Robert C. Liu

Postdoctoral Fellow

Mailing address:
Department of Physiology, Box 0444
513 Parnassus Avenue, Room HSE806B
San Francisco, CA 94143-0444

tel: (415) 476-1576
fax: (415) 476-4929
email: liu@phy.ucsf.edu

Educational background

I obtained my undergraduate degree in Physics from Stanford University in June of 1991, after completing an honors thesis on low temperature, high-Q, torsional oscillators with my undergraduate advisor, Prof. Doug Osheroff. After touring different graduate schools around the country, I decided a change of scenery was necessary and moved from the Varian Physics building to the Stanford Applied Physics department located in the E. L. Ginzton Laboratory a few buildings away (it's hard to beat the Bay Area!). After a year of rotating between groups, I settled in as Prof. Yoshihisa Yamamoto's first graduate student in the fall of 1992, and began setting up his low temperature mesoscopic physics laboratory. My research focused on quantum noise in mesoscopic electron transport, with the intention of using concepts from quantum optics to study mesoscopic physics. I obtained a Ph.D. for this work in January of 1998.
Like any other graduate student, at some point in my "graduate career" I had to decide what to do with my life. I had started physics with the idea that it would be excellent training no matter what I chose to do, and the time finally came to make that decision. Thanks to interactions I had with friends and Stanford faculty and courses in Neuroscience throughout my stay at Stanford, I found myself drawn to the questions being asked and the new approaches being tried in that field. So I made the plunge, applied for a Sloan postdoctoral fellowship at UCSF, and dived into a new field. So here I am now. . . .

Scientific interests

Neuroscience

    The motivation for my current research is to search for general principles of neural coding in the mammalian cortex. For someone with a physics background, this topic is appealing since it combines physical along with biological and psychological issues.
    The approach I plan to take is something I would loosely call "computational neuroethology." My ideal experiment would focus on the study of an organism in as natural an environment as reasonably possible in a laboratory setting. Following the ethological philosophy, I would try to find a preparation that exhibits a strong, well-characterized, stimulus-behavior link. Then, I would determine the areas of the nervous system which might be relevant for the representation of the stimulus and/or behavior, and study the neuronal responses there. By monitoring population activity in those areas, I hope to investigate possible coding algorithms, using the behavior as a way of placing constraints on plausible algorithms. One of the central themes in this approach is the role of noise and variability in the neural responses since this may also constrain the representation and processing of behaviorally relevant stimuli.
    I have been working on a project to apply this paradigm towards investigating the mouse maternal retrieval behavior elicited by ultrasonic calls from lost mouse pups. The goal is to use multicellular recordings to monitor many cells simultaneously in anesthetized and awake mice. The coding of ultrasound calls by populations of neurons will then be studied in both parentally experienced mice (who categorically perceive the calls) and naive mice (who do not recognize the calls as behaviorally relevant). This project will combine computational, electrophysiological and eventually genetic approaches to dissecting the mechanisms of auditory processing. This project is part of a larger mouse auditory effort started by myself and (postdoc) Jennifer Linden, in the groups of Mike Merzenich, Ken Miller, and Christoph Schreiner.

Physics

I still maintain some interest in developments in mesoscopic physics, and I keep occasional contact with people from my old group. The study of noise and quantum statistical effects in mesoscopic devices has become an exciting area of scientific pursuit recently, in part because of the current interest in exploring quantum computation within condensed matter systems.
For my own sake, I hope that someday I'll have an interesting neuroscience question that requires the microfabrication techniques I learned as a graduate student as an enabling technology.

Other pursuits

Skiing, volleyball and photography are my favorite hobbies.