University of Michigan, USA.
University of Michigan, USA.
Cortex. 2019 Aug;117:89-95. doi: 10.1016/j.cortex.2019.02.025. Epub 2019 Mar 6.
Synesthesia is an atypical perceptual phenomenon that has been associated with generalized differences in other cognitive and perceptual domains. Given similarities in the qualitative nature of synesthetic experiences to visual imagery perceptions, several studies have sought to examine whether synesthetes demonstrate increased visual imagery abilities. Using subjective imagery questionnaires, some studies have identified superior imaging abilities in synesthetes, while others have not. However, because most research on synesthesia uses un-blinded group membership prior to data collection, such methods for studying group differences may be prone to participant and experimenter biases (e.g., a motivated synesthete may rate themselves as having stronger visual imagery abilities due to their own bias and perceived experimenter expectations). To address this issue, we demonstrate the feasibility of double-blind designs in synesthesia research, applied here to examine differences in subjectively reported levels of imagery usage and intensity. Prior to identifying synesthetes' and non-synesthetes' group membership (in order to eliminate the potential for bias), subjects completed two common measures of visual imagery experiences. Using this approach, we replicated findings of greater visual imagery usage in synesthetes on the Spontaneous Use of Imagery Scale (SUIS) measure, but not of enhanced imagery abilities on the standardized Vividness of Visual Imagery Questionnaire (VVIQ) measure. The present study strengthens prior evidence that synesthesia is associated with heightened visual imagery and demonstrates the utility of double-blind designs in order to limit biases and promote further replicability of other findings in research on synesthesia.
联觉是一种非典型的知觉现象，与其他认知和知觉领域的普遍差异有关。鉴于联觉体验与视觉意象感知在性质上的相似性，有几项研究试图研究联觉者是否表现出增强的视觉意象能力。使用主观意象问卷，一些研究发现联觉者具有优越的成像能力，而另一些研究则没有。然而，由于大多数关于联觉的研究在收集数据之前就使用非盲组成员，因此研究组间差异的方法可能容易受到参与者和实验者偏见的影响（例如，由于自己的偏见和感知到的实验者期望，有动机的联觉者可能会认为自己具有更强的视觉意象能力）。为了解决这个问题，我们展示了在联觉研究中使用双盲设计的可行性，这里应用这种方法来检查主观报告的意象使用和强度水平的差异。在确定联觉者和非联觉者的群体成员身份之前（为了消除偏见的可能性），受试者完成了两个常见的视觉意象体验测量。使用这种方法，我们在自发性意象使用量表（SUIS）测量上复制了联觉者具有更大视觉意象使用的发现，但在标准化视觉意象生动性问卷（VVIQ）测量上没有发现增强的意象能力的发现。本研究加强了先前的证据，即联觉与增强的视觉意象有关，并展示了双盲设计的实用性，以限制偏见并促进在联觉研究中其他发现的进一步可重复性。
