TY - JOUR
T1 - Contrast reversal of the eyes impairs infants' face processing
T2 - A near-infrared spectroscopic study
AU - Ichikawa, Hiroko
AU - Otsuka, Yumiko
AU - Kanazawa, So
AU - Yamaguchi, Masami K.
AU - Kakigi, Ryusuke
N1 - Funding Information:
This study was supported by Grant-in-Aid for Scientific Research on Innovative Areas, ‘Face perception and recognition’ from MEXT KAKENHI ( 20119002 ) and a Grant-in-Aid for Scientific Research by JSPS Research Fellowships for Young Scientists ( 24 7809 ) from the Japan Society for the Promotion of Science. We thank Yuna Inada, Megumi Kobayashi, Emi Nakato, Aya Nakajima, Sakiko Ogawa, Yuiko Sakuta, Kazuki Sato, Aki Tsuruhara, Wakayo Yamashita, Yuka Yamazaki, and Jiale Yang for their help in data collection.
PY - 2013/11
Y1 - 2013/11
N2 - Human can easily detect other's eyes and gaze from early in life. Such sensitivity is supported by the contrast polarity of human eyes, which have a white sclera contrasting with the darker colored iris (Kobayashi & Kohshima, (1997). Nature, 387, 767-768; Kobayashi & Kohshima, (2001). Journal of Human Evolution, 40, 419-435). Recent studies suggest that the contrast polarity around the eyes plays an important role in infants' face processing. Newborns preferred upright face images to inverted ones in contrast-preserved faces, but not in contrast-reversed faces (Farroni et al., (2005). Proceedings of National Academy of Sciences of the United States of America, 102, p. 17245-17250). Seven- to 8-month-old infants failed to discriminate between faces when the contrast polarity of eyes was reversed (Otsuka et al., (2013). Journal of Experimental Child Psychology, 115, 598-606). Neuroimaging study with adults revealed that full-negative faces induced less activation in the right fusiform gyrus than either full-positive faces or negative faces with contrast-preserved eyes (Gilad et al., (2009). Proceedings of National Academy of Sciences of the United States of America, 106, p. 5353-5358). In the present study, we investigated whether contrast-reversed eyes diminish infants' brain activity related to face processing. We measured hemodynamic responses in the bilateral temporal area of 5- to 6-month-old infants. Their hemodynamic responses to faces with positive eyes and those with negative eyes were compared against the baseline activation during the presentation of object images. We found that the presentation of faces with positive eyes increased the concentration of oxy-Hb in the right temporal area and those of total-Hb in the bilateral temporal areas. No such change occurred for faces with negative eyes. Our results suggest the importance of contrast polarity of the eyes in the face-selective neural responses from early development.
AB - Human can easily detect other's eyes and gaze from early in life. Such sensitivity is supported by the contrast polarity of human eyes, which have a white sclera contrasting with the darker colored iris (Kobayashi & Kohshima, (1997). Nature, 387, 767-768; Kobayashi & Kohshima, (2001). Journal of Human Evolution, 40, 419-435). Recent studies suggest that the contrast polarity around the eyes plays an important role in infants' face processing. Newborns preferred upright face images to inverted ones in contrast-preserved faces, but not in contrast-reversed faces (Farroni et al., (2005). Proceedings of National Academy of Sciences of the United States of America, 102, p. 17245-17250). Seven- to 8-month-old infants failed to discriminate between faces when the contrast polarity of eyes was reversed (Otsuka et al., (2013). Journal of Experimental Child Psychology, 115, 598-606). Neuroimaging study with adults revealed that full-negative faces induced less activation in the right fusiform gyrus than either full-positive faces or negative faces with contrast-preserved eyes (Gilad et al., (2009). Proceedings of National Academy of Sciences of the United States of America, 106, p. 5353-5358). In the present study, we investigated whether contrast-reversed eyes diminish infants' brain activity related to face processing. We measured hemodynamic responses in the bilateral temporal area of 5- to 6-month-old infants. Their hemodynamic responses to faces with positive eyes and those with negative eyes were compared against the baseline activation during the presentation of object images. We found that the presentation of faces with positive eyes increased the concentration of oxy-Hb in the right temporal area and those of total-Hb in the bilateral temporal areas. No such change occurred for faces with negative eyes. Our results suggest the importance of contrast polarity of the eyes in the face-selective neural responses from early development.
KW - Contrast polarity
KW - Eyes
KW - Infants
KW - NIRS
KW - Near-infrared spectroscopy
KW - Negation
UR - http://www.scopus.com/inward/record.url?scp=84886265681&partnerID=8YFLogxK
U2 - 10.1016/j.neuropsychologia.2013.08.020
DO - 10.1016/j.neuropsychologia.2013.08.020
M3 - Article
C2 - 24012650
AN - SCOPUS:84886265681
SN - 0028-3932
VL - 51
SP - 2556
EP - 2561
JO - Neuropsychologia
JF - Neuropsychologia
IS - 13
ER -