A case of pediatric cervicofacial actinomyces masquerading as malignancy: Case report and review of the literature

Publication date: Available online 3 November 2018

Source: International Journal of Pediatric Otorhinolaryngology

Author(s): Emily Savoca, Saral Mehra, Erik H. Waldman

Abstract

Cervicofacial actinomyces is an uncommon infection, especially in children. Notoriously low culture sensitivity and malignant appearance make diagnosis challenging. Treatment requires a prolonged antibiotic course often in conjunction with surgical debridement or drainage. We report an amorphous anterior neck mass in a 10-year-old girl due to actinomyces. Diagnosis required open biopsy after non-diagnostic fine needle aspirate and core needle biopsies. The patient responded well to six-week course of parenteral penicillin followed by six months of convalescent therapy with oral penicillin. In addition to a case discussion, we review cervicofacial actinomyces in the literature with a focus on pediatrics.

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Language outcome in children with congenital hearing impairment: the influence of etiology

Publication date: Available online 3 November 2018

Source: International Journal of Pediatric Otorhinolaryngology

Author(s): Eveline Dieleman, Lone Percy-Smith, Per Caye-Thomasen

Abstract

Objectives

To investigate the possible association between the etiology of hearing impairment (HI) and language outcome in children with congenital HI after an early medical-technical intervention and three years of AVT.

Methods

A retrospective, two-center study was conducted of 53 patients who were divided in four categories of etiology (degeneratio labyrinthi acustici (DLA) congenita hereditaria, DLA congenita non specificata, DLA congenita postinfectiosa and auditory neuropathy). Language outcome was assessed by examining receptive vocabulary (Peabody Picture Vocabulary Test, PPVT-4), receptive language (Reynell test) and productive language (the Danish 'Viborgmaterialet'). All tests were conducted 1, 2 and 3 years after the children received their hearing device. Test scores were calculated from the child's chronological age. Analysis of possible associations was performed using Fisher's exact test and McNemar's test was conducted to examine possible differences between each year of testing for every speech-language test. Subsequently, univariate analyses were performed to search for other possible covariates associated with language outcome.

Results

No significant associations were found between the etiology of the HI and the language outcome of children with HI after 1 year of AVT (PPVT, p=0,234; Reynell, p=0,845; Viborgmaterialet, p=0,667), neither after 2 years of AVT (PPVT, p=0,228; Reynell, p=0,172; Viborgmaterialet, p=0,659) nor after 3 years of AVT (PPVT, p=0,102; Reynell, p=0,512 Viborgmaterialet, p=0,580). Some significant associations were found between language outcome and the type of hearing device and between language outcome and additional disabilities, however no strong evidence was found.

Conclusion

Most children with congenital HI developed a comparable level of speech and language regardless of the etiology of their HI. This study highlights the interest of further research using objective assessments techniques in a larger and more homogeneous population. If the findings from this study will be confirmed in future studies, this will have a clinical and societal impact regarding the diagnostics of HI.

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Clinical characteristics of obstructive sleep apnea versus infectious adenotonsillar hyperplasia in children

Publication date: Available online 3 November 2018

Source: International Journal of Pediatric Otorhinolaryngology

Author(s): James Johnston, Holly McLaren, Murali Mahadevan, Richard G. Douglas

Abstract

Introduction

Children who undergo adenotonsillectomy have a range of symptoms. Some present with infective symptoms, others with obstructive symptoms, and many with a combination of both. The most common surgical indication has changed over the past several decades from infective symptoms to obstructive symptoms. However, there are few data available to differentiate these groups of children in terms of their clinical characteristics. This study aimed to determine the clinical characteristics of children with obstructive sleep apnea versus infectious adenotonsillar hyperplasia.

Methods

Data were obtained from the medical records of two district health boards in Auckland, New Zealand. Extraction of clinical information was performed following the identification of all patients under the age of 16 years undergoing adenotonsillectomy between December 2015 and December 2017.

Results

A total of 1538 children were included in this study. There were 112 (7.3%) with recurrent tonsillitis (RT) symptoms only, 624 (40.6%) with RT and sleep-disordered breathing symptoms (SDB), and 802 (52.1%) with symptoms suggestive of obstructive sleep apnea (OSA). Children with OSA were more likely to be male (p < 0.001), younger (p < 0.001), and have lower body mass indexes at time of surgery (p < 0.001). There was no difference between groups in the number of antibiotic courses prescribed in the year before surgery (p=0.7). There was no significant difference in tonsil or adenoid grade between groups (p=0.2). Children with OSA were more likely to have a diagnosis of asthma (p < 0.001) and allergic rhinitis (p < 0.001), but less likely than those with RT to have a diagnosis of eczema (p < 0.001). Children with OSA were more likely to have otitis media with effusion requiring ventilation tube insertion (p < 0.001) and a documented history of speech delay (p < 0.001). Thirty-day readmission rates were higher in the OSA (8.5%) and SDB/RT (9.3%) groups when compared to those with RT (1.8%) (p=0.03).

Conclusion

Children with OSA have different perioperative characteristics than those with recurrent tonsillitis, including increased risk of postoperative bleeding and need for post op readmission. Therefore, management strategy may vary according to the indications for tonsillectomy and adenoidectomy.

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Human lung epithelial cells cultured in the presence of radon-emitting rock experience gene expression changes similar to those associated with tobacco smoke exposure

Publication date: January 2019

Source: Journal of Environmental Radioactivity, Volume 196

Author(s): Julie J. Loiselle, Jose M. Knee, Leslie C. Sutherland

Abstract

Radon is the second leading cause of lung cancer, after tobacco smoke. While tobacco smoke-induced carcinogenesis has been studied extensively, far less is known about radon-induced carcinogenesis, particularly in relation to the influence of radon on gene expression. The objectives of the work described herein were to (a) determine if and how exposure to low dose radon-emitting rock influences cells, at the gene expression level, and (b) compare any gene expression changes resulting from the exposure to radon-emitting rock with those induced by exposure to tobacco smoke. Any potential radiation-induced gene expression changes were also compared to those induced by exposure to cannabis smoke, a non-carcinogen at low doses, used here as a smoke exposure comparator. Human lung epithelial cells were exposed to radon-emitting rock, tobacco smoke or cannabis smoke, over months, and RNA-sequencing was carried out. We found that the rock-exposed cells experienced significant gene expression changes, particularly of the gene AKR1C3, and that these changes, over time, increasingly reflected those associated with exposure to tobacco, but not cannabis, smoke. We postulate that the early gene expression changes common to both the radiation and tobacco smoke exposures constitute a related - potentially pre-carcinogenic - response. Our findings suggest that the length of time a dividing population of cells is exposed to a constant low concentration of radon (with a potential cumulative absorbed dose) could be an important risk parameter for neoplastic transformation/carcinogenesis.

Graphical abstract

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Human lung epithelial cells cultured in the presence of radon-emitting rock experience gene expression changes similar to those associated with tobacco smoke exposure

Publication date: January 2019

Source: Journal of Environmental Radioactivity, Volume 196

Author(s): Julie J. Loiselle, Jose M. Knee, Leslie C. Sutherland

Abstract

Radon is the second leading cause of lung cancer, after tobacco smoke. While tobacco smoke-induced carcinogenesis has been studied extensively, far less is known about radon-induced carcinogenesis, particularly in relation to the influence of radon on gene expression. The objectives of the work described herein were to (a) determine if and how exposure to low dose radon-emitting rock influences cells, at the gene expression level, and (b) compare any gene expression changes resulting from the exposure to radon-emitting rock with those induced by exposure to tobacco smoke. Any potential radiation-induced gene expression changes were also compared to those induced by exposure to cannabis smoke, a non-carcinogen at low doses, used here as a smoke exposure comparator. Human lung epithelial cells were exposed to radon-emitting rock, tobacco smoke or cannabis smoke, over months, and RNA-sequencing was carried out. We found that the rock-exposed cells experienced significant gene expression changes, particularly of the gene AKR1C3, and that these changes, over time, increasingly reflected those associated with exposure to tobacco, but not cannabis, smoke. We postulate that the early gene expression changes common to both the radiation and tobacco smoke exposures constitute a related - potentially pre-carcinogenic - response. Our findings suggest that the length of time a dividing population of cells is exposed to a constant low concentration of radon (with a potential cumulative absorbed dose) could be an important risk parameter for neoplastic transformation/carcinogenesis.

Graphical abstract

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Sign - Up Season Begins on HealthCare.gov

Insurers are expanding their participation in the program (Source: The Doctors Lounge - Psychiatry)

MedWorm Message: Have you tried our new medical search engine? More powerful than before. Log on with your social media account. 100% free.

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Sign - Up Season Begins on HealthCare.gov

Insurers are expanding their participation in the program (Source: The Doctors Lounge - Psychiatry)

MedWorm Message: Have you tried our new medical search engine? More powerful than before. Log on with your social media account. 100% free.

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Sign - Up Season Begins on HealthCare.gov

Insurers are expanding their participation in the program (Source: The Doctors Lounge - Psychiatry)

MedWorm Message: Have you tried our new medical search engine? More powerful than before. Log on with your social media account. 100% free.

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Biobehavioral threat sensitivity and amygdala volume: A twin neuroimaging study

Publication date: 1 February 2019

Source: NeuroImage, Volume 186

Author(s): Jens Foell, Isabella M. Palumbo, James R. Yancey, Nathalie Vizueta, Traute Demirakca, Christopher J. Patrick

Abstract

Current literature on the relationship between dispositional fear (or threat sensitivity) and amygdala gray matter volume (GMV) is heterogeneous, with findings including positive, negative, and null correlations. A clearer understanding of this relationship would help to determine the potential utility of amygdala volume as a biomarker of anxious/depressive (internalizing) disorders and contribute to understanding of neural mechanisms for variations in fearfulness. The study reported here used voxel-based morphometry to quantify amygdala GMV scores from structural neuroimaging data in a sample of 44 monozygotic twins (i.e., 22 pairs). Dispositional threat sensitivity (THT) was quantified using a biobehavioral cross-domain score that combined neurophysiological indicators with a psychological scale measure. Analyses revealed expected high concordance for amygdala GMV between co-twins. With respect to the major question of the study, a negative correlation was found between biobehavioral THT scores and amygdala volume – with individuals higher in THT showing smaller amygdala GMV scores. More modest associations of amygdala GMV with symptoms of social phobia, and fear disorder symptomology more broadly, were mediated by THT. These results provide insight into prior mixed findings and support the combined use of biological and behavioral measures to quantify characteristics relevant to mental health problems.

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Carbon monofilament electrodes for unit recording and functional MRI in same subjects

Publication date: Available online 2 November 2018

Source: NeuroImage

Author(s): Miguel R. Chuapoco, Mankin Choy, Florian Schmid, Ben A. Duffy, Hyun Joo Lee, Jin Hyung Lee

Abstract

Extracellular electrophysiology and functional MRI are complementary techniques that provide information about cellular and network-level neural activity, respectively. However, electrodes for electrophysiology are typically made from metals, which cause significant susceptibility artifacts on MR images. Previous work has demonstrated that insulated carbon fiber bundle electrodes reduce the volume of magnetic susceptibility artifacts and can be used to record local field potentials (LFP), but the relatively large diameter of the probes make them unsuitable for multi- and single-unit recordings. Although single carbon fiber electrodes have recently been used to record single-unit activity, these probes require modifications in order to aid insertion and the use of these probes in fMRI has yet to be validated. Therefore, there is a need for a single-carbon fiber electrode design that (1) minimizes the volume of the susceptibility artifact, (2) can record from a wide frequency band that includes LFP and multi- and single-unit recording, and (3) is practical to insert without additional modifications. Here, we demonstrate that carbon-fiber electrodes made from single carbon monofilaments (35 μm in diameter) meet all of these criteria. Carbon monofilament electrodes modified with the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) have lower impedances and higher signal-to-noise ratio recordings than platinum-iridium electrodes, a current gold standard for chronic single-unit recording. Furthermore, these probes distort a significantly smaller volume of voxels compared to tungsten and platinum-iridium electrodes in agarose phantom and in vivo MR images, leading to higher contrast-to-noise ratio in regions proximal to the electrode implantation site during fMRI. Collectively, this work establishes that carbon monofilaments are a practical choice for combined electrophysiology-fMRI experiments.

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Stability of representational geometry across a wide range of fMRI activity levels

Publication date: Available online 2 November 2018

Source: NeuroImage

Author(s): Spencer A. Arbuckle, Atsushi Yokoi, Andrew Pruszynski, Jörn Diedrichsen

Abstract

Fine-grained activity patterns, as measured with functional magnetic resonance imaging (fMRI), are thought to reflect underlying neural representations. Multivariate analysis techniques, such as representational similarity analysis (RSA), can be used to test models of brain representation by quantifying the representational geometry (the collection of pair-wise dissimilarities between activity patterns). One important caveat, however, is that non-linearities in the coupling between neural activity and the fMRI signal may lead to significant distortions in the representational geometry estimated from fMRI activity patterns. Here we tested the stability of representational dissimilarity measures in primary sensory-motor (S1 and M1) and early visual regions (V1/V2) across a large range of activation levels. Participants were visually cued with different letters to perform single finger presses with one of the 5 fingers at a rate of 0.3–2.6 Hz. For each stimulation frequency, we quantified the difference between the 5 activity patterns in M1, S1, and V1/V2. We found that the representational geometry remained relatively stable, even though the average activity increased over a large dynamic range. These results indicate that the representational geometry of fMRI activity patterns can be reliably assessed, largely independent of the average activity in the region. This has important methodological implications for RSA and other multivariate analysis approaches that use the representational geometry to make inferences about brain representations.

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Brain network disintegration during sedation is mediated by the complexity of sparsely connected regions

Publication date: Available online 1 November 2018

Source: NeuroImage

Author(s): I. Pappas, R.M. Adapa, D.K. Menon, E.A. Stamatakis

Abstract

The precise mechanism of anaesthetic action on a neural level remains unclear. Recent approaches suggest that anaesthetics attenuate the complexity of interactions (connectivity) however evidence remains insufficient. We used tools from network and information theory to show that, during propofol-induced sedation, a collection of brain regions displayed decreased complexity in their connectivity patterns, especially so if they were sparsely connected. Strikingly, we found that, despite their low connectivity strengths, these regions exhibited an inordinate role in network integration. Their location and connectivity complexity delineated a specific pattern of sparse interactions mainly involving default mode regions while their connectivity complexity during the awake state also correlated with reaction times during sedation signifying its importance as a reliable indicator of the effects of sedation on individuals. Contrary to established views suggesting sedation affects only richly connected brain regions, we propose that suppressed complexity of sparsely connected regions should be considered a critical feature of any candidate mechanistic description for loss of consciousness.

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Intersubject similarity of personality is associated with intersubject similarity of brain connectivity patterns

Publication date: Available online 30 October 2018

Source: NeuroImage

Author(s): Wei Liu, Nils Kohn, Guillén Fernández

Abstract

Personality is a central high-level psychological concept that defines individual human beings and has been associated with a variety of real-world outcomes (e.g., mental health and academic performance). Using 2 h, high resolution, functional magnetic resonance imaging (fMRI) resting state data of 984 (primary dataset N = 801, hold-out dataset N = 183) participants from the Human Connectome Project (HCP), we investigated the relationship between personality (five-factor model, FFM) and intrinsic whole-brain functional connectome. We found a pattern of functional brain connectivity ("global personality network") related to personality traits. Consistent with the heritability of personality traits, the connectivity strength of this global personality network is also heritable (more similar between monozygotic twin pairs compared to the dizygotic twin pairs). Validated by both the repeated family-based 10-fold cross-validation and hold-out dataset, our intersubject network similarity analysis allowed us to identify participants' pairs with similar personality profiles. Across all the identified pairs of participants, we found a positive correlation between the network similarity and personality similarity, supporting our "similar brain, similar personality" hypothesis. Furthermore, the global personality network can be used to predict the individual subject's responses in the personality questionnaire on an item level. In sum, based on individual brain connectivity pattern, we could predict different facets of personality, and this prediction is not based on localized regions, but rather relies on the individual connectivity pattern in large-scale brain networks.

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Voxel-based meta-analysis via permutation of subject images (PSI): Theory and implementation for SDM

Publication date: Available online 30 October 2018

Source: NeuroImage

Author(s): Anton Albajes-Eizagirre, Aleix Solanes, Eduard Vieta, Joaquim Radua

Abstract

Coordinate-based meta-analyses (CBMA) are very useful for summarizing the large number of voxel-based neuroimaging studies of normal brain functions and brain abnormalities in neuropsychiatric disorders. However, current CBMA methods do not conduct common voxelwise tests, but rather a test of convergence, which relies on some spatial assumptions that data may seldom meet, and has lower statistical power when there are multiple findings. Here we present a new algorithm that can use standard voxelwise tests and, importantly, conducts a standard permutation of subject images (PSI). Its main steps are: a) multiple imputation of study images; b) imputation of subject images; and c) subject-based permutation test to control the familywise error rate (FWER). The PSI algorithm is general and we believe that developers might implement it for several CBMA methods. We present here an implementation of PSI for seed-based d mapping (SDM) method, which additionally benefits from the use of effect sizes, random-effects models, Freedman-Lane-based permutations and threshold-free cluster enhancement (TFCE) statistics, among others. Finally, we also provide an empirical validation of the control of the FWER in SDM-PSI, which showed that it might be too conservative. We hope that the neuroimaging meta-analytic community will welcome this new algorithm and method.

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L-DOPA reduces model-free control of behavior by attenuating the transfer of value to action

Publication date: Available online 28 October 2018

Source: NeuroImage

Author(s): Nils B. Kroemer, Ying Lee, Shakoor Pooseh, Ben Eppinger, Thomas Goschke, Michael N. Smolka

Abstract

Dopamine is a key neurotransmitter in action control. However, influential theories of dopamine function make conflicting predictions about the effect of boosting dopamine neurotransmission. Here, we tested if increases in dopamine tone by administration of L-DOPA upregulate reward learning as predicted by reinforcement learning theories, and if increases are specific for deliberative "model-based" control or reflexive "model-free" control. Alternatively, L-DOPA may impair learning as suggested by "value" or "thrift" theories of dopamine. To this end, we employed a two-stage Markov decision-task to investigate the effect of L-DOPA (randomized cross-over) on behavioral control while brain activation was measured using fMRI. L-DOPA led to attenuated model-free control of behavior as indicated by the reduced impact of reward on choice. Increased model-based control was only observed in participants with high working memory capacity. Furthermore, L-DOPA facilitated exploratory behavior, particularly after a stream of wins in the task. Correspondingly, in the brain, L-DOPA decreased the effect of reward at the outcome stage and when the next decision had to be made. Critically, reward-learning rates and prediction error signals were unaffected by L-DOPA, indicating that differences in behavior and brain response to reward were not driven by differences in learning. Taken together, our results suggest that L-DOPA reduces model-free control of behavior by attenuating the transfer of value to action. These findings provide support for the value and thrift accounts of dopamine and call for a refined integration of valuation and action signals in reinforcement learning models.

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Feasibility of functional MRI at ultralow magnetic field via changes in cerebral blood volume

Publication date: Available online 28 October 2018

Source: NeuroImage

Author(s): Kai Buckenmaier, Anders Pedersen, Paul SanGiorgio, Klaus Scheffler, John Clarke, Ben Inglis

Abstract

We investigate the feasibility of performing functional MRI (fMRI) at ultralow field (ULF) with a Superconducting QUantum Interference Device (SQUID), as used for detecting magnetoencephalography (MEG) signals from the human head. While there is negligible magnetic susceptibility variation to produce blood oxygenation level-dependent (BOLD) contrast at ULF, changes in cerebral blood volume (CBV) may be a sensitive mechanism for fMRI given the five-fold spread in spin-lattice relaxation time (T₁) values across the constituents of the human brain. We undertook simulations of functional signal strength for a simplified brain model involving activation of a primary cortical region in a manner consistent with a blocked task experiment. Our simulations involve measured values of T₁ at ULF and experimental parameters for the performance of an upgraded ULFMRI scanner. Under ideal experimental conditions we predict a functional signal-to-noise ratio of between 3.1 and 7.1 for an imaging time of 30 min, or between 1.5 and 3.5 for a blocked task experiment lasting 7.5 min. Our simulations suggest it may be feasible to perform fMRI using a ULFMRI system designed to perform MRI and MEG in situ.

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Reconfiguration of brain networks supporting inhibition of emotional challenge

Publication date: Available online 27 October 2018

Source: NeuroImage

Author(s): Morgan E. Bartholomew, Cindy M. Yee, Wendy Heller, Gregory A. Miller, Jeffrey M. Spielberg

Abstract

Reacting to the salient emotional features of a stimulus is adaptive unless the information is irrelevant or interferes with goal-directed behavior. The ability to ignore salient but otherwise extraneous information involves restructuring of brain networks and is a key impairment in several psychological disorders. Despite the importance of understanding inhibitory control of emotional response, the associated brain network mechanisms remain unknown. Utilizing functional magnetic resonance imaging (fMRI) data obtained from 103 participants performing an emotion-word Stroop (EWS) task, the present study applied graph-theory analysis to identify how brain regions subserving emotion processing and cognitive control are integrated within the global brain network to promote more specialized and efficient processing during successful inhibition of response to emotional distractors. The present study identified two sub-networks associated with emotion inhibition, one involving hyper-connectivity to prefrontal cortex and one involving hyper-connectivity to thalamus. Brain regions typically associated with identifying emotion salience were more densely connected with the thalamic hub, consistent with thalamic amplification of prefrontal cortex control of these regions. Additionally, stimuli high in emotion arousal prompted restructuring of the global network to increase clustered processing and overall communication efficiency. These results provide evidence that inhibition of emotion relies on interactions between cognitive control and emotion salience sub-networks.

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People got lost in solving a set of similar problems

Publication date: Available online 26 October 2018

Source: NeuroImage

Author(s): Furong Huang, Qingbai Zhao, Zhijin Zhou, Jing Luo

Abstract

A mental set generally refers to the human brain's tendency to persist with a familiar solution and stubbornly ignore alternatives. However, if a familiar solution is unable to solve a problem similar to a previous problem, does it continue to hinder alternative solutions, and if so, how and why? To answer these questions, a Chinese character decomposition task was adopted in this study. Participants were asked to perform a practice problem that could be solved by a familiar loose chunk decomposition (LCD) solution followed by a test problem that was similar to the practice problem but could only be solved by an unfamiliar tight chunk decomposition (TCD) solution or were asked to repeatedly perform 3–5 practice problems followed by a test problem; the former is the base-set condition, and the latter is the enhanced-set condition. The results showed that the test problem recruited more activation of the inferior frontal gyrus (IFG), middle occipital cortex (MOG), superior parietal lobule (SPL) and dorsal anterior cingulate cortex (dACC) than the practice problem in the latter operation and verification stage, but almost equal activation of the dACC occurred in the early exploration stage. This likely implied that people did not think that the familiar but currently invalid LCD solution could not be used to solve the test problem; thus, it continuously competed for attention with the unfamiliar TCD solution, which required more executive control to suppress. Moreover, compared with the base-set condition, the test problem in the enhanced-set condition recruited greater activations of the IFG, SPL and dACC in the latter verification stage but less activations of regions in the left IFG and MOG in the early exploration stage. These results revealed that people less actively explored and had to work harder to operate the unfamiliar TCD solution, particularly to resolve competition from the familiar but currently invalid LCD solution. In conclusion, people lost the ability to identify errors in the familiar but currently invalid solution, which in turn decreased the exploration efforts and increased the processing demands associated with alternative solutions in the form of attentional bias and competition. This finding broadly explains the dilemma of creative problem solving.

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Biobehavioral threat sensitivity and amygdala volume: A twin neuroimaging study

Publication date: 1 February 2019

Source: NeuroImage, Volume 186

Author(s): Jens Foell, Isabella M. Palumbo, James R. Yancey, Nathalie Vizueta, Traute Demirakca, Christopher J. Patrick

Abstract

Current literature on the relationship between dispositional fear (or threat sensitivity) and amygdala gray matter volume (GMV) is heterogeneous, with findings including positive, negative, and null correlations. A clearer understanding of this relationship would help to determine the potential utility of amygdala volume as a biomarker of anxious/depressive (internalizing) disorders and contribute to understanding of neural mechanisms for variations in fearfulness. The study reported here used voxel-based morphometry to quantify amygdala GMV scores from structural neuroimaging data in a sample of 44 monozygotic twins (i.e., 22 pairs). Dispositional threat sensitivity (THT) was quantified using a biobehavioral cross-domain score that combined neurophysiological indicators with a psychological scale measure. Analyses revealed expected high concordance for amygdala GMV between co-twins. With respect to the major question of the study, a negative correlation was found between biobehavioral THT scores and amygdala volume – with individuals higher in THT showing smaller amygdala GMV scores. More modest associations of amygdala GMV with symptoms of social phobia, and fear disorder symptomology more broadly, were mediated by THT. These results provide insight into prior mixed findings and support the combined use of biological and behavioral measures to quantify characteristics relevant to mental health problems.

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Connectome-based models predict attentional control in aging adults

Publication date: 1 February 2019

Source: NeuroImage, Volume 186

Author(s): Stephanie Fountain-Zaragoza, Shaadee Samimy, Monica D. Rosenberg, Ruchika Shaurya Prakash

Abstract

There are well-characterized age-related differences in behavioral and neural responses to tasks of attentional control. However, there is also increasing recognition of individual variability in the process of neurocognitive aging. Using connectome-based predictive modeling, a method for predicting individual-level behaviors from whole-brain functional connectivity, a sustained attention connectome-based prediction model (saCPM) has been derived in young adults. The saCPM consists of two large-scale functional networks: a high-attention network whose strength predicts better attention and a low-attention network whose strength predicts worse attention. Here we examined the generalizability of the saCPM for predicting inhibitory control in an aging sample. Forty-two healthy young adults (n = 21, ages 18–30) and older adults (n = 21, ages 60–80) performed a modified Stroop task, on which older adults exhibited poorer performance, indexed by higher reaction time cost between incongruent and congruent trials. The saCPM generalized to predict reaction time cost across age groups, but did not account for age-related differences in performance. Exploratory analyses were conducted to characterize the effects of age on functional connectivity and behavior. We identified subnetworks of the saCPM that exhibited age-related differences in strength. The strength of two low-attention subnetworks, consisting of frontoparietal, medial frontal, default mode, and motor nodes that were more strongly connected in older adults, mediated the effect of age group on performance. These results support the saCPM's ability to capture attention-related patterns reflected in each individual's functional connectivity signature across both task context and age. However, older and younger adults exhibit functional connectivity differences within components of the saCPM networks, and it is these connections that better account for age-related deficits in attentional control.

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