ABSTRACT
The developmental findings suggest some interesting parallels with the loss of meaning that occurs in cases of semantic dementia and related neuropsychological disorders. A comparison of the data on acquisition and breakdown of the semantic system suggests something like first in, last out. The chapter discovers a category of manipulable household items that our subjects differentiated from vehicles. This category when people tried to assess responding on sequential-touching test when there was only one taxonomic category available. It contrasts vehicles with what we called a junk category, namely sets of items we considered to be unrelated. The items in the sets we used seemed to us to come from different semantic categories. The claim that infants form concepts based on selected features that are defining is not meant to imply metacognitive activity. Rather the claim is that in addition to forming perceptual categories babies also form categories that are more selective in nature and less influenced by overall perceptual similarity.
