Post on 30-Oct-2014
Re-Thinking NeuroConstructivism through Dynamic (neuro)-Enskilment
Mirko Farina
Department of Cognitive Science
mirko.farina@mq.edu.au
Cognitive Science Workshop, December 5th 2012
A larger project …
• Nativism/ Modularity / Neuroconstructivism / Enculturation
• Goal: attack weak forms of nativism (typically Marcus’ neo nativism) by suggesting a revision/radicalization of the framework proposed by standard neuroconstructivism
• In this short talk, however, I am going to be presenting only the material on standard neuroconstructivism and will just hint at how it bears on the nativism debate in a concluding slide at the very end of this talk
Today’s Talk
In this paper I discuss two views - standard
neuroconstructivism, and dynamic neuro-enskilment
- that explain human cognitive and cortical
development from slightly different standpoints
I compare these views and critically analyse the
links between them
The Main Goal of this Talk!
I do so to demonstrate that what I call ‘standard neuroconstructivism’, in order to fully account for recent empirical findings, needs to be updated and radicalized along the lines envisaged by the dynamic neuro-enskilment view
Standard Neuroconstructivism (Karmiloff-Smith, Mareschal, Johnson, Westermann,
Elman, Thomas ...)
Framework for the study of cognition that draws on, and integrates, different views of brain and cognitive development such as:
(1) ‘probabilistic epigenesis which emphasizes the interactions between experience and gene expression (Gottlieb 2007)
(2) neural constructivism which focuses on the experience-dependent elaboration of neural networks in the brain (Purves 1994; Quartz & Sejnowski 1997)
(3) the interactive specialization view of brain development which focuses on the mutually constraining interactions of different brain regions in shaping the developing brain (Johnson 2001)
(4) embodiment views that emphasize the importance of the body in cognitive development and processing (Clark 1999; Smith 2005)
(5) Piaget’s constructivist approach to development that stresses the pro-active acquisition of knowledge by the child, and
(6) approaches highlighting the role of the evolving social environment for the developing child’ (Westermann, Thomas, and Karmiloff-Smith 2010, p.724).
The impact of standard neuroconstructivism in philosophy
Few Naggings …
• Much of the philosophical enthusiasm for the developmentally based work of Elman 1993, Karmiloff-Smith 1992, which culminated in the collaboration between Clark and Karmiloff-Smith (1993a,b), and more famously in the publication of Rethinking Innateness (Elman et al. 1996), hasn’t been carried through to present days and neuroconstructivism, after receiving a lot of press from philosophers in the early ‘90s, has totally dropped off the philosophical radar since
• The Philosophers' Index database lists only three papers on neuroconstructivism in the 2000s... I find this rather odd!
• In this paper, by returning (as a philosopher) to neuroconstructivism , I attempt to make it the centre of a fresh and new “theoretical” debate
The Dynamic Neuro-Enskilment View
• The dynamic neuro-enskilment view retains a standard neuro-constructivist basis *BUT* integrates within it ideas about distributed enculturated
cognition/cognitive ecologies (Roepstorff and Niewoehner [2010], Hutchins [2010]) and new work on neural plasticity in neuropsychology [Giedd 2009] and
cultural neuroscience (Chiao [2009], Kitayama and Park [2010])
• Theorizes a profound dependence of brain organization and cortical development on both patterned practices and cultural/social activities
• Emphasizes the power of brain plasticity, expertise, and rewiring throughout the entire lifespan. Crucial Tenet: adult entrenchment in different socio-cultural
contexts can generate completely dissimilar neural responses, leading to structurally different, cognitively diverse, and deeply enculturated brains.
Standard neuroconstructivism is the theory that characterizes development as a trajectory that is shaped
by multiple interacting biological and environmental constraints, in which complex representations develop
based on earlier and simpler ones
This increase in representational complexity
is realized through a progressive elaboration of
functional cortical structures, which are not
selected from a constrained juvenile stock but rather
emerge in an experience-dependent way
Standard neuroconstructivism argues for progressive elaboration of neural structures with earlier structures forming the building blocks for
later structures and describes development within a perspective of context-dependent learning
Thus, standard neuroconstructivism calls for
consistency between the neural and cognitive levels in
characterizing developmental trajectories, posits the
interrelatedness (on multiple timescales) of brain, body, and
world, and argues that the interweaving of all these factors
is crucial for cognitive development
How the Brain constructs Cognition …
‘Human intelligence is not a state (i.e., not a collection of static, built-in
modules that can be intact or impaired) but a process (i.e., the
emergent property over developmental time of dynamic,
multidirectional interactions between genes, brain, cognition, behavior, and
environment) with domain-specific outcomes impossible without the
process of development’ (Karmiloff-Smith 2009)
The brain is fundamental for cognitive development – *BUT* no reductionist standpoint – cognitive change not just
neural adaptation
Rather cortical specialization is the result of a process in which
constrained mental representations get reshaped via learning and experience
dependent activities
Thus, standard neuroconstructivists describe brain fine-tuning, its regional
specialization, and gradual development as constrained by
environmental exposure in the world
Standard Neuroconstructivism and Learning ...
Learning is a constructive process that is realized by
means of continuous changes operated on constrained cortical
structures that are moulded in early stages of infancy by
experience dependent activities
Standard Neuroconstructivism and the Sensitive Window ….
There is a sensitive period for learning for them then, in the sense that it is only if the early
structures are in place that we can get the later structures since these build on what has
occurred in early stages of life
This doesn’t imply that the brain can’t continue to change itself through learning
at later stages but just that the ways in which it can change itself are severely constrained by experience-dependent
activities undergone in infancy
Spot on! (with two concerns…)
1) Is cognitive development severely
constrained by experiences undertaken in early childhood? Unique
Sensitive Window?
2) What is the role that expertise and experience-based neuronal plasticity
play in redirecting the developmental path in
adulthood?
Giedd and colleagues (2006, 2009) demonstrated the existence
of a second period of synaptic plasticity in adolescence
This second wave of synaptic over-production (in all respects analogous to the one that takes place in early
childhood) constitutes a second window of opportunity for the
developing adolescence
‘What is most surprising is that you get a second wave of overproduction of gray matter, something that was
thought to happen only in the first 18 months of life’
1. Rewiring Constraints...
Show that the belief that the brain has fully matured by the age of 8 or 12, with the truly crucial wiring complete as early as 3, is false. The brain is an ongoing construction site
where development does not stop at age 3 or 10, but continues into the teen years and even the 20s
‘The brain undergoes dynamic changes much later than we originally thought.
Maturity is not simply a matter of slipping software (learning) into existing
equipment. Instead, the hardware changes. Think of it as nature's way of giving us a second chance’ [see Sowell
(UCLA) and Todd (Harvard/Utah)]
AREAS : corpus callosum– amygdalae – pre frontal cortex –
nucleus accumbens – hippocampus "
These results do not yet offer direct empirical evidence for the dynamic neuro-enskilment view, but question the idea of a unique phase-sensitive window
of opportunity confined to childhood and so emphasize the possibility of completely rewiring
already rewired and constrained cortical structures
Transcultural neuroimaging studies that have
highlighted the intrinsically biosocial nature of the
functional organization of the human brain
2. Evidence for the Dynamic Neuro
Enskilment view ..
London Taxi Drivers (Maguire et al. 2000)
Relative to the hippocampi of matched control subjects [non taxi
drivers and bus drivers], the hippocampi of the cab drivers
showed a substantial enlargement in the posterior part
This structural difference was related to cab driving and was
reported to be proportional with the number of years of experience as a taxi driver
Jugglers (Draganski et al. 2004)
Draganski used MRI to visualize learning-induced plasticity in the brains of trained volunteers who have learned to juggle from scratch for approximately
60 seconds without dropping a ball over a period of three months
Relative to the brain of controlled subjects (non jugglers) the
experimenters found out that there were significant changes involved in the volume of white
matter in the brain of the jugglers
Canadian Mail Sorters (Polk and Farah 1998)
Polk and Farah (1998) designed an experiment to determine whether extensive
socio-cultural activities undertaken in adulthood could have an effect on this
dissociation
They tested Canadian postal workers who spend days sorting mail by postal code
Results were fascinating: compared to fellow postal workers who do not sort mail, Canadian mail sorters, show significantly less behavioural evidence for segregated
letter and digit processing
Jazz Musicians (Vuust et al. 2005 – Vuust and Roepstorff 2008)
Jazz musicians react to rhythmic deviations more significantly and in a
shorter period of time than non-musicians
This happens because jazz musicians are routinely
engaged in musical practices that continually involve these
deviations
Classic Musicians (Ohnishi et al. 2001)
Ohnishi and colleagues (2001) compared the brain activation of expert musicians with that of non-musicians
While listening to the same piece of music (namely Bach’s
Italian Concerto), musicians and non-musicians recruited different areas of their brains
Gutchess and Park 2009 – Cultural
differences in neural function associated
with object processing
Culture and Memory (Gutchess et al. 2006)
Where do these findings leave us?
These results provide strong empirical evidence
for the intimate dependence of human
cognition (even in adulthood) on both socio-
cultural/technological environments and
patterned practices
We learn that the environments in which we live have a huge influence in initiating and orchestrating specific physiological processes as well as in organizing, both
anatomically and functionally, our cognitive architectures
We also learn that although the anatomical structures and the cognitive architectures that characterize our brains progress and
develop through a common developmental path, they continually interact with each
other and with their environments to change each other's functions
What Do We Learn?
These results urge standard neuroconstructivists to stretch
and liberalize the sixth dimension of their framework – …’Approaches highlighting the role of evolving social
environments in the developing child’...
Re-Thinking Standard Neuroconstructivism? (Conclusions)
Substantial Revision of their framework?
(Preliminary Conclusion)
OBJECTION! - The point about the sensitivity window is an empirical point in developmental
neuroscience. But is it philosophically relevant to the standard neuro-constuctivist?
What is there in the theory or in the conclusions that are drawn from the theory
that changes once we extend the sensitivity
window? Doesn’t it just require a tweak to the
theory?
Modularity theorists (e.g. Marcus) have tried
to appropriate constructivist ideas to account for the role of development. Unique Sensitive Windows =
Maturation of Modules
OK let’s agree conclusions might be the same *BUT* the framework is not. The idea of development in the
two accounts is very different. This difference becomes relevant when we look at a broader picture
So the empirical point we thought was not philosophically relevant to the neuroconstructivists turns out to be philosophically decisive. In other words, it is philosophically relevant to the neuroconstructivist
because it is relevant to the nativists in the first place….
How do nativists account for a second window of
opportunity? ‘Re-Maturation’ of already matured modules?
Sounds like an ad hoc hypothesis….
A Special Thanks to:
• John Sutton• Julian Kiverstein• Richard Menary• Andy Clark• MacNaP Audience
• Macquarie University • You All