[Eeglablist] Auditory ERP asymmetry

[Stefan Debener]

Hi Piers,

In two studies we found a similar pattern (larger left ear N100 
responses). This seems to be due to a relatively stronger right 
hemisphere involvement, which causes an asymmetry in the degree of 
contralateral responses between left and right ear.

Hine J, Thornton R, Davis A, Debener S. (2008). Does long-term 
unilateral deafness change auditory evoked potential asymmetries?
Clin Neurophysiol. 119(3):576-86.

Hine J, Debener S.(2007). Late auditory evoked potentials asymmetry 
revisited.
Clin Neurophysiol. 118(6):1274-85.

A similar result has been reported for MEG as well.

Best,
Stefan



Am 7/12/12 12:47 PM, schrieb Piers Dawes:
>
> Dear list
>
> We have obtained an odd asymmetric auditory ERP. Does anyone have an 
> explanation? Any suggestions would be welcome.
>
> 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.
>
> 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?
>
> Thanks for your help
>
> Piers Dawes PhD
>
> Audiology and Deafness Research Group
>
> School of Psychological Sciences
>
> Ellen Wilkinson Building
>
> University of Manchester
>
> Manchester M13 9PL
>
> Tel: +44 (0)161 30 61758
>
>
>
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-- 
Prof. Dr. Stefan Debener
Neuropsychology	Lab
Department of Psychology
University of Oldenburg
D-26111 Oldenburg
Germany

Office: A7 0-038
Phone: +49-441-798-4271
Fax:   +49-441-798-5522
Email: stefan.debener at uni-oldenburg.de

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