Tag Archives: plasticity

Studies in perception: At arm’s length: Plasticity of depth judgment

People have a distance at which they are best able to judge depth. That distance, it turns out, is dictated by how long people understand their arms to be. Researchers showed this in the Journal of Neuroscience by tricking subjects with virtual reality into thinking their reach was longer than it really was. The result? Their accurate perception of depth via sight moved outward and touch became more sensitive.

PROVIDENCE, R.I. [Brown University] — We need to reach for things, so a connection between arm length and our ability to judge depth accurately may make sense. Given that we grow throughout childhood, it may also seem reasonable that such an optimal depth perception distance should be flexible enough to change with a lengthening arm. Recent research in the Journal of Neuroscience provides evidence for these ideas with surprising findings: Scientists showed that they could manipulate the distance at which adult volunteers accurately perceived depth, both through sight and touch, by tricking them into thinking they had a longer reach than they really do. (more…)

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Tracking Fish Through a Coral Reef Seascape

Ear-bone ‘tree rings’ provide evidence of connectivity

Ocean scientists have long known that juvenile coral reef fishes use coastal seagrass and mangrove habitats as nurseries, later moving as adults onto coral reefs. But the fishes’ movements, and the connections between different tropical habitats, are much more complex than previously realized, according to a study published September 3 in Proceedings of the National Academy of Sciences. The findings have important implications for management and protection of coral reefs and other marine environments.

A number of studies have demonstrated a strong relationship between the presence of coastal wetlands and offshore fish abundance and fisheries yield, but it has proved difficult to develop quantitative assessment of habitat use by fish or their movement among different habitats. “The rationale for this study,”says Simon Thorrold, a biologist at Woods Hole Oceanographic Institution (WHOI), “was to determine the relative importance of different nursery habitats to reef fishes that spend their adult lives on coral reefs but may spend at least part of their juvenile residency elsewhere.” (more…)

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More Sophisticated Wiring, Not Just a Bigger Brain, Helped Humans Evolve Beyond Chimps

Human and chimp brains look anatomically similar because both evolved from the same ancestor millions of years ago. But where does the chimp brain end and the human brain begin?

A new UCLA study pinpoints uniquely human patterns of gene activity in the brain that could shed light on how we evolved differently than our closest relative. The identification of these genes could improve understanding of human brain diseases like autism and schizophrenia, as well as learning disorders and addictions.

The research appears Aug. 22 in the advance online edition of the journal Neuron. (more…)

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Distinct Brain Cells Recognize Novel Sights

The brain’s ability to learn to recognize objects plays out in the inferior temporal cortex. A new study offers a possible explanation of how two classes of neurons play distinct roles to help that happen.

PROVIDENCE, R.I. [Brown University] — No matter what novel objects we come to behold, our brains effortlessly take us from an initial “What’s that?” to “Oh, that old thing” after a few casual encounters. In research that helps shed light on the malleability of this recognition process, Brown University neuroscientists have teased apart the potentially different roles that two distinct cell types may play.

In a study published online in advance in the journal Neuron, the researchers document that this kind of learning is based in the inferior temporal cortex (ITC), a brain area buried deep in the skull. Scientists already knew the area was important for visual recognition of familiar items, but they hadn’t figured out the steps required to move from novelty to familiarity, a process they refer to as “plasticity.” (more…)

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Yale Scientists Find Molecular Glue Needed To Wire the Brain

Yale University researchers have found that a single molecule not only connects brain cells but also changes how we learn. The findings, reported in the December 9 issue of the journal Neuron, may help researchers discover ways to improve memory and could lead to new therapies to correct neurological disorders.

The junctions between brain cells over which nerve pulses pass — called synapses — are crucial for regulating learning and memory and how we think. Aberrations in the structure and function of synapses have been linked to mental retardation and autism, while synapses are lost in the aging brains of Alzheimer’s patients. (more…)

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