Developmental changes in the neural correlates for artificial grammar learning

Children start qcquiring their mother tongue early in life by being exposed to
speech, imitating speech sounds and finally by cracking the code of syntax.
During the course of childhood the development of their mother tongue
continous. When, however, a child is not exposed to adult speech, for example
in case of deafness, this child will not fully acquire its first language.
Observation that first language acquisition after puberty becomes increasingly
problematic have led to the hypothesis of a sensitive period for language
acquisition. Because most language acquisition studies focus on infants and is
in most cases not compared to adult language studies, little is known about how
neural processes related to language acquisition differ between children and
adults.

Primary Objective: The primary objective of this study is to understand to
which degree the language system of pre-pubertal children is still plastic
compared to adults and which brain areas are recruited by these groups when
learning an artificial grammar from mere exposure.

Secondary Objective(s):
The goals of the current study are twofold. We will use functional Magnetic
Resonance Imaging (fMRI) to:
1. Identify brain regions that are associated experience-dependent plasticity
during artificial grammar learning.
2. Establish to which extent the involvement of these brain areas is
influenced, in a quantitative as well as qualitative way, by both age and the
level to which new language structures can be learned from mere exposure.

This study is designed as a cross-sectional study comparing two groups: adults
and children. In this study language learning and experience-dependent
plasticity in the language domain during childhood and in adulthood will be
tested using an artificial grammar learning paradigm in Dutch monolingual
speaking children and adults. Participants will be exposed auditorily to an
artificial grammar containing abstract syntactic patterns. After this exposure
phase, participants will be tested on their ability to extract the syntactic
pattern from the speech stream. During the task, fMRI data will be obtained in
order to identify brain areas involved in the acquisition of new linguistic
structure during artificial language exposure in adults and children.

Behavioral testing: There are no risks associated with behavioral testing
except the occasional possibility of some frustration with poor performance or
fatigue. There will be breaks between tests in order to allow participants to
rest and prevent poor performance due to fatigue. Testing will stop if a
subject displays frustration or appears tired.

FMRI testing: There are no known risks associated with participating in an fMRI
study. This is a noninvasive technique involving no catheterizations or
introduction of exogenous tracers. Numerous human subjects have undergone
magnetic resonance studies without apparent harmful consequences.
Radiofrequency power levels and gradient switching times used in these studies
are within the FDA approved ranges. Some people become claustrophobic while
inside the scanner and in these cases the study will be terminated immediately
at the subject's request. The only absolute contraindications to MRI studies
are the presence of intracranial or intraocular metal, or a pacemaker. Relative
contraindications include pregnancy and claustrophobia. Subjects who may be
pregnant, who may have metallic foreign bodies in the eyes or head, or who have
cardiac pacemakers will be excluded because of potential contraindications of
MRI in such subjects.

Potential Benefits of the Proposed Research to the Participants and Others:
Although there is no direct benefit to the participants from this proposed
research, there are greater benefits to society from the potential knowledge
gained from this study, as described in the next section.