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Human Connectome Project (HCP)

What was the HCP?

The Human Connectome Project (HCP)  aimed to map the macroscale connections of the human brain. Macroscale connections are pathways created by bundles of nerve fibers.

The project began in 2010 when the National Institutes of Health (NIH) Blueprint for Neuroscience Research  awarded researchers $40 million over five years to map the brain connections of young adults in high resolution. That effort expanded to measuring macroscale brain connections across the lifespan.

The Human Connectome Project was launched in 2009 as part of the NIH Blueprint Grand Challenges .

The Blueprint Grand Challenges were intended to promote major leaps in the understanding of brain function and in approaches for treating brain disorders.

The goal of the HCP was to acquire and share data about the structural and functional connectivity of the human brain. Researchers studied the brain’s complex wiring by collecting data from thousands of research participants using state-of-the-art brain imaging technologies. Researchers also collected participants’ DNA, demographic information, and behavioral data to examine how genetics and the environment influence brain connectivity.

The project was the first time researchers combined different brain imaging technologies to map the brain’s long-range connections systematically. This research paved the way for a deeper understanding of how our brain circuitry changes as we age or because of psychiatric and neurologic conditions.

The HCP led to new data models, informatics, and analytic tools that advanced researchers’ ability to image and analyze brain connections. These advances played a major role in accelerating progress in the emerging human connectomics field and helped lead to the formation of NIH’s Brain Research Through Advancing Innovative Neurotechnologies®(BRAIN) Initiative .

Why was the HCP a priority for NIMH?

Scientists have studied the relationship between the structure and function of the human brain since the 1800s. Since then, researchers have made progress in understanding the anatomy, cell biology, physiology, and chemistry of the brain in health and disease. Yet many fundamental questions remain unanswered, including how brain function translates into mental health and why brain function declines with age.

For example, there is evidence that the growth of abnormal brain connections during early life contributes to autism and schizophrenia. Changes in connectivity also appear to occur when neurons degenerate, either because of normal aging or diseases such as Alzheimer’s disease.

In the past, a lack of adequate imaging technology made it difficult to research brain connectivity. By 2010, sophisticated versions of magnetic resonance imaging (MRI) had emerged that could look beyond the brain’s structure to find functional connections.

The HCP aimed to optimize and combine cutting-edge brain imaging technologies to deepen our understanding of brain connectivity and lay the groundwork for future research.

What was the impact of the HCP?

The HCP revolutionized the mapping of macroscale connections in the human brain and laid a foundation for using standardized brain imaging measures of connectivity to help diagnose diseases.

In five years, HCP researchers comprehensively mapped long-distance brain connections in 1,200 healthy young adults. These studies provided data about brain connectivity and its relationship to behavior, deepening our understanding of how the environment and genetics contribute to differences in brain circuitry.

Technical advances achieved by HCP researchers transformed the field and allowed the neuroscience research community to collect data in unprecedented ways. For example, HCP researchers developed a faster and more powerful MRI brain scanner system that shortened the length of scans while maintaining high-resolution images. This enabled data to be collected more efficiently than ever before. The NIH supported a data archive  to share all the HCP data with the research community.

Building on advances in neuroscience and progress made by the HCP, President Obama launched The BRAIN Initiative® in April 2013 . The BRAIN Initiative aims to revolutionize our understanding of the human brain and seeks to accelerate the development and application of innovative technologies. BRAIN researchers are working to produce a revolutionary, dynamic picture of the brain that, for the first time, shows how individual cells and complex neural circuits interact in both time and space.

Learn more about the HCP

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Last Reviewed: November 2022