Sehyr Zed Sevcikova, Midgley Katherine J, Emmorey Karen, Holcomb Phillip J
San Diego State University Research Foundation, San Diego State University, San Diego, CA, USA.
School of Speech, Language, and Hearing Sciences, San Diego State University, San Diego, CA, USA.
Neurobiol Lang (Camb). 2023 Jun 13;4(2):361-381. doi: 10.1162/nol_a_00104. eCollection 2023.
Letter recognition plays an important role in reading and follows different phases of processing, from early visual feature detection to the access of abstract letter representations. Deaf ASL-English bilinguals experience orthography in two forms: English letters and fingerspelling. However, the neurobiological nature of fingerspelling representations, and the relationship between the two orthographies, remains unexplored. We examined the temporal dynamics of single English letter and ASL fingerspelling font processing in an unmasked priming paradigm with centrally presented targets for 200 ms preceded by 100 ms primes. Event-related brain potentials were recorded while participants performed a probe detection task. Experiment 1 examined English letter-to-letter priming in deaf signers and hearing non-signers. We found that English letter recognition is similar for deaf and hearing readers, extending previous findings with hearing readers to unmasked presentations. Experiment 2 examined priming effects between English letters and ASL fingerspelling fonts in deaf signers only. We found that fingerspelling fonts primed both fingerspelling fonts and English letters, but English letters did not prime fingerspelling fonts, indicating a priming asymmetry between letters and fingerspelling fonts. We also found an N400-like priming effect when the primes were fingerspelling fonts which might reflect strategic access to the lexical names of letters. The studies suggest that deaf ASL-English bilinguals process English letters and ASL fingerspelling differently and that the two systems may have distinct neural representations. However, the fact that fingerspelling fonts can prime English letters suggests that the two orthographies may share abstract representations to some extent.
字母识别在阅读中起着重要作用，并遵循从早期视觉特征检测到抽象字母表征提取的不同处理阶段。失聪的美国手语 - 英语双语者以两种形式体验正字法：英语字母和手指拼写。然而，手指拼写表征的神经生物学本质以及这两种正字法之间的关系仍未得到探索。我们在一个无掩蔽启动范式中研究了单个英语字母和美国手语手指拼写字体处理的时间动态，其中中央呈现的目标持续200毫秒，之前有100毫秒的启动刺激。在参与者执行探测检测任务时记录事件相关脑电位。实验1研究了失聪手语者和听力正常的非手语者中英语字母到字母的启动效应。我们发现，失聪读者和听力正常读者的英语字母识别相似，将之前对听力正常读者的研究结果扩展到了无掩蔽呈现。实验2仅在失聪手语者中研究了英语字母和美国手语手指拼写字体之间的启动效应。我们发现手指拼写字体启动了手指拼写字体和英语字母，但英语字母没有启动手指拼写字体，这表明字母和手指拼写字体之间存在启动不对称性。当启动刺激是手指拼写字体时，我们还发现了类似N400的启动效应，这可能反映了对字母词汇名称的策略性提取。这些研究表明，失聪的美国手语 - 英语双语者对英语字母和美国手语手指拼写的处理方式不同，并且这两个系统可能具有不同的神经表征。然而，手指拼写字体可以启动英语字母这一事实表明，这两种正字法可能在一定程度上共享抽象表征。
