Subject: Re: Is there considerable phase locking up to 6 kHz? From: Peter Meijer <peter.b.l.meijer(at)PHILIPS.COM> Date: Wed, 17 Mar 2004 10:24:06 +0100Jan Schnupp notes > most auditory physiologists would be very surprised > if any mammal was found to phase lock appreciably to > frequencies above 4 kHz. I would be surprised too, but I am less certain, or simply less knowledgeable about phase locking (for sine waves) and the possible role of neural plasticity. Barn owls and bats are under great environmental pressure to extract as much location information from sound as possible, thus likely favouring phase-locking up to higher frequencies than in many other animals. Has anyone investigated the effect of training on phase locking range? People are again rather different from barn owls versus cats and guinea pigs for their own environment requiring dealing with speech and music, although that may not put great demands on phase locking, but blind people form yet again a different group where any learning effects in phase locking could play an important role, e.g., for echolocation. So what is really known about learning effects on the phase locking range? One can very well imagine that the collective behaviour of neurons can be refined for carrying more subtle timing effects if (and likely only if) there is a need for that. We are not talking just of static physiology here but of more plastic neural substrates that have the potential to adapt if there is a need. Best regards, Peter Meijer Seeing with Sound - The vOICe http://www.seeingwithsound.com http://www.visualprosthesis.com