PROJECT SUMMARY
There are lifelong challenges faced by adults with (Specific) Language Impairment (LI), a common
learning disability that affects 7% of the US population (Tomblin et al., 1997). Despite documented difficulties in
educational attainment, vocational outcome, and legal standing for adults with LI (Bryan et al., 2007; Conti-
Ramsden et al.,2009; Johnson et al.,2010), research on adults with LI have been all but been ignored in the
literature. As a result, we know very little about the barriers to educational and vocational attainment faced by
young adults with LI, such as the potential impairment in learning and memory.
Our recent work has found that, following perceptual training on new (nonnative) acoustic-phonetic
information, sleep facilitates improved perceptual ability in adults with typical language, but not in adults with a
history of LI. How memory consolidation in perceptual learning relates to broader memory encoding in LI is not
yet clear. To this end, we aim to establish how performance on these tasks inform relative strengths and
weaknesses in well-understood memory systems: specifically, procedural and declarative memory. Furthermore,
we must understand the neural mechanism underlying this observed behavioral failure in offline consolidation.
Therefore, the research outlined in this proposal seeks to determine the association between perceptual
learning and declarative and procedural memory, and to identify the neural mechanism underlying the
behavioral phenomenon of consolidation failure in LI. Our aims will be addressed by combining behavioral
data in established procedural and declarative learning tasks with our perceptual learning task. We will also
extend our behavioral protocol on perceptual learning to investigate neural processing of trained speech sounds
before and after sleep using functional magnetic resonance imaging (fMRI) techniques. The knowledge to be
gained through this research will inform the time course of memory consolidation in individuals with LI, and inform
the cognitive substrates of speech sound acquisition in adulthood more broadly. Furthermore, by defining a
potentially critical obstacle to achievement, this knowledge may contribute to improving remediation outcomes
for young adults with this common developmental disability. The knowledge to be gained through the proposed
project will contribute to four areas of research: (Specific) Language Impairment, speech perception, second
language learning, and memory consolidation.
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