The R package for DICOM to brain imaging data structure conversion.

The BIDSconvertR package is the first R-based tool for organizing magnetic resonance imaging (MRI) research data in accordance with the Brain Imaging Data Structure (BIDS) specification. Key features are the DICOM (Digital Imaging and Communications in Medicine) to NIfTI (Neuroimaging Informatics Technology Initiative) and NIfTI to BIDS conversion, the implementation of the BIDS Validator and a MRI data viewer to efficiently manage MRI neuroimaging data sets. The BIDSconvertR offers an interactive user dialogue and a graphical user interface. BIDS validation is facilitated by color-coding of the BIDS sequence-IDs. Data cleaning is simplified by the option of using regular expressions. The BIDSconvertR contributes to the growing efforts to improve reproducibility in neuroimaging research by facilitating researchers to share and organize data in a standardized and transparent manner.

Inhibitory control in young adult women with fetal alcohol syndrome: Findings from a pilot functional magnetic resonance imaging study.

BACKGROUND: Executive dysfunction, especially impaired inhibitory control, is a common finding in individuals with fetal alcohol syndrome (FAS). Previous research has mostly focused on neural correlates of inhibitory deficits in children and adolescents. We investigated inhibitory functions and underlying cerebral activation patterns in young adult women with FAS. METHODS: Task performance and functional magnetic resonance imaging (fMRI) data were acquired during a Go/NoGo (GNG) inhibition task in 19 young adult women with FAS and 19 healthy female control subjects. Whole-brain activation and task performance analyses were supplemented by region of interest (ROI) analyses of fMRI data within a predefined cognitive control network (CCN). RESULTS: Task performance did not differ significantly between groups on errors of commission, associated with inhibitory control. Similarly, overall activation within the preselected ROIs did not differ significantly between groups for the main inhibitory contrast NoGo > Go. However, whole-brain analyses revealed activation differences in the FAS group when compared to controls under inhibitory conditions. This included hyperactivations in the left inferior frontal, superior temporal, and supramarginal gyri in the FAS group. Likewise, lateralization tendencies toward right-hemispheric ROIs were weaker in FAS subjects. In contrast to comparable inhibitory performance, attention-related errors of omission were significantly higher in the FAS group. Correspondingly, FAS subjects had lower activity in attention-related temporal and parietal areas. CONCLUSIONS: The known alterations of inhibitory functions associated with prenatal alcohol exposure in children and adolescents were not seen in this adult sample. However, differential brain activity was observed, reflecting potential compensatory mechanisms. Secondary results suggest that there is impaired attentional control in young adult women with FAS.

Sex-Specific Causes and Consequences of White Matter Damage in a Middle-Aged Cohort.

Objective: To evaluate potential sex-specific effects of multiple cardiovascular risk factors on white matter pathology in normal aging men and women, as well as potential sex-differences in the association of white matter pathology and cognitive functions. Methods: We analyzed cross-sectional data of 581 participants (median age: 53 years, 54% women) of the population-based cohort of the BiDirect Study who completed clinical examinations, five neuropsychological tests, and an 3T MRI examination. White matter pathology was determined by the extent of white matter hyperintensities (WMH) on FLAIR images as well as the magnitude of global fractional anisotropy (FA) based on diffusion tensor imaging. Main effects, interaction as well as sex-stratified generalized linear regression models were used to evaluate the moderating effect of sex on the association of hypertension, diabetes mellitus, smoking, and obesity with WMH and FA, respectively. Associations of imaging markers with cognitive test results were determined with linear regression models. Results: Hypertension showed stronger associations with more extensive WMH and less FA in women compared to men. Current smoking was associated with more severe WMH in women only. Adjusted for age and education, WMH were not significantly associated with cognitive tests, but higher FA was associated with better performance in motor function in both sexes and with executive functions in men, even after adjustment for cardiovascular risk factors. Conclusion: We observed a stronger association of hypertension and smoking with white matter damage in women, suggesting a higher susceptibility for vascular pathology in women. However, there was no association of WMH with cognition, and FA was associated with executive function tests only in men, suggesting a higher cognitive reserve in women.

Approaching altered inhibitory control in phenylketonuria: A functional MRI study with a Go-NoGo task in young female adults.

Subtle executive function deficits, particularly regarding inhibitory control, have been reported in patients with phenylketonuria (PKU) despite early dietary treatment. Purpose of this study was to assess whether young female adults with PKU exhibit altered neural activity underlying such deficits, particularly in a fronto-parietal cognitive control network (CCN). Behavioural data and functional magnetic resonance imaging (fMRI) data were acquired during a Go-NoGo task in 16 young adult patients with PKU and 17 control subjects. Hypothesis-driven analyses of behavioural and fMRI data in the CCN were supplemented by exploratory whole brain activation analyses. PKU patients exhibited a trend towards higher errors of commission. Patients exhibited marginally increased activation associated with inhibitory control in only one CCN core region (right middle frontal gyrus, p = .043). Whole brain analyses revealed widespread relatively increased activation in adults with PKU in the main task contrast (NoGo > Go). This increased activation was mainly observed outside the CCN and largely overlapped with the default mode network (DMN). In conclusion, only subtle inhibitory control deficits and associated brain activity differences were observed in young adults with PKU. Thus, this work adds to the notion that this particular population seems to be only slightly affected by such cognitive deficits. While there were also only minimal increases when compared to healthy subjects in brain activity in a cognitive control network, we observed more widespread activation increases outside this network. These results support the assumption of DMN dysfunction in PKU.

Reduced hippocampal recruitment during response conflict resolution in mesial temporal lobe epilepsy.

Recent evidence suggests that the human hippocampus (HC) is not only involved in the processing of motivationally relevant approach-avoidance conflicts but is also engaged in the resolution of more general response conflicts as measured in the Stroop paradigm. Here we investigated whether neural activity in the HC is necessary for successful response conflict resolution. We compared hippocampal recruitment during an auditory Stroop paradigm in 20 patients with mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis and 20 age-matched healthy controls using functional magnetic resonance imaging (fMRI). We analyzed hippocampal activation and behavioral performance in conflict trials relative to non-conflict trials. Moreover, functional connectivity (FC) analyses with left and right HCs as seeds were performed. Subjects' regional gray matter volumes were analyzed based on high-resolution T2-weighted MRI scans. The current study replicated previous results showing increased activation in left HC during the processing of conflict trials in healthy subjects. By contrast, MTLE patients showed higher behavioral costs of response conflict resolution and reduced conflict-related HC activation. In patients with left MTLE, left HC activation was predictive of faster conflict-related response times (RTs). By contrast, right HC activation was related to RT slowing, suggestive of a maladaptive compensation attempt in MTLE patients. Our results provide evidence that left hippocampal activation is required for the successful resolution of response conflicts.

Subtle changes of gray matter volume in fibromyalgia reflect chronic musculoskeletal pain rather than disease-specific effects.

Fibromyalgia syndrome (FMS) is a chronic pain syndrome. Neuroimaging studies provided evidence of altered gray matter volume (GMV) in FMS but, similarly, in chronic pain of other origin as well. Therefore, the purpose of this study was to evaluate the disease specificity of GMV alterations in FMS by direct comparison. Structural MRI data of the brain were acquired in 25 females with FMS and two different control groups: 21 healthy subjects and 23 patients with osteoarthritis. Regional GMVs were compared by voxel-based morphometry and additional ROI-analyses. In conclusion, we did not identify significant GMV alterations in either FMS or OA patients compared to healthy controls when adopting a conservative statistical approach with multiple comparison correction. However, even under a more liberal approach no FMS-specific GMV changes were found because both pain groups presented increased gray matter volumes in the precentral gyrus and decreased GMV in the angular gyrus/middle occipital gyrus and middle temporal gyrus in comparison with healthy controls. Since no differences between both pain groups could be detected cortical GMV changes in FMS should not be interpreted as FMS-specific but might rather reflect changes in chronic pain in general. This previously held notion is confirmed in this study by direct comparison with a control group consisting of another pain disorder.

Impact of pressure as a tactile stimulus on working memory in healthy participants.

Studies on cross-modal interaction have demonstrated attenuated as well as facilitated effects for both neural responses as well as behavioral performance. The goals of this pilot study were to investigate possible cross-modal interactions of tactile stimulation on visual working memory and to identify possible neuronal correlates by using functional magnetic resonance imaging (fMRI). During fMRI, participants (n = 12 females, n = 12 males) performed a verbal n-back task (0-back and 2-back tasks) while tactile pressure to the left thumbnail was delivered. Participants presented significantly lower behavioral performances (increased error rates, and reaction times) during the 2-back task as compared to the 0-back task. Task performance was independent of pressure in both tasks. This means that working memory performance was not impacted by a low salient tactile stimulus. Also in the fMRI data, no significant interactions of n-back x pressure were observed. In conclusion, the current study found no influence of tactile pressure on task-related brain activity during n-back (0-back and 2-back) tasks.

Maternal perception of children's fear: A fMRI study in mothers of preschool children.

A secure attachment relationship is facilitated by a mother´s ability to perceive her child´s emotions, especially her child´s fear. Prior studies showed that maternal perception of an own child activated a neural network including amygdala, insula and nucleus accumbens (NAcc). Results for different emotions were inconsistent and there are no reports on children´s fear. The goal of this study was to investigate neural responses of 17 mothers to photos of their own and an unknown preschool child with happy and fearful expressions by functional magnetic resonance imaging (fMRI). Whole brain analyses showed that a fearful (vs. happy) own child elicited larger activity in the visual cortex. Region of interest (ROI) analyses (amygdala, insula, NAcc) revealed stronger responses to a happy (vs. fearful) unknown child, but equally strong responses to one´s own child´s expressions. Moreover, an own (vs. unknown) fearful child elicited larger activity in the insula and NAcc. This suggests that mothers allocated more visual attention towards their own child´s fear, but showed consistent emotional involvement with their own child across expressions. Mothers might respond with stronger empathy and approach motivation towards an own (vs. unknown) fearful child, in line with a key role of fear in the attachment relationship.

Development and initial Experience of an online Exchange Platform on Sex and Gender Aspects in Medicine: "GenderMed-Wiki".

Goal: Knowledge about sex/gender aspects in medicine is often lacking, even though this serves as base for individualized patient-centered care. Thus we developed an online exchange platform on sex and gender aspects in medicine: "GenderMed-Wiki" [www.gendermed-wiki.de]. This was funded by the German Federal Ministry of Education and Research (BMBF; FKZ: 01FP1506). Our goal is to facilitate the integration of sex and gender in all areas of medicine. Therefore we evaluated if "GenderMed-Wiki" is suitable to provide knowledge on sex and gender aspects in medicine adequately. Methods: Qualitative evaluation of "GenderMed-Wiki" was done 6 months after project start by 4 focus groups with a total of 30 participants (students, lecturers, physicians, and the public). The discussions in each focus group were minuted, requirements pooled and new categories derived inductively. After further optimization of the platform a quantitative survey was done by an online questionnaire (SoSci Survey). 149 students of the medical faculties of Muenster and Duisburg-Essen (as well as students of dentistry from the medical faculty of Muenster) participated (return rate of 3.3%). Evaluation of the content of the articles was done by assessing three professional articles: Sex/gender and medicine (both study courses medicine and dentistry), depression (medicine only) and periodontitis (dentistry only). The results were reported in relative and absolute frequencies and associations were assessed by Chi-Quadrat-tests. Results: Four categories which needed further optimization were deducted from the responses given by our focus groups prior to evaluation: aspects related to content, technical requirements, usability of the platform and legal challenges. Most of the students found "GenderMed-Wiki" to be informative, however they didn´t think it to be relevant for their current studies. In contrast, many thought that the platform may be useful when working as physicians. Students who reported that topics related to sex and gender were not of importance to them, evaluated the platform more neutrally and answered questions related to sex/gender in depression more often incorrectly. Conclusions: Focus groups are a useful approach to identify necessary changes in projects in a systematic way. After further optimizations, "GenderMed-Wiki" seems to be suitable to facilitate the integration of sex/gender into medical teachings. It is of importance, however, to change the attitude of students towards sex/gender sensitive medicine (e.g. by integration into the medical curriculum), since this influences strongly how this platform is perceived and how someone deals with its contents.