The Human Connectome Project, a five-year project to link brain connectivity to human behavior, has released a set of high-quality imaging and behavioral data to the scientific community. The project has two major goals: to collect vast amounts of data using advanced brain imaging methods on a large population of healthy adults, and to make the data freely available so that scientists worldwide can make further discoveries about brain circuitry.
The initial data release includes brain imaging scans plus behavioral information—individual differences in personality, cognitive capabilities, emotional characteristics, and perceptual function—obtained from 68 healthy adult volunteers. Over the next several years, the number of subjects studied will increase steadily to a final target of 1,200. The initial release is an important milestone because the new data have much higher resolution in space and time than data obtained by conventional brain scans.
The data set includes information about brain connectivity in each individual, using two distinct magnetic resonance imaging (MRI) approaches. One, called resting-state functional connectivity, is based on spontaneous fluctuations in functional MRI signals that occur in a complex pattern in space and time throughout the gray matter of the brain. Another, called diffusion imaging, provides information about the anatomical pathways traversing the brain's white matter. Each method has its own limitations, and analyses of both functional connectivity and structural connectivity in each subject should allow deeper insight than by either method alone.
Each subject is also scanned while performing a variety of tasks within the scanner, thereby providing extensive information about "Task-fMRI" brain activation patterns. Behavioral data using a variety of tests performed outside the scanner are being released along with the scan data for each subject. The subjects are drawn from families that include siblings, some of whom are twins. This will enable studies of the heritability of brain circuits.

