White matter abnormalities in adults with bipolar disorder type-II and unipolar depression

Discerning distinct neurobiological characteristics of related mood disorders such as bipolar disorder type-II (BD-II) and unipolar depression (UD) is challenging due to overlapping symptoms and patterns of disruption in brain regions. More than 60% of individuals with UD experience subthreshold hypomanic symptoms such as elevated mood, irritability, and increased activity. Previous studies linked bipolar disorder to widespread white matter abnormalities. However, no published work has compared white matter microstructure in individuals with BD-II vs. UD vs. healthy controls (HC), or examined the relationship between spectrum (dimensional) measures of hypomania and white matter microstructure across those individuals. This study aimed to examine fractional anisotropy (FA), radial diffusivity (RD), axial diffusivity (AD), and mean diffusivity (MD) across BD-II, UD, and HC groups in the white matter tracts identified by the XTRACT tool in FSL. Individuals with BD-II (n = 18), UD (n = 23), and HC (n = 24) underwent Diffusion Weighted Imaging. The categorical approach revealed decreased FA and increased RD in BD-II and UD vs. HC across multiple tracts. While BD-II had significantly lower FA and higher RD values than UD in the anterior part of the left arcuate fasciculus, UD had significantly lower FA and higher RD values than BD-II in the area of intersections between the right arcuate, inferior fronto-occipital and uncinate fasciculi and forceps minor. The dimensional approach revealed the depression-by-spectrum mania interaction effect on the FA, RD, and AD values in the area of intersection between the right posterior arcuate and middle longitudinal fasciculi. We propose that the white matter microstructure in these tracts reflects a unique pathophysiologic signature and compensatory mechanisms distinguishing BD-II from UD

What is behind a summary-evaluation decision?

Research in psychology has reported that, among the variety of possibilities for assessment methodologies, summary evaluation offers a particularly adequate context for inferring text comprehension and topic understanding. However, grades obtained in this methodology are hard to quantify objectively. Therefore, we carried out an empirical study to analyze the decisions underlying human summary-grading behavior. The task consisted of expert evaluation of summaries produced in critically relevant contexts of summarization development, and the resulting data were modeled by means of Bayesian networks using an application called Elvira, which allows for graphically observing the predictive power (if any) of the resultant variables. Thus, in this article, we analyzed summary-evaluation decision making in a computational framewor

The effects of imaginal and verbal strategies on prose comprehension in adults

Includes bibliographical references (p. 12-13)Supported in part by the National Institute of Education under Contract No. US-NIE-C-400-76-011

Inter-regional connectivity within the win/loss anticipation network in depressed individuals with bipolar disorder, in depressed individuals with major depressive disorder and healthy controls

Identifying biomarkers distinguishing depressed individuals with bipolar disorder (BDD) from those with major depressive disorder (MDD) would help to develop better therapeutic strategies and improve treatment outcomes. Depressed individuals are often biased (i.e., pessimistic bias) in their anticipation of future negative outcomes. Goal: to determine the differences in connectivity within the reward anticipation network between BDD, MDD and HC (healthy controls) using a graph modelling method. BDD had denser connectivity among fronto-striatal regions, while MDD had denser connectivity among occipital regions. BDD and MDD had similar fronto-striatal connectivity that was less dense compared to HC. Altered fronto-striatal and occipital connectivity patterns during win anticipation distinguished BDD from MDD and HC and might reflect a neurobiological mechanism for impaired processing of positive stimuli in BDD