Exploration of implicit and explicit learning of a handwriting task in children born very preterm

Motor skills can be learned implicitly and explicitly. Implicit learning is the
ability to acquire a new skill by doing it unaware of the regularities
governing the task. The procedural knowledge gained is difficult or even
impossible to access consciously and has been shown to be relatively
independent of both age (Meulemans et al., 1998) and IQ (Reber et al., 1991).
In explicit learning, on the other hand, declarative knowledge is used to build
up a set of performance rules that guides motor output. Berry and Broadbent
(1988) demonstrated that the application of declarative knowledge requires the
availability of working memory, whereas, the application of procedural
knowledge does not.
Ample studies on implicit and explicit learning in neurologically intact
individuals have assumed that explicit learning may only proceed with intact
working memory (Maxwell et al., 2003). In the proposed project, we will examine
motor learning in preterm children. There are only few studies on motor
learning in preterm born babies (Jongbloed-Pereboom et al., 2012). At school
age, this has not been investigated yet, while we know that these children are
highly at risk to develop motor performance and learning problems (De Kieviet
et al., 2009; De Kleine et al., 2006). These children are also likely to
develop working memory deficits, despite the absence of known neurological
disorders (Aarnoudse-Moens et al., 2009; Jongbloed-Pereboom et al., 2012).
Our previous study, is the first study in which motor learning is tested at
school age in children born very preterm, and in which the influence of working
memory on motor learning is tested directly (Jongbloed-Pereboom et al., in
prep). In our previous study, we examined implicit and explicit learning of a
simple motor task. We did not find differences between groups (children born
very preterm and controls) in learning, although working memory scores were
significantly lower in children born very preterm. We did found a more general
positive relation between working memory and learning, although this was not
different for implicit and explicit learning. In our previous study, we
included children based on the motor performance score. This made it difficult
to include enough children. Furthermore, at the moment children do not com to
the follow-up clinic at the age of 5 years. Data of motor performance are
therefore not available. In this new study, we have chosen to not use their
motor performance score as an inclusion, but take motor performance into
account as a covariate in the analysis. In other, similar, studies, we found
that attention also is an important covariate in the learning process, in the
present study we therefore also want to examine the role of attention.
In this study, we want to investigate if children born very preterm do differ
form controls when learning a fine motor relevant in childrens' daily life, a
writing task. It is known that children born preterm have difficulties in
writing (e.g. Feder et al., 2005, Guarini et al. 2012). We expect that the
writing task will be more sensitive for differences in implicit and explicit
learning, and that effects of working memory and attention will be more
pronounced. This task could give us more insight in the learning mechanisms,
and in time these insights can be used to develop therapies or educational
methods.

The first aim of this study is to examine differences in implicit and explicit
learning in children born very preterm.

The second aim is to test the alleged role of working memory and attention on
(explicit) motor skill learning in preterm children examine the relation
between implicit and explicit learning in preterms. This is especially
relevant, as the potential mediating role of explicit working memory for this
interaction can be unveiled. Specifically, if working memory is indeed an
important factor mediating the (as facilitator or inhibitor) interaction
effects found in previous studies, we do not expect such effects in the group
preterms with profound working memory deficits. Finding such an absence of
interference in preterms with deficits in working memory allows us to draw more
specific inferences related to cognitive substructure of motor learning.

The third aim of this study is to measure how often motor problems co occur
with working memory problems.

The fourth aim of the proposed project is to examine the relation between
implicit and explicit learning in preterm born children compared to term born
healthy peers. These peers have already been tested as part of a bigger project
on implicit and explicit motor learning in children (project approved by the
ethical committee of the faculty of Social Sciences).

An experimental design with 5-10 year old children born very preterm. Implicit
and explicit motor learning will both be tested with a modified version of a
serial response time task (SRTT). In this writing task, children will learn to
write abstract patterns that have characteristics of letter writing (making
loops, stopping). This task will be assessed with a digitizer and is based on a
task by Overvelde and Hulstijn (2011). The SRT task is probably the most robust
paradigm to study implicit and explicit learning, and is already successfully
applied in typically developing children and clinical groups.
In the basic set-up of the SRT tasks the participant is required to react as
quickly as possible to stimuli that are displayed on the computer monitor by
moving the pen to the corresponding location on the digitizing tablet. In the
implicit learning trials, children are instructed to follow a yellow moving
target with their pen (their pen is visualized on the screen by a small blue
dot). This yellow moving target moves along the abstract pattern, the pattern
itself is not shown, neither is the pen trace shown on screen.

For the explicit trials, the pattern is shown on screen. Participants are
instructed to write the pattern as good and as quickly as possible. As soon as
the children start to write, the pattern disappears. During writing,
participants see their pen position and pen trace. At the end of a trial, the
written pattern will be shown above the example. This way, children receive
feedback on their results.
The implicit and explicit conditions both have 25 training trials. After
training, there is a short break, in which children play a game with the
assessor. After the break there is for each condition a 10 trial posttest and a
10 trial transfer test. In the posttest, children only see the start and end
position in each trial, when writing they see their pen position and pen trace.
Children are instructed to write the learned pattern as good and as quickly as
possible. The instructions for the transfer test are similar to the posttest,
but children will write with their non dominant hand. Half of the children will
start in the implicit condition, and half of the children will start in the
explicit condition. Different patterns are used per condition with similar
characteristics and length (counterbalanced design).

Several background measures will be assessed, including a short intelligence
test (Wechsler Non Verbal NL)(Wechsler & Naglieri, 2008). Working memory will
be assessed with two subtest of the Automated Working Memory Assessment
(AWMA)(Alloway, 2007), one to test verbal working memory and one to test visual
working memory. Attention will be tested with the Bourdon-Vos Test (Vos, 1998).
Motor skills will be tested with the Movement Assessment Battery for Children
(MABC 2-NL)(Henderson et al., 2010).

Parents fill in some questionnaires. For executive functioning of the children,
parents fill in the questions of the working memory subscale of the Dutch
version of the Behavior Rating inventory of Executive Functioning
(BRIEF)(Huizinga & Smidts, 2012). For motor problems in daily life, a screening
questionnaire for developmental coordination disorder (DCD) is assessed, the
DCD Q (Schoemaker et al., 2006). Parents also fill in a questionnaire about
general health of their child and school functioning.

The tasks are not burdensome and are not risk associated, task are age
appropriate and children like to learn such computer tasks. All tasks can be
assessed in one session. This session will be maximally 2.5 hours, in which
time is reserved for breaks between tasks.
For the parents of the children some burden is present because at this age
they have to transport them or to reserve time in their own time schedule for
the visits. Parents are also asked to fill in questionnaires (max. duration 30
minutes). However, insight in learning processes in this group of children is
of great importance to build up a body of knowledge in the rehabilitation
programs. An advantage for paqrents is that their children are evaluated one
time extra. Results of the study will be shared with parents, and if necessary
, accompanied by an advice.