Poster #66 - Variation in infants' finger movements depending on the size of hemispherical objects

• In Event: Poster Session 03

Abstract

Finger dexterity is associated with brain development. For example, a previous study on finger dexterity exercises and calculation ability in 5- to 6-year-old children found a correlation between the two (Asakawa and Sugimura, 2009). Based on these findings, we believe that inducing appropriate finger movements has an important effect on infant development (Huang et al., 2019). However, few toys or daily tools are designed to induce proper finger movements in infants. In toys and daily tools that infants come into contact with on a daily basis, a quantitatively evaluated design based on scientific evidence should be able to promote brain development. Therefore, this study aimed to clarify how infants' finger movements change in response to objects of different sizes.
Twenty-three infants, aged 6–8 months, participated in the experiment. Six hemispherical objects (from 1 cm to 6 cm in diameter) were presented in front of the infants, and their playing was recorded using video cameras. In the analysis, we classified finger movements into five categories: "Pinch A" (using two or three fingers at the first joint), "Pinch B" (using two or three fingers including the second and third joints), "Grip" (using four or five fingers regardless of the finger joint), "One finger" (scratching and rolling an object with one finger), and "Push" (touching, tapping, or pushing an object with one to five fingers). The frequency of finger movements for each object size was calculated and compared between the object sizes. The results of the Friedman test showed significant differences between object sizes of 2 cm and 5 cm and between 2 cm and 6 cm for "Pinch A" (p<.05). In other words, Pinch A, which means precision finger movement, is induced by a 2 cm object. In "Grip," the number of trials tended to increase with increasing object size, with significant differences for object sizes larger than 3 cm for 1 cm object sizes (p<.05) and for 5 cm and 6 cm object sizes for 2 cm object sizes (p<.05). These results indicate that different object sizes can induce different finger movements. Accordingly, we expect to see applications for toys and daily tools designed to induce appropriate finger movements in infants.

Authors

• Ayaka Ohnuki, Shibaura Institute of Technology
  Presenting Author

• Kaito Kurita

• Youko Shimada

• Shoji Itakura, Doshisha University

• Hiroki Sato