THE FIVE SENSES, AND BEYOND
percent.This means only that the system can detect subtle differences in expressions, not necessarily the emotions behind them, but psy- chologists are working on associating specific emotions with specific combinations of AUs, so there is potential for artificial beings to be able to perceive the fine points of human feelings.
The techniques that work for detecting and recognizing faces, such as the probabilistic approach, can also be applied to objects like automobiles and paper money, so machine vision will grow in capa- bility.What has been achieved so far is only a part of general human visual cognitive ability.
GETTING THE WORD OUT
Despite the long way left to go, though, recognizing people and read- ing their faces represents a landmark in the development of synthetic creatures. But to achieve a comfortable relation with people, an artifi- cial being also requires intelligent hearing and speech. Both the vir- tual and the real histories of artificial beings recognize the power of meaningful discourse—from the brass talking head supposedly made by Albertus Magnus in the thirteenth century, to the Turing test. As noted earlier, in 1637 René Descartes asserted that it might be pos- sible to construct a machine that uttered words. But he went on to say,
It is not conceivable that such a machine should produce different ar- rangements of words so as to give an appropriately meaningful answer to whatever is said in its presence, as even the dullest of men can do.
We do not yet have machines that converse as well as “even the dullest of men”: but we do have transducers that change sound waves into computer bits, and vice-versa.This is a start, and researchers have created systems that hear what is said to them and give appropriate spoken responses, but only within limited arenas. However, these ma- chines also display qualities that Descartes might never have consid- ered:They sound human, and in addition to grasping the meaning of the words, they grasp how the words are said and the qualities of the voice that says them.