? taR .rM, siht si egaugnal tahW
Various news organizations, like
Al
Jazeera and
CNN,
are running with a great new animal language story. You might prefer to
get it from the horses mouth -
full text of the
Journal of Experimental Psychology article.
It turns out that Spanish rats can be trained to prefer synthesized
pseudo-Japanese over synthesized pseudo-Dutch, or vice versa, more
easily than Spanish rats can be trained to prefer backwards
synthesized pseudo-Japanese over backwards synthesized
pseudo-Dutch, or vice versa. I'm not sure whether the rats actually
consider themselves Spanish, as they reside in Barcelona. But they're
hardly Catalan, as they come from a strain of rattus norwegicus which
was originally cross-bred here in California. But as usual, I digress.
Digression is so much easier than in the old days. How on earth did
people manage to digress effectively before Google?
Anyhow, you can guess why the press is excited. A language log
favorite.
Talking animals.
Indeed, the authors of the paper put their result in roughly the talking animal category, albeit in a much more finely nuanced way: animals are surprisingly well
attuned to prosodic properties of language as against other physically
similar stimuli. The researchers, Juan M. Toro, Josep B. Trobalon, and
Nuria Sebastian-Galles, are sensible people, and do not take a Dolittlian
inter-species communication or new age conclusion from this. Rather, they think it is evidence
that in the development of human language, features already present in
the mammalian auditory system were co-opted.
I am intrigued by the study, and I have the impression it was carried out carefully and effectively. But personally, I never had any doubt whatsoever that in the development of
human language, features already present in the mammalian auditory
system were co-opted. Moreover, I'm skeptical that Toro
et al's study shows this.
The problem is that Toro
et al don't actually know which features of Japanese and Dutch
were the ones that mattered, the relevant differences between the two
languages that are more easily extracted forwards than backwards. And this leads me to some very general mathematical questions:
- Are there types of pattern recognizer such that those recognizers can
differentiate between certain classes of pattern they are presented with in one order,
but not differentiate between those classes of pattern when presented in the
reverse order?
-
Are there types of formal language recognizer (e.g. with a limited
working memory, like just two states, or a limited stack, whatever)
that can recognize classes of languages in one direction, but cannot
recognize classes of language consisting of the same strings except in
reverse?
-
Are there types of learning algorithm such that these algorithms can
learn to recognize certain classes of pattern presented in one
direction but not learn to recognize the same classes of pattern
presented in in the other direction?
-
Are there types of learning algorithm such that these classes can
learn to recognize certain formal languages but not
learn to recognize the languages which consist of the same set of
strings except in reverse?
I'll put money on the answers being 4 * yes with even a quite modest
definition of what a "type of pattern recognizer" etc is. In which case,
the difference between Japanese and Dutch prosody might be
intrinsically more learnable for a large class of abstract learning
systems than is the difference between the reverse of these langagues. And this class of learning systems might well include every organic learning system
that has ever muddied its feet, scales or other protuberances on our wonderful planet, not just mammals, and not just animals with
auditory systems. In which case, all the results of Toro
et al's study would show is that
Dutch and Japanese evolved in such a way that they are potentially
recognizable and learnable by some creature, whereas Hctud and Esenapaj
did not.
Would this surprise us?
Posted by David Beaver at January 10, 2005 02:24 AM