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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">I'd probably verify that the "system is OK" this with some young controls. i.e., i don't think there's any reason to find this asymmetry in young controls. Usually there's a slight
contralateral effect (i.e., FC3 vs FC4), about ~10% larger for contralateral stimulation.
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<div>cheers</div>
<div>andrew</div>
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<pre class="moz-signature" cols="72"><span style="font-family:Tahoma">----------------------------------
Andrew Dimitrijevic PhD
Assistant Professor
Communication Sciences Research Center
https://csrc.cchmc.org/
Cincinnati Children's Hospital
Department of Otolaryngology, University of Cincinnati
3333 Burnet Ave. - S1.313
MLC 15008
Cincinnati, OH 45229-3026
tel. 513.636.3469
andrew.dimitrijevic@cchmc.org</span></pre>
<pre class="moz-signature" cols="72"><span style="font-family:Tahoma"><a href="https://csrc.cchmc.org/andrew-dimitrijevic" target="_blank">https://csrc.cchmc.org/andrew-dimitrijevic</a> </span></pre>
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<div id="divRpF636835" style="direction: ltr; "><font face="Tahoma" size="2" color="#000000"><b>From:</b> eeglablist-bounces@sccn.ucsd.edu [eeglablist-bounces@sccn.ucsd.edu] on behalf of Javier Lopez-Calderon [javlopez@ucdavis.edu]<br>
<b>Sent:</b> Thursday, July 12, 2012 3:25 PM<br>
<b>To:</b> Piers.Dawes@manchester.ac.uk<br>
<b>Cc:</b> eeglablist@sccn.ucsd.edu<br>
<b>Subject:</b> [Eeglablist] Auditory ERP asymmetry (Piers Dawes)<br>
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<div>Hi Piers,</div>
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<div>Were your subjects regular hearing aid device users? If so, which ear was commonly used for this?</div>
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<div>I hope this helps.</div>
<div>Best,</div>
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<div>Javier Lopez-Calderon</div>
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<span style="font-family:Helvetica; font-size:medium; color:rgb(127,127,127)"><b>From: </b></span><span style="font-family:Helvetica; font-size:medium">Piers Dawes <<a href="mailto:Piers.Dawes@manchester.ac.uk" style="color:blue; text-decoration:underline" target="_blank">Piers.Dawes@manchester.ac.uk</a>><br>
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<span style="font-family:Helvetica; font-size:medium; color:rgb(127,127,127)"><b>Subject: </b></span><span style="font-family:Helvetica; font-size:medium"><b>[Eeglablist] Auditory ERP asymmetry</b><br>
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<span style="font-family:Helvetica; font-size:medium; color:rgb(127,127,127)"><b>Date: </b></span><span style="font-family:Helvetica; font-size:medium">July 12, 2012 3:47:39 AM PDT<br>
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<span style="font-family:Helvetica; font-size:medium; color:rgb(127,127,127)"><b>To: </b></span><span style="font-family:Helvetica; font-size:medium">"<a href="mailto:eeglablist@sccn.ucsd.edu" style="color:blue; text-decoration:underline" target="_blank">eeglablist@sccn.ucsd.edu</a>"
<<a href="mailto:eeglablist@sccn.ucsd.edu" style="color:blue; text-decoration:underline" target="_blank">eeglablist@sccn.ucsd.edu</a>><br>
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Dear list</div>
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We have obtained an odd asymmetric auditory ERP. Does anyone have an explanation? Any suggestions would be welcome.</div>
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We recorded ERPs to pure tone beeps of 500 and 3000 Hz at 3 intensity levels. Tones were randomised and played separately to left and right ears, with responses recorded at Cz with a nose tip reference using a Neuroscan system. Insert headphones were calibrated
before testing and re-checked after; left and right headphones provide identical levels of output. Participants were 58 older people (mean age 70 years) with age-related hearing loss (Mean HL of 45 dB at 2kHz). Selection criteria included symmetrical hearing
(not greater than 15dB difference at any frequency), and overall mean HL is symmetrical.</div>
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Grand mean ERPs are higher in amplitude for tones played to left ear compared to right ear (by about ~1uV for N1 and ~.5uV for P2), and this is a consistent pattern among participants. Latencies are similar. I would have thought amplitudes should also be very
similar between left and right ear. What is happening here?</div>
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Thanks for your help</div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">Piers Dawes PhD</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">Audiology and Deafness Research Group</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">School of Psychological Sciences</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">Ellen Wilkinson Building</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">University of Manchester</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">Manchester M13 9PL</span></div>
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<span style="font-size:10pt; font-family:Arial,sans-serif; color:navy">Tel: +44 (0)161 30 61758H</span></div>
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