Researchers reveal how the brain remains focused on long-term goals. "Are we there yet?" As anyone who has traveled with young children knows, maintaining focus on distant goals can be a challenge. A new study suggests how the brain achieves this task, and indicates that the neurotransmitter dopamine may signal the value of long-term rewards. The findings may also explain why patients with Parkinson's disease -- in which dopamine signaling is impaired -- often have difficulty in sustaining motivation to finish tasks.