by Maya Lecker and Doron Arbiv
In this blog, we will discuss the ethical issues arising from consciousness disorders and scientists attempts to tap into patients mental states. Specifically, we will discuss reports of monitoring the emotional states of a sub-group of patients suffering from a condition called Locked-in Syndrome. Our main question will be this: Is it permissible to use procedures of brain-computer interface (BCI) as an informative and satisfactory tool to get access to the patient's feeling, and even to determine cessation of a treatment?
Locked-in patients are considered by physicians to possess little to no ability of intentionally communicating with their environment. Since existing diagnostic tools rely on the integrity of cortico-spinal tracts, there is a possibility that while an individual is incapable of executing motor actions, he or she are still aware of their environment and able to intentionally attend to both internal and external representations.
The gap between standard diagnosis relying solely on overt behavior and advances made in both neuroimaging technics and scientific understanding of mental states, had led to great interest in developing methods of communicating with locked-in patients who possess intact cognitive abilities. This is done mostly via neuroimaging technics that allow direct access to the neuronal activity without the mitigation of motor responses. This way of communicating is a form of brain-computer interface (BCI), that is, a direct communication pathway between the brain and an external device.
However, the process of establishing the right technological and physiological conditions required to even begin to determine whether a locked-in patient is capable of non-motor communication is one that might be stressful and even painful for both the patient and the family. For example, preparing a patient for an fMRI scan requires reducing pain-relieving medications. If the patient was communicating we would certainly have required his consent. Is it acceptable not to require consent in case of a locked-in patient? Furthermore, even if the patient is capable of non-motor communication, actually communicating with this patient via neuroimaging methods is usually limited to the researchers' questions and objectives, not the patient or families' needs.
A possible way of tackling this issue could come from monitoring a patient's emotional state, via neuroimaging. This has the advantage of being a more immediate and relevant measure of a patients' distress or discomfort. It is worth to note that there has yet to be a research that had done this procedure. Aside from studies in which BCI is used to communicate with locked-in patients (e.g. Owen, Coleman, Boly, Davis, Laureys, & Pickard, 2006; Birbaumer, 2006), the studies in the BCI field concerning emotions are limited to healthy subjects (for example, Phan, Wager & Taylor, 2002). Therefore, this discussion is quite hypothetical. Nonetheless, it addresses important ethical issues regarding the entangled relationship between neuroscience and medical treatment.
When debating over this subject, we should ask ourselves whether BCI will be a reliable tool to reflect accurately various mental states, and specifically emotional ones. While BCI has been proven to be effective and reliable in other manners of communication and operations (e.g. motor actions), it is not certain that the same logic applies to emotions and feelings.
In other words, when we focus, For example, on negative feelings, we are asking: how is verbally reporting pain or discomfort different from its neural correlates? When a research is performed on healthy subjects, their articulate answers can be compared with the pattern presented by the machine, something that cannot be done in our case. However, even if we could compare the two of them, we cannot make a complete reduction from one to another. The verbal description and the neural pattern are both linked to a term called "phenomenal consciousness" (Block, 2005), a concept relates to "what it is like"' to have this subjective feeling. Philosophically speaking, there is a large debate regarding the issue of putting a "neural tag" on mind states, because there is no agreement on the definition of the essence of those mind states. Therefore, we cannot assume that there is a full overlap between experiencing an emotion and the neural pattern revealed by BCI.
And even if we would find that BCI, as a tool used for reflecting the neural correlates of an emotion, is reliable. That is, we have a direct access to the patient's feelings and emotions, and we can know accurately the exact instance he is feeling discomfort. Can BCI be used as a tool to determine changing or discontinuing medical treatment?
In most western societies, patients are entitled to make decisions regarding their medical care. This is true to some extent even for life-terminating decisions such as those facing terminal patients. It seems only fair, that locked-in patients should also enjoy this right, and BCI seems to provide a means for this right to be realized .However, is communicating through BCI equivalent to verbal communication?
From the little that we know, there are differences. For instance, we do not know the extent to which the patient's ability to perceive and comprehend is intact. This is because BCI usually affords only "yes" "no" responses that might not provide the medical stuff with enough information regarding the patient's mental state. This is crucial if we want to grant the patient the right to make vital decisions about his medical treatment. We are still missing a lot of nuances that verbal, face to face communication provides such as prosody, tone of speech, facial expressions and body language. Emotional information would seem to be more vulnerable in this type of communication, and is it not crucial for a patient's caregivers to obtain this very information when making, what could be, life transforming decisions?
Another important issue to address regarding the neural pattern itself, assuming that there is a full overlap between experiencing an emotion, reporting it and a specific neural pattern in healthy subjects. How neural activity associated with emotions differs from locked-in patients to healthy people? All BCI procedures require training on the same individual for successful classification of brain activity to a specific mental task or representation. This would seem to be the case also when BCI is used to assess emotional states. One problem might be that validating the association between emotional state and brain activity requires asking the patient to report his actual feelings. This seems impossible where locked-in patients are concerned. But even if we manage over this hump, there is still a big difference between reporting being sad, and being in a locked-in state and feeling sad. The mere act of speaking our emotions often has a mediating effect on the way we feel. For instance, talking about our emotions can alleviate stress and anxiety to a certain extent. In a locked-in patient, this important mechanism is lacking. This obviously has a profound effect on the way a patient experiences and regulates his feelings. Hence, we might be measuring something that does not fully correspond to what we usually think of when we think of (and study) feelings.
Some final thoughts: what is the authentic way for a person to convey his will, intentions, desires and thoughts? BCI for that matter is a unique case because it makes this hypothetical question very real and important. If a person is the sum of his neural activity, then whatever information we could get from his brain will bring us closer to unraveling his true "self". If, on the other hand, one sees a person as a phenomena that does not fully lend itself to scientific reductionism, than it would be difficult to accept that there is a full correspondence between the "self" and a persons' neural activity, thus questioning whether BCI really taps into a person's authentic thoughts and feelings.
To conclude, BCI offers intriguing possibilities for people who have been cut out of the world around them. Locked-in patients, like all patients, have a right to determine their fates, and BCI seems to offer hope in that regard. However, certain ethical issues we have mentioned briefly in this article raise important issues that medical and research personnel should take into account: The correspondence between mental states and neural states is unclear, the ability to assess the emotional and cognitive capacities of the patients is limited, and the missing mechanism of spoken language could mean that the inner state of these patients is one that we cannot simply infer from what we know about healthy individuals.
Birbaumer, N. (2006). Breaking the silence: brain–computer interfaces (BCI) for communication and motor control. Psychophysiology, 43(6), 517-532.
Block, Ned. "Two neural correlates of consciousness." Trends in cognitive sciences 9.2 (2005): 46-52.
Owen, A. M., Coleman, M. R., Boly, M., Davis, M. H., Laureys, S., & Pickard, J. D. (2006). Detecting awareness in the vegetative state. Science, 313(5792), 1402-1402.
Phan, K. L., Wager, T., Taylor, S. F., & Liberzon, I. (2002). Functional neuroanatomy of emotion: a meta-analysis of emotion activation studies in PET and fMRI. Neuroimage, 16(2), 331-348.