Our eyes may be our window to the world, but how do we make sense of the thousands of images that flood our retinas each day? Scientists at the University of California, Berkeley, have found that the brain is wired to put in order all the categories of objects and actions that we see. They have created the first interactive map of how the brain organizes these groupings. Continue reading
Caltech biologists locate brain’s processing point for acoustic signals essential to human communication Continue reading
3dThe incredible ability of our brain to create a three-dimensional (3D) representation from an object’s two-dimensional projection on the retina is something that we may take for granted, but the process is not well understood and is likely to be highly complex. Now, new research published by Cell Press in the January 12 issue of the journal Neuron provides the first direct evidence that specific brain areas underlie perception of different 3D structures and sheds light the way that the primate brain reconstructs real-world objects. Continue reading
Cell communication is essential for the development of any organism. Scientists know that cells have the power to “talk” to one another, sending signals through their membranes in order to “discuss” what kind of cell they will ultimately become — whether a neuron or a hair, bone, or muscle. And because cells continuously multiply, it’s easy to imagine a cacophony of communication.
But according to Dr. David Sprinzak, a new faculty recruit of Tel Aviv University’s Department of Biochemistry and Molecular Biology at the George S. Wise Faculty of Life Sciences, cells know when to transmit signals — and they know when it’s time to shut up and let other cells do the talking. In collaboration with a team of researchers at the California Institute of Technology, Dr. Sprinzak has discovered the mechanism that allows cells to switch from sender to receiver mode or vice versa, inhibiting their own signals while allowing them to receive information from other cells — controlling their development like a well-run business meeting.
Dr. Sprinzak’s breakthrough Continue reading
LONDON – Scientists at the University College London have found that the hippocampus in the brain is responsible for our ability to organize the world into separate concepts.
Forming a concept involves selecting the important characteristics of our experiences and categorizing them.
The degree to do this effectively is a defining characteristic of human intelligence.
However, not much is known about how conceptual knowledge is created and used in the brain.
Thus, to identify the brain regions responsible, Dharshan Kumaran and colleagues at the Wellcome Trust Centre for Neuroimaging, UCL, showed 25 volunteers, pairs of fractal patterns that represented the night sky and asked them to forecast the weather – either rain or sun – based on the patterns.
Conceptual rules based on the positions and combinations of the patterns governed whether the resulting outcome would be rain or sun, but the volunteers were not told this.
Instead, they rewarded correct predictions with cash prizes, encouraging the volunteers to deduce these conceptual rules.
In an initial learning phase, the different possible combinations were repeatedly shown to the participants, so that they could make their predictions by simply memorizing previous outcomes and could also begin to realize that rules based on the positions and combinations of the patterns governed whether the result would be rain or sun.
In a second phase, the volunteers were provided with less information to encourage them to apply the rules they had identified, which made the researchers to separate those volunteers who had formed the concept in the learning phase from those who hadn’t.
During both experiments FMRI scanning was used to identify areas of brain activity.
It was found that in the first phase, they could tell if a volunteer would go on to apply concepts in the second phase by the degree of activity in their hippocampus, which is known to be responsible for learning and memory.
In the second phase, activity centered on the ventromedial prefrontal cortex (VMPFC), important in decision-making, was active.
The team concluded that the hippocampus creates and stores concepts, and passes this information onto the VMPFC where it is put to use during the making of decisions.
People with amnesia are also known to have problems forming concepts, so Kumaran is expecting his findings to lead to the development of improved teaching methods and other tools for the treatment of amnesiacs.
The study has been published in the journal Neuron.