| 摘要: | 他種族效應（other-race effect, ORE）是指辨識自己種族臉孔的能力優於辨識其他種族臉孔的現象。近年Walker & Tanaka （2003）曾提出他種族效應很可能是早在知覺登錄的時候就已經產生了差異，導致個體對於自身種族臉孔間與對非自身種族臉孔間的辨識能力有非常明顯的差異，在此稱之為「本種族效應的知覺登錄優勢假說」。
他種族效應早在知覺登錄階段就已有所分別，導致個體對於本種族與他種族臉孔的辨識表現有明顯差異。此假說尚未在亞洲國家獲得佐證，因此，本研究將以Walker & Tanaka 的變形臉孔典範來測試學齡期兒童和成人對於亞洲人及白種人無外輪廓的各種臉孔變形比例的辨識能力，讓受試者依序觀看兩張照片，第一張是100%亞洲人(亞洲人母片)或100%白人(白人母片)，第二張則可能與前一張相同，也可能是不同比例的變形臉孔；另外本研究還採用了新的作業-『卡片排序作業』來測量學齡期兒童對於臉孔細微變化的能力。實驗一以黑白無外廓訊息的女性亞洲人及女性白種人等比例變形臉孔圖像(Morphed faces)（0%,15%, 30%, 45%, 60%），測試24名中國醫藥大學大學生。實驗二以相仿的臉孔刺激，測試6-12歲學齡期兒童區辨臉孔細微變化的能力，在做完主作業之後，會接著做『卡片排序作業』。同樣的這些卡片也是以黑白無外廓訊息的男性亞洲人及男性白種人以10%為間距之等比例變形臉孔圖像共計8張，兒童需要將這些卡片按照順序排列到對的位置。
我們發現在變形臉孔辨認作業中，大學生在辨認亞洲人臉孔均顯示出優異的區辨能力，且在亞洲人情境有比白人情境更高的辨識能力，只需要23%的變形就能達到0.5拒絕率，在白人情境則需要約29%的變形比例。兒童實驗結果發現，在5-6歲及7-8歲組未見在亞洲人情境與白人情境下的表現差異，這樣的差異直到9-10歲才出現，11-12歲時變大。大抵而言，臉孔辨認作業隨年齡增長而逐漸接近成人水準,值得注意的是，兩個情境差異變大的原因是來自本種族臉孔辨認能力的顯著進步，而白人臉孔的辨認能力則進步緩慢。卡片排序作業亦得到類似隨年齡增長表現也會進步的趨勢。5-6歲和7-8歲組的兒童在排序白種人情境和亞洲人變形臉孔情境沒有差異；9-10歲組在辨認亞洲人變形臉孔情境已顯著優於白種人情境，11-12歲組則辨認亞洲人臉孔的能力更加進步，而且辨認白種人臉孔也有進步，只是進步幅度較小。簡言之，本研究成人結果支持本種族臉孔的知覺登錄優勢假說，而兒童研究則發現需到大約9歲才支持本種族臉孔的知覺登錄優勢假說。
The other-race effect (ORE) refers to better recognition for faces of one’s own race than faces of other unfamiliar races. The present study extended Walker and Tanaka (2003)’s approach to examine the encoding advantage hypothesis in 6- to 12-year-old school-aged Taiwanese children and a group of adults as a comparison. The participants were to perform a same/different face discrimination task. In addition, the present study introduced a novel “card-ordering task” to a subgroup in the Children Experiment. In the same/ different face discrimination task, participant viewed an Asian or Caucasian parent face for 1 s, followed by either the same parent face or a different morphed face with equal probability. In the “different” trials, the Asian (or Caucasian) parent face was followed by a morphed face consisting of 0%, 15%, 30%, 45%, 60% contribution from that parent face and the remaining percent contribution morphed from the Caucasian (or Asian) parent face. In the “card-ordering task”, children were ask to order the 8 printed photos created using the morph face paradigm with a 10% increment of morph level to the right position.
As predicted, the adults exhibited a smaller discrimination threshold and a sharper slope in the Asian condition, supporting the encoding advantage hypothesis. In the face discrimination task, the 5-6 year-olds and 7-8 year-olds did not differ in rejection rates at each morph level across the two race conditions. The 9-10 year-old group started to show a marginally higher rejection rates in the Asian-parent than in the Caucasian-parent condition at the morph level 30%. In the 11-12 year-old group, the difference continued to enlarge at the morph level 30%. Similarly in the card ordering task, the younger groups (aged 5-8) still not exhibit own-race advantage yet; it seems to be emerge around 9-10 as they can better sort the cards in order in Asian-parent condition than in Caucasian-parent condition. For group aged 11-12, they performed better in the Asian- than the Caucasian-parent condition, yet their performance in the Caucasian-parent condition was also slightly improved but not as prominent as in the Asian-parent condition. In sum, the results of the adult experiment demonstrated an encoding advantage for own-race faces; meanwhile, the results of school-age children suggested that such an advantage may emerge from the age of 9. Nevertheless, the ability to discriminate among faces generally improved from age 6 to 12, with more pronounced progress in the own-race condition. |
