Information-theoretic gradient flows in mouse visual cortex

28 Nov

Sentence comprehension in Lewy body diseases: a functional magnetic resonance imaging study

Lewy body diseases, including Parkinson's disease and dementia with Lewy bodies, often involve mild cognitive impairment at diagnosis (mild cognitive impairment with Lewy bodies (MCI-LB). Language dysfunction in MCI-LB patients is often unrecognized. This study aimed to assess syntactic comprehension deficits in MCI-LB patients and to explore their neural correlates. A total of 25 MCI-LB patients (mean ± sd: 72 ± 5.6 years old, 10 women) and 25 healthy controls (HC, mean ± sd: 66 ± 4.0 years old, 12 women) performed task functional MRI Test of Sentence Comprehension (ToSC). Functional connectivity was analysed using psychophysiological interaction (PPI) method, focusing on the striatum and language networks. MCI-LB patients had lower ToSC scores than HC (MCI-LB: 74.7 ± 15.7, HC: 88.5 ± 9.0, P < 0.001) and their PPI analysis revealed decreased connectivity from the striatum to the cuneus, precuneus, and left supramarginal gyrus, and reduced connectivity particularly in the dorsal pathway during noncanonical (syntactically more complex) sentence processing. Taken together, in this cross-sectional study MCI-LB patients showed impaired sentence comprehension related to decreased subcortical-cortical and dorsal language network connectivity. 

28 Nov

The Pattern Glare Test: Further Exploration of Methodological and Demographic Factors

Purpose: The Pattern Glare Test (PGT) is a widely used tool for assessing visual discomfort and perceptual distortions elicited by repetitive, high-contrast patterns. It has been applied across diverse populations and research fields, including neuroscience, cognitive psychology, optometry, orthoptics, and ophthalmology. Despite its broad use, considerable variation exists in how the PGT is implemented, particularly regarding stimulus parameters, participant characteristics, and scoring methods. Such variability introduces potential confounding factors that may obscure the psychological and neurological mechanisms underlying pattern-induced visual discomfort.

Methods: We analyzed PGT data from 184 neurotypical young adults (72 males and 112 female; mean age = 24.29 years, SD = 4.75) to examine methodological influences on reports of associated visual distortions (AVDs) and discomfort. Our main analyses utilized cumulative link mixed models and cluster analysis of intraindividual responses.

Results: Significant effects of trial progression and sex (biological; male/female) on subjective responses have been revealed, with the effect of sex not accounted for by migraine occurrence. Substantial overlap among color-related AVDs supported their consolidation into a single category.