196 11 Stages of Cognitive Development Stage 1: Infantile \ Inference Rules Knowledge ea > conte ge Inference Control Strategy | Fig. 11.4: Uncertain Inference in the Infantile Stage word-object associations: e.g. learning that when the word “ball” is uttered in various contexts (“Get me the ball,” “That’s a nice ball,” etc.) it generally refers to a certain type of object. The key point regarding these “infantile” inference problems, from the CogPrime perspective, is that assuming one provides the inference system with an appropriate set of perceptual and motor ConceptNodes and SchemaNodes, the chains of inference involved are short. They involve about a dozen inferences, and this means that the search tree of possible PLN inference rules walked by the PLN backward-chainer is relatively shallow. Sophisticated inference control is not required: standard AI heuristics are sufficient. In short, textbook narrow-AI reasoning methods, utilized with appropriate uncertainty-savvy truth value formulas and coupled with appropriate representations of perceptual and motor inputs and outputs, correspond roughly to Piaget’s infantile stage of cognition. The simplistic approach of these narrow-AI methods may be viewed as a method of creating building blocks for subsequent, more sophisticated heuristics. In our theory Piaget’s preoperational phase appears as transitional between the infantile and concrete operational phases. 11.4.2 The Concrete Stage At this stage, the mind is able to carry out more complex chains of reasoning regarding the world, via using inference control schemata that adapt behavior based on experience (reasoning about a given case in a manner similar to prior cases). In the concrete operational stage (Figure 11.5), an entity is able to carry out more complex chains of reasoning about the world. Inference control schemata which adapt behavior based on experience, using experientially learned heuristics (including those learned in the prior stage), are app