Consistency of synesthetic associations over time is a widely used test of synesthesia. Since many studies suggest that consistency is not a completely reliable feature, we compared the consistency and strength of synesthetes' grapheme-color associations. Consistency was measured by scores on the Synesthesia Battery and by the Euclidean distance in color space for the specific graphemes tested for each participant. Strength was measured by congruency magnitudes on the Implicit Association Test. The strength of associations was substantially greater for synesthetes than non-synesthetes, suggesting that this is a novel, objective marker of synesthesia. Although, intuitively, strong associations should also be consistent, consistency and strength were uncorrelated, indicating that they are likely independent, at least for grapheme-color synesthesia. These findings have implications for our understanding of synesthesia and for estimates of its prevalence since synesthetes who experience strong, but inconsistent, associations may not be identified by tests that focus solely on consistency.

中文翻译：

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字素-颜色关联的一致性和强度是联觉体验的可分离方面。

随着时间的推移，联觉关联的一致性是一种广泛使用的联觉测试。由于许多研究表明一致性不是一个完全可靠的特征，我们比较了联觉者的字素-颜色关联的一致性和强度。一致性是通过联觉电池的分数和颜色空间中的欧几里得距离来衡量的，用于为每个参与者测试的特定字素。强度是通过隐式关联测试中的一致性大小来衡量的。联觉者的关联强度明显大于非联觉者，这表明这是一种新颖的、客观的联觉标记。虽然，直觉上，强关联也应该是一致的，但一致性和强度是不相关的，表明它们很可能是独立的，至少对于字形颜色联觉。这些发现对我们对联觉的理解和对其流行率的估计具有重要意义，因为那些经历强烈但不一致的关联的联觉者可能无法通过仅关注一致性的测试来识别。