It is relatively common to hear an object described as being "bigger than a breadbox," and most people have little trouble making this type of comparative judgment. However, how the human brain makes such comparisons based on continuous quantities is quite complex and not completely understood. Now, a new research study published in the March 25 issue of Neuron provides significant new information about how the brain interprets spatial and nonspatial sensory information to make comparative judgments about quantities such as number, size, and luminance.
Previous work suggests that a region of the brain called the intraparietal sulcus (IPS) is active during comparative operations. Dr. Philippe Pinel and colleagues from the Unit of Cognitive Neuroimaging in Orsay, France designed a study to investigate how the brain processes the information that is used to make comparative judgments about numerical information and nonnumerical stimuli like size and luminance. Specifically, the researchers were interested in determining whether comparative judgments on each continuum involve the activity of specific defined regions of the IPS. Human subjects were scanned using a sophisticated brain imaging technique called functional magnetic resonance imaging (fMRI) while they made comparative judgments about pairs of Arabic digits that varied in actual physical size, numerical size, and luminance. This experimental paradigm allowed the researchers to examine interference evoked by the other two irrelevant dimensions as well as specific regions of brain activity.
The authors observed that, during comparative judgments, the relative continuous quantities of number, size, and luminance are represented in distributed and overlapping regions of the cortex, with no single region uniquely selective for one particular stimulus. According to Dr. Pinel, "Our results demonstrate that, during comparative judgments, continuous dimensions such as luminance and size are neither processed by distinct regions of highly specialized cortex nor by a single generic comparison system. Instead, processing appears to be distributed along the length of the IPS, with partially different local peaks for each dimension. There is considerable overlap between the local brain regions, and although there may be some neurons that respond to stimuli from a single dimension, those neurons are not likely to exist in a unique, well-delimited anatomical area."
Heidi Hardman | EurekAlert!
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
17.07.2018 | Life Sciences
17.07.2018 | Information Technology
17.07.2018 | Power and Electrical Engineering