through the whole sentence in order to find the target. Second, they examined
the role of interferences within these retrieval operations, appealing to the
hypothesis of cue overload (Watkins and Watkins 1975) to explain why, in some
cases (for example, in center-embedding), retrieval produces slowdowns or even
fails: if the retrieval cues become not distinctive enough, i.e. if it turns out that
it is possible to associate them with many recently processed items, the probability
of correct retrieval is diminished. In the language we are using here, if the
activation of an item does not match the target item or matches more than one
target item, the probability of Merge generating the target item again in an
operation of refreshing will decrease.
If, as stated before, the prefrontal cortex within the MD network seems to
be responsible for increasing the representational resolution of specific items
(Mercado 2008), the acquisiti on and deployment of grammar would crucially
involve MD network activity that would be in charge of reducing interferences
and disambiguating. However, it should be noted that the acquisition of lan-
guage is a gradual process that coincides with the protracted development of
the prefrontal cortex in humans. Chrysikou and Thompson-Schil l (2011) hypoth-
esize that this protracted development may facilitate the acquisition of language,
as acquisition would start by incorporating more basic structures, converting
them into chunks by repeated exposure, creating in this way a bootstrapping
process that, as long as the MD bandwidth allows it, will finally attain more
complicated patterns. Interestingly, the authors link the stages previous to the
acquisition of a full-fledged grammar to a higher frequency of out-of-the-box
thinking, giving the example of German and Defeyter (2000), an experiment
in which it was shown that children younger than five years old were more able
to come up with the idea of using a box as a platform to reach an object than
were older children, who tended to see the box as just a container. Within the
picture being developed, out-of-the-box, creative thinking would be a result of
stochastic activity entering the global workspace as a result of low prefrontal
activation, while a combination of high and low prefrontal activation would
render a focused but flexible way of thinking. The acquisition or proceduraliza-
tion of grammar, therefore, should behave exactly as its deployment, being a
combination of the basal-ganglia-related and prefrontal-cortex-related states
within the prefrontal-thalamic-basal ganglia network, but taking place gradually
as cognitive control abilities develop and bootstrap the emergence of the more
complex structures.
Regarding the domain-specificity of the language subregions in Broca’s area,
special attention should be paid to the phenomenon of disambiguation, which
would be produced when an item triggers multiple potential candidates. Taking
into account that Broca’s area can be divided into multiple subregions, probably
with a different function for each (cf. Embick and Poeppel 2006), a ge neral
cognitive control role for this area can be to prevent Merge from falling into
interferences that may disrupt the achievement of complex goals, a capacity that
will vary according to the species, and that may find its maximum exponent in
humans. The functioning of Broca’s area, nonetheless, would still reduce to
Language and working memory 121