtual representations may provide an alternative to benefit from the illusion of a natural environment. For this purpose and in most previous studies, conventional photos of nature have been used. Immersive virtual reality (VR) environments, however, can induce a higher sense of presence compared to conventional photos. Whether this higher sense of presence leads to increased positive impacts of virtual nature exposure is the main research question of this study. Therefore, we compared exposure to a forest and an urban virtual environment in terms of their respective impact on mood, stress, physiological reactions, and cognition. The environments were presented via a head-mounted display as (1) conventional photo slideshows or (2) 360$$^{\circ }$$ ∘ videos. The results show that the forest environment had a positive effect on cognition and the urban environment disturbed mood regardless of the mode of presentation. In addition, photos of either urban or forest environment were both more effective in reducing physiological arousal compared to immersive 360$$^{\circ }$$ ∘ videos.

Childhood trauma moderates morphometric associations between orbitofrontal cortex and amygdala: implications for pathological personality traits

2020 ◽  
pp. 1-10
Author(s):  
Nadia Bounoua ◽  
Rickie Miglin ◽  
Jeffrey M. Spielberg ◽  
Curtis L. Johnson ◽  
Naomi Sadeh
Keyword(s):  
Personality Traits ◽  
Childhood Trauma ◽  
Orbitofrontal Cortex ◽  
Functional Neuroimaging ◽  
Trauma Exposure ◽  
Diagnostic Interview ◽  
Emotional Dysregulation ◽  
Self Report ◽  
Traumatic Experiences ◽  
Pathological Personality Traits

Abstract Background Research has demonstrated that chronic stress exposure early in development can lead to detrimental alterations in the orbitofrontal cortex (OFC)–amygdala circuit. However, the majority of this research uses functional neuroimaging methods, and thus the extent to which childhood trauma corresponds to morphometric alterations in this limbic-cortical network has not yet been investigated. This study had two primary objectives: (i) to test whether anatomical associations between OFC–amygdala differed between adults as a function of exposure to chronic childhood assaultive trauma and (ii) to test how these environment-by-neurobiological effects relate to pathological personality traits. Methods Participants were 137 ethnically diverse adults (48.1% female) recruited from the community who completed a clinical diagnostic interview, a self-report measure of pathological personality traits, and anatomical MRI scans. Results Findings revealed that childhood trauma moderated bilateral OFC–amygdala volumetric associations. Specifically, adults with childhood trauma exposure showed a positive association between medial OFC volume and amygdalar volume, whereas adults with no childhood exposure showed the negative OFC–amygdala structural association observed in prior research with healthy samples. Examination of the translational relevance of trauma-related alterations in OFC–amygdala volumetric associations for disordered personality traits revealed that trauma exposure moderated the association of OFC volume with antagonistic and disinhibited phenotypes, traits characteristic of Cluster B personality disorders. Conclusions The OFC–amygdala circuit is a potential anatomical pathway through which early traumatic experiences perpetuate emotional dysregulation into adulthood and confer risk for personality pathology. Results provide novel evidence of divergent neuroanatomical pathways to similar personality phenotypes depending on early trauma exposure.

scholarly journals From cognitive to neural models of working memory

2007 ◽  
Vol 362 (1481) ◽  
pp. 761-772 ◽  
Author(s):  
Mark D'Esposito
Keyword(s):  
Working Memory ◽  
Functional Neuroimaging ◽  
Empirical Studies ◽  
Brain Regions ◽  
Cognitive Models ◽  
Neural Mechanisms ◽  
Long Term Memory ◽  
Cognitive Mechanisms ◽  
Internal Representations ◽  
Active Maintenance

Working memory refers to the temporary retention of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be stored for longer periods of time through active maintenance or rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behaviour. Empirical studies of working memory using neuroscientific techniques, such as neuronal recordings in monkeys or functional neuroimaging in humans, have advanced our knowledge of the underlying neural mechanisms of working memory. This rich dataset can be reconciled with behavioural findings derived from investigating the cognitive mechanisms underlying working memory. In this paper, I review the progress that has been made towards this effort by illustrating how investigations of the neural mechanisms underlying working memory can be influenced by cognitive models and, in turn, how cognitive models can be shaped and modified by neuroscientific data. One conclusion that arises from this research is that working memory can be viewed as neither a unitary nor a dedicated system. A network of brain regions, including the prefrontal cortex (PFC), is critical for the active maintenance of internal representations that are necessary for goal-directed behaviour. Thus, working memory is not localized to a single brain region but probably is an emergent property of the functional interactions between the PFC and the rest of the brain.

Directionality of cross-linguistic influence: Which referring choices do bilingual Ukrainian–English children make?

2016 ◽  
Vol 21 (1) ◽  
pp. 99-121 ◽  
Author(s):  
Roksolana Mykhaylyk ◽  
Elinor Ytterstad
Keyword(s):  
Language Development ◽  
Dual Language ◽  
Research Question ◽  
Age Groups ◽  
Direct Object ◽  
Object Language ◽  
Related Factors ◽  
Main Research ◽  
Null Object ◽  
Significant Difference

Aims and research questions: This paper presents a new study addressing the issue of cross-linguistic influence in acquisition of referring expressions. The main research question is how to predict directionality of this influence in a dual language development. Methodology: The method is an elicited production task. We consider the phenomenon of direct object referring choices, i.e. noun, pronoun and null element, in a ‘null-object’–‘overt-object’ language pair (Ukrainian and English). Data and Analysis: Participants of the experiment are 4–6-year-old Ukrainian–English bilinguals (N20) and Ukrainian monolinguals (N21). The data are analyzed in the statistical program R, utilizing the R-library function lme4. The results are presented as odds ratios (ORs) of each direct object type. Findings: Our data reveal that while there is no significant difference in Ukrainian object types in most of the age groups, there is a considerable amount of null object usage in English at the ages of four to five. Originality: The innovative nature of this study lies in: (i) the consideration of a licit object omission at a later stage of language development (from 4 to 6 years of age); (ii) the examination of an under-investigated language combination (i.e. English and Ukrainian); and (iii) the innovative approach to linguistic data analysis (e.g. comparing OR values). Implications: Our findings suggest that the directionality of influence in dual language acquisition depends on the developmental stage, language-specific means of syntax–pragmatics interaction, and extra-linguistic input-related factors. At the early stages of development, the null-object language is likely to influence the overt-object language, especially under conditions of limited exposure to the latter.

Changing family model, social capital and caring: how to reconcile? the case of Lithuania

2013 ◽  
pp. 75-105
Author(s):  
Vida Cesnuityte
Keyword(s):  
Social Capital ◽  
Social Networks ◽  
Nuclear Family ◽  
Extended Family ◽  
Research Question ◽  
Main Research ◽  
Family Practices ◽  
Mother’S Day ◽  
To Receive ◽  
Family Models

The aim of the research presented in the paper is to explore the inter-relations between care processes and personal social networks as social capital in the light of the changing family models. Research of interdependence of care, social capital and family models is based on the idea of family practices suggested by Morgan. The main research question is what family practices of various family models create such social capital that ensure caring for its' members? The research hypothesis is that participation in various activities together with family members and persons beyond nuclear and extended family create dense social networks of caregivers. The analysis is based on data of representative quantitative survey carried out in Lithuania between 2011 November-2012 May within the ESF supported research project "Trajectories of family models and social networks: intergenerational perspective". Research results only partly support this hypothesis: particular family practices create networks of caregivers, but in order to involve particular persons into network of caregivers, different family practices in various family models are needed. Usually, inhabitants of Lithuania primarily expect to receive care from persons who depend to nuclear family created through marriage and extended family arisen from this relation. But persons from whom it is expected to receive care and care received differ in Lithuania. In reality, caregivers usually are children in families with children and parents in families without children. Family practices that create social networks of caregivers, and are common for all family models include annual feasts like Christmas Eve, Christmas, Easter, All Soul's Day, New Year party, Mother's Day. Various family practices differently impacting creation social networks of caregivers for different family models but usually its include joint dinner daily, Sunday lunch together, vacations with family, communication face-toface, by the telephone or Internet, consultations on important decision-making, All Soul's Day feast, Christmas celebration, Mother's Day, Gatherings of relatives, Birthday, Name-day feast, visiting cultural event together.

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