Predicting decisions by taking a glimpse into the brain
Recent studies have indicated that the brain makes decisions on visual and auditory stimuli using accumulated sensory evidence, and that this process is orchestrated by a network of neurons from the front (the prefrontal area) and the back (the parietal area) of the brain.
Ksander de Winkel and his colleagues from the Department of Prof. Bülthoff at the Max Planck Institute for Biological Cybernetics investigated whether these findings also apply to decisions on self-motion stimuli (passive motion of one’s own body). The results showed that the scientists could predict how well a participant was able to tell the different motions apart, which is an indication that an accumulation of sensory evidence of self-motion was measured.
These findings provide support for the idea that the network of prefrontal and parietal neurons is ‘modality-independent’, meaning that the neurons in this network are dedicated to collect evidence and to make decisions using any type of sensory information and are not dependent on visual and vestibular (concerning the equilibrium) cues.
The scientists placed participants in a motion simulator and rotated them around an earth-vertical axis that was aligned with the spine. More specifically, participants experienced a large number of pairs of such rotations, for which one was always slightly more intense than the other.
The order of the smaller and larger rotations was randomized for each pair, and participants had to judge which rotation of each pair was more intense. While the participants performed the task, the blood flow in the prefrontal and parietal areas were measured using a novel technique: functional Near-Infrared Spectroscopy (fNIRS). The scientists then used these recordings to try whether it was possible to predict the participants’ judgments for every single pair of rotations.
Research on brain activity of participants or patients in motion is scarce, because the readings of common neuroimaging methods, such as electroencephalography (EEG) or functional magnetic resonance imaging (fMRI), are distorted by the body motion and electro-magnetic inference, such as electric noise in vehicles. This is not the case with fNIRS. Infrared light is emitted through the scalp into the brain tissue with the reflection to be measured.
Since the light intensity of infrared light is very low, this method is non-invasive and harmless. The blood flow and the oxygen level increase in the active brain regions (haemodynamic response), which is captured via this method. Through this, it is possible to draw conclusions about activities in these brain areas.
“This method is very promising”, de Winkel gladly announces. “Up to now, we had to rely on what the participants could tell us about their perception. Now we get to glance directly into the brain.” The results showed that they could predict how well a participant could tell the motions apart using the fNIRS recordings, and therefore indicated that the areas under investigation were indeed involved in decision making on self-motion. The more sensory evidence participants collect, the better they will be able to tell two motions apart.
“If we know how the brain makes decisions and what areas are involved, we can relate specific behavioral problems and physical traumata to these areas”, de Winkel explains. Moreover, considering the fact that conventional neuroimaging techniques are not suitable to use with moving participants, the results are encouraging for the use of fNIRS to perform neuroimaging in participants in moving vehicles and simulators. This might pave the way for a completely new line of research.
Authors: Dr. Ksander de Winkel, Alessandro Nesti, Hasan Ayaz, Heinrich H. Bülthoff
Scientist Dr. Ksander de Winkel
Phone: +49 7071 601- 643
Media Liaison Officer Beate Fülle
Head of Communications and Public Relations
Phone: +49 (0)7071 601-777
Max Planck Institute for Biological Cybernetics
The Max Planck Institute for Biological Cybernetics deals with the processing of signals and information in the brain. We know that our brain must constantly process an immense wealth of sensory impressions to coordinate our behavior and enable us to interact with our environment. It is, however, surprisingly little known how our brain actually manages to perceive, recognize and learn. The scientists at the Max Planck Institute for Biological Cybernetics are therefore looking into the question of which signals and processes are necessary in order to generate a consistent picture of our environment and the corresponding behavior from the various sensory information. Scientists from three departments and seven research groups work on fundamental questions of brain research using different approaches and methods.
Presse- und Öffentlichkeitsarbeit | Max-Planck-Institut für biologische Kybernetik
Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen
New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Earth Sciences
15.08.2018 | Physics and Astronomy