Subject: Re: The Auditory Continuity Illusion/Temporal Induction From: Bob Carlyon <bob.carlyon(at)MRC-CBU.CAM.AC.UK> Date: Wed, 14 Dec 2005 10:02:10 +0000--=====================_2200424==.ALT Content-Type: text/plain; charset="us-ascii"; format=flowed Those interested in electrophysiological correlates of the continuity illusion might also be interested in the following paper, which argues that the illusion is at least partially complete at the stage of processing where the mismatch negativity is generated: Micheyl, C., Carlyon, R. P., Pulvermuller, F., Shtyrov, Y., Hauk, O. and Dodson, T. (2003). "Neurophysiological correlates of a perceptual illusion: A Mismatch Negativity Study," J. Cog. Neurosci. 15, 747-758. bob At 06:28 14/12/2005, Israel Nelken wrote: >Dear all, > There's some electrophysiological work in animals that has bearing on > the issue of continuity. Mitch Sutter has strong evidence that the > illusion is operative in macaques, and he has some accompanying > electrophysiology (that has not been published yet to the best of my > knowledge) showing correlates of induction in primary auditory cortex. We > (Las et al. J. Neurosci. 2005) published data related to the coding of a > pure tone in fluctuating masker. Although our main emphasis was on > comodulation masking release, the results can be interpreted in terms of > continuity. In short, the responses of neurons in A1 of cats to the > interrupted noise were very strong and locked to the noise envelope. > Adding a low-level tone close to the BF of the neurons suppressed the > envelope locking, resulting in responses that were similar to those > evoked by tones in silence. Thus, these neurons seem to reflect the > perceived continuity of the tone, ignoring the noise. We have further > demonstrated that neurons with these responses are present in the > auditory thalamus but not in the inferior colliculus. All of this would > suggest that activity that reflects the continuity of the tone is already > present in thalamus/primary auditory cortex (although anesthetized cats > are certainly not awake humans). We don't know however whether this > activity is generated there or whether we see a reflection of processing > at higher brain areas. > Eli > >-- >================================================================== >Israel Nelken >Dept. of Neurobiology >The Alexander Silberman Institute of Life Sciences >Edmond Safra Campus, Givat Ram | Tel: Int-972-2-6584229 >Hebrew University | Fax: Int-972-2-6586077 Jerusalem >91904, ISRAEL | Email: israel(at)md.huji.ac.il >================================================================== > Dr. Bob Carlyon MRC Cognition and Brain Sciences Unit 15 Chaucer Rd. Cambridge CB2 2EF England Phone: (44) 1223 273717 Fax: (44) 1223 359062 email: bob.carlyon(at)mrc-cbu.cam.ac.uk --=====================_2200424==.ALT Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <html> <body> Those interested in electrophysiological correlates of the continuity illusion might also be interested in the following paper, which argues that the illusion is at least partially complete at the stage of processing where the mismatch negativity is generated:<br><br> <font face=3D"Times, Times" size=3D4>Micheyl, C., Carlyon, R. P., Pulvermuller, F., Shtyrov, Y., Hauk, O. and Dodson, T. (<b>2003</b>). "Neurophysiological correlates of a perceptual illusion: A Mismatch Negativity Study," J. Cog. Neurosci. <b>15</b>, 747-758. <br><br> <br> </font>bob<br><br> <br><br> At 06:28 14/12/2005, Israel Nelken wrote:<br> <blockquote type=3Dcite class=3Dcite cite>Dear all,<br> There's some electrophysiological work in animals that has bearing on the issue of continuity. Mitch Sutter has strong evidence that the illusion is operative in macaques, and he has some accompanying electrophysiology (that has not been published yet to the best of my knowledge) showing correlates of induction in primary auditory cortex. We (Las et al. J. Neurosci. 2005) published data related to the coding of a pure tone in fluctuating masker. Although our main emphasis was on comodulation masking release, the results can be interpreted in terms of continuity. In short, the responses of neurons in A1 of cats to the interrupted noise were very strong and locked to the noise envelope. Adding a low-level tone close to the BF of the neurons suppressed the envelope locking, resulting in responses that were similar to those evoked by tones in silence. Thus, these neurons seem to reflect the perceived continuity of the tone, ignoring the noise. We have further demonstrated that neurons with these responses are present in the auditory thalamus but not in the inferior colliculus. All of this would suggest that activity that reflects the continuity of the tone is already present in thalamus/primary auditory cortex (although anesthetized cats are certainly not awake humans). We don't know however whether this activity is generated there or whether we see a reflection of processing at higher brain areas.<br> Eli<br><br> -- <br> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D<br> Israel Nelken<x-tab> </x-tab> &= nbsp; <x-tab> </x-tab><br> Dept. of Neurobiology &nbs= p; <br> The Alexander Silberman Institute of Life Sciences<br> Edmond Safra Campus, Givat Ram | Tel: Int-972-2-6584229<br> Hebrew University = | Fax: Int-972-2-6586077 Jerusalem 91904, ISRAEL | Email: israel(at)md.huji.ac.il<br> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D<br><br> </blockquote> <x-sigsep><p></x-sigsep> Dr. Bob Carlyon<br> MRC Cognition and Brain Sciences Unit<br> 15 Chaucer Rd.<br> Cambridge CB2 2EF<br> England<br> Phone: (44) 1223 273717<br> Fax: (44) 1223 359062<br> email: bob.carlyon(at)mrc-cbu.cam.ac.uk<br><br> </body> </html> --=====================_2200424==.ALT--