Brain Stimulation and Mind Control: Is it Possible?

I just finished reading a recently published study that measured how brain stimulation influences moral decision-making in humans. The study used a form of noninvasive brain stimulation called ‘trans-cranial direct current stimulation’ (tDCS). For those who are not familiar with it, tDCS is a technique that involves applying a low level electrical current to the brain (and thus stimulating or inhibiting specific brain regions) through application of electrodes to particular regions of the scalp. To learn more about tDCS see the article that I have written about tDCS (What is Transcranial Stimulation).

I found the headline of that particular study interesting because it inferred that moral decision-making could be influenced by an external electrical stimulus (tDCS). I’ve read up on many studies involving tDCS’s role in treating depression, chronic pain, addiction, and other neurological/psychiatric illness, but oddly I never came across studies that measured tDCS’s influence on human morality. But I guess that makes sense, since morality arises from the brain.


A Brief Background on how the brain makes moral decisions:

There are two major aspects involved in moral decision making: the emotional response and the logical, practical response (often labeled the ‘utilitarian’ response). When we are faced with a tough moral decision, the emotional and the practical/utilitarian responses battle each other. Whichever response is strongest wins, and leads to the ultimate moral decision that is made.

Moral dilemmas are classified into two categories: moral-impersonal dilemmas and moral personal dilemmas.

Let’s consider a situation in which a trolley is hurtling toward five people. Let’s say you are given the option to throw a switch that changes the direction of the trolley so that its trajectory would now be aimed at a single, but separate individual. Throwing the switch would kill only one person, but would save the five people it initially would have killed. Would you throw the switch? Based on research, most people would. This type of moral dilemma is called moral impersonal dilemma because throwing a switch is fairly impersonal, and thus does not invoke a strong emotional reaction. This makes for an easy win for the utilitarian moral response over the emotional response.

Now place yourself in a different scenario. You are standing next to a stranger on a bridge over a set of train tracks. A train below is hurtling towards five people. If you push the stranger off the bride onto the tracks, you would bring the train to a halt, and thus save the five people it had been hurtling toward. Would you do it? Most people would not push the stranger off the bridge. This is because this type of moral judgment involves strong activation of emotional regions of the brain. The dilemma in the latter scenario is called the moral personal dilemma. When faced with these types of dilemmas, emotional responses are often so strong that they influence the logical parts of the brain and lead to a decision that includes a strong emotional component. Emotion wins over utilitarianism.

There are two regions of the brain thought to play a role in moral decision making: the dorsolateral prefrontal cortex (DLPFC) and the temporal-parietal junction (TPJ). There has been much debate regarding the specific roles the two regions play in morality. Some studies suggest that the DLPFC is involved in logical,rational, non-emotional decision making. However, other studies have shown that people who have had their frontal lobes removed make more utilitarian, and less emotional, responses.


The Highlights of the tDCS and Morality Study

I’m not going to go into too much detail about this study for fear of boring you to death. I will give you the highlights and if you’d like to refer to the details, here’s the article. The study hypothesized that by stimulating either the dorsolateral prefrontal cortex (DLPFC) or the temporal-parietal junction (TPJ) via tDCS, moral decision-making could be manipulated. The study included 100 participants, split up into five groups of 20 people each that stimulated various regions of the brain as follows: right DLPFC, left DLPFC, right TPJ, left TPJ, and a sham control group. After tDCS stimulation of the respective brain regions, each participant was given a series of stories involving moral dilemmas.

Results: The group who underwent stimulation of the right DLPFC rated a utilitarian responses in moral-personal dilemmas (i.e. deciding to push someone off a bridge to block a trolley from killing five people) as inappropriate significantly more often than the control group. Interestingly, stimulating the right DLPFC did not change decision making in moral impersonal dilemmas. Stimulation of the other regions of the brain did not produce any significant change in moral decision making.

The conclusion: Electrical stimulation of the Right Dorsolateral Prefrontal Cortex can influence moral decisions in emotionally taxing moral dilemmas.

What does that mean? The frontal lobe likely plays a role in integrating emotions with rational thinking when faced with tricky moral scenarios, rather than purely being involved in rational thinking. While the frontal lobes have been thought to be the source of logical thinking, this study suggests that the frontal lobes also help integrate our emotions with our rational thinking.


Does this mean people’s minds can be controlled?

We have a long way to go to total mind control (hopefully we never get there) but studies such as this one suggest that it is possible in the future. Technology is already on its way to advancing in this realm. For instance, there are ongoing studies involving invasive brain stimulation, many of which are funded by DARPA (Defense Advanced Research Project Agency). In fact, I bore witness to these studies during my clinical neurophysiology fellowship at Emory University. As a part of treatment for medication-resistant epilepsy, my patients would undergo a presurgical evaluation in our Epilepsy Monitoring Unit. The presurgical evaluation involved placing electrodes in brain regions that were thought to cause the seizures. By implanting the electrodes into the brain, we could measure the regions where the seizures began so that they could be surgically removed, thus curing the patient of his/her seizures. These implanted electrodes also were used for research purposes as a means to directly stimulate regions of the brain and identify what behavioral effect was produced. During my morning rounds, I would often encounter the researchers stimulating various implanted electrodes in my patients.

During one particularly memorable experience, I witnessed a patient induced into a euphoric state after direct stimulation of an electrode implanted in a region of the brain called the anterior cingulate gyrus.

After stimulation, he suddenly became giddy, and instantly thought everything was funny. He was asked to think of the saddest moment in his life. He thought of his grandmother dying (a few personal details of this story have been changed to protect the privacy of the patient) – he continued to smile and say that, yes, that was an extremely sad time for him but that he did not currently feel sad about it.

Another patient of mine experienced an intense fearful reaction during stimulation of an electrode in a brain region called the amygdala. As the researchers increased stimulation, he mentioned that he felt an overwhelming feeling of doom and fear. The intensity of the fear grew with increasing stimulation until he could no longer handle it and implored the researchers to stop (which they did).

Studies, such as the one described above performed at Emory, are implemented because we are still trying to learn more about the brain. In fact, the goal of that particular study was to identify brain regions that could be stimulated to improve memory (which potentially could hold therapeutic benefits to those with dementia).


The Future of Brain Stimulation: Should we worry?

Brain stimulation technology (i.e., deep brain stimulation) is already being used in people with neurological illnesses such as Parkinson’s Disease and Epilepsy. Will this technology ever become advanced enough for mind control? My suspicion is yes. When? Not sure. Would it be used for mind control? In a military setting, perhaps (DARPA is funding many of these studies, and not because of a generous heart). In a civilian setting, I don’t know. Hopefully brain stimulation will never be used for mind control on any one, although that seems like a naive conclusion. Nonetheless, the potential is there, and so discussions regarding ethical use should start now. 

However, it is important to note that brain stimulation (both noninvasive and invasive) also holds therapeutic potential for people with neurological and psychiatric illness. It also holds the potential to enhance brain functioning of those who are neurologically healthy (the ethical implications of this are debatable and will be the topic of another discussion). As with most matters regarding topics involving technology + the human brain, brain stimulation is complicated and fascinating, and serves as a promising tool for the future (think brain-machine interface), but whose consequences (both good and bad) should be discussed sooner rather than later.