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!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Physics and Astronomy
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering