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Re: OT: "Musicians may soon be able to play instruments using just the power of the mind"



In my life outside looping, I earn my living as a clinical 
neurophysiologist.  For the last 29 years, I have been performing numerous 
neurophysiological examinations, including EEGs, on a daily basis.  This 
would be a total of at least 30,000 EEGs.  I have been running a busy 
department for the last 8 years, and like to think I have a fair amount of 
knowledge in the subject.

My heart sinks when I see articles such as this.  Be aware that the 
research in this article is funded by the 'Arts and Humantities Research 
Council'; I suspect that the researchers would have had little luck 
getting funding from a scientific institution.

The BBC aren't particularly great at presenting these type of popular 
science stories. They always leave me frustrated and yearning for more 
information and detail.  I haven't read the original research paper, so 
for this reason, I'd be inclined to give Dr. Grierson the benefit of the 
doubt.  However, there are so many flaws in the research presented here, 
it's difficult to know where to begin.

1.  A routine EEG recording requires 23 electrodes over the whole of the 
scalp, this giving adequate coverage of most of the important areas of 
brain function.

2.  This research appears to use just 2 electrodes.  The one placed over 
the pre-frontal cortex would probably be the 'reference electrode'.  The 
'active' electrode appears to be placed in the Cz position, which is 
roughly over the foot/leg area for motor control.  The only conceivable 
way that using this electrode to control a pitched noted would possibly to 
imagine that you are using your foot to play a note on a floor pedal.  But 
the numbers were displayed too quickly on the screen for this to be viable.

3.  If the pre-frontal electrode were the active electrode, it is most 
likely that the eye movement artefact (ie electrical signals generated by 
the ocular movement - NOT from the mind - these are the 'blips' on the 
screen that Dr.G shows) would be generating the note.  This is just about 
feasible IF each note is displayed on exactly the same position on the 
screen each time, but still very unlikely for all sorts of technical 
reasons (eg, if eye fixation is maintained in one position, it would 
require a DC amplifier to be able to register this steady position - 
looking at the EEG trace, this is defintely an AC amplifier he's using.  
There are several other reasons I can think of, but won't bore you with).  
In any case, using eye movements to control a device is definitely not 
utilising 'the power of the mind'.

4.  If I remember correctly, the part of the brain for processing musical 
information is likely to be the temporal lobes, and it is probable that 
both temporal lobes are involved in this simultaneously. This 
demonstration has no electrodes anywhere the temporal lobes.  I should 
check the real paper to see where the electrodes were actually placed.

5. Any changes in brain activity in this type of task are very subtle, and 
would not be visible in an EEG recording.  It would require a separate 
technique known as 'signal averaging' to pick out these minute changes.  
Unfortunately, this would take at least several minutes to register each 
note - therefore cannot be used in real times.

Like I said, it is possible that this was just a quick rigged set up to 
demonstrate the basic principles, and the research may well be valid.  If 
so, my sincere apologies to Dr. Grierson, and 'Grrrrr!' to the BBC.

Apologies for the rant.

I'm now getting off my high horse.

Stephen


--- On Fri, 6/13/08, Stefan Tiedje <Stefan-Tiedje@addcom.de> wrote:

> From: Stefan Tiedje <Stefan-Tiedje@addcom.de>
> Subject: Re: OT: "Musicians may soon be able to play instruments using 
>just the power of the mind"
> To: Loopers-Delight@loopers-delight.com
> Date: Friday, June 13, 2008, 7:40 AM
> Per Boysen schrieb:
> > http://news.bbc.co.uk/2/hi/technology/7446552.stm
> 
> This is so seventies, and the guy wants to sell it as
> "new technology", 
> and the journalists also don't know its old and think
> its worth to note...
> My brain to music interface works much better already, its
> my fingers 
> which play an instrument, its available since milleniums...
> 
> Stefan
> 
> -- 
> Stefan Tiedje------------x-------
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