Max Murphy

Max Murphy

PhD, Bioengineering

Posts by Collection

news

Successful Dissertation Defense

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Successful Defense!

I successfully defended my doctoral thesis (Neurophysiological mechanisms of sensorimotor recovery from stroke), with honors! Read more

Carnegie Mellon talk

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Virtual presentation: Carnegie Mellon University

I presented a modified version of my thesis to the Weber lab and affiliate faculty, going into a little more technical detail about the results from Aim 1 of my dissertation. Read more

Thoughts on Peer Review

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First Post: On Academic Service

Check out my thoughts on modern peer review. I see peer review as the main way in which I can currently provide a service to my academic peers. However, I have a real bone to pick with the details of how peer review is conducted in practice. Read more

Thoughts on TCOE

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Thoughts on TCOE

I am an avid fan of Dungeons & Dragons (5e), which means I run games for some of my friends (more frequently the case in the past). Recently, Wizards of the Coast released a new supplement (Tasha’s Cauldron of Everything; TCOE), which introduces new optional class features. I had an immediate dislike to one of the new Fighter class features, so I decided to do some simulations. Read more

Active Inference Model-Stream

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Active Inference Model-Stream

I’ll be participating in the Active Inference ModelStream #001.0: “A Step-by-Step Tutorial on Active Inference” today at 11am CST. Please join me here if you would like to watch live! Read more

Neuro-Activities

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Neuro-Activities

One of the graduate students at our lab (Monica) made this really cool website with interactive neuroscience activities for teaching key concepts related to some of the more abstract parts of research going on in motor systems neuroscience. Read more

NML Behavioral Tasks

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Behavioral Task Docs

I have been working to upgrade the documentation and make more modular the codebase running behavioral tasks. Specifically, I wanted to make a networked protocol compiled in c/c++ that allowed for very-high fidelity in logging from devices across several different operating systems/distributions. I’ve included the relevant doxygen documentation on the NML-WTF website. Read more

Fitts Law Tasks

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Fitts Law

Fitts’ Law is a way of measuring motor throughput in point-to-point movements. The framework has been extended to evaluating human-computer interactions, but may need refinement depending on the nature of the task and what type of information we care about specifically. Read more

Accidental Malware

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Accidental Malware

After more-or-less finalizing several web-based clicking games to measure motor information throughput, I figured I should make it possible to interface to the tasks using more than just a mouse, trackpad, or touchscreen. My idea was to write a compiled c/c++ executable, which I could easily run from any Windows-11 device (i.e. most of my normal lab workstations), that would run in the background as a “controller emulator server.” I got to work writing an Input_Utilities code repository. You may have guessed where this is headed. Read more

publications

Current challenges facing the translation of brain computer interfaces from preclinical trials to use in human patients

Published in Frontiers in Cellular Neuroscience, 2016

This is a review of the challenges facing the translation of brain computer interfaces from preclinical trials to widespread use in the clinic. There is an emphasis on activity-dependent stimulation and similar paradigms. Read more

Recommended citation: Murphy, M. D., Guggenmos, D. J., Bundy, D. T., Nudo, R. J. (2016). Current challenges facing the translation of brain computer interfaces from preclinical trials to use in human patients. Frontiers in cellular neuroscience, 9, 497. (Link)

Comprehensive spatial analysis of the Borrelia burgdorferi lipoproteome reveals a compartmentalization bias toward the bacterial surface

Published in Journal of Bacteriology, 2017

This paper is about the localization of lipoproteins to a particular side and layer of the bilayer membrane of Borrelia, the causative agent of Lyme disease. It is a descriptive study that catalogues this specific property of each putative lipoprotein identified in the Borrelia lipoproteome. Read more

Recommended citation: Dowdell, A. S., Murphy, M. D., Azodi, C., Swanson, S. K., Florens, L., Chen, S., Zuckert, W. R. (2017). Comprehensive spatial analysis of the Borrelia burgdorferi lipoproteome reveals a compartmentalization bias toward the bacterial surface. Journal of bacteriology, 199(6). (Link)

Assessing Perturbations to Neural Spiking Response Dynamics Caused By Electrical Microstimulation

Published in International Symposium on Circuits and Systems, 2018

This paper is about a proof-of-concept nonlinear dynamical systems approach applied to peri-stimulus epochs to see if it could detect longitudinal differences in how open- and closed-loop influence the system response to electrical microstimulation of sensory cortex in ambulatory rats. Read more

Recommended citation: Murphy, M. D., Dunham, C., Nudo, R. J., Guggenmos, D. J., Averna, A. (2018, May). Assessing Perturbations to Neural Spiking Response Dynamics Caused By Electrical Microstimulation. In 2018 IEEE International Symposium on Circuits and Systems (ISCAS) (pp. 1-5). IEEE. (Link)

Improving an open-source commercial system to reliably perform activity-dependent stimulation

Published in Journal of Neural Engineering, 2019

We modified the Intan Stimulation/Recording controller to deliver closed-loop stimulation using a finite state machine to improve artifact rejection, such as may occur due to electrical microstimulation or other physiological events such as chewing and whisking. Read more

Recommended citation: Murphy, M., Buccelli, S., Bornat, Y., Bundy, D., Nudo, R., Guggenmos, D., Chiappalone, M. (2019). Improving an open-source commercial system to reliably perform activity-dependent stimulation. Journal of neural engineering, 16(6), 066022. (Link)

Chronic stability of single-channel neurophysiological correlates of gross and fine reaching movements in the rat

Published in PLoS ONE, 2019

Rats were trained on a gross (lever-press) and fine (pellet-retrieval) forelimb task, implanted with microwire arrays spanning unilateral sensorimotor cortex contralateral to the moving limb, and then tested over the course of days and weeks to determine the longitudinal stability of both spiking unit signals as well as gamma LFP in this context. Read more

Recommended citation: Bundy, D. T., Guggenmos, D. J., Murphy, M. D., Nudo, R. J. (2019). Chronic stability of single-channel neurophysiological correlates of gross and fine reaching movements in the rat. PloS one, 14(10), e0219034. (Link)

Differential effects of open-and closed-loop intracortical microstimulation on firing patterns of neurons in distant cortical areas

Published in Cerebral cortex, 2020

Intracortical microstimulation (ICMS) was applied to the rat primary sensory cortex in healthy anesthetized rats using both closed- and open-loop paradigms. Changes in firing rates and regimes were tested over the course of a few hours to determine if an effect differentiating the protocols could be detected during this time. Read more

Recommended citation: Averna, A., Pasquale, V., Murphy, M. D., Rogantin, M. P., Van Acker, G. M., Nudo, R. J., Guggenmos, D. J. (2020). Differential effects of open-and closed-loop intracortical microstimulation on firing patterns of neurons in distant cortical areas. Cerebral Cortex, 30(5), 2879-2896. (Link)

Effects of tDCS on spontaneous spike activity in a healthy ambulatory rat model

Published in Brain Stimulation, 2020

We tested whether transcranial direct-current stimulation (tDCS) had any effect on the spike rate or LFP content in ambulatory rats using a within-subject design to test anodal, cathodal, and sham stimulation cases. Read more

Recommended citation: Milighetti, S., Sterzi, S., Fregni, F., Hanlon, C. A., Hayley, P., Murphy, M. D., Nudo R. J., Guggenmos, D. J. (2020). Effects of tDCS on spontaneous spike activity in a healthy ambulatory rat model. Brain Stimulation, 13(6), 1566-1576. (Link)

research

Data pipelines

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Data processing pipeline for neurophysiological data collected in studies related to rehabilitation from injury to the nervous system.
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Cortical population dynamics after stroke in reaching rats.

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We recorded extracellular field potentials from microwire arrays embedded in the contralateral rostral forelimb area (RFA) and the ipsilateral caudal forelimb area (CFA) with respect to the preferred forelimb used during pellet retrievals by rats. A subset of rats received a focal vasoconstrictive ischemia in CFA contralateral to the preferred reaching forelimb, which led to clear motor deficits on this task.
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scripts

talks

Neuroplasticity and Neurorehabilitation

Talk, Rockhurst, 2017

I gave an invited guest lecture describing principles of neuroplasticity as it applies to neurorehabilitation, with emphasis on brain-computer interfaces and closed-loop stimulation strategies designed to augment physical therapy. Read more

Capitol Graduate Research Summit

Poster, State Capitol Building, 2017

I presented a poster on a Hidden Markov Model that decoded the information transfer rate of nodes in a network within anesthetized rat rostral forelimb area (RFA) as a potential model for evaluating changes in information rate following different intracortical microstimulation (ICMS) modalities. Read more

State Machine for Low-Latency High-Fidelity Spike Detection

Talk, University of Kansas Medical Center, 2019

I made it to the final round of the KUMC three-minute thesis competition where I presented work that was ultimately published in Journal of Neural Engineering, describing a low-latency, high-fidelity spike discriminator that I implemented for the Intan Stimulation/Recording controller together with my collaborator, Stefano Buccelli. Read more