MARC 主機 00000nam a2200349 4500
001 AAI10117225
005 20161128143928.5
008 161128s2016 ||||||||s|||||||| ||eng d
020 9781339786285
035 (MiAaPQ)AAI10117225
040 MiAaPQ|cMiAaPQ
100 1 Krizman, Jennifer
245 10 Influence of Second Language Experience on Auditory
Processing in Adolescents: Consequences for Real-World
Listening
300 202 p
500 Source: Dissertation Abstracts International, Volume: 77-
10(E), Section: B
500 Adviser: Nina Kraus
502 Thesis (Ph.D.)--Northwestern University, 2016
520 The sounds of our lives, including the sounds of our
language, serve as a training ground that engenders neural
plasticity. Experience with more than one language
facilitates plasticity beyond that seen in monolinguals,
shaping cognitive processes that support juggling two
languages in one mind, with the most notable enhancement
seen for focusing on relevant, and ignoring irrelevant,
information, a process known as inhibitory control. During
communication, cognitive and sensory systems interact,
making it unlikely that this additional bilingual
plasticity is merely within the purview of cognitive
systems, but rather is evident in sensory systems as well.
This dissertation is built on the hypothesis, tested
across five studies, that bilingualism is a form of
enrichment that induces plasticity in those auditory
processes that interact with cognitive function during
real-world communication. The first two studies, which
tested subcortical evoked responses in adolescents, asked
if bilinguals and monolinguals differed in their sensory
encoding. Bilinguals had larger responses to the pitch of
speech syllables that tracked with their greater
inhibitory control abilities. The third study asked
whether bilingual experience drives these sensory
enhancements. Subcortical pitch encoding was found to be
stronger in children who had more bilingual experience,
suggesting this plasticity resulted from experience rather
than pre-existing differences. Though these three studies
used speech syllables that lacked the complexity of real-
world communication, the studies confirm bilingual
auditory-processing enhancements and establish their
tethering to cognitive processes important for
communication. Interestingly, while these findings
highlight the potential for bilingual plasticity to
facilitate real-world listening, previous literature has
found bilinguals to struggle in this realm relative to
monolinguals. To understand the interplay between
cognitive-sensory advantages and real-world listening
disadvantages, the next study compared bilingual and
monolingual adolescents on listening-in-noise tests that
differed in linguistic complexity. Bilinguals showed an
advantage when the targets were tones; monolinguals
outperformed bilinguals when stimuli were sentences. The
observed performance shift highlights how bilingual
experience can engender plasticity that leads to both
advantages and disadvantages, which presumably has
consequences for real-world communication. Identification
of these consequences was the goal of the final study.
Auditory selective attention, a fundamental part of
everyday communication, involves the very processes found
to be enhanced in bilinguals. Bilinguals and monolinguals
were compared on this task to yield insights into the
consequences of bilingual plasticity for real-world
listening. Bilinguals and monolinguals did not differ in
performance. Additionally, both bilinguals and
monolinguals showed an attention effect on neural
processing, in which cortical responses during active
listening increased while subcortical responses decreased.
However, there were differences in the neural and
cognitive processes engaged to complete the task.
Consistent with the first study, bilinguals showed greater
subcortical encoding of the pitch of the stimuli. They
also used inhibitory control to complete this task, as
evidenced by a correlation between their inhibitory
control abilities and task performance. From these results,
we suggest that bilingualism enhances both cognitive and
sensory processes important for real-world listening.
Furthermore, this series of studies demonstrates that the
bilingual cannot be thought of as the sum of two
monolinguals, but rather as a mental juggler of two
languages that results in unique obstacles and distinct
neuroplasticity
590 School code: 0163
650 4 Neurosciences
650 4 Psychobiology
650 4 Physiology
690 0317
690 0349
690 0719
710 2 Northwestern University.|bCommunication Sciences and
Disorders
773 0 |tDissertation Abstracts International|g77-10B(E)
856 40 |uhttps://pqdd.sinica.edu.tw/twdaoapp/servlet/
advanced?query=10117225
912 PQDT
