The dancer that the director admired was going to school.
However, RC processing studies in Turkish revealed contrary results,
showing easier SRC processing (Bulut et al., 2019; Kahraman, 2015;
Kahraman et al., 2010; Özge, 2010). It was also found that participants
who learn Turkish as a second language process SRCs easier than ORCs
(Altan, 2016; Uzundag & Küntay, 2019). On the other hand, it was
claimed that there is no difference between processing SRCs and ORCS if
they are given in a context (Boran, 2018). Furthermore, Özge et al.
(2015) divided the stimuli sentences into different segments and
compared the ORC and SRC reading performances in a self-paced reading
test. The authors have reported SRC or ORC processing advantages in
different segments of the sentences, but no difference between SRCs and
ORCs in total reading times. To the best of our knowledge, RC processing
has only been investigated with behavioral metrics in Turkish. Thus, the
brain dynamics of RC processing in Turkish remained elusive.
On the other hand, RC processing was investigated with neuroimaging
methods in other languages. For instance, a functional magnetic
resonance imaging study showed left perisylvian cortex activity during
relative clause processing tasks and that processing ORCs was more
difficult, even though there were no significant differences in accuracy
and reaction time measurements (Caplan et al., 2002). Kovelman, Baker,
et al. (2008) have reported that activity in left and right inferior
cortices (i.e., Brodmann Area (BA) 44, 45) increases during relative
clause processing. Moreover, the authors found that ORC processing is
more difficult than SRC processing and caused greater neuronal activity
in both left and right inferior cortices, as well as BA 46 and 47 in the
right hemisphere, while there was no significant difference in terms of
reaction times. Another neuroimaging study showed that processing
relative clauses compared to processing unintelligible speech causes an
increase in the activity of both left and right dorsolateral prefrontal
cortex (DLPFC) (Hassanpour et al., 2015). This study also failed to find
a significant difference in terms of behavioural metrics. Lastly, Ding
et al. (2021) compared syntax processing in monolingual and bilinguals
with different sentence types and found that left DLPFC is amongst the
active regions for processing relative clauses and ORCs induced greater
neuronal activity than SRCs in both left and right DLPFC.
In summary, neuroimaging studies showed that a robust processing
difference between SRCs and ORCs in various languages and that both left
and right DLPFC are crucial in RC processing. The findings about the
relative processing in Turkish depend solely on behavioural paradigms
and are not fully consistent. As stated above, behavioural findings can
fail to reveal the processing difficulty differences between SRCs and
ORCs. Therefore, we aimed to investigate the prefrontal cortex
hemodynamics during relative clause processing in Turkish. We
hypothesized that the left DLPFC would be the primary region for
neuronal activity since it covers the classical language areas (i.e.,
Broca’s). Furthermore, we have expected to observe processing difficulty
differences between ORCs and SRCs, especially in the lateral parts of
the prefrontal cortex.