A role for the fornix in temporal sequence memory.

Converging evidence from studies of human and nonhuman animals suggests that the hippocampus contributes to sequence learning by using temporal context to bind sequentially occurring items. The fornix is a white matter pathway containing the major input and output pathways of the hippocampus, including projections from medial septum and to diencephalon, striatum, lateral septum and prefrontal cortex. If the fornix meaningfully contributes to hippocampal function, then individual differences in fornix microstructure might predict sequence memory. Here, we tested this prediction by performing tractography in 51 healthy adults who had undertaken a sequence memory task. Microstructure properties of the fornix were compared with those of tracts connecting medial temporal lobe regions but not predominantly the hippocampus: the Parahippocampal Cingulum bundle (PHC) (conveying retrosplenial projections to parahippocampal cortex) and the Inferior Longitudinal Fasciculus (ILF) (conveying occipital projections to perirhinal cortex). Using principal components analysis, we combined Free-Water Elimination Diffusion Tensor Imaging and Neurite Orientation Dispersion and Density Imaging measures obtained from multi-shell diffusion MRI into two informative indices: the first (PC1) capturing axonal packing/myelin and the second (PC2) capturing microstructural complexity. We found a significant correlation between fornix PC2 and implicit reaction-time indices of sequence memory, indicating that greater fornix microstructural complexity is associated with better sequence memory. No such relationship was found with measures from the PHC and ILF. This study highlights the importance of the fornix in aiding memory for objects within a temporal context, potentially reflecting a role in mediating inter-regional communication within an extended hippocampal system.

A systematic review and meta-analysis on the prevalence of mental disorders among children and adolescents in Europe.

Most mental disorders appear by age 14, but in most cases, they remain undiagnosed and untreated well into adulthood. A scoping review showed an absence of systematic reviews that address prevalence rates of mental disorders among children and adolescents in Europe that are based on community studies conducted between 2015 and 2020. To estimate the updated pooled prevalence of Anxiety Disorder, Depressive Disorder, Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder (CD), Oppositional Defiant Disorder (ODD), Autism Spectrum Disorder, Eating Disorders, Substance Use Disorders (SUD), among children and adolescents living in Europe, a search strategy was conducted using MEDLINE, Embase and Psych Info and studies were also identified from reference lists and gray literature. Eligible studies were evaluated for reliability, validity, and bias. Trends of prevalence rates for each mental disorder were calculated. Almost one in five young people in Europe were found to suffer from a mental disorder, with a pooled prevalence rate of 15.5%. Anxiety disorders had the highest pooled prevalence rate (7.9% (95% CI 5.1-11.8%, I2: 98.0%)), followed by ADHD (2.9% (95% CI 1.2-6.9%, I2 = 94.3%)), ODD (1.9% (95% CI 1.0-3.7%, I2 = 98.4%)), depressive disorder (1.7% (95% CI 1.0-2.9%, I2 = 97.7%)), CD (1.5% (95% CI 0.6-3.8%, I2 = 98.8%)) and ASD (1.4% (95% CI 0.4-5.4%, I2 = 99.7%). No studies on SUD were identified. The mental health of children and adolescents may be improved by introducing routine screening, refining diagnostic sensitivity, raising awareness of mental disorders, minimizing stigma and socioeconomic inequality, as well as developing early intervention services. These facilitators of good mental health need to be prioritized, especially at a time of unprecedented risk factors for poor mental health.

Investigating the Association Between Obsessive-Compulsive Disorder Symptom Subtypes and Health Anxiety as Impacted by the COVID-19 Pandemic: A Cross-Sectional Study.

BACKGROUND: Since the COVID-19 outbreak was declared a global pandemic, public health messages have emphasised the importance of frequent handwashing in limiting the transmission of the virus. Whilst crucial in controlling transmission, such messaging may have an adverse effect on individuals with OCD. METHODS: A cross-sectional study was conducted, with a total of 332 participants recruited. Participants who scored above the optimal cut-off score on the Obsessive-Compulsive Inventory Revised edition (OCI-R) were included in the analysis (n = 254). Scores on the six subscales of the OCI-R were correlated with responses to a COVID-19 Impact measure. RESULTS: Factor analysis of the COVID-19 Impact measure revealed that items loaded on two components of the measure (handwashing and distress-avoidance). Canonical correlation analyses revealed significant associations between the OCI-R subscales and COVID-19 Impact measure, F (12, 490) = 8.14, p = 0.001, and the SHAI subscales with the COVID-19 Impact Measure, F (4, 498) = 8.18, p = 0.001). Specifically, washing and checking OCI-R subscales correlated with both components of the COVID-19 Impact measure, as did the health anxiety and beliefs SHAI subscales. Content analysis revealed disruption to treatment delivery and worsening symptom severity in participants with contamination-related OCD. DISCUSSION: Contamination and checking OCD subtypes have been associated with increased hand-washing behaviour and avoidance of distress-inducing cues. Consideration should be given to targeted support tailored to patients with these subtypes of OCD.

Anterior cingulate cortex neurometabolites in bipolar disorder are influenced by mood state and medication: A meta-analysis of 1H-MRS studies.

The anterior cingulate cortex (ACC), a brain region that mediates affect and cognition by connecting the frontal cortex to limbic structures, has been consistently implicated in the neurobiology of Bipolar Disorder (BD). Proton magnetic resonance spectroscopy (1H-MRS) studies have extensively compared in vivo neurometabolite levels of BD patients and healthy controls (HC) in the ACC. However, these studies have not been analyzed in a systematic review or meta-analysis and nor has the influence of mood state and medication on neurometabolites been examined in this cortical region. A systematic review and a meta-analysis of 1H-MRS studies comparing ACC neurometabolite profiles of adult BD patients and HC subjects was conducted, retrieving 27 articles published between 2000 and 2018. Overall increased ACC levels of Glx [glutamine (Gln) + glutamate)/Creatine], Gln, choline (Cho) and Cho/Creatine were found in BD compared to HC. Bipolar depression was associated with higher Cho levels, while euthymia correlated with higher glutamine (Gln) and Cho. Mood stabilizers appeared to affect ACC Glu and Gln metabolites. Increased ACC Cho observed in euthymia, depression and in medication-free groups could be considered a trait marker in BD and attributed to increased cell membrane phospholipid turnover. Overall increased ACC Glx was associated with elevated Gln levels, particularly influenced by euthymia, but no abnormality in Glu was detected. Further 1H-MRS studies, on other voxels, should assess more homogeneous (mood state-specific), larger BD samples and account for medication status using more sensitive 1H-MRS techniques.

Neurochemical correlates of scene processing in the precuneus/posterior cingulate cortex: A multimodal fMRI and 1 H-MRS study.

Precuneus/posterior cingulate cortex (PCu/PCC) are key components of a midline network, activated during rest but also in tasks that involve construction of scene or situation models. Despite growing interest in PCu/PCC functional alterations in disease and disease risk, the underlying neurochemical modulators of PCu/PCC's task-evoked activity are largely unstudied. Here, a multimodal imaging approach was applied to investigate whether interindividual differences in PCu/PCC fMRI activity, elicited during perceptual discrimination of scene stimuli, were correlated with local brain metabolite levels, measured during resting-state 1 H-MRS. Forty healthy young adult participants completed an fMRI perceptual odd-one-out task for scenes, objects and faces. 1 H-MRS metabolites N-acetyl-aspartate (tNAA), glutamate (Glx) and γ-amino-butyric acid (GABA+) were quantified via PRESS and MEGA-PRESS scans in a PCu/PCC voxel and an occipital (OCC) control voxel. Whole brain fMRI revealed a cluster in right dorsal PCu/PCC that showed a greater BOLD response to scenes versus faces and objects. When extracted from an independently defined PCu/PCC region of interest, scene activity (vs. faces and objects and also vs. baseline) was positively correlated with PCu/PCC, but not OCC, tNAA. A voxel-wise regression analysis restricted to the PCu/PCC 1 H-MRS voxel area identified a significant PCu/PCC cluster, confirming the positive correlation between scene-related BOLD activity and PCu/PCC tNAA. There were no correlations between PCu/PCC activity and Glx or GABA+ levels. These results demonstrate, for the first time, that scene activity in PCu/PCC is linked to local tNAA levels, identifying a neurochemical influence on interindividual differences in the task-driven activity of a key brain hub.

Evidence for Integrated Visual Face and Body Representations in the Anterior Temporal Lobes.

Research on visual face perception has revealed a region in the ventral anterior temporal lobes, often referred to as the anterior temporal face patch (ATFP), which responds strongly to images of faces. To date, the selectivity of the ATFP has been examined by contrasting responses to faces against a small selection of categories. Here, we assess the selectivity of the ATFP in humans with a broad range of visual control stimuli to provide a stronger test of face selectivity in this region. In Experiment 1, participants viewed images from 20 stimulus categories in an event-related fMRI design. Faces evoked more activity than all other 19 categories in the left ATFP. In the right ATFP, equally strong responses were observed for both faces and headless bodies. To pursue this unexpected finding, in Experiment 2, we used multivoxel pattern analysis to examine whether the strong response to face and body stimuli reflects a common coding of both classes or instead overlapping but distinct representations. On a voxel-by-voxel basis, face and whole-body responses were significantly positively correlated in the right ATFP, but face and body-part responses were not. This finding suggests that there is shared neural coding of faces and whole bodies in the right ATFP that does not extend to individual body parts. In contrast, the same approach revealed distinct face and body representations in the right fusiform gyrus. These results are indicative of an increasing convergence of distinct sources of person-related perceptual information proceeding from the posterior to the anterior temporal cortex.

Cultural differences in sensitivity to the relationship between objects and contexts: evidence from P3.

Cross-cultural differences in Easterners and Westerners have been observed in different cognitive domains. Differential sensitivity to the relationship between objects and contexts might be an underlying cognitive mechanism for these differences. Twenty-one Chinese and 22 Germans participated in a three-stimulus event-related potential oddball task. They were instructed to monitor geometrical forms filled in black (targets) that were presented among a series of blank geometrical forms (standards). Novel stimuli were colored images of common objects. Robust novelty P3 and target P3 over the entire scalp were observed in both groups. As compared with the German group, Chinese participants showed larger amplitudes of novelty P3 and target P3 over frontal regions and earlier peak latency for target P3. This indicates a higher sensitivity to the relationship between contexts and objects in the Chinese as compared with the German group, which might be an underlying mechanism for cross-cultural differences reported in many cognitive domains.

Culture-specific familiarity equally mediates action representations across cultures.

Previous studies have shown that we need to distinguish between means and end information about actions. It is unclear how these two subtypes of action information relate to each other with theoretical accounts postulating the superiority of end over means information and others linking separate means and end routes of processing to actions of differential meaningfulness. Action meaningfulness or familiarity differs between cultures. In a cross-cultural setting, we investigated how action familiarity influences recognition memory for means and end information. Object directed actions of differential familiarity were presented to Chinese and German participants. Action familiarity modulated the representation of means and end information in both cultures in the same way, although the effects were based on different stimulus sets. Our results suggest that, in the representation of actions in memory, end information is superordinate to means information. This effect is independent of culture whereas action familiarity is not.

An action video clip database rated for familiarity in China and Germany.

Stimulus material for studying object-directed actions is needed in different research contexts, such as action observation, action memory, and imitation. Action items have been generated many times in individual laboratories across the world, but they are used in very few experiments. For future studies in the field, it would be worthwhile to have a larger set of action stimulus material available to a broader research community. Some smaller action databases have already been published, but those often focus on psycholinguistic parameters and static action stimuli. With this article, we introduce an action database with dynamic action stimuli. The database contains action descriptions of 1,754 object-directed actions that have been rated for familiarity in Germany and in China. For 784 of these actions, action video clips are available. With the use of our database, it is possible to identify actions that differ in familiarity between Western and Eastern cultures. This variable may be of interest to some researchers in the field, since it has been shown that familiarity influences action information processing. Action descriptions are listed and categorized in tables that can be downloaded, along with the corresponding video clips, as supplemental material.

fMRI correlates of working memory: specific posterior representation sites for motion and position information.

We assume that working memory is provided by a network comprising domain-general anterior and different domain-specific posterior brain areas depending on the type of stimulus and the task demands. Based on imaging studies from perception, we hypothesized that dynamic spatial (motion) and static spatial (position) information can be dissociated during retention in working memory. Participants were presented with a moving dot. About one second after stimulus presentation, a cue indicated whether its motion or end position should be held in memory. Six seconds later, a second stimulus was shown which was to be compared with the first one with respect to identity on the cued dimension. In the baseline condition, the cue indicated that no memory task would follow. We contrasted activity during maintenance of the different features. Differential activations in regions related to motion perception (area hMT/V5+, superior temporal sulcus) were observed in the motion working memory task. For position working memory, enhanced activations in a right brain region at the temporo-parieto-occipital junction emerged. The results are discussed with respect to domain-specific regions active in perception and how they can be also involved in short term retention for those very features. It is suggested that two types of spatial information categories can be dissociated: dynamic spatial (motion) and static spatial (position) information seem to be processed by different working memory structures.