Neurotechnology Brain Stimulation

Neurotechnology refers to the field of technology that is used to measure and manipulate the brain's processes. Researchers have created a variety of new brain stimulation neurotechnologies that may find increasing use in the future for those who have different types of brain disorders. Often brain disorders can have a devastating impact on the affected person. Neurotechnology is moving at a rapid pace and may allow researchers to shape the brain is some really interesting ways. New neurotechnologies include transcranial direct current stimulation, deep brain stimulation, deep transcranial magnetic stimulation and ultrasound. These technologies can alter brain chemistry for beneficial effect. Most of them use electricity to modify the functioning of the brain.

Transcranial direct current stimulation (tDCS) is a way of non-invasively stimulating the brain using a small amount of electricity. This treatment is actually very different than electroconvulsive therapy (ECT), which is another way to stimulate the brain with electricity. ECT requires a person to have anaesthesia and gives the brain a 1 amp jolt that causes a seizure. ECT causes massive changes in brain functioning and can be effective for many brain disorders such as depression and schizophrenia. Transcranial direct current, though, is a much more selective and benign treatment. Instead of 1 amp of electricity, tDCS uses 1-2 milliamps of current. tDCS can be performed on a person when they are fully awake and conscious. The only noticable side effect is a transient scalp irritation that occurs when the electricity is turned on. So basically for this technology, researchers place two sponge electrodes on specific areas of your head. These sponge electrodes are connected to the anode and cathode parts of a nine volt battery. The sponge electrode that is connected to the anode increases brain activity underneath it, while the sponge electrode attached to the cathode tends to decrease brain activity. So doctors are able to selectively increase or decrease brain activity in brain regions that are near to a person's head. You can even perform this type of brain stimulation on yourself as shown by the man below.

Researchers have targeted specific areas of the brain using tDCS. They have found that they can improve working memory when they stimulate an area of the brain called the left dorsolateral prefrontal cortex. Working memory refers to the brain's processes for storing information temporarily. You would use your working memory, for instance, to remember a phone number for 30 seconds to a couple minutes. So increasing working memory would allow a person to remember more numbers for that time. tDCS can also improve a person's driving skills and make them more cautious when that same area of the brain is activated.

Transcranial direct current stimulation has been used for stroke rehabilition too. By targeting specific brain areas for activation, they can help people who have many disablements due to a stroke. So tDCS may find use for a number of other brain injuries and not just stroke.

In the future, researchers will have many interesting experiments that can be run using this relatively recent technology. It could potentially help a number of people improve their brain disorders.

Deep Brain Stimulation (DBS) involves implanting a brain implant deep within the brain. The DBS device requires a person to undergo brain surgery to get fitted with it. The deep brain stimulation implant delivers electricity to the surrounding brain tissue and this appears to alter the brain's functioning. Deep brain stimulation is believed to cause selective deactivation of the brain region that surrounds the device. The DBS device is connected to a battery that is implanted inside a person's chest. Deep brain stimulation has already been used for a number of different disorders including depression and parkinson's disease. Deep brain stimulation devices are continuing to get better and smaller as time goes on. There are, unfortunately, some dangers to getting this device implanted. A person who gets a deep brain stimulation implant could get an infection in their brain.  This could be deadly if the infection is antibiotic resistant. There is also the possiblity of brain bleeding due to this implant, which could become very serious. So deep brain stimulation may never become as useful as other non-invasive brain stimulation techniques like TMS or tDCS. However doctors are continually improving the procedure as time goes forward. So it will likely become safer in the future.

Deep transcranial magnetic stimulation (TMS) is another way of non-invasively stimulating the brain. Unlike deep brain stimulation, deep TMS does not required a person to undergo surgery. All a person has to do is have their head positioned in that hair dryer looking type device shown above. The deep TMS device uses electromagnetism to generate an electric current deep within the brain.  The electromagnetic pulse is able to easily pass through a person's skull.  Unlike transcranial direct current stimulation, deep TMS is able to penetrate deep within the brain.  The deep TMS device adds up several magnetic fields simultaneously and this allows it to reach almost any brain region selectively.  Adding up the fields allows scientists to stimulate inner brain regions without unecessarily stimulating outer brain regions. 

Transcranial direct current stimulation and conventional TMS are only able to reach brain regions that are close to a person's skull. Deep TMS can excite or inhibit any brain region with centimeter precision.  Conventional transcranial magnetic stimulation has been around since 1985.  It has shown a lot of promise for brain disorders and has been recently approved as an antidepressant treatment.  The problem with conventional transcranial magnetic stimulation is that his been limited in its brain stimulation capacity.  Conventional TMS can only reach 1-2 cm within the brain.  Deep TMS, however, has been able to overcome that limitation.

Deep transcranial magnetic stimulation is being tested to treat a variety of disorders such as depression, addiction and schizophrenia. Researchers are now able to directly target the reward related regions of the brain. Electric stimulation of a brain area called the nucleus accumbens, for instance, has been shown to be very rewarding and pleasurable. Now scientists will be able to use this device to non-invasively stimulate those brain regions that were previously out of reach. This could allow a person to increase their hedonic capacity for reward and make life more enjoyable. This would especially be useful for people who can't experience pleasure (anhedonia) such as those with depression or who are addicted to drugs.

Researchers are also testing this device to help those who are overweight or obese.  By stimulating a deeper brain stimulation called the hypothalamus, they may be able to alter the functioning of the body's metabolic processes.  This would allow a person to shed the pounds, without having to do any work at all.   

Below you can watch a demonstration of this technology.

Researchers from the Arizona State University have recently discovered that they can use ultrasound to non-invasively alter brain functioning.  In the past, ultrasound has been used for imaging diagnostics.  However, it is only recently have scientists discovered its ability to alter the firing pattern of neurons. 

Ultrasound has the capability of moving through a person's skull unimpeded. It can be targeted to selectively excite or inhibit deeper brain areas. The benefits of using ultrasound is that it has a much greater focal accuracy when compared to deep transcranial magnetic stimulation. It can stimulate brain regions that are .5 - 2 mm in diamter, while TMS can only stimulate areas 1 cm or greater. This would enable a very good selectively and would reduce off target activation of brain regions. Scientists may be able to use this technology to increase or decrease activity in almost any brain region.

There is also the possiblity of beaming sensory experiences into a person's head. Ultrasound could activate brain areas that are associated with sight, sound or other senses. This could allow virtual reality sensations to be created in the brain by way of non-invasive stimulation.  The researchers also speculated that ultrasound may be able to implant memories into a person's brain, similar to the movie Total Recall.  Obviously this is highly speculative currently.  However, ultrasound will likely enable scientists to glean a much better understanding of the functioning of the brain.  Transcranial magnetic stimulation, for instance, has been used to selectively "knock down" the functioning of brain regions temporarily to see the resulting effect.  This temporary lesion is a powerful way of learning about how the brain actually works.  So ultrasound could be used in much the same way.  This type of brain mapping could go a long way in our understanding of the human mind.

Ultrasound as a tool for neuromodulation may eventually replace transcranial magnetic stimulation as the preferred method of brain stimulation. The researchers at Arizona State University are already forming a new company to further develop this technology. So there could very well be clinical trials using this technology in the near future.