学術国際会議への派遣報告(心理学専攻)
学術国際会議への派遣を行いましたので、報告いたします。
(文学部教授・山口真美)
【会議名】
Vision Science Society (視覚科学会)
【主催機関名】
Vision Science Society (視覚科学会)
【発表日】
2008年5月10日(土),11日(日),13日(火)
【開催地】
アメリカ合衆国,フロリダ州,Naples
【講演・研究発表のテーマ】
Perception of mother’s face using near-infrared spectroscopy (近赤外線分光法を用いた母親の顔の知覚に関する研究) 他3件
【講演・発表の内容】
・Emi Nakato, Yumiko Otsuka, Masami Yamaguchi, Ryusuke Kakigi "Perception of mother’s face using near-infrared spectroscopy" : Near-infrared spectroscopy (NIRS) can detect the change in hemodynamic responses on infants’ brain. Our previous studies used NIRS to measure the concentration of oxy-Hb and total-Hb on infants’ face processing (Otsuka et al., 2007; Nakato et al., in press). These studies indicated that (1) the right hemisphere in the brain was activated when infants looked at the upright faces as compared the inverted faces, and (2) the developmental differences between 5- and 8-month-olds appeared in the presentation on the frontal views and the profile views. The results suggest that the right temporal area is dominant for the perception of faces in infants as well as adults. Recognition of mother’s face is important for infants to develop their social communication. Previous studies demonstrated that 3-month-olds could discriminate between their mother’ face and stranger’ face (Barrera and Maurer, 1981), and the ability of recognition of mother’s face is developed by 6 months of the age (de Haan and Nelson, 1997). We investigated the infants’ brain activity on their mother’s face presentation by NIRS. The participants were seven healthy 6- to 8-month-olds. The stimuli consisted of full color photo images of 5 vegetables, 5 unfamiliar female faces, and mother face. Infants looked each photo image passively
as long as they could. Our finding was that the data of total-Hb concentrations in the right temporal regions increased in the presentation of both mother’s and unfamiliar faces. This result is consistent with the previous NIRS data (Otsuka et al., 2007; Nakato et al., in press) which showed the right temporal regions are involved in perception of faces in infants. And more interestingly, the concentration of total-Hb was greater activated for mother’s face, as compared strangers’ faces. This increased hemodynamic response implies the specific mechanism for mother’s face recognition in infants’ brain.
・Jiale Yang, So Kanazawa, Masami K Yamaguchi "Perception of neon color spreading in 3- to 6- month old infants" : Although lots of studies about neon color spreading have been reported, there are few studies about the early perceptual development of it in human infants. The aim of this present study was to explore the perceptual development of neon color spreading in infants. A total of 28 infants, aged 3-4 and 5-6 months, participated in the present study. There were two conditions (experimental condition vs. control condition), and each infant participated in both conditions. In the experimental condition, two kinds of stimulus were presented side by side: an Ehrenstein neon color spreading pattern and a non-neon color spreading pattern. The latter was made by reversing the color arrangement of the Ehrenstein neon pattern. In the control condition, we separated the differently colored parts of the Ehrenstein neon color spreading pattern and the non-neon color spreading pattern in the experimental condition. Each experimental condition consisted of 2 trials. In each trial, stimulus was presented for 15 s. In this paradigm, we infer that if infants could perceive neon color spreading, they would show a preference for the neon pattern only in the experimental condition. The current results showed that the 5~6-month-old infants had a significant preference for the neon pattern, but the 3~4-month-old infants did not. Neither age group showed preference in the stimuli of the control condition. These results suggest that the 5~6-month-old infants could perceive neon color spreading.
・Aki Tsuruhara, So Kanazawa, Masami Yamaguchi "Effects of reference frame on the perception of human-body orientation in infancy" : We investigated the effects of reference frame on the perception of stimulus orientation in infancy. The human-body figure was used as the stimulus, because the human-body is an ecologically important stimulus. This result was compared with the results of previous studies using a grating as the stimulus (Jouen, 1985; Tsuruhara et al. 2007). We used the preferential looking technique. The stimuli were vertical and oblique human-body silhouette. The infants’ looking times for each stimulus were measured. In Experiment 1, only human-body figures were presented. In Experiment 2, each human-body figure was surrounded by a vertical square, and in Experiment 3, the surrounding square was oblique. Additionally, control experiments were conducted. In the control experiments, the stimuli in each experiments were inverted. These inverted human-body figures didn’t seem to be human-bodies. The results showed that, in Experiment 2 and 3, the results using the human-body figure were similar to the previous results using a grating stimulus. Vertical surrounding squares induced the preference to the oblique human-body figure and the grating over the vertical human-body figure and the grating. Oblique surrounding squares induced no preference. In the control experiments, the inverted human-body figure produced the same results. On the other hand, in Experiment 1, the results using the human-body figure differed from the previous results using a grating stimulus. Previous studies showed that infants preferred the vertical grating over the oblique grating. By contrast, in our experiment, infants preferred the oblique human-body figure over the vertical human-body figure. In the control experiments, the inverted human-body figure produced no preference. The results of this study suggest that, in infancy, the perception of human-body orientation differs from the perception of grating orientation, although the reference frame have the similar effects on these two stimuli.
・Yumiko Otsuka, Yuka Yamazaki, Yukuo Konishi, So Kanazawa, Masami Yamaguchi "Perception of illusory transparent surface by young infants" : Most developmental studies consistently show that only infants aged at least 6-7 months and older can perceptually integrate disconnected image fragments and complete missing structures based solely on pictorial information (e.g. Bertenthal, 1980). Here, we show an example of early emergence of visual completion using purely static two-dimensional pictorial information. We created mixed polarity Kanizsa figures that are either consistent or inconsistent with perception of an illusory transparent surface. Both configurations have the same local geometry and also contain very similar contrast polarity variations across the four inducers. The perception of transparency is manipulated by the distribution of contrast polarity variations in each configuration. A total of 48 Japanese infants aged 3-4 and 5-6 months participated in the preferential looking study. In the Experiment 1, we presented either the transparent or the non-transparent Kanizsa figure side by side with their respective control configurations that consisted of identical but rotated elements. We found that both 3-4 and 5-6 months significantly preferred the transparent Kanizsa figure to its rotated control. There was no such preference between the non-transparent Kanizsa figure and its rotated control configuration. In the Experiment 2, we directly compared infants’ preference between the two types of Kaniza figures. As the two types of the Kanizsa figures slightly differed in terms of the local contrast intensity, we presented the rotated version of these figures side by side as a control condition. We found that both 3-4 and 5-6 months significantly preferred the Kanizsa figure that induces perception of illusory transparent surface than the one which does not. No preference was observed in the control condition. The results from two experiments clearly demonstrate that both 3-4 and 5-6 months perceived the illusory transparent surface in the mixed polarity Kanizsa figure.