Biology subjects

Weigand, M.

Publications and source records attributed to Weigand, M..

4 recordsLinked to original sources

bioRxiv2026

More is better: Improved visual discrimination through local feature diversity in naturalistic objects

Visual discrimination is traditionally studied with highly controlled, artificial stimuli such as gratings. Yet real-world object discrimination relies on many interacting image dimensions. Here we compared human discrimination performance of oriented gratings with that of natural object morphs, and then asked which stimulus dimensions are most important for morph discrimination. In Experiment 1, participants discriminated between two artificial gratings, two natural grating-like textures, and two natural, morphed stimuli. Morph stimuli were discriminated faster and over a larger stimulus range. In Experiment 2, we separated the contribution of distinct image features, specifically colour, texture, and shape, to the discriminability of the morph stimuli. To this end, we varied two feature dimensions at a time while keeping the third dimension constant. Discrimination was best when colour and texture varied together, resulting in steeper psychometric functions and faster responses than when shape changed. Together, these results suggest a discriminative advantage for natural-object morphs over gratings, driven primarily by local colour and texture information rather than global shape.

neuroscience↗

bioRxiv2025

Utilizing combined spatial transcriptomics to elucidate localized immune responses within human coronary arteries throughout the progression of atherosclerosis

Atherosclerosis is a complex inflammatory disease characterized by the accumulation of lipids and immune cells in the arterial wall, leading to the narrowing and stiffening of blood vessels. The involvement of both innate and adaptive immunity in the pathogenesis of human atherosclerosis is increasingly recognised. However, the spatial organization and specific roles of immune cells during the various stages of disease progression remain poorly understood, underscoring the necessity for additional research to elucidate their functions throughout the disease course. A better understanding of the immune responses contribution to atherosclerosis progression could unveil novel therapeutic targets to mitigate plaque development and rupture, ultimately reducing the burden of cardiovascular events. In this study, we utilised NanoString GeoMx(R) and CosMx technologies to analyse serial sections of human coronary arteries from patients with varying degrees of atherosclerotic lesion severity. Our work consists of a series of investigations, and integrated findings from both the GeoMx(R) and CosMx datasets, including pathway analyses, cell typing, and neighbourhood analysis. This workflow underscores the power of combining these spatial transcriptomics platforms to elucidate biological processes at the single-cell level, hence unbiasedly providing molecules and pathways of relevance to aid in the understanding of disease pathogenesis and assessing the opportunity of novel therapies.

immunology↗

bioRxiv2022

DomeVR: A setup for experimental control of an immersive dome virtual environment created with Unreal Engine 4

1Immersive virtual reality (VR) environments are a powerful tool to explore cognitive processes ranging from memory and navigation to visual processing and decision making - and to do so in a naturalistic yet controlled setting. As such, they have been employed across different species, and by a diverse range of research groups. Unfortunately, designing and implementing behavioural tasks in such environments often proves complicated. To tackle this challenge, we created DomeVR, an immersive VR environment built using Unreal Engine 4 (UE4). UE4 is a powerful game engine with photo-realistic graphics containing a visual scripting language designed for use by non-programmers. As a result, virtual environments are easily created using drag-and-drop elements. DomeVR aims to make these features accessible to neuroscience experiments. This includes a logging and synchronization system to solve timing uncertainties inherent in UE4; an interactive GUI for scientists to observe subjects during experiments and adjust task parameters on the fly, and a dome projection system for full task immersion in non-human subjects. These key features are modular and can easily be added individually into other UE4 projects. Finally, we present proof-of-principle data highlighting the functionality of DomeVR in three different species: human, macaque and mouse.

neuroscience↗

bioRxiv2020

A simple model for detailed visual cortex maps predicts fixed hypercolumn sizes

Orientation hypercolumns in the visual cortex are delimited by the repeating pinwheel patterns of orientation selective neurons. We design a generative model for visual cortex maps that reproduces such orientation hypercolumns as well as ocular dominance maps while preserving retinotopy. The model uses a neural placement method based on t-distributed stochastic neighbour embedding (t-SNE) to create maps that order common features in the connectivity matrix of the circuit. We find that, in our model, hypercolumns generally appear with fixed cell numbers independently of the overall network size. These results would suggest that existing differences in absolute pinwheel densities are a consequence of variations in neuronal density. Indeed, available measurements in the visual cortex indicate that pinwheels consist of a constant number of [~]30, 000 neurons. Our model is able to reproduce a large number of characteristic properties known for visual cortex maps. We provide the corresponding software in our MAPStoolbox for Matlab. In briefWe present a generative model that predicts visual map structures in the brain and a large number of their characteristic properties; a neural placement method for any given connectivity matrix. HighlightsO_LIGenerative model with retinotopy, orientation preference and ocular dominance. C_LIO_LIPrediction of constant neuronal numbers per orientation hypercolumn. C_LIO_LICurated data shows constant [~]30, 000 neurons per pinwheel across species. C_LIO_LISimple explanation for constant pinwheel and orientation hypercolumn ratios. C_LIO_LIPrecise prediction of [~]80% nearest neighbour singularities with opposing polarity. C_LIO_LIModel asymptotically approaches realistic normalised pinwheel densities. C_LIO_LISmall brains with < [~]300 potential pinwheels exhibit salt-and-pepper maps. C_LIO_LIDifferent map phenotypes can exist even for similar connectivity. C_LI

neuroscience↗