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Concepts of containment, support, and degree of fit were investigated using nonverbal, preferential-looking tasks with 9-to 14-month-old infants and adults who were fluent in either English or Korean. Two contrasts were tested: tight containment vs. loose support (grammaticized as ÔinÕ and ÔonÕ in English by spatial prepositions and ÔkkitaÕ and ÔnohtaÕ in Korean by spatial verbs) and tight containment vs. loose containment (both grammaticized as ÔinÕ in English but separately as ÔkkitaÕ and ÔnehtaÕ in Korean). Infants categorized both contrasts, suggesting conceptual readiness for learning such spatial semantics in either language. English-speaking adults categorized tight containment vs. loose support, but not tight vs. loose containment. However, Korean-speaking adults were successful at this latter contrast, which is lexicalized in their language. The adult data suggest that some spatial relations that are salient during the preverbal stage become less salient if language does not systematically encode them.

We tested amnesic patients, patients with frontal lobe lesions, and control subjects with the deferred imitation task, a nonverbal test used to demonstrate memory abilities in human infants. On day 1, subjects were given sets of objects to obtain a baseline measure of their spontaneous performance of target actions. Then different event sequences were modeled with the object sets. On day 2, the objects were given to the subjects again, first without any instructions to imitate the sequences, and then with explicit instructions to imitate the actions exactly as they had been modeled. Control subjects and frontal lobe patients reproduced the events under both uninstructed and instructed conditions. In contrast, performance by the amnesic patients did not significantly differ from that of a second control group who had the same opportunities to handle the objects but were not shown the modeled actions. These findings suggest that deferred imitation is dependent on the brain structures essential for declarative memory that are damaged in amnesia, and they support the view that infants who imitate actions after long delays have an early capacity for long-term declarative memory.

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The development of conceptual categories from 7 to 11 months of age was explored in 5 experiments using an object-examination task. Infants in this age range categorized the global domains of animals, vehicles, and furniture. Plants and kitchen utensils were tested at 11 months, and these domains were also categorized. When 9-month-olds were tested on kitchen utensils, they did not categorize them. Subdivisions within the animal and furniture domains were also examined. Infants did not show any subcategorization of furniture. In the animal domain both 9- and 11-month-olds responded to the life-form distinction between dogs and birds, but they did not differentiate the mammal categories of dogs and cats until 11 months. This early organization of the conceptual system into global domains that become increasingly differentiated is discussed in relation to the adult conceptual system and its breakdown in semantic dementia.