Shimizu, Y.(志水勇之進), Ogawa, K.(小川一美), Kimura, M.(木村昌紀), Fujiwara, K.(藤原 健), & Watanabe, N. (2024).
The influence of emotional facial expression intensity on decoding accuracy: High intensity does not yield high accuracy.
表情における感情表出の強度が解読の正確さに及ぼす影響：強度が高くなっても解読の正確さは高まらない
Japanese Psychological Research, 66(4).
https://onlinelibrary.wiley.com/doi/10.1111/jpr.12529
This study examined the relationship between the intensity of emotional expressions in facial stimuli and receivers’ decoding accuracy for six basic emotions: anger, disgust, fear, happiness, sadness, and surprise. A laboratory experiment was conducted using the forced-choice method, in which the intensity of each stimulus was manipulated at every 10% interval using the morphing technique. To explore whether a linear relationship would be observed when the intensity was finely manipulated at 10% intervals, a hierarchical multiple regression analysis was performed. The mean percentage of correct responses for each stimulus was the dependent variable, and the linear, quadratic, and cubic terms of the stimulus intensity were the independent variables. The results showed that the linear model was not adopted as the final model for all facial expressions; that is, the effect of the squared term of intensity was significant for anger, disgust, fear, and sadness, while the effect of the cubic term of intensity was significant for happiness and surprise. Our findings indicate that a higher intensity of emotional expression does not yield higher decoding accuracy.
・怒り，嫌悪，恐れ，喜び，悲しみ，驚きの6つの基本感情について，表情刺激における感情表出の強度と受け手の解読の正確さとの関係を検討した。
・各刺激の強度はモーフィングを用いて, 0 (中立表情)～100%の10％間隔で操作した。
・各刺激の平均正答率を従属変数，刺激の強度の線形項，2乗項，3乗項を独立変数として表情カテゴリーごとに階層的重回帰分析を行った。
・怒り，嫌悪，恐れ，悲しみでは強度の2乗項の効果が有意であり，喜びと驚きでは強度の3乗項の効果が有意であった。
以上より，感情表出の強度が高いほど解読の正確さが線形的に高まるわけではないことが明らかになった。