Data Analysis_Children_corrected SDT 20171109.xlsx

<p>We investigated perceptual discriminability for Asian-like versus Caucasian-like morph faces in school-age Taiwanese children and adults. One-hundred-and-two 5- to 12-year-old children and twenty-three adults performed a sequential same/different face matching task, where they viewed an Asian- or a Caucasian-parent face followed by either the same parent face or a different morphed face (containing 15%, 30%, 45%, or 60% contribution from the other parent face) and judged if the two faces looked the same. We computed the <i>d’</i> as the sensitivity index for each age groups. We also analyzed the group mean rejection rates as a function of the morph level and fitted with a cumulative normal distribution function. Results showed that the adults and the oldest 11-12-year-old children exhibited a greater sensitivity (<i>d</i>’) and a smaller discrimination threshold (<i>m</i>) in the Asian-parent condition than those in the Caucasian-parent condition, indicating the presence of an own-race advantage. On the contrary, 5- to 10-year-old children showed an equal sensitivity and similar discrimination thresholds for both conditions, indicating an absence of the own-race advantage. Moreover, a gradual development in enhancing the discriminability for the Asian-parent condition was observed from age 5 to 12; however, the progression in the Caucasian-parent condition was less apparent. In sum, our findings suggest that expertise in face processing may take the entire childhood to develop, and supports the <i>perceptual learning view</i> of the other-race effect--the own-race advantage seen in adulthood likely reflects a result of prolonged learning specific to faces most commonly seen in one’s visual environment such as own-race faces. </p

Morphed female faces stimuli.

<p>An example of a set of linearly morphed female faces produced by image averaging of one Asian- and Caucasian-parent face pair. The numerator indicates the percent contribution to the morphed face from Asian parent and the denominator indicates the percent contribution from the Caucasian parent.</p

Illustration of a sample trial of the sequential same/different face matching task.

<p>Illustration of a sample trial of the sequential same/different face matching task.</p

The development of the own-race advantage in school-age children: A morphing face paradigm (adult's data)

We investigated perceptual discriminability for Asian-like versus Caucasian-like morph faces in school-age Taiwanese children and adults. One-hundred-and-two 5- to 12-year-old children and twenty-three adults performed a sequential same/different face matching task, where they viewed an Asian- or a Caucasian-parent face followed by either the same parent face or a different morphed face (containing 15%, 30%, 45%, or 60% contribution from the other parent face) and judged if the two faces looked the same. We computed the <i>d’</i> as the sensitivity index for each age groups. We also analyzed the group mean rejection rates as a function of the morph level and fitted with a cumulative normal distribution function. Results showed that the adults and the oldest 11-12-year-old children exhibited a greater sensitivity (<i>d</i>’) and a smaller discrimination threshold (<i>m</i>) in the Asian-parent condition than those in the Caucasian-parent condition, indicating the presence of an own-race advantage. On the contrary, 5- to 10-year-old children showed an equal sensitivity and similar discrimination thresholds for both conditions, indicating an absence of the own-race advantage. Moreover, a gradual development in enhancing the discriminability for the Asian-parent condition was observed from age 5 to 12; however, the progression in the Caucasian-parent condition was less apparent. In sum, our findings suggest that expertise in face processing may take the entire childhood to develop, and supports the <i>perceptual learning view</i> of the other-race effect--the own-race advantage seen in adulthood likely reflects a result of prolonged learning specific to faces most commonly seen in one’s visual environment such as own-race faces

The estimated discrimination thresholds (<i>μ</i>) and slope parameters (σ) of the group psychometric functions for the Asian-parent and Caucasian-parent conditions.

<p>The numbers in the parenthesis are standard errors (<i>SE</i>) of the estimates by <i>bootstrap resampling</i> with an iteration size of 200. Eleven iterations were performed for the adults’ psychometric functions, and ten iterations were performed for the children’s functions).</p

Adults’ mean rejection rates.

<p>The adults’ mean rejection rate (Y-axis) as a function of the morph level (X-axis) for the Asian-parent (black circles) and the Caucasian-parent condition (white circles). The rejection rate is the probability of judging the comparison face as “different” from the target face (i.e., the same as the <i>P</i>(diff) in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0195020#pone.0195020.t001" target="_blank">Table 1</a>). The morph level denotes the physical difference (in linear unit) between the target parent face and the comparison face.</p

The group mean probability of judging the comparison faces as “different” (<i>P</i>(diff)) at the 5 morph levels and the computation using the signal detection theory (showing correct rejections, false alarms, misses, hits, and d primes) for the Asian-parent and Caucasian-parent conditions in children and adults.

<p>The numbers in the parenthesis denote the standard errors (SE) of the group means.</p