Subject: Re: Pitch orientation-discriminating feature detectors? From: vijaykumar narne <vijaynarne(at)MSN.COM> Date: Sun, 27 Oct 2002 21:18:47 +0530------=_NextPart_001_0000_01C27DFE.700C88B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable sir i am student working on the topic AERPs in semantic and phonetic pro= cessing . i n an article i have come across component in AERP called the= late negativity. i could not procure any information regarding this in = the regular text books .. kindly give me the information regarding this .= .i shall be grateful to you for the same. ----- Original Message ----- From: Daniel Pressnitzer Sent: Tuesday, September 24, 2002 11:28 PM To: AUDITORY(at)LISTS.MCGILL.CA Subject: Re: Pitch orientation-discriminating feature detectors? Dear Eliot, There is a perceptual asymmetry that is linked to the direction of pitch movement. Frequency peaks (upward-then-downward frequency modulation) are more salient and produce much lower difference limens than frequency troughs (downward-then-upward FM). This has been described in detail by Demany and colleagues in a series of studies published in JASA (see refs below). We are in fact starting a project to record cortical activity associated with FM peaks and troughs, using magnetoencephalography -- together with Laurent Demany and Andre Rupp. What we see up to now is that the source waveforms in response to FM peaks consistently display longer N1 latencies and larger N1-P2 amplitudes, when compared to responses to matched FM troughs. Such an asymmetry might have something to do with previous reports of EEG recordings examining upward vs. downward frequency glides. For instance, Ruhm (1971) showed that upward glides produce bigger and later N1-P2 responses than downward glides. The next question is of course why would it be useful in the real world to process differently upward vs. downward frequency movements... Cheers, Daniel --- (at)Article{demany94, author =3D {Demany, L. and McAnally, K.}, title =3D {The perception of frequency peaks and troughs in wide frequency modulations}, journal =3D {J. Acoust. Soc. Am.}, year =3D 1994, volume =3D 96, pages =3D {706-715} } (at)Article{demany95a, author =3D {Demany, L. and Cl=E9ment, S.}, title =3D {The perception of frequency peaks and troughs in wide frequency modulations. II. Effects of frequency register, stimulus uncertainty and intensity}, journal =3D {J. Acoust. Soc. Am.}, year =3D 1995, volume =3D 97, pages =3D {2454-2459} } [there are two other Demany and Cl=E9ment papers in JASA, 1995 and 1997] (at)Article{ruhm71, author =3D {Ruhm, H. B.}, title =3D {Directional sensitivity and laterality of electroencephalic responses evoked by acoustic sweep frequencies}, journal =3D {J. Auditory Res.}, year =3D 1971, volume =3D 11, pages =3D {9-16} }Get more from the Web. FREE MSN Explorer download : http://explorer.msn= .com ------=_NextPart_001_0000_01C27DFE.700C88B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <HTML><BODY STYLE=3D"font:10pt verdana; border:none;"><DIV>sir i am stude= nt working on the topic AERPs in semantic and phonetic processing .= i n an article i have come across component in AERP called the lat= e negativity. i could not procure any information regarding this in= the regular text books .. kindly give me the information regarding this = ..i shall be grateful to you for the same.</DIV> <DIV> </DIV> <BLOCK= QUOTE style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; B= ORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10= pt Arial">----- Original Message -----</DIV> <DIV style=3D"BACKGROUND: #e= 4e4e4; FONT: 10pt Arial; COLOR: black"><B>From:</B> Daniel Pressnitzer</D= IV> <DIV style=3D"FONT: 10pt Arial"><B>Sent:</B> Tuesday, September 24, 2= 002 11:28 PM</DIV> <DIV style=3D"FONT: 10pt Arial"><B>To:</B> AUDITORY(at)LI= STS.MCGILL.CA</DIV> <DIV style=3D"FONT: 10pt Arial"><B>Subject:</B> Re: P= itch orientation-discriminating feature detectors?</DIV> <DIV> </DIV= >Dear Eliot,<BR><BR>There is a perceptual asymmetry that is linked to the= direction of<BR>pitch movement. Frequency peaks (upward-then-downward fr= equency<BR>modulation) are more salient and produce much lower difference= limens<BR>than frequency troughs (downward-then-upward FM). This has bee= n<BR>described in detail by Demany and colleagues in a series of studies<= BR>published in JASA (see refs below).<BR><BR>We are in fact starting a p= roject to record cortical activity<BR>associated with FM peaks and trough= s, using magnetoencephalography --<BR>together with Laurent Demany and An= dre Rupp. What we see up to now is<BR>that the source waveforms in respon= se to FM peaks consistently display<BR>longer N1 latencies and larger N1-= P2 amplitudes, when compared to<BR>responses to matched FM troughs.<BR><B= R>Such an asymmetry might have something to do with previous reports of<B= R>EEG recordings examining upward vs. downward frequency glides. For<BR>i= nstance, Ruhm (1971) showed that upward glides produce bigger and<BR>late= r N1-P2 responses than downward glides.<BR><BR>The next question is of co= urse why would it be useful in the real<BR>world to process differently u= pward vs. downward frequency<BR>movements...<BR><BR><BR>Cheers,<BR><BR>Da= niel<BR><BR>---<BR><BR>(at)Article{demany94,<BR> author =3D  = ; {Demany, L. and McAnally, K.},<BR> title = =3D {The perception of frequency peaks and troughs in wide<BR> freq= uency modulations},<BR> journal =3D {= J. Acoust. Soc. Am.},<BR> year =3D &nb= sp; 1994,<BR> volume =3D &= nbsp; 96,<BR> pages =3D {= 706-715}<BR>}<BR><BR>(at)Article{demany95a,<BR> author =3D = {Demany, L. and Cl=E9ment, S.},<BR> title = =3D {The perception of frequency peaks and troughs in wide<BR> freq= uency modulations. II. Effects of frequency register, stimulus<BR> = uncertainty and intensity},<BR> journal =3D = {J. Acoust. Soc. Am.},<BR> year =3D &= nbsp; 1995,<BR> volume =3D  = ; 97,<BR> pages =3D = {2454-2459}<BR>}<BR><BR>[there are two other Demany and Cl=E9ment = papers in JASA, 1995 and 1997]<BR><BR>(at)Article{ruhm71,<BR> author =3D= {Ruhm, H. B.},<BR> title =3D {= Directional sensitivity and laterality of electroencephalic<BR> res= ponses evoked by acoustic sweep frequencies},<BR> journal =3D = {J. Auditory Res.},<BR> year =3D &nbs= p; 1971,<BR> volume =3D &n= bsp; 11,<BR> pages =3D &nb= sp; {9-16}<BR>}<BR></BLOCKQUOTE></BODY></HTML><br clear= =3Dall><hr>Get more from the Web. FREE MSN Explorer download : <a href=3D= 'http://explorer.msn.com'>http://explorer.msn.com</a><br></p> ------=_NextPart_001_0000_01C27DFE.700C88B0--