The Audiovisual Tau Effect in Infancy

Perceived spatial intervals between successive flashes can be distorted by varying the temporal intervals between them (the “tau effect”). A previous study showed that a tau effect for visual flashes could be induced when they were accompanied by auditory beeps with varied temporal intervals (an audiovisual tau effect).We conducted two experiments to investigate whether the audiovisual tau effect occurs in infancy. Forty-eight infants aged 5–8 months took part in this study. In Experiment 1, infants were familiarized with audiovisual stimuli consisting of three pairs of two flashes and three beeps. The onsets of the first and third pairs of flashes were respectively matched to those of the first and third beeps. The onset of the second pair of flashes was separated from that of the second beep by 150 ms. Following the familiarization phase, infants were exposed to a test stimulus composed of two vertical arrays of three static flashes with different spatial intervals. We hypothesized that if the audiovisual tau effect occurred in infancy then infants would preferentially look at the flash array with spatial intervals that would be expected to be different from the perceived spatial intervals between flashes they were exposed to in the familiarization phase. The results of Experiment 1 supported this hypothesis. In Experiment 2, the first and third beeps were removed from the familiarization stimuli, resulting in the disappearance of the audiovisual tau effect. This indicates that the modulation of temporal intervals among flashes by beeps was essential for the audiovisual tau effect to occur (Experiment 2).These results suggest that the cross-modal processing that underlies the audiovisual tau effect occurs even in early infancy. In particular, the results indicate that audiovisual modulation of temporal intervals emerges by 5–8 months of age

Cortical signatures of visual body representation develop in human infancy

Human infants cannot report their experiences, limiting what we can learn about their bodily awareness. However, visual cortical responses to the body, linked to visual awareness and selective attention in adults, can be easily measured in infants and provide a promising marker of bodily awareness in early life. We presented 4- and 8-month-old infants with a flickering (7.5 Hz) video of a hand being stroked and recorded steady-state visual evoked potentials (SSVEPs). In half of the trials, the infants also received tactile stroking synchronously with visual stroking. The 8-month-old, but not the 4-month-old infants, showed a significant enhancement of SSVEP responses when they received tactile stimulation concurrent with the visually observed stroking. Follow-up experiments showed that this enhancement did not occur when the visual hand was presented in an incompatible posture with the infant's own body or when the visual stimulus was a body-irrelevant video. Our findings provide a novel insight into the development of bodily self-awareness in the first year of life.</p

Eye contrast polarity is critical for face recognition by infants

Just as faces share the same basic arrangement of features, with two eyes above a nose above a mouth, human eyes all share the same basic contrast polarity relations, with a sclera lighter than an iris and a pupil, and this is unique among primates. The current study examined whether this bright-dark relationship of sclera to iris plays a critical role in face recognition from early in development. Specifically, we tested face discrimination in 7- and 8-month-old infants while independently manipulating the contrast polarity of the eye region and of the rest of the face. This gave four face contrast polarity conditions: fully positive condition, fully negative condition, positive face with negated eyes ( negative eyes ) condition, and negated face with positive eyes ( positive eyes ) condition. In a familiarization and novelty preference procedure, we found that 7- and 8-month-olds could discriminate between faces only when the contrast polarity of the eyes was preserved (positive) and that this did not depend on the contrast polarity of the rest of the face. This demonstrates the critical role of eye contrast polarity for face recognition in 7- and 8-month-olds and is consistent with previous findings for adults

大学体育における水泳授業によってクロールと平泳ぎを「続けて長く泳ぐこと」ができるようになるプロセス ─ 当事者の語りの分析から ─

　　The purpose of this study is to elucidate through an interview-based survey the process by which someone unable to swim becomes able to swim for long periods doing front crawl and breaststroke. The survey participant was a woman who could not swim a meter before taking university swimming classes. Owing to the swimming classes, she learnt to swim for long periods doing front crawl and breaststroke. Data was collected via a semi-structured interview. Trajectory Equifinality Modeling (TEM) was used for the analysis. 　　The following three conclusions were made: 　　1) Students who could not swim at all became able to swim front crawl by first learning to breathe underwater. 　　2) For breaststroke, the students timed their breathing by watching others swim, thereby learning to time their breathing with their swimming strokes. 　　3) Those who could not swim became able to swim for long periods doing front crawl and breaststroke, by going through the following three stages: a stage at which they could not think of anything, a stage at which they swam while thinking, and a stage at which they could swim without thinking

集中講義で開講される水泳授業が大学生の泳力に与える効果

　　This study clarifies the effects of intensive swimming classes on university students’ swimming ability. The results of our analysis are： 　　In front crawl swimming activity, swimming velocity (V) and stroke rate (SR) decreased significantly, and stroke length (SL) improved significantly. In movement evaluation, glide, stroke movement, and total score improved significantly, but breathing movement, kick movement, and body position showed no significant difference. In breaststroke, there was no significant difference in V, but SL improved significantly, and SR decreased significantly. In motion evaluation, pull movement, and total score improved significantly, but kick movement and body position showed no significant difference. 　　These results suggest that the classes did not affect the improvement of students’ V, but they did have a certain effect on improving swimming form