Editing Symbolic artificial intelligence (section)

=== Situated robotics: the world as a model ===

Another critique of symbolic AI is the [[embodied cognition]] approach:
{{blockquote
|text=The [[embodied cognition]] approach claims that it makes no sense to consider the brain separately: cognition takes place within a body, which is embedded in an environment. We need to study the system as a whole; the brain's functioning exploits regularities in its environment, including the rest of its body. Under the embodied cognition approach, robotics, vision, and other sensors become central, not peripheral.{{sfn|Russell |Norvig|2021|p=982}} }}

[[Rodney Brooks]] invented [[behavior-based robotics]], one approach to embodied cognition. [[Nouvelle AI]], another name for this approach, is viewed as an alternative to ''both'' symbolic AI and connectionist AI. His approach rejected representations, either symbolic or distributed, as not only unnecessary, but as detrimental. Instead, he created the [[subsumption architecture]], a layered architecture for embodied agents. Each layer achieves a different purpose and must function in the real world. For example, the first robot he describes in ''Intelligence Without Representation'', has three layers. The bottom layer interprets sonar sensors to avoid objects. The middle layer causes the robot to wander around when there are no obstacles. The top layer causes the robot to go to more distant places for further exploration. Each layer can temporarily inhibit or suppress a lower-level layer. He criticized AI researchers for defining AI problems for their systems, when: "There is no clean division between perception (abstraction) and reasoning in the real world."{{sfn|Brooks|1991|p=143}} He called his robots "Creatures" and each layer was "composed of a fixed-topology network of simple finite state machines."{{sfn|Brooks|1991|p=151}}  In the Nouvelle AI approach, "First, it is vitally important to test the Creatures we build in the real world; i.e., in the same world that we humans inhabit. It is disastrous to fall into the temptation of testing them in a simplified world first, even with the best intentions of later transferring activity to an unsimplified world."{{sfn|Brooks|1991|p=150}}  His emphasis on real-world testing was in contrast to "Early work in AI concentrated on games, geometrical problems, symbolic algebra, theorem proving, and other formal systems"{{sfn|Brooks|1991|p=142}} and the use of the [[blocks world]] in symbolic AI systems such as [[SHRDLU]].