Different neural systems for recognizing plants, animals, and artifacts.

The purpose of this study was to investigate functional organization in the human brain involved in the representation of knowledge regarding plants. We measured the brain activity of eight male volunteers during the recognition of visual stimuli representing plants, animals and artifacts, using positron emission tomography. The participants were presented with and were required to name silently two different images each of 15 entities belonging to three ontological categories, and 30 series of four to six digits. Marked increases in regional cerebral blood flow were found in the hippocampus and the parahippocampal areas bilaterally and the right lateral occipital cortex during the silent naming of all three categories, compared with that during the silent reading of digits. The right lateral occipital cortex was specifically activated in association with the naming of plants, and the right fusiform cortex was specifically activated in association with the naming of animals. In addition, the right temporo-occipital cortex was activated only during animals and plants, not artifacts. Our results indicate that there were a few characteristic activations for the different categories, and that entities belonging to the different categories are not necessarily represented in different locations of the brain.

The effect of Kana literacy acquisition on the speech segmentation unit used by Japanese young children.

Three experiments were undertaken to investigate whether young children's segmentation units would change as they learned to read kana letters, which represent morae (subsyllabic rhythmic units). The first 2 experiments used a vocal-motor segmentation task to examine whether 4- to 6-year-olds preferred to segment spoken words containing the special syllables CVN, CVQ, or CV: into syllables or into morae. The third experiment used a target monitoring task for CVN to examine whether children's detection of the target syllable in a series of words would vary depending on the moraic constitution of the target and the moraic-syllabic status of the word initial in which the target was embedded. Results indicated that the children's conscious segmentation of words, except for those having a geminate stop consonant (CVQ), developed from being a mixture of syllable- and mora-based to being predominantly mora-based as they learned to read kana letters. The tendency toward mora-based segmentation was also found in the target monitoring task, which required segmentation at a less conscious level.

Role of dorsal neck proprioceptive inputs to vestibular compensation in humans.

To investigate the role of cervical proprioceptive inputs in the process of vestibular compensation, we performed static posturography in patients with acute and compensated unilateral vestibular dysfunction, by applying vibratory stimulation to the dorsal neck muscles. Neck vibration induced disequilibrium in both groups of patients, but was more pronounced in the compensated patients. These results indicate that manipulation of the neck afferents causes discompensation in subjects whose vestibular dysfunction has already been compensated by multisensory inputs including neck afferents.

Young children's recognition of commonalities between animals and plants.

In 4 experiments, we examined whether young children have grasped commonalities between animals and plants as one of the essential components of an autonomous domain of biology. Experiment 1 revealed that by age 5, children distinguished both animals and plants from nonliving things in terms of growth (i.e., changes in size over time). Experiments 2 and 2A indicated that a considerable number of 5-year-olds, when given brief vitalistic descriptions about properties of all living things, constrained inductive projections of these properties using the category of living things. They attributed not only growth but also taking food/water and being taken ill to both animals and plants only. In Experiment 3, when 5-year-old children were asked directly whether plants or nonliving things would manifest phenomena similar to those observed for animals, they responded affirmatively for plants and could offer specific phenomena for growth, feeding, and aging/dying in support of their answers (e.g., watering for plants as analogous to feeding for animals). Overall, contrary to Carey, children as young as 5 years have an integrated category of living things. The possibility that early biology is established around taking food/water and growth is discussed.

[The role of cervical input in vestibular compensation].

The role of proprioceptive input from cervical receptors in vestibular compensation was investigated. Vibratory stimulation to the dorsal neck muscle was given to patients with unilateral vestibular lesions. The length of the displacement of the center of gravity, maximum sway length, and sway area increased markedly during vibratory stimulation to the dorsal neck. In patients in whom compensation had been achieved, a position vector to the side of the lesion increased and the center of gravity moved to the side of the lesion. From these results, it can be speculated that cervical input plays an important role in the process of vestibular compensation.

Young children's naive theory of biology.

This article aimed at investigating the nature of young children's naive theory of biology by reviewing a large number of studies conducted in our laboratories. More specifically, we tried to answer the following five critical questions. What components does young children's knowledge system for biological phenomena (or naive biology) have? What functions does it have in children's lives? How is it acquired in ontogenesis? How does its early version change as children grow older? Is it universal across cultures and through history? We propose that young children's biological knowledge system has at least three components, that is, knowledge needed to specify the target objects of biology, ways of inferring attributes or behaviors of biological kinds, and a non-intentional causal explanatory framework, and that these three constitute a form of biology, which is adaptive in children's lives. We also claim that the core of naive biology is acquired based on specific cognitive constraints as well as the general mechanism of personification and the resultant vitalistic causality, but it is differently instantiated and elaborated through activity-based experiences in the surrounding culture.

Young children's understanding of the mind-body distinction.

A experiments investigated children's understanding of the mind-body distinction. Children of ages 4 and 5 recognized not only the differential modifiability of changeable versus unchangeable human properties and bodily versus mental properties, but also the independence of activities of bodily organs from a person's intention (Experiment 1). When presented 3 types of causal explanations (i.e., intentional, vitalistic, mechanical), 6-year-olds chose most often as most plausible for bodily functions vitalistic explanations (i.e., those ascribing the phenomena to a relevant bodily organ's initiative and effortful engagement in activity); 8-year-olds chose the vitalistic explanations second most often, following mechanical ones (Experiment 2). However, 6-year-olds, as well as 8-year-olds and adults, did not always choose vitalistic explanations over intentional explanations (Experiment 3); whereas they tended to prefer vitalistic explanations for biological phenomena, they predominantly accepted intentional ones for psychological phenomena (Experiment 3A). These results suggest that children as young as 6 years of age have acquired a form of biology as an autonomous domain which is separate from that of psychology.