[Eeglablist] Can amygdala activity be detected on the scalp?

["Pål G. Larsson"]

Teresa Wong wrote:

> Dear colleagues,
>  
> I would like to hear your views on whether scalp ERPs can reflect 
> activity of the amygdala.
> Is it possible/valid to localize dipole sources (using 128-channel 
> recordings, emotional faces as stimuli) in subcortical brain regions, 
> limbic areas, amygdala, etc?


One of Paul Nunez works look into the possibilty of recording small 
foci. I guess to make it simple, it all cooks down to the degree of 
syncrony and the signal/noise ratio. E.g. you can record brainstem 
potentials, but you have to "cheat" by doing averanging (thousand of 
samples).

To record spontanious amygdala activity, you have a signal that is low 
due to distance. On the other side you have cortical activity from large 
cortex-areas that are near the recording givening lots of "noise". You 
need to get rid of the noise -> averaging. So, in ERP-studies you must 
average. Then you get the next problem: Can you have a paradigm that 
gives stable response for hundreds or probably thousands of avergares?

Regards

Pål G. Larrson

Head of. dept
Dept. of neurodiagnostics
National Centre for Epilepsy, Norway

>  
> Wishing you all a very happy and healthy 2006 with much success in 
> research!
>  
> Teresa
> -- 
> Teresa Ka Wai Wong
> PhD Student
> Department of Psychiatry
> The University of Hong Kong
>  
>
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