The Human Connectome Project (HCP) aims to map the structural and functional connectivity patterns in the healthy adult human brain and provide these data as a public resource for biomedical research. However, individual differences in these patterns are significant, and they are associated with variations in cognitive and behavioral variables that affect real-world function. The HCP collects behavioral measures of a range of motor, sensory, cognitive, and emotional processes to understand the relationship between brain connectivity and human behavior. Additionally, the HCP uses task-fMRI (tfMRI) to explore the relationships between individual differences in neurobiological substrates of mental processing and both functional and structural connectivity. This paper describes the logic and rationale behind the development of the behavioral, individual difference, and tfMRI batteries and provides preliminary data on the patterns of activation associated with each of the fMRI tasks, at both a group and individual level. The HCP also includes measures of subthreshold symptoms of mood, anxiety, and substance abuse, additional measures of visual, memory, and emotion processing, personality, delay discounting, fluid intelligence, menstrual cycle and hormonal function for women, and sleep function. The tfMRI data will help characterize and validate the connectivity analyses to be conducted on the structural and functional connectivity data. The HCP uses a variety of tasks to identify nodes that can guide, validate, and interpret the results of the connectivity analyses. These tasks include working memory, recognition memory, incentive processing, motor, language processing, social cognition, relational processing, and emotion processing. The HCP also includes measures of physical function, handedness, and psychiatric, neurological, and substance use assessments. The data collected will be used to examine how variation in human structural and functional connectivity plays a role in adult and pediatric neurological and psychiatric disorders. The HCP is a large-scale study that involves a wide range of participants and uses a variety of tasks and measures to collect data on brain connectivity and behavior. The data will be used to understand the relationship between brain connectivity and human behavior and to develop new treatments for neurological and psychiatric disorders.The Human Connectome Project (HCP) aims to map the structural and functional connectivity patterns in the healthy adult human brain and provide these data as a public resource for biomedical research. However, individual differences in these patterns are significant, and they are associated with variations in cognitive and behavioral variables that affect real-world function. The HCP collects behavioral measures of a range of motor, sensory, cognitive, and emotional processes to understand the relationship between brain connectivity and human behavior. Additionally, the HCP uses task-fMRI (tfMRI) to explore the relationships between individual differences in neurobiological substrates of mental processing and both functional and structural connectivity. This paper describes the logic and rationale behind the development of the behavioral, individual difference, and tfMRI batteries and provides preliminary data on the patterns of activation associated with each of the fMRI tasks, at both a group and individual level. The HCP also includes measures of subthreshold symptoms of mood, anxiety, and substance abuse, additional measures of visual, memory, and emotion processing, personality, delay discounting, fluid intelligence, menstrual cycle and hormonal function for women, and sleep function. The tfMRI data will help characterize and validate the connectivity analyses to be conducted on the structural and functional connectivity data. The HCP uses a variety of tasks to identify nodes that can guide, validate, and interpret the results of the connectivity analyses. These tasks include working memory, recognition memory, incentive processing, motor, language processing, social cognition, relational processing, and emotion processing. The HCP also includes measures of physical function, handedness, and psychiatric, neurological, and substance use assessments. The data collected will be used to examine how variation in human structural and functional connectivity plays a role in adult and pediatric neurological and psychiatric disorders. The HCP is a large-scale study that involves a wide range of participants and uses a variety of tasks and measures to collect data on brain connectivity and behavior. The data will be used to understand the relationship between brain connectivity and human behavior and to develop new treatments for neurological and psychiatric disorders.