Fingerspelling occurs frequently in American Sign Language (ASL) and is integral to the lexicon. In a single letter unmasked priming paradigm, we investigated whether fingerspelling fonts and English letters have similar abstract representations and a similar time course of processing. We examined the priming effects between fingerspelled letter fonts, English letters, and across the two systems. Event-related brain potentials (ERPs) were recorded over 29 scalp sites while deaf signers performed a probe detection task (detect the printed or fingerspelled letter Y, 12% of trials). Targets were 23 single letters presented in a typical printed English font or in an ASL fingerspelling font, tested in separate blocks, and presented centrally for 200ms immediately preceded by a clearly visible 100ms prime that was either an English letter or fingerspelled font.
Eighteen deaf ASL signers participated in the study. Both English letters and fingerspelling fonts clearly primed English letter targets, indicating that both prime types pre-activated English letter representations. When fingerspelling targets were preceded by letter primes, there was a smaller difference between related and unrelated pairs suggesting that fingerspelling representations may only weakly pre-activate English letter primes. Recoding English letters into fingerspelling for reading might be inefficient. This result is consistent with a previous study showing that printed words were not recoded into fingerspelling in short-term memory tasks (Sehyr et al. 2017).
In regard to the priming of abstract letter representations, only letter-to-letter pairs showed a pattern of priming similar to Petit et al. where related pairs elicited less positive-going waveform than unrelated pairs between 200-300ms. Thus, it appears that abstract ASL fingerspelling and English letter representations are processed differently. A priming effect also emerged at ~250ms whose polarity was consistent with classic repetition effects on the N400 where related pairs elicited less negative-going waveforms than unrelated pairs. We speculate that this effect might reflect strategic access to lexical names of letters triggered by the presence of fingerspelling. Alternatively, this effect might be due to our detection task and the supraliminal character of the primes (i.e., participants covertly named the letter stimuli), or the priming effect arises as a result of more general differences in letter processing between deaf and hearing readers. We addressed the last possibility in a follow-up experiment where we examined priming effects for only the letter-to-letter pairs with 19 hearing English speakers. Preliminary results reveal that English speakers exhibit priming effects for letter-to-letter pairs that are similar to the deaf signers in the original study, thus eliminating the possibility that the priming effect was due to group specific factors.
*This project is generously supported by NIH and Dr. Emmorey's LLCN lab. Data collection for this project is ongoing and preliminary data will be presented at the Society for the Neurobiology Conference (SNL) 10th Annual Meeting in Quebec, August 16-18, 2018.
Sehyr, Sevcikova Z., Renna, J., Osmond, S., Midgley, K. J., Holcomb, P. J., & Emmorey, K. (2018) Priming effects between fingerspelled fonts and printed letters. Poster presented at the Society for the Neurobiology Conference (SNL) 10th Annual Meeting in Quebec, August 16-18, 2018. Zed Sehyr is supported by the SNL 2018 Travel Award www.neurolang.org/2018/2018-award-winners/