Impact of talker variability on language development in two-year-olds.

This research investigated the impact of the number of talkers with whom children engage in daily conversation on their language development. Two surveys were conducted in 2020, targeting two-year-olds growing up in Japanese monolingual families. Caregivers reported the number of talkers in three age groups and children's productive vocabulary via questionnaires.

Preschoolers' Development of Theory of Mind: The Contribution of Understanding Psychological Causality in Stories.

This study investigated the relationship between children's abilities to understand causal sequences and another's false belief. In Experiment 1, we tested 3-, 4-, 5-, and 6-year-old children ( = 28, 28, 27, and 27, respectively) using false belief and picture sequencing tasks involving mechanical, behavioral, and psychological causality. Understanding causal sequences in mechanical, behavioral, and psychological stories was related to understanding other's false beliefs.

Are higher-frequency sounds brighter in color and smaller in size? Auditory-visual correspondences in 10-month-old infants.

Previous research has shown that not only adults but also two-and-a-half-year-old children associate higher-frequency sounds with smaller objects and with objects of brighter colors, suggesting that these intersensory correspondences are based on neural connections present very early in life. The present research examined whether 10-month olds are sensitive to these intersensory correspondences using a violation-of-expectation procedure. The results of Experiment 1 indicated that 10-month-olds associate a higher-frequency tone with an object of a brighter color and a lower-frequency tone with an object of a darker color.

[Inferring the meaning of a novel adjective by Japanese preschoolers].

This study examined how Japanese preschoolers infer the meaning of a novel adjective and noun. The participants, 41 three-year-olds and 44 four-year-olds, were introduced to a novel adjective or a novel noun in association with a familiar object. They were then shown five test objects and asked to choose all the objects to which they could apply the novel word.

Object similarity bootstraps young children to action-based verb extension.

Young children often fail to generalize a novel verb based on sameness of action since they have difficulty focusing on the relational similarity across events while at the same time ignoring the objects that are involved. Study 1, with Japanese-speaking 3- and 4-year-olds (N = 28 in each group), found that similarity of objects involved in action events plays a scaffolding role in children's extraction of relational similarity across events when they extend a verb. Study 2, with 4-year-olds (N = 47), further showed that repeated experience of action-based verb extension supported by object similarity leads children to be better able to extend a novel verb based on sameness of action, even without support from object similarity.

A developmental shift from similar to language-specific strategies in verb acquisition: a comparison of English, Spanish, and Japanese.

The world's languages draw on a common set of event components for their verb systems. Yet, these components are differentially distributed across languages. At what age do children begin to use language-specific patterns to narrow possible verb meanings? English-, Japanese-, and Spanish-speaking adults, toddlers, and preschoolers were shown videos of an animated star performing a novel manner along a novel path paired with a language-appropriate nonsense verb.

Novel noun and verb learning in Chinese-, English-, and Japanese-speaking children.

When can children speaking Japanese, English, or Chinese map and extend novel nouns and verbs? Across 6 studies, 3- and 5-year-old children in all 3 languages map and extend novel nouns more readily than novel verbs. This finding prevails even in languages like Chinese and Japanese that are assumed to be verb-friendly languages (e.g.

[Understanding the symbolic values of Japanese onomatopoeia: comparison of Japanese and Chinese speakers].

Do non-native speakers of the Japanese language understand the symbolic values of Japanese onomatopoeia matching a voiced/unvoiced consonant with a big/small sound made by a big/small object? In three experiments, participants who were native speakers of Japanese, Japanese-learning Chinese, or Chinese without knowledge of the Japanese language were shown two pictures. One picture was of a small object making a small sound, such as a small vase being broken, and the other was of a big object making a big sound, such as a big vase being broken. Participants were presented with two novel onomatopoetic words with voicing contrasts, e.

Mapping novel nouns and verbs onto dynamic action events: are verb meanings easier to learn than noun meanings for Japanese children?

The present research examined how 3- and 5-year-old Japanese children map novel nouns and verbs onto dynamic action events and generalize them to new instances. Studies 1 to 3 demonstrated that although both 3- and 5-year-olds were able to map novel nouns onto novel objects, only 5-year-olds could generalize verbs solely on the basis of the sameness of the action. Study 4 showed that the difficulty young children experience in learning verbs lies mainly in mapping the appropriate element to a verb rather than in encoding and remembering an action itself.

Reorganizing the lexicon by learning a new word: Japanese children's interpretation of the meaning of a new word for a familiar artifact.

This research investigated how children interpret the meaning of a new word associated with a familiar artifact. The existing literature has shown that syntactic form-class information plays an important role in making this kind of inference. However, this information is not available to Japanese children, because Japanese language does not have a grammatical distinction between count nouns and mass nouns, proper nouns and common nouns, or singular and plural.