032708 - 1 Brain Machine Interface(BMI Using signals from...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
March 27, 2008 1: Brain Machine Interface (BMI) Using signals from patient brains to control robotic devices. 1 st thing to do: understand basic representation of the brain - They need to be awake. - Must be animals Move manipulandem in response to light, by juice reward - electrode in brain to measure activity as they make movement 2: Each line is single trial, tick marks represent times of AP 1) Neurons change response when they make movement - Involved in planning movement 2) Response is maximal at certain point - Suppressed at rightward movement Tuning curve- shows fine rate of neuron, rate of AP before movement initiated - Firing rate low for movements near the right or down to the right - Maximal firing rate at around 135-180 degrees or in the region o AKA neuron’s preferred direction - As you move further away from preferred movement, response decreases - Response of one neuron doesn’t specify movement that animal will make o Need multiple neurons to rpresent movement o Next day, neuron nearby has same tuning curve but preferred direction will be different From many neurons, you have population of preferred direction Each neuron gives a volt of its preferred direction 3: Scientist (Giodropolis??) says brain uses vector average. - All neurons combined vectoral average - Each plot at each location reps response of all neurons before animal makes particular movement - Black portion: each line reps single neuron, direction of line reps preferred direction of that neuron and length of line reps strength of that preference - Pointing to opposite direction of red line reps suppressed neurons - Red arrow is close to actual movement (dashed black arrow): average of neurons o There is deviation from actual direction of motion bc we’re only recording from a hundred neurons whereas there are tens of millions in the cortex. o This is why we want large population, to become more reliable and more robust
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Neurons die and go through processes that could modulate the response. From a large population, this wouldn’t affect much and makes it reliable and robust and faster to obtain results 4: Electrode array is different from before (sharp needles): insulated wires, more flexible and blunt. Take an array and press into brain, sits and each wire records wire of one or few neurons near tip of electrode - Record few hundred neurons simultaneously - Implanted for many months, record activity from same regions Can we take signal from electrodes and do what Gerodropolis did before and predict movement in a short period of time?
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern