Remco Renken - Academia.edu (original) (raw)

Papers by Remco Renken

Psychosis is frequently associated with the occurrence of visual hallucinations (VH), but their e... more Psychosis is frequently associated with the occurrence of visual hallucinations (VH), but their etiology remains largely unknown. While patients with psychosis show deficits on various behavioral visual and attentional tasks, previous studies have not specifically related these deficits to the presence of VH. This suggests that tasks used in these studies do not target the visual-cognitive neural mechanisms that mediate VH, which in turn limits the development of effective therapies. We therefore designed a study to target these mechanisms directly. In this case control study we asked patients with psychosis who had previously experienced VH to indicate when they recognized objects that were gradually emerging from dynamic visual noise, while scanning their brains using functional Magnetic Resonance Imaging. In a previous study, this recognition task was used to identify the neural basis of VH in patients with Parkinson’s Disease. Based on this earlier work, we decided to test the f...

NeuroImage: Clinical

Spinocerebellar ataxia type 3 (SCA3) is a rare genetic neurodegenerative disease. The neurobiolog... more Spinocerebellar ataxia type 3 (SCA3) is a rare genetic neurodegenerative disease. The neurobiological basis of SCA3 is still poorly understood, and up until now resting-state fMRI (rs-fMRI) has not been used to study this disease. In the current study we investigated (multi-echo) rs-fMRI data from patients with genetically confirmed SCA3 (n = 17) and matched healthy subjects (n = 16). Using independent component analysis (ICA) and subsequent regression with bootstrap resampling, we identified a pattern of differences between patients and healthy subjects, which we coined the fMRI SCA3 related pattern (fSCA3-RP) comprising cerebellum, anterior striatum and various cortical regions. Individual fSCA3-RP scores were highly correlated with a previously published 18 F-FDG PET pattern found in the same sample (rho = 0.78, P = 0.0003). Also, a high correlation was found with the Scale for Assessment and Rating of Ataxia scores (r = 0.63, P = 0.007). No correlations were found with neuropsychological test scores, nor with levels of grey matter atrophy. Compared with the 18 F-FDG PET pattern, the fSCA3-RP included a more extensive contribution of the mediofrontal cortex, putatively rep- resenting changes in default network activity. This rs-fMRI identification of additional regions is proposed to reflect a consequence of the nature of the BOLD technique, enabling measurement of dynamic network activity, compared to the more static 18 F-FDG PET methodology. Altogether, our findings shed new light on the neural substrate of SCA3, and encourage further validation of the fSCA3-RP to assess its potential contribution as im- aging biomarker for future research and clinical use. of more widespread functional changes in cerebellar-thalamo-cerebral and striatal-cortical networks. In-vivo insights into brain networks involved in SCA3 can be provided with functional neuroimaging combined with advanced computational algorithms. The main principle of functional neuro-imaging is that brain activity can be mapped by measuring energy metabolism or hemodynamics, (indi-rectly) reflecting the underlying cellular events. In the present study we employed Functional Magnetic Resonance Imaging (fMRI) to measure resting-state regional cerebral hemodynamics in order to identify SCA3*

Insights Into Imaging, Mar 28, 2022

Virchows Archiv, 2021

Colitis is a common, but poorly understood, adverse event of immune checkpoint inhibitors that ar... more Colitis is a common, but poorly understood, adverse event of immune checkpoint inhibitors that are standard-of-care for an expanding range of cancer types. This explorative study aimed to describe the immune infiltrates in the colon from individuals developing checkpoint inhibitor colitis and compare them to well-known immunophenotypes of acute graft-versus-host disease, ulcerative colitis, and Crohn’s disease. Colon biopsies (n = 20 per group) of patients with checkpoint inhibitor colitis, acute graft-versus-host disease, ulcerative colitis and Crohn’s disease, all colitis treatment-naïve, and of individuals with a normal colon were analyzed using immunohistochemistry: CD8 for cytotoxic T cells, CD4 for T helper cells, and CD68 to identify cells of macrophage lineage. CD8 + T cell, CD4 + T cell, and CD68 + cell counts were performed. Cell infiltration was scored as scattered/patchy or band-like in the superficial and deep gut mucosa. Checkpoint inhibitor colitis was found to be hea...

Frontiers in Aging Neuroscience, 2022

In glaucoma participants, both structural and functional brain changes have been observed, but we... more In glaucoma participants, both structural and functional brain changes have been observed, but we still have insufficient understanding of how these changes also affect the integrity of cortical functional networks, and how these changes relate to visual function. This is relevant, as functional network integrity may affect the applicability of future treatments, as well as the options for rehabilitation or training. Here, we compare global and local functional connectivity in local and global brain networks between glaucoma and control participants. Moreover, we study the relationship between functional connectivity and visual field (VF) loss. For our study, 20 subjects with primary open-angle glaucoma (POAG) and 24 age-similar healthy participants were recruited to undergo an ophthalmic assessment followed by two resting-state (RS) (f)MRI scans. For each scan and for each group, the ROIs with eigenvector centrality (EC) values higher than the 95th percentile were considered the mo...

Stress and Health, 2021

Studying individuals who recently experienced a romantic relationship breakup allows us to invest... more Studying individuals who recently experienced a romantic relationship breakup allows us to investigate mood disturbances in otherwise healthy individuals. In our study, we aimed to identify distinct depressive symptom trajectories following breakup and investigate whether these trajectories relate to personality traits and cognitive control. Subjects (n=87) filled out questionnaires (RRS-NL-EXT trait rumination and NEO-FFI neuroticism) and performed cognitive tasks (trail making test, Stroop task) during a period of 30 weeks. To identify distinct depressive symptom trajectories ('trajectory groups'), we performed K-means clustering on the consecutive (assessed every two weeks) Major Depression Inventory scores. This resulted in four trajectory groups; 'resilience', 'fast recovery', 'slow recovery' and 'chronic distress'. The 'slow recovery group' and the 'chronic distress group' were found to have higher neuroticism and trait rumination levels compared to the 'resilience group', and the 'chronic distress group' also had higher neuroticism levels than the 'fast recovery group'. Moreover, the 'chronic distress group' showed worse overall trail making test performance than the 'resilience group'. Taken together, our findings show that distinct patterns of depressive symptom severity can be observed following breakup and that personality traits and cognitive flexibility seem to play a role in these depressive symptom patterns. This article is protected by copyright. All rights reserved.

Brain and Cognition, 2021

Different types of physical activity are thought to differentially affect children's brain ac... more Different types of physical activity are thought to differentially affect children's brain activation, via physiological mechanisms, or by activating similar brain areas during physical and cognitive tasks. Despite many behavioral studies relying on these mechanisms, they have been rarely studied. This study looks at both mechanisms simultaneously, by examining effects of two physical activity interventions (aerobic vs. cognitively-engaging) on children's brain activation. Functional Magnetic Resonance Imaging (fMRI) data of 62 children (48.4% boys, mean age 9.2 years) was analyzed. Children's visuospatial working memory related brain activity patterns were tested using a Spatial Span Task before and after the 14-week interventions consisting of four physical education lessons per week. The control group followed their regular program of two lessons per week. Analyses of activation patterns in SPM 12.0 revealed no activation changes between pretest and posttest (p > ....

Perception, 2009

corner. This deviation was reflected in the direction of movement at each point in time, and it r... more corner. This deviation was reflected in the direction of movement at each point in time, and it revealed when the subject made his or her choice between the two responses; a moment in time we propose to call the decision time. This decision time was 356ms after onset of the word in the congruent condition, compared to 529ms in the incongruent condition. In contrast, the final response times did not show a significant conflict effect, suggesting that response trajectories are a more sensitive measure. We conclude that spatial prepositions give rise to conflict like colour words do in a classic Stroop task, and that this conflict happens roughly between 350ms and 550ms after word onset.

Frontiers in Neuroscience, 2021

Connective Field (CF) modeling estimates the local spatial integration between signals in distinc... more Connective Field (CF) modeling estimates the local spatial integration between signals in distinct cortical visual field areas. As we have shown previously using 7T data, CF can reveal the visuotopic organization of visual cortical areas even when applied to BOLD activity recorded in the absence of external stimulation. This indicates that CF modeling can be used to evaluate cortical processing in participants in which the visual input may be compromised. Furthermore, by using Bayesian CF modeling it is possible to estimate the co-variability of the parameter estimates and therefore, apply CF modeling to single cases. However, no previous studies evaluated the (Bayesian) CF model using 3T resting-state fMRI data. This is important since 3T scanners are much more abundant and more often used in clinical research compared to 7T scanners. Therefore in this study, we investigate whether it is possible to obtain meaningful CF estimates from 3T resting state (RS) fMRI data. To do so, we a...

Journal of Biomedical Engineering and Medical Imaging, 2016

Parkinson’s disease (PD) is a neurodegenerative disease which is difficult to diagnose at an earl... more Parkinson’s disease (PD) is a neurodegenerative disease which is difficult to diagnose at an early stage. Brain imaging techniques like [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) may aid to identify disease-related changes in cerebral glucose metabolism. The scaled subprofile model with principal component analysis (SSM/PCA) is applied to FDG-PET data to extract features and corresponding patterns of glucose metabolism which can be used to distinguish PD subjects from healthy controls. From a previous study, the decision tree (DT) classifier’s performance to separate the PD group from healthy controls was below chance level. This could be attributed to the small number of subjects in the dataset, combined with the early disease progression. In this study, we make use of an additional PD dataset, consisting of subject brain images obtained at a later disease stage. The features extracted by the SSM/PCA method are used for distinguishing PD subjects from healthy...

Medicine & Science in Sports & Exercise, 2006

Frontiers in Behavioral Neuroscience, 2021

Experiencing stress can have a disadvantageous effect on mental well-being. Additional to the rel... more Experiencing stress can have a disadvantageous effect on mental well-being. Additional to the relation between suffering from chronic stress and depression, both stress (acute and chronic) and depression are associated with cognitive alterations, including working memory. The breakup of a relationship is considered to be a stressful event that can lead to symptoms of depression in otherwise healthy people. Additional to elevated depression scores, stress-related cognitive alterations may occur in this population as well. Therefore, in the present fMRI study we investigated whether experiencing a relationship breakup is associated with working memory alterations and whether this is related to depressive symptom severity. A three workload version of the n-back task (0-back, 1-back, 2-back) was used to measure working memory in subjects who experienced a breakup in the preceding 6 months (“heartbreak group”, n = 70) and subjects in a romantic relationship (“relationship group”, n = 46)...

In the current study we show that non-verbal food-evoked emotion scores significantly improve foo... more In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. L...

Translational Vision Science & Technology, 2021

The majority of neurons in the human brain process signals from neurons elsewhere in the brain. C... more The majority of neurons in the human brain process signals from neurons elsewhere in the brain. Connective Field (CF) modeling is a biologically-grounded method to describe this essential aspect of the brain’s circuitry. It allows characterizing the response of a population of neurons in terms of the activity in another part of the brain. CF modeling translates the concept of the receptive field (RF) into the domain of connectivity by assessing the spatial dependency between signals in distinct cortical visual field areas. Standard CF model estimation has some intrinsic limitations in that it cannot estimate the uncertainty associated with each of its parameters. Obtaining the uncertainty will allow identification of model biases, e.g. related to an over- or under-fitting or a co-dependence of parameters, thereby improving the CF prediction. To enable this, here we present a Bayesian framework for the CF model. Using a Markov Chain Monte Carlo (MCMC) approach, we estimate the underl...