Dr. Lawrence Behmer with Loyola University Chicago is
interested in the cognitive and neural processes that control and regulate
planned actions and investigates how the brain perfectly executes such actions.
Behmer hopes to improve current models of the brain-computer interface (BCI), a
promising form of technology that could improve the quality of life of patients
with disabilities and change the way that we manipulate the world. In light of
a recent article published in The New
York Times, “A Pioneering Neuroscientist Reports From ‘the Border of Life
and Death,” the BCI may also allow patients in a vegetative state to
communicate with those around them. The article, written by George Johnson,
explains how a neuroscientist found evidence of life in patients who have
suffered from traumatic brain injuries; he believes that this could change the
way these patients are seen by their families and health-care professionals,
which may then lead to better outcomes for traumatic brain injury.
According to Behmer, BCIs link the brain and technology in a
way that allows computers to read the electrical activity of the brain and
translate it into what the brain aims to accomplish in the physical world.
Behmer provided the audience with many examples of BCIs, like an EEG band that
aids in meditation, a toy car controlled by the mind, and prosthetic limbs. He
especially focuses on the prosthetic arm, which moves according to electrical
signals in the brain. While Behmer acknowledges that this is promising for
patients with movement disabilities, he emphasizes that there is a lot of
progress to be made for the technology. In the video he presented, the arm
reaches for a water bottle and picks it up, an action facilitated by a
paralyzed wearer. However, Behmer asserts that if someone were to move that
water bottle after the command had been initiated, the arm would have carried
out the task to termination, failing to pick up the water bottle. As we know,
individuals with normal mobility would easily compensate for the movement of
the water bottle, smoothly changing the trajectory of their reaching arm and
successfully picking it up. Unfortunately, that is not the reality of this
prosthetic arm, and Behmer aims to improve its technology through his research.
In a recent study, Behmer used TMS,
EEG, and behavioral data to investigate two models for executing planned
actions: a serial chaining model and an inhibitory control model. The serial
chaining model predicts that our actions are executed in an “N-1 feedback”
(Behmer, November 27, 2018) in which subsequent actions are dependent on
feedback from the previous actions. For example, if typists were typing truck, the letter R should be highly
active after typing the letter T, while the U, C, and K would remain inactive.
In the inhibitory control model, activation of letters follows a gradient in
which early responses in the sequence should be highly active and slope off as
the typist moves further away from them. If typing the letter R in truck, for example, the R would be at peak
activation while the U becomes active. Once the participant types the letter U,
R becomes less active and C becomes more active. The data indicate that the
actions followed the inhibitory control model. Behmer points out that this is
only a small piece of the puzzle and he is excited to continue investigating
skilled motor performance.
In researching the brain-computer
interface, I read a compelling article from The
New York Times that expands the list of practical implications for Behmer’s
research and the BCI. However, it does not directly relate to Behmer’s research
on skilled motor performance. Rather, it shares a theme with the practical
implications of his research: communication. Behmer presented the BCI as a
means for paralyzed patients and amputees to actively manipulate the physical
world - to communicate with the world again through their own actions. As
someone who is passionate about medicine and the quality of life of patients,
Johnson’s article, along with Behmer’s presentation, allowed me to see the BCI
as a potential means for both physical and linguistic communication.
In his article “A Pioneering Neuroscientist Reports From
‘the Border of Life and Death,” George Johnson recounts an interview with Dr.
Adrian Owen, a cognitive neuroscientist and the author of the book Into The Gray Zone: A Neuroscientist
Explores the Border Between Life and Death. According to Johnson, Owen
studies the brains of patients who have experienced traumatic brain injury and
have been left in a vegetative state. Many of the patients that Johnson
mentions had been in a vegetative state for years prior to their encounters
with Owen. Despite this, Owen found evidence of life. One patient, for example,
showed evidence of higher cognitive processing while watching a movie under an
fMRI scanner; Johnson quotes Owen, saying “At all the critical twists and turns
in the plot… Jeff’s frontal and parietal lobes responded exactly like those of
a person who was conscious and aware” (Johnson, 2017). However, Johnson
explains that this was not enough for Owen to demonstrate that the patients
were mentally alive, and developed a method that would prove that his patients
were thinking and feeling - he had to “catch their brains in the act of making
a willful decision” (Johnson, 2017).
This is when Johnson introduces
Carol, a patient who sustained a craniectomy after being struck by two
vehicles. She had been in a vegetative state for months. While under the fMRI
scanner, Owen asked Carol to image herself playing a game of tennis. This
activated the premotor cortex in the same way it would in a healthy person.
Next, Owen asked Carol to imagine herself walking through her house, and the
parahippocampal gyrus (the area of the brain responsible for spatial memory)
responded in the same way it would in a healthy person. This convinced Owen
that she had made a deliberate choice. He then took these findings and applied
them to a patient named Scott. He asked Scott if he was in pain, and if the
answer was yes, he asked Scott to imagine walking through his house. If the
answer was no, he asked Scott to imagine himself playing a game of tennis. The
premotor cortex responded, signalling that Scott was not in pain. Although
there is a possibility that the signals observed by Owen may not be as significant
or as reliable as they seem, Owen’s findings make him hopeful for the future of
vegetative patients.
Owen’s work shows signs of higher cognitive functioning in
vegetative patients consistent with that of a normal person. He believes that
brain-computer interfaces may allow patients to have conversations, type
emails, and take courses. However, it is a stretch to claim that a scanner
could reliably translate electrical signals into thoughts and intentions. With
more work to find clearer, yes-or-no signals from the brain, I believe it is
feasible to develop a BCI that would allow patients to communicate with
yes-or-no answers. This would allow them to express themselves, interact with
their families, and get involved in their care, improving their quality of
life. Whether the signals originate from the motor cortex (as if the patient is
trying to produce speech) or from other regions of the brain that Johnson
describes, Behmer’s work can aid in the production of BCIs for linguistic
communication as well as physical communication.
Johnson,
G. (2017, August 22). A Pioneering Neuroscientist Reports From ‘the Border of
Life and Death.’ The New York Times,
p. 13.
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