The Science of Reading Minds.

Othello: If thou dost love me, show me thy thought.

Iago: Though I am bound to every act of duty, I am not bound to that all slaves are free to. Utter my thoughts? It were not for your quiet nor your good, nor for my manhood, honesty, or wisdom, to let you know my thoughts.

--William Shakespeare

If the technology existed for public mental telepathy--for reading minds--would there be appropriate uses for such an invasion of privacy? Perhaps in medicine or politics, in schools or courtrooms, in government or business, or personal relationships? Amazingly, modern brain science is making such questions more than idle curiosities or science-fiction musings.

Likely since the dawn of consciousness, people have yearned to know what goes on in the minds of others. It is often a theme in literature, as illustrated by the lines from Othello, and is a common motif in popular culture. For example, Mr. Spock of Star Trek used the "Vulcan mind meld" to gain access to others' thoughts.

What would you do with such a power?

Truth or Consequences

Of course, many people today and throughout history have claimed to be telepathic. Some of these self-proclaimed psychics cling to the old idea that the mind is a nonphysical spirit, floating freely, that can be whisked from the air by people with special, mysterious abilities. However, more commonly today psychics give elusive and silly but scientific-sounding explanations for their gifts. The mind produces energy, they say, and this energy passes through space in some physical form and is received by the brains of those who are particularly sensitive.

In fact, these psychics are right about one thing: brain activity does produce physical data. But this physical data is not easily detected at even a small distance, and most certainly no one possesses the necessary receptors to receive and sense such data. Here's where scientific technology can help. The physical phenomena produced by brain cell firings can be measured with modern equipment, and the data can be correlated with various cognitive and emotional states of the subjects. With the right equipment, we can all be telepathic!

If we could read the minds of others, one of the most obvious uses would be to determine whether someone is telling the truth. The technique now used for such a goal--the polygraph --isn't reliable. The polygraph measures various physiological functions, such as heart rate, blood pressure, breathing, and skin conductance. It is often called a "lie detector," since its main use is based on the idea that prevaricators will be nervous and the corresponding changes in their autonomic nervous systems will be detected. However, since even an innocent person may show increased physiological response to an upsetting question--such as "Did you rob the bank?"--polygraphers often use a technique called guilty knowledge, in which they ask questions like "Did the bank teller wear glasses?" based on the idea that a guilty person will know things that an innocent person won't. Even so, the most sophisticated polygraph interview still isn't reliable since there are many ways to disrupt the readings and because (as one might guess) some people don't get nervous when they lie. For greater accuracy, we need to get closer to the source of thought--the brain.

Mind Matters

When a person reads a sentence, hears a speech, experiences an emotion, or thinks a thought, a cluster or network of brain cells fires in a certain pattern with particular intensity and timing. This cellular activity can be monitored using a number of contemporary technologies. Neuronal activity produces electrical waves, sugar metabolism, magnetic fields, and other physical data that can be detected with sophisticated machinery such as the electroencephalograph (EEG), positron emission tomography (PET scan), and functional magnetic resonance imaging (fMRI). As these brain-imaging technologies advance, they will undoubtedly become more precise at identifying the specific thoughts and mental states of subjects. In fact, contemporary brain-imaging techniques are even now verging on having mind-reading capabilities.

Over 100 years ago, scientists discovered that a brain does not work as a whole for all tasks but, rather, is made of interconnected subunits that each have specialized functions. For example, certain brain areas process language, others store memories, some control body movements, others regulate emotions and motivation, and still others process vision. This localization of function initially led to the discovery of brain regions for vision, hearing, movement, touch, and language.

Since the advent of contemporary brain-imaging technologies, scientists have discovered a large number of localized regions for such things as smell, taste, color perception, doing arithmetic, paying attention, spatial perception, various kinds of memory, estimating quantity, and an array of other quite specific and sometimes surprising mental and emotional states, such as religious belief, recognizing faces, and appreciation of the culinary arts. Dr. Oliver Sacks has made a career of writing about people with mental oddities due to damage to specific localized brain areas (for example, his book The Man Who Mistook His Wife for a Hat).

There are many other examples of research demonstrating the brain's localization of function:

* Researcher Joseph LeDoux, for instance, has traced the formation of an emotional memory as it progresses along a pathway from one brain nucleus to the next.

* Antonio Damasio has shown that damage to the brain's emotion centers can disrupt a person's cognitive abilities, such as the ability to make judgments.

* Researchers have described people with damage to a particular brain region resulting in their developing an intense interest in high cuisine as having gourmand syndrome.

* Two schoolgirls reportedly have no ability to remember any events that happen to them because of damage to a small region beneath their temporal lobes. They continue to learn and remember facts in school but have no episodic memory, no recollection of their personal experiences.

* Scientists recently reported that brain wave recordings made in newborn infants could predict which of the children would later develop dyslexia.

* The brain pathway for normal reading has also been identified (from visual area to angular gyrus to Wernicke's area to Broca's area), as have the sequences involved in memory storage.

It has also been demonstrated that these brain areas are somewhat dynamic--that they can change with experience. For example, the brain region that controls the movement of a finger will increase in size as that finger is exercised.

There have been many similar findings that together are forming an intricate, detailed map of brain functioning vis a vis mental, emotional, and cognitive states. To a large extent it is becoming possible to read someone's mind by observing his or her brain activity.

Pictures at an Exhibition

A common tool used today for pinpointing where certain mental functions occur in the brain is the PET scan. A person is injected with a small dose of a radioactive isotope that is absorbed into brain cells. As the isotope decays, it releases positrons (positively charged electrons) that are detected by a screen that surrounds the person's head. A brain image is then created while the person engages in some mental task. A similar technology for localizing mental functions in the brain is fMRI. In this procedure, electromagnets and radiowave pulses are used to detect the amount of oxygen in various regions of the brain, thus indicating the amount of cellular activity.

These brain scans can tell us if a person is thinking about a noun or a verb, a color, a sound, a particular direction, whether the person is recalling a semantic or episodic memory, creating a sentence, imagining a visual image, feeling depressed, having a false memory, having a hallucination, or a myriad of other mental and emotional states.

Neuroscientists who study regions of the brain devoted to memory have found that activity in certain brain locations is associated with the degree to which something being learned will later be remembered. That is, the amount of neuronal activity in the hippocampal and parietal regions during the learning process indicates whether the material being learned will later be remembered well, with difficulty, or not at all. Imagine a future classroom in which brain scans are used to determine whether students have learned their lessons. It would give new meaning to "Students, put on your thinking caps." Would this be an advance in pedagogy or an invasion of privacy?

Researchers have found that depression is associated with a particular set of brain region activities. Also, brain scans indicate that activity in a certain locale predicts whether or not a depressed person will benefit from medication. Would the use of brain scans for medical diagnosis and prescriptive treatment be an appropriate use of mind reading?

Psychiatrists have also discovered that certain personality traits are associated with distinctive brain patterns. For example, PET scan studies have shown that introverted and extraverted people have distinctly different patterns of blood flow in the brain. What if an employer used such technology for selecting employees? Would this be a proper screening tool for certain occupations? Should dating services or marriage counselors use this technique?

It is sometimes possible to tell from localized brain activity whether a person has imagined something or actually witnessed it. Future brain images will likely be highly reliable in detecting such differences. Imagine a legal proceeding in which we wish to determine whether a witness actually saw a crime. Brain-imaging technology could be used to determine if the visual memory is present. Should courtrooms and psychotherapists use brain images to determine who has a false memory? Would such use of brain technology be ethical?

Brain scientists have recently identified the cerebral area involved in intention--the region responsible when thoughts are converted into actions. Perhaps child molesters and other criminals in the future will wear headgear that will monitor that brain region in order to determine when their intentions will be carried out. Would this be a reasonable method of crime prevention or a human rights violation? Should everyone wear such headgear? Could it come with designer labels for fashion-conscious people?

Mind, Reading

The oldest noninvasive brain-measuring technology is the EEG. Neurons transmit signals by electrical charges (similar to a battery) and hence give rise to signals that combine to form brain waves. These electrical patterns vary in intensity and frequency, qualities of electrical energy that can be measured by sensitive electrodes placed on a person's scalp. The EEG gives a physical indication of the rhythmic electrical firing of clusters of brain cells and is a useful tool for reading minds because its resolution time is very short. A word, for example, is processed in the human brain in a split second--too short for PET or fMRI to detect. Also, brain waves are important for rapid brain communication across large neural distances, coordinating and binding together various mental functions. For this reason, it is likely that the EEG will ultimately prove to be useful, even necessary, for pinpointing the neural basis of global qualities of the mind, such as identity and consciousness.

Some neuroscientists study people who are in the act of reading. These researchers are creating a science of reading minds. The localized brain areas involved in reading have been identified, and the next step is to discover the underlying processes. The results of preliminary work on this topic show there is a great deal of similarity from one person to another in the pattern of brain activity that occurs during reading--so much so that it can nearly be determined what people are reading by looking at their brain waves. This similarity from one brain to another while reading might be an evolutionary development that was advantageous because it allowed people to have the same or similar understandings of words and sentences--a significant advantage for communication. Because of the similarities in brain activity from person to person, the science of reading minds may indeed lead to a science of mind reading!

Researchers at Stanford University are using the EEG to record brain activity while subjects see or hear words and sentences. The huge amount of electrophysiological data they collect from each subject is then mathematically screened to hone it to a manageable level. The early results show that some salient differential features can be detected using this method. For example, the researchers have discovered a remarkable similarity in the brain waves emitted when different people read a particular word: one wave means a person is thinking "two," and another wave indicates a person is thinking "left."

Similar results were obtained when subjects were reading sentences. The researchers reported they were able to recognize correctly 90 percent of the brain waves generated by different subjects reading sentences about geography. They could tell what sentence the person had read by looking at the filtered brain wave pattern. They obtained the same rate of success when subjects read simple words such as blue, circle, first, and yes. Finally, when test subjects looked at colors or shapes, their brain waves were similar to those produced when they read the corresponding words, and the researchers could correctly recognize from 60 percent to 75 percent of the brain wave patterns. Although in the very earliest stages and not 100 percent accurate, this line of research is providing results and inspiring questions that are intriguing, to say the least.

Show Me Thy Thought

Perhaps one day a more precise measure than the EEG will be available. Perhaps the new technology will be safe, cheap, and easy. What should we think about such a possibility?

A first thought might be that the government will surely latch onto mind-reading methodology and use it for snooping and other sinister and ominous purposes. This fear seems justified in light of the importance our society places on what people think.

Thinking, in fact, seems to have a higher value than behavior. In the criminal justice system, for example, what a person was thinking--her or his intentions, plans, beliefs, and state of mind--are the main focus of interest and are the main criteria in deciding guilt and allocating punishment. But that's only one example. Talk shows, religion and other institutions, the educational system, political banter, and a legion of other examples indicate that people are obsessed with what others are thinking. Would mind-reading technology be a Pandora's box in such a culture?

While government use of scientific mind-reading techniques may be a legitimate and major worry, there is an even more insidious threat. It is far more likely in our society that advertisers and corporations would be the primary users of a mind-reading technology. Already they inundate us with incessant queries and pryings about our interests, wants, and needs. Grocery stores track our purchases. Junk mail and telemarketing are delivered by use of demographic information. Television, radio, and print advertisements aim at target groups of consumers. Internet services query about interests. We are swamped with polls and surveys. If they could know our thoughts, marketing directors would have a field day.

What if our government, schools, institutions, advertisers, and corporations had scientific mind-reading technology? What kind of future world would that be? Will future marketing surveys record the brain activity of potential consumers as they contemplate products? Will stores have remote scanners that read the minds and moods of incoming customers? Will churches use such technology to discern the faithful from the sinners? Will students and employees be required to wear caps that monitor brain waves? Will the face of political campaigns change if we are able to detect candidates' true thoughts?

What are the ethical considerations of such a world and what should be done about it? Perhaps, soon, I'll be able to read your mind to find out what you really think about all this.

Bruce H. Hinrichs is a professor of psychology and film studies at Century College in Minnesota. His latest book is Mind As Mosaic: The Robot in the Machine, focusing on cognitive neuroscience.