Subject: Re: pitch discrimination From: Athanassios Protopapas <protopap(at)PANTEION.GR> Date: Wed, 9 Jun 1999 00:07:12 +0300Dear Dr. Watson and List, Someone please kick me if I'm dragging on too long (I guess I'm interested in this stuff). The 'g' issue is extremely interesting and in fact I started reading about 'g' after I saw the results of our psychoacoustic measurements. So in this sense you're right on the mark. On the other hand there's a group of measures that cluster together very strongly, a more encompassing group clustering sort of, and a bunch of measures not related to the above (unfortunately 50-100 subjects are not enough for a serious factor analysis of so many measures---yes I tried and it doesn't work). So the question is what makes reading ability cluster strongly with, say, frequency representation, less with loudness representation, and not at all with gap detection? Similar questions arise with a nonverbal intelligence measure which also groups with some but certainly not all of the psychoacoustic measures and not as strongly as (non)word reading does. There's something interesting there beyond 'g' (which, BTW, seems to be an offensive word in the psychological literature nowadays thanks to zealots of the JJ Gould sort but that's a-whole-nother can of worms). With respect to individual differences and group correlations: Yes and yes. That is, I wouldn't despise either. In the Norfolk, VA ASA meeting I presented data on 54 normally developing schoolchildren for whom backward detection masking was correlated (.42) with their language score (CELF-3 receptive language quotient). The masking task was similar (identical in stimulus properties, different in interface and adaptive procedure) to the one used by Wright et al who showed very substantial differences between normal and language impaired children (Nature 387:176, 1997). That is, there is a general tendency/relationship there which even spans the (arbitrary) boundary betwen "normal" and "impaired" and pretty much holds across the board. So something can be said for group correlations. Then again this same measure does not correlate significantly with reading ability in adults. There goes the clean story down the drain along with the 'g' factor :-) I guess you've had enough of me for this year---I'm crawling back under my rock now. Thanassi Protopapas