Click here to watch a lecture Jill Taylor gave describing the experience of having a left hemisphere stroke in a video.
A student at Wellesley recently posted a blog describing the experience of visiting her professor after she had suffered a stroke. The insights into left and right hemisphere function suggest just how little we understand about our perceptions of our individuality. The link to the post is below.
Caitlin Schneider, Stroke Hits Close to Home, on the Dana Press Blog
Sunday, January 30, 2011
Tuesday, January 25, 2011
Connectonics: Mapping Neural Byways and Highways in the Brain
A map-making revolution is underway in the field of neuroscience. Just as we use global positioning systems (GPS) to navigate from one place to another, neuroscientists are building GPS systems for the brain. BrainNavigator and the Connectome Project are just a few of the new on-line resources to help visualize structure-function relationships in the nervous system. The more traditional approaches for studying brain structure have been limited because the information is two-dimensional, rudimentary, and fragmented. But newer high-resolution imaging methods will map brain structure and function within three- and four-dimensions.
The Connectome is a joint venture between multiple labs that study the delicate terminals between neurons. While the basic layout is genetically determined in the growing embryo, synaptic contacts are maleable and undergo subtle changes with experience and learning throughout life. A dedicated and visionary group of scientists now aim to chart every one of these contacts between the billions of neurons in the human brain, through serially sectioning the brain, deconstructing these images into single cells and then digitally reconstructing the neural circuit.This method, called serial block face scanning electron microscopy, is allowing neuroscientists to digitally reconstruct segments of the mouse brain. It is also possible to correlate connectome data with cytoarchitectonics, the well-characterized and distinctive architectural features of the cerebral cortex that allow neuroscientists to parcel out different functional areas. Just as the facades of old and new buildings change drammatically along a city block, brain cytoarchitecture distinguishes local demarcations in the packing density and size of neurons and glia that are the building blocks of the brain. Cytoarchitectural features have been used to subdivide the human cerebral cortex into over 40 functionally distinct areas in the different lobes. While subtle changes in the sizes, shapes, and density of cells suggest areal borders, one problem with this method is that two scientists working on the same set of brain sections often disagree about the exact boundaries of different cortical areas in the same individual. Now however, computer software and visual scanning devices are beginning to map areal borders with high precision, speed, and reliability.
Once the major highways and byways linking the brain's different neighborhoods are digitally charted, the information becomes part of a world-wide, open-access database designed to help neuroscientists study how brain structure changes over the lifespan. By studying structural differences in identical and non-identical twins, the Connectome effort will help distinguish heritable traits from those shaped by experience and environment. Imagine having a navigational tool that not only shows a child's brain growing into that of an adult, but also spotlights the particular bridges and highways forming or undergoing renovations in the brain as the child learns to speak, make moral judgements, and form emotional attachments.
As scientists identify the blueprints for constructing cortical circuits in the developing human brain, they will also begin to understand how, when, and where circuit abnormalities emerge in autism and schizophrenia. Research on the connectome may even reveal how learning takes place and how we forget. Watch Sebastian Seung, one of the pioneers in connectome research, explain how our individual experiences and memories may be revealed by studying our connectome.
The Connectome is a joint venture between multiple labs that study the delicate terminals between neurons. While the basic layout is genetically determined in the growing embryo, synaptic contacts are maleable and undergo subtle changes with experience and learning throughout life. A dedicated and visionary group of scientists now aim to chart every one of these contacts between the billions of neurons in the human brain, through serially sectioning the brain, deconstructing these images into single cells and then digitally reconstructing the neural circuit.This method, called serial block face scanning electron microscopy, is allowing neuroscientists to digitally reconstruct segments of the mouse brain. It is also possible to correlate connectome data with cytoarchitectonics, the well-characterized and distinctive architectural features of the cerebral cortex that allow neuroscientists to parcel out different functional areas. Just as the facades of old and new buildings change drammatically along a city block, brain cytoarchitecture distinguishes local demarcations in the packing density and size of neurons and glia that are the building blocks of the brain. Cytoarchitectural features have been used to subdivide the human cerebral cortex into over 40 functionally distinct areas in the different lobes. While subtle changes in the sizes, shapes, and density of cells suggest areal borders, one problem with this method is that two scientists working on the same set of brain sections often disagree about the exact boundaries of different cortical areas in the same individual. Now however, computer software and visual scanning devices are beginning to map areal borders with high precision, speed, and reliability.
Once the major highways and byways linking the brain's different neighborhoods are digitally charted, the information becomes part of a world-wide, open-access database designed to help neuroscientists study how brain structure changes over the lifespan. By studying structural differences in identical and non-identical twins, the Connectome effort will help distinguish heritable traits from those shaped by experience and environment. Imagine having a navigational tool that not only shows a child's brain growing into that of an adult, but also spotlights the particular bridges and highways forming or undergoing renovations in the brain as the child learns to speak, make moral judgements, and form emotional attachments.
As scientists identify the blueprints for constructing cortical circuits in the developing human brain, they will also begin to understand how, when, and where circuit abnormalities emerge in autism and schizophrenia. Research on the connectome may even reveal how learning takes place and how we forget. Watch Sebastian Seung, one of the pioneers in connectome research, explain how our individual experiences and memories may be revealed by studying our connectome.
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