Research News Winter 2017 Issue 40

Research News

Tomaso Poggio, a professor of brain and cognitive sciences at MIT and director of the Center for Brains, Minds, and Machines, has long thought that the brain must produce “invariant” representations of faces and other objects, meaning representations that are indifferent to objects’ orientation in space, their distance from the viewer, or their location in the visual field. Image: MIT News
Tomaso Poggio, a professor of brain and cognitive sciences at MIT and director of the Center for Brains, Minds, and Machines, has long thought that the brain must produce “invariant” representations of faces and other objects, meaning representations that are indifferent to objects’ orientation in space, their distance from the viewer, or their location in the visual field. Image: MIT News

Tomaso Poggio and colleagues have developed a new computational model for how the brain learns to recognize faces. Their model, which is based on known properties of neurons, takes account of the symmetry of faces and, like real brains, learns to recognize faces as they turn to either the left or right.

Synthetic biology allows scientists to design genetic circuits that can be placed in cells, giving them new functions such as producing drugs or other useful molecules. Ed Boyden and colleagues have now demonstrated that these circuits can be encapsulated within synthetic cell-like structures known as liposomes, preventing them from disrupting each other. The researchers can also control communication between these cells, allowing for circuits or their products to be combined at specific times.

Alan Jasanoff’s lab has devised a new class of probes that allow scientists to image brain molecules without using any chemical or radioactive labels. The new sensors consist of proteins designed to detect a particular target, which causes
them to dilate blood vessels in the immediate area. This produces a local change in blood flow that can be imaged with magnetic resonance imaging (MRI) or other imaging techniques.

John Gabrieli and colleagues have used MRI to identify brain differences that may underlie dyslexia. When a stimulus is presented repeatedly, the brain response decreases with each repetition, a phenomenon known as neural adaptation. The researchers, led by Tyler Perrachione, found that this effect was diminished in people with dyslexia, including both adults and children. The difference was seen in multiple brain regions, suggesting that the deficit responsible for dyslexia affects many different brain functions. The authors speculate that reading may be especially sensitive to subtle deficits, because it involves so many brain processes.

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