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Welcome!
Welcome!
Thank you for taking the time to view my page! My name is Peter and I am excited to share with you who I am, my work in the Science Research Program, and the plans I have moving forward. I hope you enjoy it!
Intracortical Microstimulation of the Somatosensory Cortex
(and the improvement of prosthetic arm control and feedback)
My principal work in the Science Research Program involved the study of intracortical microstimulation of the human cortex. So what is it?
Intra- : within, cortic- : cortex
Intra- : within, cortic- : cortex
Intracortical microstimulation (ICMS) involves sending weak electrical currents via electrode arrays to targeted parts of the brain. This mimics the natural movement of electrical signals throughout the nervous system. In effect, because we "feel" in the brain, stimulating it evokes certain sensations that that part of the brain would be responsible for processing.
Utah Array - Blackrock Microsystems
Somatotopy of projected field maps in S1
The targeted cortex in this research is the somatosensory cortex (S1) which is responsible for processing cutaneous sensations. These sensations are the ones felt on your skin, specifically on the hand, like pressure or texture.
To assign electrodes to certain locations on the hand/fingers, we must map the signals to a spot on S1.
Medial Lemniscal Pathway
A feature of ICMS technology is that it bypasses the medial lemniscal pathway (above) which is the natural anatomical pathway for afferent signals on the hand to travel to the cortex. Therefore, if we map sensors on a robotic hand to the corresponding neuron populations in S1, if the robotic hand touches a surface, the patient will "feel" touch coming from the robotic hand.
Demonstration of successful finger identification
Testing of ICMS in restoring touch has been successful and gives merit to the possibility of clinical use of the technology. In the above video, a perfect score is earned when using ICMS to identify digits of the hand. (For ease of viewing, watch in full-screen mode).
Personal Interest
Personal Interest
As of now, the primary focus in ICMS research was improving the sense of touch in terms of pressure. It is the primary afferent signal when interacting with objects in the real world. However, texture, and more importantly slip, are not fundamentally pressure-related, and instead are features of vibration. If you notice, scanning your finger across a rough surface leads to very small, high-frequency vibration in the skin. The frequency and the amplitude of the vibrations determine the texture. Slip is similar in that the surface moves past the finger rather than the finger scanning the surface; it is merely a change of the frame of reference. Ruffini and Pacinian corpuscles (right) are most sensitive to vibrations. Therefore, I hypothesize that in modulating the pulse train frequencies and amplitudes, it is possible to also restore the sense of texture and in turn, slip.
Afferents within the skin
My Paper
My Paper
Throughout the research process, I wrote a review of all the scientific literature that I read about my topic. The above information is only a peek at the biology, techniques, and other analysis necessary to understand ICMS technology. I hope that you take a look at the other interesting features of this developing field. Beware, the material is 35 pages long. :)
Video Presentation
Video Presentation
Here is a more in-depth video presentation about my research. For a complete list of sources, please reference the paper review. Enjoy! (For ease of viewing, watch in full-screen mode).
ICMS Symposium Presentation.mp4Second Project: Application of Magnetic Skyrmions for Data Storage
After completing my main work based around ICMS, I researched magnetic skyrmions and their applications. In summary, skyrmions are just spiral/ vortex-like configurations in magnetic materials. In computers, by changing the orientation of the spin, also known as the chirality, of the skyrmion, we can assign a 1 or a 0 to them. This is the fundamental principle behind binary, a numeric system used to store data in computers. Feel free to take a look at this paper also!
Takeaways from the Science Research Program
Although it appears that I have had a solid commitment to research involving ICMS technology, it wasn't always the case. My first ever topic in the Science Research Program was studying nuclear fusion reactions (as opposed to fission reactions that you would find at Indian Point Energy Center) to generate electricity and to power rockets and satellites. At first studying the topic was fair; I studied nuclear equations, reactor designs, and communicated with a professor at Princeton University. However, by the end of my first year, the mathematics had gotten so difficult, my mind felt like it was melting, not to mention that the real-world research was quite slow. I chose to abandon the topic and move on to ICMS research. I'd like to speak about this "letting go" moment because it was rather difficult to do, but it was necessary for my success. After putting many months of work into the research, I felt like starting over was foolish and inhibitory to my success in the program. Yet continuing on a path that no longer excited me, and quite frankly that would have left me in the same position for all three years, would've been worse than just quitting the program entirely. In starting over, I was able to better understand what truly interested me, and understanding that enabled me to work more productively, rather than busily, an idea that Dr. Schuchman emphasized throughout my research. Had I not chosen to start over, I would have wasted the opportunity to learn and be excited about scientific research, I would have been less productive, and I would have increased difficulty in assimilating to the real world.
I would like to thank Dr. Schuchman for the continuous support, encouragement, guidance throughout my three years in the Science Research Program. His help has opened to me countless opportunities and he has fostered my spirit of inquiry.
I would also like to thank Dr. Sharlene N. Flesher who has developed my understanding of the amazing field of ICMS technology with patience and reinforcement.
What's Next?
What's Next?
In the fall, I will be attending Binghamton University and majoring in Neuroscience. Binghamton offered me the greatest financial freedom and solid academic reputation to both take part in research that interested me and to get involved in my other passions, including music and my faith. I am excited to meet other academically driven students and better understand what career field I would like to pursue!
Thank you again for visiting my page. Feel free to meet me at the Q & A!
To view image and video citations, please click here.
To view image and video citations, please click here.
Binary Numeric System Background. pixy.org/src2/575/5759748.jpg.
Image shaded and tinted with cyan.
Binghamton University Campus Scene. www.commonapp.org/static/28c2c42935c19de20dcc1ba520a243eb/suny-binghamton-university_35.jpg.
Binghamton University Twitter Profile. pbs.twimg.com/profile_images/601475591918002177/qeftl81n_400x400.png.
Hue has been shifted blue.
Everschor-Sitte, Karin, and Matthias Sitte. “The Vector Field of Two, Two-Dimensional Magnetic Skyrmions: a) a Hedgehog Skyrmion and b) a Spiral Skyrmion.” File:2skyrmions.PNG, 21 Nov. 2015, commons.wikimedia.org/wiki/File:2skyrmions.PNG.
The image has been cropped to depict only spiral magnetic skyrmion in b).
Flesher SN, Collinger JL, Foldes ST, Weiss JM, Downey JE, Tyler-Kabara EC, Bensmaia SJ, Schwartz AB, Boninger ML, Gaunt RA. Intracortical microstimulation of human somatosensory cortex. Sci Transl Med. 2016 Oct 19;8(361):361ra141. doi: 10.1126/scitranslmed.aaf8083. Epub 2016 Oct 13. PMID: 27738096.
Flesher, Sharlene N (2018) Intracortical microstimulation of human somatosensory cortex as a source of cutaneous feedback. Doctoral Dissertation, University of Pittsburgh.
Pile of Papers. p0.pikist.com/photos/788/563/pile-paper-page-list-a-pile-of-papers-office-leaf-work-bureaucracy.jpg.
Rye, Connie, et al. “36.2 Somatosensation.” Biology, openstax.org/books/biology/pages/36-2-somatosensation.
The image has been stretched vertically.
“Slate Texture BW Background.” Designshack.net, designshack.net/wp-content/uploads/Slate-Texture-BW-Background.jpg.
“Utah Array.” DigitalOne, www.brainlatam.com/manufacturers/besa/utah-array-335.
Image citation only.
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