Room for Thought: Brain Region That Watches for Walls Identified
To move through the world, you need a sense of your surroundings, especially things that might get in your way: the walls, ceiling and other barriers that define the geometry of the space around you. An international team of neuroscientists has identified an area of the brain dedicated to perceiving this geometry. This brain region encodes the spatial constraints of a scene at lightning-fast speeds, and likely contributes to our instant sense of our surroundings; orienting us in space, so we can avoid bumping into things and navigate safely through our environment.
“The speed with which our brains sense the basic geometry of our surroundings is an indication of the importance of having this information quickly,” said a lecturer in neuroscience at Aalto. “It is key to knowing whether you’re inside or outside, or what might be your options for navigation.”
“Vision gives us an almost instant sense where we are in space, and in particular of the geometry of the surfaces — the ground, the walls — which constrain our movement. It feels effortless, but it requires the coordinated activity of multiple brain regions,” said , PhD, a principal investigator at Columbia’s Zuckerman Institute and the paper’s senior author.
To figure out how the brain perceives the geometry of its surroundings, the research team asked volunteers to look at images of different three-dimensional scenes. An image might depict a typical room, with three walls, a ceiling and a floor. The researchers then systematically changed the scene: by removing the wall, for instance, or the ceiling. Simultaneously, they monitored participants’ brain activity through a combination of two cutting-edge brain-imaging technologies at Aalto’s neuroimaging facilities.
The study focused on a region of the brain called the occipital place area (OPA). “Previous studies had shown that OPA neurons encode scenes, rather than isolated objects,” said Dr. Kriegeskorte, “But we did not yet understand what aspect of the scenes this region’s millions of neurons encoded.”
After analyzing the participants’ brain scans, Drs. Kriegeskorte and Henriksson found that the OPA activity reflected the geometry of the scenes. The OPA activity patterns reflected the presence or absence of each scene component — the walls, the floor and the ceiling — conveying a detailed picture of the overall geometry of the scene. However, the OPA activity patterns did not depend on the components’ appearance; the textures of the walls, floor and ceiling — suggesting that the region ignores surface appearance, so as to focus solely on surface geometry. The brain region appeared to perform all the necessary computations needed to get a sense of a room’s layout extremely fast: in just 100 milliseconds.
Moving forward, the research team plans to incorporate virtual reality technology to create more realistic 3D environments for participants to experience. They also plan to build neural network models that mimic the brain’s ability to perceive the environment.
“We would like to put these things together and build computer vision systems that are more like our own brains, systems that have specialized machinery like what we observe here in the human brain for rapidly sensing the geometry of the environment,” said Dr. Kriegeskorte.
The full paper is titled
This research was supported by the Academy of Finland (Postdoctoral Research Grant; 278957), the British Academy (Postdoctoral Fellowship; PS140117) and the European Research Council (ERC-2010-StG 261352).
Read more news
New ultrasonic needle yields samples 2–3 times larger, potentially reshaping cancer diagnostics
Developed at Aalto University over several years, a new ultrasonic needle for tumour diagnostics has been trialled in collaboration with Helsinki University Hospital (HUS). According to the resulting peer-reviewed study, salivary gland tumours could be diagnosed with far greater precision using the innovative needle.
Music industry stakeholders: the industry’s value will double by 2040 through large-scale equality initiatives
The industry aims to establish a self-regulatory body and double the value of the music industry, as outlined in the report “An Equal Music Industry in Finland by 2040”, to be published 11 May.
Research becomes real-world solutions in autumn exhibition – Designs for a Cooler Planet showcases work by researchers and students
Aalto University’s largest annual exhibition, Designs for a Cooler Planet, will point the way to the future this autumn. It will feature more than 20 practical solutions, experiments and ideas from researchers and students.