Many folks have heard about the gorilla who learned sign language, but few have seen the depth revealed in "Koko: A Talking Gorilla". In 1977 Barbet Schroeder and Nestor Almendros teamed up to explore the world of this gentle ape and her researcher friends, and the film raises difficult issues, questioning basic assumptions of scientists and skeptics alike. Of vital importance to both sides of the arguments on topics as diverse as animal rights and artificial intelligence is the question of whether Koko understood abstract concepts in the same way we do, which is no clearer now than then. The film, though, is careful to follow the gorilla's entire range of behavior and helps individuals decide for themselves what was happening behind her eyes. Powerful, thought-provoking, and even heartbreaking, "Koko: A Talking Gorilla" is essential viewing for anyone interested in intelligence, communication, and the nature of humanity. "--Rob Lightner"