Re: Perception as memory / models of pitch

[Martin Braun <nombraun@xxxxxxxxx>]

Dear Eric and list,

"1) I'd be grateful if you could clarify my thoughts......  (How) does it
necessarily follow that categorization must be coupled as an integral part
of this temporal pitch extraction process??  My understanding is that it
likely occurs at a different location e.g. language areas (?)"

Neither the assumed prelinguistic categorization in the thalamus (see our
2005 paper), nor the linguistic one in the neocortex are parts of the
periodicity analysis. This occurs, according to all data that we have, in
the inferior colliculus, i.e. the nucleus that almost exclusively delivers
all ascending auditory input into the thalamus. The periodicity filters in
the midbrain, e.g. formed by tuned neuronal membrane time constants, are
vulnerable to slight biochemical detuning.


"3) Another question, how stable must a neural reference (?pacemaker) be to
equal the known stability of AP normally (<50 cents) ?  Does such a
pacemaker exist for all phase-locking frequencies or even just spanning an
octave?"

The verbal categories "C", "C#", "D", etc are stable within ca +/- 50 Cent.
The periodicity detectors in the midbrain probably do not categorize very
much. We have APers who can reply things like "D, but 20 Cent sharp".

Martin

---------------------------------------------------------------------
Martin Braun
Neuroscience of Music
S-671 95 Klässbol
Sweden
web site: http://w1.570.telia.com/~u57011259/index.htm




----- Original Message ----- 
From: "Eric LePage" <ericlepage@xxxxxxxxxxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Wednesday, September 02, 2009 11:01 AM
Subject: Re: Perception as memory / models of pitch


Dear Martin and list,

Thanks for the reminder.  When you first reported the carbamazepine effect,
I was fully prepared to try it myself, but a veterinarian friend talked me
out of it!

1) I'd be grateful if you could clarify my thoughts......