Freethought & Rationalism Archive

Jesse · 06-30-2003, 04:55 PM

Here's an interesting article about the use of transcranial magnetic stimulation to enhance certain mental skills by suppressing activity in other areas of the brain, based on the theory that this is similar to what goes on in the brains of autistic savants:

http://www.nytimes.com/2003/06/22/ma...faffe3&ei=5070

Quote:

The research of a test in which a research subject was asked to draw a picture of a dog four times, at different stages of his exposure to transcranial magnetic stimulation.

Elvithriel · 06-30-2003, 05:42 PM

Cool.

Elvithriel · 06-30-2003, 07:30 PM

I just thought of something clever.

"We use 100% of our brain, imagine what we could do if we only used 10% of our brain!"

eh · 06-30-2003, 09:52 PM

You definitely win a prize for that one

Arken · 07-01-2003, 05:48 AM

But would it really be worth the brain tumors?

Ab_Normal · 07-01-2003, 08:24 AM

Quote:

Originally posted by Arken
But would it really be worth the brain tumors?

Precisely what I was wondering. I'll stick to coffee, thank you.

Jesse · 07-01-2003, 01:55 PM

Quote:

Originally posted by Arken
But would it really be worth the brain tumors?

Well, our brains generate natural electromagnetic fields all the time, and I think the issue of whether electromagnetic fields generated by various artificial sources like cellphones can cause cancer hasn't been completely settled, but most researchers seem to doubt it (see this article and this one). I think the field from TMS is stronger than that from a cellphone, though.

According to this page:

Quote:

The issue of long-term adverse effects has not been resolved. rTMS has been used since 1983, and there are no reports of long-term adverse effects; however, rTMS has only recently been widely used, and the number of patients who received treatment years ago is still small. Some studies in populations exposed to extremely low-intensity electromagnetic fields, such as those surrounding electrical power transmission lines or electrical appliances, suggest some potential for carcinogenesis, but this is controversial (73). The high-energy, but extremely short-lived, magnetic field created during rTMS is very different from low-energy continuous environmental exposure, and one cannot confidently extrapolate between these areas. Further, exposure to magnetic resonance imaging (MRI) scanners, which create intense magnetic fields that approximate those of rTMS, is not associated with cancer (74).

This page also suggests that a lot is unknown about long-term effects:

Quote:

Both TMS and rTMS can disrupt cognition during the period of stimulation. However, the safety concerns are about alterations in cognitive function beyond the period of stimulation. The limited investigation of short-term neuropsychological effects of TMS has not demonstrated significant changes.[39] Little information is available about long-term effects. The technique has been in use for more than a decade without reports of long-term adverse consequences. The rate of cancer is not increased in individuals with prolonged exposure to high-intensity magnetic fields, such as MRI technicians.[145] However, TMS involves extremely brief, focal exposure to high-intensity magnetic fields and thus safety information from MRI technicians, or even people who live near power lines (lengthy exposure to low-intensity magnetic fields) may not be germane.[146]

New pharmacological agents undergo extensive examination of safety in animals and normal volunteers before testing efficacy in clinical trials.[147] To some extent, this scenario has been reversed with rTMS. Controlled trials across a variety of neuropsychiatric conditions are underway, yet safety information is limited. Reassuringly, single-pulse and other TMS measures of cortical excitability are believed to be devoid of significant safety concerns. However, rTMS has shown potential to ameliorate neuropsychiatric symptoms. The potential for adverse cognitive effects must be considered precisely because it is hypothesized that rTMS is a sufficiently powerful modulator of regional functional activity to have therapeutic properties. More comprehensive neuropsychological evaluations of the short- and long-term effects of rTMS are needed.

At present, seizure elicitation is the major safety issue linked to rTMS. To avoid seizures, the magnetic intensity delivered with rTMS is adjusted for each individual relative to their motor threshold.[10,133] This dose-adjustment method rests on the unproven assumption that the seizure risk of rTMS over diverse brain areas is predicted by the threshold for a single TMS pulse to depolarize pyramidal neurons in the motor strip. More needs to be learned about the contribution of rTMS parameters to seizure induction, and validated methods should be established to minimize seizure risk. Much of this work could be conducted in animals. Alternatively, ECT presents the one situation in humans in which seizures are provoked for therapeutic purposes. A reliable method of seizure induction with TMS may have important advantages over traditional ECT by offering better control over the intensity and spatial distribution of current density in the brain.[148] Developing a TMS form of convulsive therapy is largely an issue of technological advances in stimulator output and coil design. Such a development may also foster better understanding of the safety of nonconvulsive uses of rTMS.

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06-30-2003, 05:42 PM	#2
Elvithriel Regular Member Join Date: Feb 2003 Location: Canada Posts: 127	Cool.

06-30-2003, 07:30 PM	#3
Elvithriel Regular Member Join Date: Feb 2003 Location: Canada Posts: 127	I just thought of something clever. "We use 100% of our brain, imagine what we could do if we only used 10% of our brain!"

06-30-2003, 09:52 PM	#4
eh Senior Member Join Date: Sep 2000 Location: Canada Posts: 624	You definitely win a prize for that one

07-01-2003, 05:48 AM	#5
Arken Veteran Member Join Date: Jun 2003 Location: North Hollywood, CA Posts: 6,303	But would it really be worth the brain tumors?

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