Understanding Estimations of Magnitudes: An fMRI Investigation

The current study examined whether discrete numerical estimation is based on the same cognitive process as estimation of continuous magnitudes such as weight and time. While the verbal estimation of numerical quantities has a contingent unit of measurement (e.g., how many cookies fit in a cookie jar? _X_ cookies), estimation of time and weight does not (e.g., how much time does it take to fill a bath with water? _X_ minutes/hours/seconds). Therefore, estimation of the latter categories has another level of difficulty, requiring extensive involvement of cognitive control. During a functional magnetic resonance imaging (fMRI) scan, 18 students performed estimations with three estimation categories: number, time, and weight. Estimations elicited activity in multiple brain regions, mainly: (1) visual regions including bilateral lingual gyrus), (2) parietal regions including the left angular gyrus and right supramarginal gyrus, and (3) the frontal regions (cingulate gyrus and the inferior frontal cortex). Continuous magnitude estimations (mostly time) produced different frontal activity than discrete numerical estimations did, demonstrating different profiles of brain activations between discrete numerical estimations and estimations of continuous magnitudes. The activity level in the right middle and inferior frontal gyrus correlated with the tendency to give extreme responses, signifying the importance of the right prefrontal lobe in estimations.

Disrupted Dynamic Functional Connectivity of the Visual Network in Episodic Patients with Migraine without Aura

Background. Visual symptoms are common in patients with migraine, even in interictal periods. The purpose was to assess the association between dynamic functional connectivity (dFC) of the visual cortex and clinical characteristics in migraine without aura (MwoA) patients. Methods. We enrolled fifty-five MwoA patients as well as fifty gender- and age-matched healthy controls. Regional visual cortex alterations were investigated using regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF). Then, significant regions were selected as seeds for conducting dFC between the visual cortex and the whole brain. Results. Relative to healthy controls, MwoA patients exhibited decreased ReHo and ALFF values in the right lingual gyrus (LG) and increased ALFF values in the prefrontal cortex. The right LG showed abnormal dFC within the visual cortex and with other core brain networks. Additionally, ReHo values for the right LG were correlated with duration of disease and ALFF values of the right inferior frontal gyrus and middle frontal gyrus were correlated with headache frequency and anxiety scores, respectively. Moreover, the abnormal dFC of the right LG with bilateral cuneus was positively correlated with anxiety scores. Conclusions. The dFC abnormalities of the visual cortex may be involved in pain integration with multinetworks and associated with anxiety disorder in episodic MwoA patients.

Watershed Brain Regions for Characterizing Brand Equity-Related Mental Processes

Brand equity is an important intangible for enterprises. As one advantage, products with brand equity can increase revenue, compared with those without such equity. However, unlike tangibles, it is difficult for enterprises to manage brand equity because it exists within consumers’ minds. Although, over the past two decades, numerous consumer neuroscience studies have revealed the brain regions related to brand equity, the identification of unique brain regions related to such equity is still controversial. Therefore, this study identifies the unique brain regions related to brand equity and assesses the mental processes derived from these regions. For this purpose, three analysis methods (i.e., the quantitative meta-analysis, chi-square tests, and machine learning) were conducted. The data were collected in accordance with the general procedures of a qualitative meta-analysis. In total, 65 studies (1412 foci) investigating branded objects with brand equity and unbranded objects without brand equity were examined, whereas the neural systems involved for these two brain regions were contrasted. According to the results, the parahippocampal gyrus and the lingual gyrus were unique brand equity-related brain regions, whereas automatic mental processes based on emotional associative memories derived from these regions were characteristic mental processes that discriminate branded from unbranded objects.

Tracking tDCS induced grey matter changes in episodic migraine: a randomized controlled trial

Background Occipital transcranial direct current stimulation (tDCS) is an effective and safe treatment for migraine attack prevention. Structural brain alterations have been found in migraineurs in regions related to pain modulation and perception, including occipital areas. However, whether these structural alterations can be dynamically modulated through tDCS treatment is understudied. Objective To track longitudinally grey matter volume changes in occipital areas in episodic migraineurs during and up to five months after occipital tDCS treatment in a single-blind, and sham-controlled study. Methods 24 episodic migraineurs were randomized to either receive verum or sham occipital tDCS treatment for 28 days. To investigate dynamic grey matter volume changes patients underwent structural MRI at baseline (prior to treatment), 1.5 months and 5.5 months (after completion of treatment). 31 healthy controls were scanned with the same MRI protocol. Morphometry measures assessed rate of changes over time and between groups by means of tensor-based morphometry. Results Before treatment, migraineurs reported 5.6 monthly migraine days on average. A cross-sectional analysis revealed grey matter volume increases in the left lingual gyrus in migraineurs compared to controls. Four weeks of tDCS application led to a reduction of 1.9 migraine days/month and was paralleled by grey matter volume decreases in the left lingual gyrus in the treatment group; its extent overlapping with that seen at baseline. Conclusion This study shows that migraineurs have increased grey matter volume in the lingual gyrus, which can be modified by tDCS. Tracking structural plasticity in migraineurs provides a potential neuroimaging biomarker for treatment monitoring. Trial registration ClinicalTrials.gov, NCT03237754. Registered 03 August 2017 – retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03237754.

Callous-Unemotional Traits Moderate the Relationship Between Irritability and Threatening Responding

Background: Irritability and callous-unemotional (CU; reduced guilt/empathy) traits vary dimensionally in the typically developing population but may be particularly marked in youth with conduct disorder (CD). While these dimensional traits are positively correlated, they have been associated with divergent forms of dysfunction, particularly with respect to threat processing (i.e., irritability with increased, and CU traits with decreased, threat responsiveness). This suggests that interactions between these two dimensions may be complex at the neurobiological level. However, this issue has received minimal empirical attention.Methods: The study included 105 adolescents (typically developing and cases with CD; N = 59). They were scanned with fMRI during a looming threat task that involved images of threatening and neutral human faces or animals that appeared to be either looming or receding.Results: Significant irritability-by-CU traits-by-Direction-by-Emotion interactions were seen within right thalamus/PAG, left lingual gyrus and right fusiform gyrus; irritability was positively associated with the BOLD response for Looming Threatening vs. Receding Threatening trials, particularly for youth with low CU traits. In contrast, CU traits were negatively associated with the same differential BOLD response but particularly for youth showing higher levels of irritability. Similar findings were seen within left ventral anterior and posterior cingulate cortices, though the addition of the interaction with CU traits was only seen at slightly more lenient thresholds.Conclusions: The results support previous work linking irritability to increased, and CU traits to reduced, threat responsiveness. However, for adolescents with high irritability, if CU traits are also high, the underlying neuropathology appears to relate to reduced, rather than increased, threat responsiveness.

Altered Spontaneous Brain Activity Related to Neurologic and Sleep Dysfunction in Children With Obstructive Sleep Apnea Syndrome

Childhood obstructive sleep apnea (OSA) is a common chronic sleep-related breathing disorder in children, which leads to growth retardation, neurocognitive impairments, and serious complications. Considering the previous studies about brain structural abnormalities in OSA, in the present study, we aimed to explore the altered spontaneous brain activity among OSA patients, using amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) methods based on resting-state functional magnetic resonance imaging (MRI). Thirty-one untreated OSA children and 33 age-and gender-matched healthy children (HC) were included in this study. Compared with controls, the OSA group showed significant lower ALFF in the right lingual gyrus, decreased fALFF in the left middle frontal gyrus (MFG), but increased fALFF in the left precuneus. Decreased ReHo was found in the left inferior frontal gyrus (orbital part) and left middle frontal gyrus. Notably, the mean fALFF value of left MFG was not only significantly related to multiple sleep parameters but also demonstrated the best performance in ROC curve analysis. These findings revealed OSA children were associated with dysfunctions in the default mode network, the frontal lobe, and the lingual gyrus, which may implicate the underlying neurophysiological mechanisms of intrinsic brain activity. The correlation between the altered spontaneous neuronal activity and the clinical index provides early useful diagnostic biomarkers for OSA children as well.

Structural and Functional Correlates of Hallucinations and Illusions in Parkinson’s Disease

Background: Visual illusions (VI) in Parkinson’s disease (PD) are generally considered as an early feature of the psychosis spectrum leading to fully formed visual hallucinations (VH), although this sequential relationship has not been clearly demonstrated. Objective: We aimed to determine whether there are any overlapping, potentially graded patterns of structural and functional connectivity abnormalities in PD with VI and with VH. Such a finding would argue for a continuum between these entities, whereas distinct imaging features would suggest different neural underpinnings for the phenomena. Methods: In this case control study, we compared structural and resting state functional MRI brain patterns of PD patients with VH (PD-H, n = 20), with VI (PD-I, n = 19), and without VH or VI (PD-C, n = 23). Results: 1) PD-H had hypo-connectivity between the ILO and anterior cingulate precuneus and parahippocampal gyrus compared to PD-C and PD-I; 2) In contrast, PD-I had hyper-connectivity between the inferior frontal gyrus and the postcentral gyrus compared to PD-C and PD-H. Moreover, PD-I had higher levels of functional connectivity between the amygdala, hippocampus, insula, and fronto-temporal regions compared to PD-H, together with divergent patterns toward the cingulate. 3) Both PD-I and PD-H had functional hypo-connectivity between the lingual gyrus and the parahippocampal region vs. PD-C, and no significant grey matter volume differences was observed between PD-I and PD-H. Conclusion: Distinct patterns of functional connectivity characterized VI and VH in PD, suggesting that these two perceptual experiences, while probably linked and driven by at least some similar mechanisms, could reflect differing neural dysfunction.

Distinct neurostructural signatures of anxiety-, fear-related and depressive disorders: a comparative voxel-based meta-analysis

Internalizing disorders encompass anxiety, fear and depressive disorders. While the DSM-5 nosology conceptualizes anxiety and fear-related disorders as an entity, dimensional psychopathology models suggest that generalized anxiety disorders (GAD) and major depression originate from an overarching "anxious-misery" factor whereas fear-related disorders originate from the "fear" factor. Given that a neurobiological evaluation is lacking, we conducted a comparative neuroimaging meta-analysis of gray matter volume alterations to determine common and disorder-specific brain structural signatures in these disorders. The PubMed, Web of Knowledge, and Scopus databases were searched for case-control voxel-based morphometric studies through December, 2020 in GAD, fear-related anxiety disorders (FAD, i.e., social anxiety disorders, SAD; specific phobias, SP; panic disorders, PD; and agoraphobia, AG) and major depressive disorder (MDD). Neurostructural abnormalities were assessed within each disorder group followed by quantitative comparison and conjunction analyses using Seed-based d-Mapping (SDM-PSI). GAD (9 studies, 226 patients) showed disorder-specific decreased volumes in left insula (z=-2.98, pFWE-corrected <0.05) and lateral/medial prefrontal cortex (z=-2.10, pFWE-corrected<0.05,) as well as increased right putamen volume (z=1.86, pFWE-corrected<0.05) relative to FAD (10 SAD, 11 PD, 2 SP studies, 918 patients). Both GAD and MDD (46 studies, 2,575 patients) exhibited decreased prefrontal volumes compared to controls and FAD. While FAD showed less robust alterations in lingual gyrus (p < 0.0025, uncorrected), this group presented intact frontal integrity. No shared structural abnormalities were found. Unique clinical features characterizing anxiety-, fear-related and depressive disorders are reflected by disorder-specific neuroanatomical abnormalities. Targeting the disorder-specific neurostructural signatures could improve therapeutic efficacy.

NEURAL CORRELATES OF SIMPLE SENSOMOTOR REACTION AS MARKERS OF INFORMATION PROCESSING SPEED IN MILITARY VETERANS

We examined the latent periods (LP) of simple sensorimo- tor reaction (SSMR) and peculiarities of brain connectiv- ity during carrying out tests on SSMR in the group of veterans of Joint Forces Operation (JFO) and in military men-patients with post-traumatic stress disorder (PTSD) and with mild traumatic brain injury (mTBI). To this aim, we used a computer test with coherent analysis of EEG. Differences in brain activation were analyzed by LORETA method. It was shown that the speed of SSMR in the group of JFO veterans was significantly lower than in the con- trol group. The LP of SSMR in the group of JFO veterans were 279 ms vs 258 ms in the control group. Comparative analysis of SSMR LP in the group of JFO veterans and in the group with PTSD as well as group with mTBI did not reveal significant differences. The EEG study and coherent analysis showed a significant decrease in the brain connectivity in the group of JFO veterans compared to control group, especially in the low frequency ranges. There were no significant differences in brain activation between the JFO veterans, PTSD and mTBI patients, but JFO veterans had significantly lower activation of cu- neus, middle occipital gyrus and lingual gyrus compared to control group. Conclusively, in order to detect hidden brain lesions, an additional medical examination may be recommended for JFO veterans.