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Exploring Brandeis’ labs: Spacial Orientation Lab

By Blake Linzer

Section: Features

September 23, 2016

If you enter the left building of the Rabb Graduate Center you will be surrounded by offices where much history, philosophising and other fine humanities research occur every day. But below these historians and philosophers, down a “U”-shaped staircase and through a door you will find fascinating and interdisciplinary science laboratories at Brandeis and, likewise, beyond.

Down those stairs and through that door is a large lab, with human centrifuges, a chair setup that can rotate you in two dimensions at one time and far more. Down those stairs is a team of neuroscientists, physicists, computer scientists and mathematicians. Down those stairs is the Ashton Graybiel Spatial Orientation Laboratory.

The laboratory is officially part of the psychology department and is a founding lab of the Volen Center. Janna Kaplan, senior research associate at the spatial orientation lab, explained some of the laboratory’s research. She began by introducing some fundamental but highly neglected thoughts about human body control.

The Research

When a human stands normally (assuming a healthy individual) our body is able to balance by shifting one’s weight equally on our two legs. This is the equilibrium state. Each of our legs have gathered enough strength throughout our lifetime to be able to support half our body weight.

Indeed our legs are strong enough to support more than the amount normally required of them. This is evidenced by the fact that humans can stand on one leg or wear a heavy backpack with little strain to the legs. But since our arms and core are not adapted to carry the weight, we strain when we do a pushup, and our back hurts when we lift a bag.

Our two legs support our body’s weight without us falling so long as our center of gravity is within a range of circumference that our legs are physically able to support. When that center of gravity extends beyond that circumference, we fall or require a cane or walker. Older people, who tend to slouch because of poor muscular-skeletal health and who can not keep their center of gravity within their circumferences, therefore require canes or walkers.

When a human goes into a novel environment such as different gravity environments (or when an elderly person stoops), his or her center of mass is not in the same location and can extend outside the circumference we are generally accustomed to. There are two ways to deal with this problem. One is to introduce a cane. But without a cane, the body must adopt on its own to its new environment.

Using a human centrifuge, the Spatial Orientation Laboratory can create variety of novel environments to examine how well humans adapt under a variety of atypical different force circumstances. The lab creates different environments by, for example, changing how far one stands from the center of the centrifuge or the degree of tilt one is on inside the centrifuge.

In addition to studying these so-called sensory motor adaptation, the lab also hopes to understand the basic science of posture control, including making mathematical models of posture control. A lot goes into posture control—from muscle memory to visual cues to balancing systems we have within our ears.

One can easily imagine the range of application posture control research can have, especially for those with deficient systems, such as the elderly. To give a perspective of what goes into posture control close your eyes. Place your hand above your head. How do you know how to get it there? You have gained a muscle memory, and can naturally intuit where above your head is.

Posture control can be studied by varying the environment, and it can also be studied from a more technical perspective in a natural environment. One set-up used to study posture control is that a participant will stand on force plates in different ways: two legs in front and behind each other or side to side with different force plates set up also to measure hand force measurements (if someone goes to balance with their hand).

One finding the lab has made is that participants attempting to balance with their hands can do so with an extremely low forces, even just by using a finger. By adding oil to the hand force plate, the lab has found that the forces used to balance are shear frictional forces. This explained one physical-therapist-turned-graduate-student’s queries as to why her former patients used to, when they lost their balance, simply tap a railing with one finger lightly.

In addition to this research, the lab studies spatial illusions. The most obvious example of a spacial illusion is the common event of sitting in a train and not knowing whether it is your train that is moving or whether it is the one adjacent to you.

These illusions may seem trivial at first, but they can have a huge effect in high-stake situations, such as when someone in the Air Force is traveling on an aircraft through different forces and has to target specific locations. The Air Force has funded a study in the Spatial Orientation Lab where participants sit in a specially designed Air Force seat inside the centrifuge and try to pinpoint locations on a screen in front of them.

A summary of the lab’s work (albeit a non-exhaustive summary like this one) cannot conclude without mentioning the laboratory has a chair set-up that is capable of moving a participant in two dimensions at once.

One of the many factors that influences motion is fluid in our inner ear, which is divided into different parts that control perception of different dimensions of movement. This system of perception is called the vestibular system. By blindfolding a participant and examining how well they are able to control themselves, the lab can study this system.

Similarly the lab can study the visual system in isolation, using video games with participants seated in a stable environment. Aly Fassett-Carman, a graduate student who just joined the lab, demonstrated how these experiments work. My first task was to keep an inverted pendulum on a screen swinging back and forth in the middle without it hitting the ground.

This allowed me to test both locational perception (I was able to see how far off the ground the pendulum top was) as well as my velocity perception (I got a sense of how fast it was going and in what direction it was moving). She then showed me a similar test that only tested my velocity perception, a ramble of dots spinning that I had to stop from spinning. Because I had concrete perception of the location of any dot relative to any ground (I had a perception of the pendulum top relative to the ground), I had only to rely on how fast the dots were moving and try to use the joystick to get them to stop.

Crazily enough, the laboratory can actually study both vestibular and visual systems together, by the use of an Oculus Virtual Reality headset with a specific program running that a participant would wear while riding the two-dimension chair.

Interdisciplinarity of the Lab

In all of its studies, the Spatial Orientation Lab requires an interdisciplinary scientific approach. Kaplan explained how an interdisciplinary approach has become essential to modern science laboratories.

This lab began as a psychology lab, hiring consultants from computer science, engineering and other fields. Kaplan noted that that practice is long outdated and would no longer work.

“Given with what we are dealing with and the complexity of the environment and the human body and the human brain and the variety of interactions … we really needed to have a lab where a lot of expertise are combined and not only meet each other, but that there are specialists that are multidisciplinary in him or herself,’ she said.

Kaplan explained that although one of the lab’s directors, James Lackner (PSYC), did work at MIT in both physics and neuroscience, his study of neuroscience was with the physics background.

In addition to having someone with those talents, one asset is an ability to articulate their multidisciplinary ideas, because science is a groupwork phenomena. A big feature of 21st century neuroscience is the need to be a jack of all trades and not just an amateur. If one is a specialist, one must have certain strengths to overcome their limitations, Kaplan explained.

In addition, Kaplan talked about how Brandeis does a good job of recognizing interdisciplinary nature of science through, for example, the Volen Center.

“Brandeis was one of the very first universities in the United States … [that] came up with and committed itself to raising the funds and proving there is a need for this aggregate approach to neuroscience—how the brain works from every possible viewpoint from biochemistry to physics and mathematics and artificial intelligence and biology, chemistry, colored vision … A Brandeis type of education gives you the ability to also pick up stuff from disciplines that may affect your future professional interests, and you have to have the maturity to recognize that if you want to do serious research,” Kaplan continued.

Kaplan said that although many graduate students in the lab officially do their work with physics, they are exposed to biology, mechanical motion, interaction of forces, gravitational forces, computer science techniques in heavy-duty technology that are built in the lab or with specific needs of the lab.

Fassett-Carman attested to the interdisciplinary nature of the lab. She noted that physical systems like the inverted pendulum could be used to model human perception. She also said she had only taken one computer science class before and really liked it but never had a chance to take another one. By working in the Spatial Orientation Lab, she is learning computer science and is very much enjoying it.

The Undergraduate Lab Experience

“Ours is a very active lab in terms of undergraduate … involvement, so we involve people on every stage. Even before they become undergraduates we often take high school interns.”

According to Kaplan, she does a lot of “cradle-to-grave popularization of science because … the earlier [that kids] get inspired the more confidence they will have to gear themselves through their educational environments into serious science, especially girls or especially minority people from minority groups … It takes not just the natural-born talent and hard work, it takes also an inspiration and the ability to put yourself and your mind into that environment if you’ve never seen … [that environment] that you can relate to then you are at a disadvantage even given all other talents.”

Kaplan gives talks at preschools to inspire kids, as well as nursing homes in order to explain to the elderly the lab’s work on posture control.

The involvement of students is part of that scientific chain, and the more they train with scientists, the better they will be able to contribute in the scientific research field or in any field they go into, Kaplan said.

She noted that the lab starts undergraduates on basic science and that many undergraduates get into the highest levels of research. By doing research as undergraduates, students will go into their disciplines with “deep understanding of what the goals of research should be and how they should formulate it, and how clean experiments need to be designed.”

Kaplan defined clean experiments as those with “no shortcuts. There are no neglected factors that are relevant. That there is no conflict with the accumulated body of knowledge in that area, and if there is a conflict that it is addressed. So there is a lot of discipline of research and ethic of research that we teach our students that is an integral part of research. Without it research will be compromised.”

Kaplan expressed her confidence that, despite the proliferation of lack of ethics in scientific experiments, students who come out of the Spatial Orientation Lab and who went into industry do not take shortcuts.

As you leave the Spatial Orientation Lab, as you ascend the U-shaped staircase and rejoin the historians and philosophers who make their home at Brandeis in Rabb, you get a sense of the modernity of the laboratory you are leaving. That a laboratory that is committed to both basic and applied science in a remarkably curious field, that has a truly 21st-century, interdisciplinary enterprise, and that has a commitment to the next generation of scientists, doing its interdisciplinary research under a team of modern historians and philosophers really makes one proud to attend this liberal arts research university we call home.

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