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Category: computing – Page 160

‘Weird shading’ tricks the brain into seeing 3D forms from simple lines

Shading brings 3D forms to life, beautifully carving out the shape of objects around us. Despite the importance of shading for perception, scientists have long been puzzled about how the brain actually uses it. Researchers from Justus-Liebig-University Giessen and Yale University recently came out with a surprising answer.

Previously, it has been assumed that one interprets shading like a physics-machine, somehow “reverse-engineering” the combination of and lighting that would recreate the shading we see. Not only is this extremely challenging for advanced computers, but the visual is not designed to solve that sort of problem. So, these researchers decided to start instead by considering what is known about the brain when it first gets signals from the eye.

“In some of the first steps of visual processing, the brain passes the image through a series of ‘edge-detectors,’ essentially tracing it like an etch-a-sketch,” Professor Roland W. Fleming of Giessen explains. “We wondered what shading patterns would look like to a brain that’s searching for lines.” This insight led to an unexpected, but clever short-cut to the shading inference problem.

Inverse Graphics: How Your Brain Turns 2D Into 3D

“This gives us evidence that the goal of vision is to establish a 3D understanding of an object,” said study senior author Ilker Yildirim, an assistant professor of psychology in Yale’s Faculty of Arts and Sciences.

“When you open your eyes, you see 3D scenes — the brain’s visual system is able to construct a 3D understanding from a stripped-down 2D view.”

Researchers have dubbed this process “inverse graphics,” describing how the brain’s visual processing system works like a computer graphics process, but in reverse, from a 2D image through a less view-dependent “2.5D” intermediate representation, and up to a much more view-tolerant 3D object.

Extracting Nonlinear Dynamical Response Functions from Time Evolution

We develop a general framework based on the functional derivative to extract nonlinear dynamical response functions from the temporal evolution of physical quantities, without explicitly computing multipoint correlation functions. We validate our approach by calculating the second-and third-order optical responses in the Rice—Mele model and further apply it to a many-body interacting system using a tensor network method. This framework is broadly applicable to any method that can compute real-time dynamics, offering a powerful and versatile tool for investigating nonlinear responses in dynamical systems.

Quantum Breakthrough Could Make Your Devices 1,000 Times Faster

Your days of being frustrated by a sluggish smartphone or laptop could be coming to an end: scientists have discovered a new technique for controlling electronic states in quantum materials that could eventually make our gadgets up to 1,000 times faster.

Quantum materials are those that display strange behaviors and properties governed by quantum mechanics. They provide a glimpse into a separate realm of physics, where the standard laws don’t apply.

Here, researchers from institutions across the US manipulated the temperature of a layered quantum material called 1T-TaS₂, enabling it to instantly shift between two opposite electronic phases: insulation and conduction. That ability to block or allow the flow of electricity is key to how transistors in computer chips work.

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