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Today’s
cognitive science largely follows the tradition of empiricism
by looking for correspondences between ‘stimuli’
in the external world and their responses or ‘representation’
in the brain. This approach works well (sort of) in
primary sensory areas but typically fails when cognitive,
emotional mechanisms are to be investigated. The empiricist
method is a bit like learning words of a foreign language,
i.e., collecting correspondences between a known and
a new language. The initial progress is fast; one can
get by in Hungary with just 100 words of vocabulary.
However, when it comes to a true understanding of an
unknown language, such as a hieroglyphs or the language
of the brain, one needs to know about the grammar, the
syntactical rules that allow for the generation of a
virtually infinite number of combinations from a finite
number of lexical elements using a minimal number of
rules. Syntax allows for segmentation of information
(tempo, punctuation, etc), temporal progression of discrete
elements into ordered and hierarchical relations, resulting
in congruent interpretation of meaning.
I
try to understand the brain, using this ‘inside-out’
approach by investigating “neural syntax”.
In brain networks, especially those serving cognitive
functions, packaging and segmentation of neural information
is supported by the numerous rhythms the brain generates.
Brain rhythms provide temporal correlations at multiple
time scales, which can be mathematically defined. Rhythms
and other non-rhythmic ‘chunking’ patterns
can be conceived of as ‘order parameters’
and often recognized in the local field potentials.
These mesoscopic patterns are the telltale of grouping
and segregation of transient cell assemblies and their
evolving sequences. Work in my lab focuses largely on
the generation of these various oscillations, their
spatial and temporal relationships, and the role of
inhibition in the enforcement of syntactic rules. These
mesoscopic temporal structures are fully preserved throughout
the mammalian evolution and constrain both evolutionary
and ontogenetic scaling of brain structures. We monitor
large-scale neuronal firing patterns and the local fields
they generate in behaving rodents and relate the assembly
patterns and order parameters to overt and covert behaviors.
The advantage of our ‘inside-out’ approach
to brain function is that it is free of philosophical
connotations and takes brain mechanisms as independent
variables, as opposed to attempts to find ‘correspondences’
or ‘representations’ between subjectively
derived categories and boundaries and brain responses.
If you remain skeptic of our approach, just ask any
practicing psychiatrist how well the boundaries set
up by DSM-IV translate to the diseases they treat.
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