Working Memory Relates to Second Language American Sign Language Comprehension in Deaf Adults, But First Language...

This study examined relationships among English reading comprehension, nonverbal working memory, and American Sign Language (ASL) receptive comprehension in prelingually deaf adults who acquired English as an early first language (L1) and learned ASL as a second language (L2) after childhood.

Participants (N = 74) were prelingually deaf adults who acquired English early (age of acquisition ≤ 3 years) and learned ASL later in life (mean age of ASL acquisition = 18.3 years, range: 14-30). Measures included English reading comprehension (Peabody Individual Achievement Test-Revised), nonverbal working memory (backward Corsi), and ASL receptive comprehension (ASL Comprehension Test).

Reading skills were strong, but ASL skills were highly variable. English reading comprehension and age of ASL acquisition were not significantly associated with ASL receptive comprehension. Nonverbal working memory was positively and significantly associated with ASL receptive comprehension and showed an association with English reading comprehension, but only when four participants who completed the Corsi in forward order were included.

Results indicate that for deaf L2 signers, strong English reading skills do not guarantee strong ASL receptive outcomes. Differences in when ASL learning began after childhood did not explain variability in ASL skills. Nonverbal working memory may contribute to language outcomes across modalities, although its role appears clearer for L2 ASL than for L1 English. These findings complicate accounts of L2 learning that assume a direct relationship between L1 and L2 proficiency. Delaying early exposure to accessible language input may pose risks for optimal L2 sign language outcomes in deaf populations.