Developmental changes in semantic knowledge organization

Development of inductive generalization with familiar categories

“…However, development and learning concepts become increasingly differentiated into groups that capture a larger number of more subtle relationships, leading to the formation of Btaxonomic^clusters. There is recent evidence that this developmental trajectory characterizes changes in representational similarity not only in computational models but also in human participants (Fisher, Godwin, Matlen, & Unger, 2014;Unger, Fisher, & MacLellan, 2014). Therefore, developmental changes in representational similarity explain why Sloman's feature-based model would provide a good fit to performance of older children (whose representational similarity of familiar categories is in many ways similar to that in adults) but not that of preschoolers (whose representational similarity of familiar categories is dramatically different from that of adults; Fisher et al, 2014;.…”

“…Recall that early in development, semantic representations are poorly differentiated but become increasingly differentiated in accordance with taxonomic relations in the course of learning and development Hills, et al, 2009;Kemp & Tenenbaum 2008;Rogers & McClelland, 2004;Unger et al, 2014). For example, Unger et al (2014) observed that preschoolers and kindergarteners were likely to group together items, such as whale, seaweed, and water lily (likely due to similarity in habitat); however, by second grade children grouped items largely in accordance with the plants-animals distinction.…”

“…As stated above, representational similarity changes as children learn an increasing number of attributes associated with different categories; and these changes in representational similarity result in semantic knowledge becoming increasingly organized in accordance with taxonomic relations Kemp & Tenenbaum 2008;Rogers & McClelland, 2004;Unger et al, 2014). Changes to representational similarity are driven by experience (both direct and indirect); therefore, semantic organization in individual children will vary based on both the available input and a child's ability to encode and store this input.…”

Development of Inductive Generalization

“…Similarity ratios predicted the pattern of children's inferences on an induction task; that is, inductive inference to Test 1 items increased gradually as the similarity ratio of Test 1 items approached 9. As discussed earlier, we recently estimated representational similarity of familiar animal concepts based on the idea that physical distance can be used as a proxy for psychological distance . Thus, a similarity‐based approach can be used to account for people's inferences even when we cannot individuate features.…”

“…Recent empirical evidence supports the idea of increased semantic differentiation with development . In a series of studies, we asked 4‐ to 7‐year‐olds to arrange line drawings or unpainted wooden blocks representing animals on a game board so items of similar kind were placed together and different kinds of items were placed apart. Physical distance between the items on the board was the measure of representational similarly between pairs of concepts .…”