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!
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering