School of Psychology, University of Sussex, Brighton, UK; Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK.
Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK; School of Engineering and Informatics, University of Sussex, Brighton, UK.
Cortex. 2021 Jun;139:249-266. doi: 10.1016/j.cortex.2021.02.031. Epub 2021 Mar 26.
People with synaesthesia have been reported to show atypical electrophysiological responses to certain simple sensory stimuli, even if these stimuli are not inducers of synaesthesia. However, it is unclear whether this constitutes a neural marker that is relatively specific to synaesthesia or whether it reflects some other trait that co-occurs with synaesthesia, but is not specific to it. One candidate is atypical sensory sensitivity (e.g., strong aversion to certain lights and sounds, 'sensory overload') which is a feature of both synaesthesia and autism and that varies greatly in the neurotypical population. Using visual evoked-potentials (to stimuli varying in spatial frequency) and auditory-evoked potentials (to stimuli varying in auditory frequency), we found that synaesthetes had a modulated visual evoked-potential around P1/N1 (emanating from fusiform cortex), a greater auditory N1, as well as differences in the time-frequency domain (increased alpha and beta induced power for visual stimuli). This was distinct from that found in non-synaesthetes. By contrast, no significant electrophysiological differences were found that were linked to neurotypical variation in sensory sensitivity.
有人报告称，联觉者对某些简单的感官刺激会表现出非典型的电生理反应，即使这些刺激不是引发联觉的诱因。然而，目前尚不清楚这是否构成了一个相对特异于联觉的神经标记，还是反映了与联觉共同发生但并非特异于联觉的其他特征。一个候选特征是感觉敏感性异常（例如，对某些光和声强烈反感，“感觉过载”），这是联觉和自闭症的共同特征，并且在神经典型人群中差异很大。我们使用视觉诱发电位（针对空间频率变化的刺激）和听觉诱发电位（针对听觉频率变化的刺激），发现联觉者在 P1/N1 周围（从中梭状回发出）有调制的视觉诱发电位，听觉 N1 更大，以及时频域的差异（对视觉刺激的 alpha 和 beta 诱导功率增加）。这与非联觉者的发现明显不同。相比之下，没有发现与神经典型感觉敏感性变化相关的显著电生理差异。
