Design a captivating poster that illustrates the collaboration between AI and humans. The background should feature a large, stylized AI brain composed of digital art pieces. In the foreground, show human hands reaching out towards the brain, symbolizing creativity and partnership. The event title, "International AI Art Competition," should be positioned at the top in an elegant serif font, contrasted against the digital background. Use dramatic lighting with a spotlight effect on the brain, and apply color grading to enhance the visual impact.