welcome covers

Your complimentary articles

You’ve read one of your four complimentary articles for this month.

You can read four articles free per month. To have complete access to the thousands of philosophy articles on this site, please


Hacking the Brain

Could advances in technology soon give us perfect knowledge of other minds? Bora Dogan investigates.

I may not know what you’re thinking, but I know a machine that can – several, in fact. With names like Cerebus and BrainGate, these machines wouldn’t sound out of place in a sci-fi movie, but they’re real and they’re here to read your mind. The latest devices in brain-machine interface technology have been developed to analyze the neural activity of the brain and figure out what you’re thinking. This branch of neuroscience promises a future where we can operate computers and machinery by thought alone.

Why should philosophers care? Philosophy has a history of handing over its domains of enquiry to other disciplines – or, it might be said more generously that philosophy has given birth to other disciplines. Physics, which was called natural philosophy until the end of the 19th century, started to break away from philosophy after the efforts of Francis Bacon to establish the importance of the scientific method. Likewise, philosophical investigations into what emotions are became psychology. Today, cognitive science is revealing so much about the workings of the mind/brain that it may soon encroach on the fundamental problems in philosophy of mind. A survey of recent developments should give philosophers an idea of what to expect.

The Cerebus, which is being developed by Media Lab Europe, is worn over the head and can read brain waves using a technique called electroencephalography (EEG). It tunes into nodes in the brain that are associated with processing information such as light, color and distance, allowing the wearer to manipulate a computer connected to the Cerebus. This is one of several methods used to read the activity of the brain. A more powerful but also invasive method requires small chips to be implanted on the surface of the brain, while yet another involves attaching electrodes. As yet theoretical, but ultimately most practical of all, is a method called magnetoencephalography (MEG), which is as noninvasive as EEG but as capable of reading neural activity as electrodes or chips.

Science has a way of sneaking up on the public’s awareness. When a technology makes the headlines, we often wonder where on earth it came from. But in fact, there are untold years, even decades, of work done by scientists that lead up to the eureka moments. The completion of the human genome project five years ago is a case in point: the project had started in 1990 when few people knew that dozens of machines had been tasked with reading all 30,000 of our genes. Brain-machine interface technology has also been developing for some time now, but it’s still under the radar.

The principles at the heart of the technology have been around since the 1920’s when electroencephalography was first invented. It is simply a matter of recording the electrical activity in a brain. Typically, two electrodes are placed on the scalp to measure the voltage between two points. This very low voltage electricity (about 10 millionth of the voltage found in a residential mains socket) is the so-called brain waves. The frequency of the waves varies depending on the activity of the person. Very low frequency ‘delta waves’ occur during deep sleep. High frequency ‘beta waves’ are associated with intense activity, anxiety or concentration. However, the correlation between brain wave frequencies and states of the mind doesn’t tell us much about how the brain is processing its sensory input and sending out commands to the rest of the body. But decades of study have enabled scientists to look at the patterns of electrical activity in the brain and infer what’s going on inside.

Miguel Nicolelis and John Chapin were the scientists who undertook the daunting task of reverse-engineering the brain in the 1990’s. In timeless fashion, they started their research with rats. They used several pairs of electrodes to record the simultaneous neural activity in a number locations in the rats’ brains. So, when the rat performed a task such as pressing a lever to release food, they would record the pattern of neural activity that went along with it. After the rat had practiced this trick a number of times, the food reward was no longer released when the rat pressed the lever. Instead the rat received the food when the previously-established neural activity was detected in the rat’s brain. Soon the rat learned that it did not need to press the lever at all. It only needed to think about pressing it, and the food would be released. At Duke University’s Center for Neuroengineering, Nicolelis and Chapin moved on to training monkeys with more complicated tasks. By 2003, they had macaque monkeys controlling robot arms by thought alone. The monkeys’ neural patterns were established for the movement of their own arms. Then, through a computer that read their brain output, they could control the robot arms to reach, grab and move objects as competently as with their own arms.

There are three different types of brain wave technology being developed right now. Cyberkinetics, an American company, is testing a system called BrainGate, which uses a 2-millimeter-square computer chip surgically attached to the brain. The chips read a large array of neurons and transmit the data via cables to a computer. Five quadriplegic patients are testing the system by using it to control a cursor on a computer screen. If the trials are successful, the system should allow a disabled person to control prosthetic limbs and other devices by thought alone.

Another application of brain wave technology is in computer games. Media Lab Europe in Ireland recently demonstrated a system called the Cerebus that allows a computer game character to be controlled by thought. Mind Balance, the game they have created, is very rudimentary: the player only controls his character’s leaning to the left or right. But unlike Cyberkinetics’ BrainGate, the Cerebus does not require a chip to be surgically implanted on the person’s brain to read his or her brain waves. Instead it uses electroencephalography, reading the brain’s electrical output through the scalp. The noninvasive nature of the system means that it can be developed into a marketable product far more easily.

The third application is being developed by an American company called Brain Fingerprinting Laboratories, which is using the brain wave patterns to reveal what a person knows or remembers. When we are given a stimulus that we recognize, such as a sound, word or image, our brain waves jump to a noticeable peak after 300 milliseconds. This peak is called the P300. The company has already used the technology to test if a murder suspect, who has been waiting on death row for the last ten years in Oklahoma, recognized objects from the scene of a crime. The tests suggested that he didn’t recognize the objects as the murderer should.

Criticisms and concern about brain wave technologies are bound to get louder as the science grows apace and people become more aware of its implications. There will be many applications for brain-machine interfaces that no one has conceived of yet. But even those that are in the labs right now raise questions of ethics, privacy and the future of society. The development of Cyberkinetics’ BrainGate and similar systems seems entirely benevolent, offering a unique opportunity for people to overcome their disabilities. But military minds such as those at the Defense Advanced Research Projects Agency (DARPA) are looking for ways to use this technology to create remote-controlled and ‘enhanced’ robot soldiers. There is already some research to indicate that neural activity – hence thoughts – can be manipulated as well as read from outside the brain. If that capability becomes fully developed, it will carry a great risk of being abused.

The course set by the Mind Balance computer game also presents certain dangers ahead. Young people today are already comfortable with virtual worlds. Is it possible that a fully functioning brain-machine interface could tear society apart between those who favor a virtual reality and those who prefer a real one, as in the movie eXistenZ?

And what of the intrusive nature of brain fingerprinting? Unlike a lie detector, this technology doesn’t even require its subject to reply to questions. The 300 milliseconds in which the telltale brain wave peak occurs is not enough time for the owner of the brain to become conscious of his thought. The machine knows whether he recognizes the stimulus before he does. As the technology for reading brain waves improves, the privacy of our most private possessions, our minds, may become jeopardized.

Aside from social and ethical considerations, brain-machine interfaces have some interesting implications for the philosophy of mind. The mind-body problem is concerned with how a physical entity such as the body (or, specifically, the brain) can house non-physical things such as thoughts, emotions and consciousness. Can machines that can read thoughts give us any help in solving this ancient problem? It appears not. We have already been capable for some time of making rudimentary readings of the ‘contents’ of the mind through measuring physical activity in the brain. Even if we can develop technology to give us very accurate readings, we are still only making measurements. It would be pure speculation to suggest that a quantitative increase in our ability to read the brain will reach a ‘critical mass’ and give us a qualitatively different grasp on the mind-body problem.

So what about the two related problems of empathy and of other minds? If our machines are able to reveal the contents of the mind at ever-increasing resolutions – until we can pinpoint the subtlest of changes in thought or emotion – will we be any closer to confirming that other people feel and think as we do? And can we overcome the Cartesian demon and prove that other minds exist? A simple thought experiment may illuminate both of these problems. Suppose that progress with brain-machine technology reaches a point where we have a machine that can read the contents of a human brain with full accuracy. Suppose further that we also develop the reverse technology, until we have a machine that can transmit any thought into a person’s brain. We could then use this as a two-way communication device between two people, say Hector and Anita (see article), who would then be able to communicate without the use of speech, writing or any other outwardly visible means. Would these two people be in a position to confirm the existence of each other’s minds? It is tempting to thinks so. But Descartes’ demon has not been entirely vanquished. The machine, acting as medium, might be fooling Hector into thinking Anita’s mind exists, or vice versa. It might be no more reliable than more conventional mediums – sound and light waves – that we use to communicate.

But if Anita assumes that Hector’s mind exists, does the device enable her to know his thoughts and feelings with complete accuracy? At first this looks promising. Our understanding of other people is usually limited by the language in which we communicate. Different people use the same words in subtly different ways, and even if they use a word the same way, there are limits to the shades of meaning it can convey. In our thought experiment, language is bypassed as Hector’s feelings and emotions generate corresponding feelings and emotions in Anita. Doesn’t this enable Anita to know exactly how Hector feels?

There are two problems with this. First, however good the technology, the machine reading Hector’s brain must be encoding the information in some way to pass it to the machine creating thoughts and feelings in Anita’s brain. The code, whatever it is, is another sort of language and thus inevitably prone to the distortions and ambiguities of natural language. Second, even if this were not the case, the fact is that Anita’s mind is different from Hector’s and this alone ensures that reproducing the electrical impulses in Hector’s brain will not give Anita perfect knowledge of Hector’s emotions.

It is not every day that science reveals depths of our existence that we consider to be fundamental and in need of philosophical inquiry. In the 20th century, it happened with nuclear physics, and then again with quantum mechanics. It may soon happen again with cognitive science and brain-machine interfaces. How we will prepare for that day is something to think about.

© Bora Dogan 2005

Bora Dogan studied philosophy in London and journalism at Columbia University, and is online editor of Philosophy Now.

This site uses cookies to recognize users and allow us to analyse site usage. By continuing to browse the site with cookies enabled in your browser, you consent to the use of cookies in accordance with our privacy policy. X