Defining the exact mechanisms by which the brain processes visual objects and scenes remains an unresolved challenge. Valuable clues to this process have emerged from the demonstration that clusters of neurons ("modules") in inferior temporal cortex apparently respond selectively to specific categories of visual stimuli, such as places/scenes. However, the higher-order "category-selective" response could also reflect specific lower-level spatial factors. Here we tested this idea in multiple functional MRI experiments, in humans and macaque monkeys, by systematically manipulating the spatial content of geometrical shapes and natural images. These tests revealed that visual spatial discontinuities (as reflected by an increased response to high spatial frequencies) selectively activate a well-known place-selective region of visual cortex (the "parahippocampal place area") in humans. In macaques, we demonstrate a homologous cortical area, and show that it also responds selectively to higher spatial frequencies. The parahippocampal place area may use such information for detecting object borders and scene details during spatial perception and navigation.
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http://dx.doi.org/10.1371/journal.pbio.1000608 | DOI Listing |
PLoS One
January 2025
School of Business, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil.
The impact of COVID-19 has extended beyond the health toll it has taken on populations. The global economy has experienced significant downturns, with unemployment rates reaching unprecedented highs for this century. Nonetheless, the agricultural sector has been uniquely affected by the pandemic, particularly given its crucial role in food supply.
View Article and Find Full Text PDFPLoS Comput Biol
January 2025
Complex Systems Research Center, Shanxi University, Taiyuan, Shanxi, China.
Human mobility between different regions is a major factor in large-scale outbreaks of infectious diseases. Deep learning models incorporating infectious disease transmission dynamics for predicting the spread of multi-regional outbreaks due to human mobility have become a hot research topic. In this study, we incorporate the Graph Transformer Neural Network and graph learning mechanisms into a metapopulation SIR model to build a hybrid framework, Metapopulation Graph Transformer Neural Network (M-Graphormer), for high-dimensional parameter estimation and multi-regional epidemic prediction.
View Article and Find Full Text PDFJ Physiol
January 2025
Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Motor cortical high-gamma oscillations (60-90 Hz) occur at movement onset and are spatially focused over the contralateral primary motor cortex. Although high-gamma oscillations are widely recognized for their significance in human motor control, their precise function on a cortical level remains elusive. Importantly, their relevance in human stroke pathophysiology is unknown.
View Article and Find Full Text PDFTransl Vis Sci Technol
December 2024
Department of Biomedical Engineering, University of Houston, Houston, TX, USA.
Purpose: To assess the safety of acoustic radiation force optical coherence elastography in the crystalline lens in situ.
Methods: Acoustic radiation force (ARF) produced by an immersion single-element ultrasound transducer (nominal frequency = 3.5 MHz) was characterized using a needle hydrophone and used for optical coherence elastography (OCE) of the crystalline lens.
Background: White matter hyperintensities (WMH) are very common brain MRI signal abnormalities linked to age, small vessel cerebrovascular disease, cognitive impairment, and dementia. Despite extensive research on WMH in Alzheimer's disease (AD), their prevalence in behavioral variant Frontotemporal dementia (bvFTD) remains less explored. Additionally, Latin American countries (LA) exhibit a higher prevalence of cerebrovascular disease due to distinct demographic, socioeconomic, cultural, and ethno-racial factors.
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