Subject: Re: The climb of absolute pitch From: Chuck Larson <clarson@xxxxxxxx> Date: Tue, 4 Dec 2012 22:38:21 +0000 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>To all of you experts on absolute pitch, I have a question for you. I've been following your discussion on AP musicians in hopes that I would learn something from you that would explain some of our EEG results. We have tested musicians with absolute pitch and relative pitch on a vocalization experiment in which they heard their voice (through headphones) either shift up 100 cents or down 100 cents. The shifting was done with a harmonizer. We also recorded ERPs triggered by the onset of the pitch-shift stimulus. In general the musicians with AP had larger magnitude left hemisphere potentials (P200) than did the relative pitch musicians. However, we also noted that for the UPWARD pitch-shift stimulus, the P200 in the AP musicians, in contrast to the RP musicians, was more strongly left lateralized than for DOWNWARD pitch shifts. I am trying to figure out why an upward shift in voice pitch auditory feedback in AP musicians would show stronger left hemisphere activation than a downward pitch shift. I'D greatly appreciate any ideas you may have on this. Thanks, Chuck ________________________________________ Chuck Larson Dept. of Communication Sciences and Disorders Room 3-348 2240 Campus Dr. Northwestern University Evanston, IL 60208 Phone: 847-491-2424 Cell: 847-830-5432 Fax: 847-491-4975 email: clarson@xxxxxxxx On 12/3/12 7:38 PM, "Kevin Austin" <kevin.austin@xxxxxxxx> wrote: >Thanks. > >I had been led to believe that frequency was encoded along the BM, and >that pitch was the interpretation of this stimulus. > >Kevin > > > >On 2012, Dec 2, at 8:47 AM, Bob Masta wrote: > >> Can someone explain the supposed mechanism behind neural timing and >>pitch shift? I don't understand what is being proposed. As I >>undestand it, since pitch is encoded as *place* along the BM, the >>neurons respond with a firing rate that encodes *loudness* for their >>particular frequency place. The firing rate does not encode the >>frequency of the sound itself. >> >> What am I missing here? >> >> Best regards, >> >> Bob Masta >> >> ============= >> On 1 Dec 2012 at 9:50, Pierre Divenyi wrote: >> >>> Hi Oded, >>> >>> Your three-step reasoning makes sense but, indeed, it should be >>> experimentally verified. As to the age-related change of neural >>> oscillations, Art Wingfield believes that the brain "slows down" as we >>>get >>> older. Such a slowing-down could also explain the upward AP shift >>>because >>> our reference would shift downward. How this central effect squares >>>with the >>> peripheral, BM-stiffening effect is unknown but, again, could be >>>studied in >>> the lab. >>> >>> -Pierre >>> >>> On 12/1/12 5:17 AM, "Oded Ghitza" <oghitza@xxxxxxxx> wrote: >>> >>> Hi Pierre, >>> If (1) you accept Julius's model of pitch perception, (2) interpret -- >>>as he >>> did -- the central component of the model as a mechanism that adjusts >>>f0 of >>> an internal harmonic sieve to the point where the MMSE between the >>>sieve and >>> the input pattern is minimum, and (3) assume that such mechanism is >>>realized >>> by a neuronal circuitry with oscillations ("rhythms") at the core >>>(maybe >>> related to Langer, in the late 80's and in the context of pitch >>>perception, >>> who measured "temporal rings" in chicks); then, a possible way to >>>examine >>> the phenomenon (whether perceived pitch should go up or down, in >>> particular), is to look at how the frequency range of neuronal >>>oscillations >>> change with age. >>> -- >>> Oded. >>> >> Bob Masta >> >> D A Q A R T A >> Data AcQuisition And Real-Time Analysis >> www.daqarta.com >> Scope, Spectrum, Spectrogram, Signal Generator >> Science with your sound card!