Wellcome Trust scientists have shown for the first time that exactly how we see our environment depends on the size of the visual part of our brain.
We are all familiar with the idea that our thoughts and emotions differ from one person to another, but most people assume that how we perceive the visual world is usually very similar from person to person. However, the primary visual cortex – the area at the back of the brain responsible for processing what we see in the world around us – is known to differ in size by up to three times from one individual to the next.
Now, researchers at the Wellcome Trust Centre for Neuroimaging at UCL (University College London) have shown for the first time that the size of this area affects how we perceive our environment. Their study is published online today in the journal Nature Neuroscience.
Dr D Samuel Schwarzkopf, Chen Song and Professor Geraint Rees showed a series of optical illusions to thirty healthy volunteers. These included the Ebbinghaus illusion, a well-known illusion in which two circles of the same size are each surrounded by circular 'petals'; one of the circles is surrounded by larger petals, the other by smaller petals. Most people will see the first circle as smaller than the second one
In a second optical illusion, the Ponzo illusion, the volunteers were shown two identically sized circles superimposed onto the image of a tunnel. In this illusion, the circle placed further back in the tunnel appears larger than that placed near the front.
By adapting these illusions, the researchers were able to show that individual volunteers saw the illusions differently. For example, some people saw a big (although illusory) difference in size between the two circles, but others barely saw any difference in apparent size.
Using functional magnetic resonance imaging (fMRI), the researchers were also able to measure the surface area of the primary visual cortex in each volunteer. They found a great deal of variability in the size of this area. Surprisingly, there was a strong link between its size and the extent to which volunteers perceived the size illusion – the smaller the area, the more pronounced the visual illusion.
"Our work is the first to show that the size of part of a person's brain can predict how they perceive their visual environment," explains Dr Schwarzkopf.
"Optical illusions mystify and inspire our imagination, but in truth they show us that how we see the world is not necessarily physically accurate, but rather depends a lot on our brains. Illusions such as the ones we used influence how big something looks; that is, they can trick us into believing that two identical objects have different sizes.
"We have shown that precisely how big something appears to you depends on the size of a brain area that is necessary for vision. How much your brain tricks you depends on how much 'real estate' your brain has put aside for visual processing."
Craig Brierley | EurekAlert!
Finnish research group discovers a new immune system regulator
23.02.2018 | University of Turku
Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy