Re: Schyns Comms 10-12 french gauker grossberg

From: Valenti Gianni (gv195@coglit.soton.ac.uk)
Date: Tue Apr 28 1998 - 16:05:34 BST


Reply to BECK [ab>] on French/Gauker/Grossberg on SCHYNS et al.

ab> According to French the fixed features are untenable strawmen.
ab> However schyns believes fixed features to be an influential
ab> approach.
ab>
ab> French and Weaver believe that is is unlikely that we are
ab> born with all the features we need to have throughout life,
ab> features are therefore learned.

This could be possible but for all categories to be learned still some
generalising mechanism must be present as learning the category of
every single objet animal and so forth to even more abstract concepts
such as emotional states would take an incredibly large amount of time
and memory space in the brain.

ab> However, there is no evidencfor this.

On the other hand our innate fear of snakes could be a possible
evidence for the opposite: the existence of inborn known feature
detection.
Yet to have all possible features for all instances could be
over-loading the system as well as being under the danger of possible
genetic mutation.

ab> Schyns demonstrates which French and Weaver acknowledge
> that there is a aquisition of new features during catagory learning.
ab> French and Weaver do not follow that the aquisition of new features
ab> is a typical part of catagory learning.

What is therefore possible is that a general inborn facility to
distinguish dangerous animals with non dangerous animals, could be
possible (being this an evolutionary advantage), but that finer
subgrouping has to be acquired using a "feature subgrouping" type of
system.

ab> French and Weaver argue that working assumption is reasonable because
> if you look at the evolving constraints and universally
> shared experiences with objects
> in the world this suggests that by the time of adulthood,
> most of the primitives
> humans need to handle concrete categories will already have been
> learned which is why we argue that fixed feature approach for the
> learning of concrete categories is a reasonable working assumption.

Following this argument, it is understandably so.
 
ab> They finish by concluding that working assumption of fixed categories
ab> in learning is justified. However, there needs to be far more work
ab> done in this area.

I agree.

ab> Feature based theoriesd of concept formation have two dilemmas.
ab> 1= for many natural concepts it is hard to see how the concept of the
ab> features could be developmentally more basic.
ab> 2= the concept formation must be guided by abstraction heuriotics.
ab>
ab> Schyns theory argues that the concepts of the
ab> features need not be developmentally more basic. They don't explain
ab> how novel features might be formed.
ab>
ab> Yet all agree that on one thing
> a theory of conceptual development has to explain how children learn
> to apply category words to roughly the same sort of things as'
> others who have learned language.

yet their application seems to follow a prototype similarity approach,
therefore indicating a prototype formation of the concept, as a product of
learning guided by an inborn "generalising concept". In fact, children
make the mistake of calling whales and dolphins as fishes, as opposed to
their correct classification as mammals. They do this probably because the
general habitat of these animals as well as their form is more
prototype-like of fishes than other groups. The same goes for penguins and
birds.

ab> No two peoples abstracts general concepts form exactly the same
ab> clas of instances. Yet people agree on categories.
ab> These categories, it is being argues, maybe innate or shared
ab> principles of abstraction.
 
Or it is an innate ability for category formation, using immediately
identifiable variables (such as form an environment of interaction).

ab> 3 Grossberg
ab>
ab> Grossberg uses adaptive resonance theory ( ART ) to illustrate some
ab> theories.
> ART works to bind together features of the group via a bottom up
> adaptive filter that activates a category which represents this new
> combination of features.
ab>
ab> i.e. a prototype.
ab>
ab> Prototypes are used to match other objects. If the matched object is
ab> good enough the system learns to incorporate a novel boundary of
ab> groupings into learned categories.
ab>
ab> There are two levels.
> the lower level deals with new features that
> contribute to the larger categories.
> This higher category level can selectively bind together or fuse
> certain combinations of new features in one contexed and different
> combinations in another.
ab>
ab> This process generates large categories and conserves memory
ab> reserves.

This could be a very good representation of the actual human module, but
it limits itself to explain the categorisation of external concrete
objects, leaving emotional states and complex situations unaccounted

Definitely a greater investigation into the matter is required, were the
answer will probably lie in-between the two opposing viewpoints.

Gianni



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