The schema effect in children: the neuronal mechanism of memory facilitation via prior knowledge

Prior knowledge (schemas) facilitates learning and consolidation (Bartlett
1932, Craik & Lockhart 1971): During encoding new related material can be
linked to already consolidated memories. This process is thought to be mediated
by the mPFC (Tse et al. 2007, van Kesteren 2010): during encoding or retrieval
of unrelated items the hippocampus shows increased activity whereas for
schema-related items the mPFC gets activated (Van Kesteren 2012).

With the PFC only maturing at the end of adolescence (Gogtay et al 2004, Shaw
et al. 2008) it is unclear whether children already use their prior knowledge
as efficiently as adults. Parallel to the time of the maturation of the mPFC
children acquire vast amounts of semantically-related material in high school
where exactly this capability would be extremely useful.

Compared to children adults show more detailed memories and are in general
better in memory tasks (Ofen et al. 2007, Ghetti et al. 2010). The improvement
in memory details is linked to changes in the PFC (Ofen et al. 2007) and MTL
(Ghetti et al. 2010) whereas the general improvement is hypothesized to be
linked to the increased use of strategies and the maturation of the dlPFC
(Craik & Tulving 1975, Kapur et al. 1994, Shing et al. 2008, Maril et al.
2011).

Already young children use semantic information to facilitate consolidation of
newly learned words (Henderson et al. 2013): Five to nine year old children
learned words either coupled to information about its form or its meaning.
Immediately after learning there was no difference between the two groups,
after a week however the words coupled with semantic information were better
integrated indicated by an increase in lexical competition. This suggests that
already young children can use semantic information to facilitate
consolidation. Different to prior schemas the semantic information was coupled
to the word during encoding. Furthermore, children show different activation
patterns for shallow versus deep encoding compared to adults (McAuley 2007).
How children and young adolescents use the mPFC to benefit from prior knowledge
is not known. Recent work has also shown that children are better at converting
implicit to explicit knowledge during sleep (Wilhelm et al. 2013). Children and
adults implicitly learned motor sequences. After sleep children showed a higher
explicit memory of the sequence compared to adults. This could indicate that
the children are faster at building a sequence-schema.

The aim of the study is to examine learning induced changes in brain and
behavior.

The proposed study has a multi-session within-subject design. Participants will
learn object-location associations while playing a *Memory* game on a computer.
Over multiple sessions they have to learn locations of 100 items for two boards
of cards. For one board the card positions switch between the sessions for the
other board positions are constant enabling the formation of a schema. Four
days after the last learning session the children perform a cued-recall task in
the MRI scanner to test the differences in integration for the schema vs. non
schema items.

There are no risks associated with participating in this study. The burden of
the study mostly comes from the time the task takes, however we expect the task
to be engaging and enjoyable for the children. The outcome will increase
understanding of brain and behaviour and may lead to advances in education and
practice. Participants will not benefit from participating in the study.