Joonkoo Park

Ph.D. Candidate
Cognition & Cognitive Neuroscience Area
Department of Psychology
University of Michigan

email: joonkoo -at- umich -dot- edu
phone: +1 734 763 0343
fax: +1 734 763 7480
lab: B316, East Hall
mailbox: 4027, East Hall
address: 530 Church St. Ann Arbor, MI 48109

Research

My research interests in general are in neural representation and computation of concepts and categorization and the emergence of these systems based on the biological and cultural inheritance. Under this broader theme, I am working on a couple of specific research projects.

Nature and Nurture of the Functional Neural Organization

How is concept represented in the brain and what influences its organization?
I study the role of nature and nurture on the functional organization of the human brain under the supervision of my primary advisor Dr. Thad Polk. With recent efforts in the field of cognitive neuroscience, it is now well known that the distinct regions or networks of brain are selectively activated for specific cognitive tasks; however, it is not yet well known how a particular neural substrate has become the locus of a particular cognitive function. It is then natural to ask the role of the biological or cultural inheritance on the functional organization of human cortex. In this context, we use fMRI (functional magnetic resonance imaging) technique to identify the genetic influence (using identical and fraternal twin pairs as subjects) on the functional organization of human brain in performing various cognitive tasks. We collaborate with Dr. Denise Park and her research group at the University of Texas at Dallas.

Perceptual Decision Making

How does the brain compute and categorize perceptual information?
I use mathematical models and techniques to analyze single cell recording data of monkeys in order to identify the functional role of the neuronal firing activity in the perceptual decision making paradigm. Extending the work of Dr. Jun Zhang, I work on a project that investigates the sensorimotor role of the monkey MT (middle temporal) and LIP (lateral intraparietal) neurons as well as computational models of decision making such as random walk models. I am further planning to apply this technique to the fMRI paradigm of human perceptual decision making and categorization.

fMRI Data Analysis Using Multivariate Statistical Techniques

How can we identify task-related brain regions based on patterns of activation?
Recently, multivariate data analysis approaches (as opposed to the traditional univariate methods) are applied to fMRI dataset in order to examine patterns of activation across multiple voxels, as opposed to finding voxelwise regions of activations. This approach has shown to be powerful in many cases in which univariate method lacks statistical power. Furthermore, it is more natural to believe that our brains work as a whole, not by each voxel. I am currently investigating how these techniques can be used in the neuroimaging data to reveal interesting aspects of human cognition.

Publications

Journal Articles

Park J, Carp JM, Hebrank A, Park DC, & Polk TA (in prep). Neural specialization predicts processing efficiency (but not crystallized knowledge) in older adults.
Carp JM, Park J, Polk TA, & Park DC (in prep). Age differences in neural distinctiveness revealed by multi-voxel pattern analysis.
Berman MG, Park J, Gonzalez R, Polk TA, Gehrke A, Knaffla S, & Jonides J (revise and resubmit). Evaluating functional localizers: The case of the FFA.
Park J & Zhang J (revise and resubmit). Sensorimotor locus of the buildup activity in monkey lateral intraparietal area neurons.
Park J, Newman LI, & Polk TA (2009). Face processing: The interplay of nature and nurture. The Neuroscientist. 15(5):445-9.
Polk TA, Park J, Smith MR, & Park DC (2007). Nature versus nurture in ventral visual cortex: an fMRI study of twins. Journal of Neuroscience. 27(51):13921-5.

Conference Presentations

Park J, Zhu J, Polk TA (2009). A better approach to identifying functional regions of interest: using ridge logistic regression for multivariate voxel selection. Cognitive Neuroscience Society.
Park J & Zhang J (2008). Sensorimotor locus of the buildup activity in monkey lateral intraparietal area (LIP) neurons. Society for Neuroscience
Polk TA, Park J, Smith MR, & Park DC (2008). Nature versus nurture in ventral visual cortex: an fMRI study of twins. Cognitive Neuroscience Society.
Park J & Zhang J (2007) Sensorimotor locus of neuronal buildup activity in monkey lateral intraparietal (LIP) area during a choice reaction-time task. Society for Mathematical Psychology.

Education

Since August 2006, I am pursuing a Ph.D. degree at the Cognition and Cognitive Neuroscience Area of the Department of Psychology at the University of Michigan. I received M.S. in Psychology along the way, and I am concurrently pursuing Masters degree in Statistics. I work with Dr. Thad Polk in the field of cognitive neuroscience and with Dr. Jun Zhang in mathematical psychology. I am really enjoying the welcoming and collaborative nature of our department especially to a person like myself who started the program with a completely different background, and I am grateful that through this challenging but rewarding program I am slowly becoming a real cognitive psychologist and cognitive neuroscientist.

I received a masters degree in Human-Computer Interaction (HCI) in August 2005 from the School of Computer Science at Carnegie Mellon University. I learned computer science, design, and psychology with the goal of designing a system that is physically and psychologically easy to use. Through these processes, I was able to gain bigger perspectives on each of the fields related to HCI. My invaluable experience at CMU gave me the confidence to follow my passion in pursuing a higher degree in cognitive psychology.

I graduated with honors with the Bachelor of Science degree in Industrial Engineering in February 2004 from Seoul National University. I was specifically interested in human factors and ergonomics, which in hindsight showed me a path toward cognitive psychology.

Teaching

Advanced Statistical Methods (Psych 614)

Graduate Student Instructor (GSI) with Professor Pam Davis-Kean in Winter 2009.
Responsible for leading worksheet sections and grading assignments, total of 30 graduate students.

This course was the second part of the two-semester course on a graduate level statistics class. The topics covered multivariate statistical analyses including multiple regression, logistic regression, MANOVA, factor analysis, principal component analysis, canonical correlation, discriminant analysis, and cluster analysis. As a GSI, I gave mini-lectures during the worksheet sections every week trying to explain the material in various ways as possible and advised students to learn the conceptual as well as practical statistical knowledge.

Advanced Statistical Methods (Psych 613)

Graduate Student Instructor (GSI) with Professor Kai Cortina in Fall 2008.
Responsible for leading worksheet sections and grading assignments, total of 30 graduate students.

This course was the first part of the two-semester course on a graduate level statistics class. Topics covered principal components, factor analysis, MANCOVA, canonical correlation, discriminant analyses, cluster analyses, multiple regressions, logistic regression, and a brief introduction to structural equation model. As a GSI, I gave mini-lectures during the worksheet sections every week trying to explain the material in various ways as possible and advised students to learn the conceptual as well as practical statistical knowledge.

Intro to Cognitive Psychology (Psych 240)

Graduate Student Instructor (GSI) with Professor Thad Polk in Fall 2007.
Responsible for three discussion sections, total of 80 undergraduate students.

The topics covered include various aspects of the psychology of human perception, attention, memory, language, judgment and decision making, problem solving, and reasoning. The material includes data and theory about the relationship between cognition and brain function. The course emphasizes not only the content material represented by these topics, but also the process by which researchers develop theories and collect evidence about relevant issues evaluated by term paper. Performance is evaluated via objective examinations that will stress knowledge of the material and understanding of the relationship between theory and data, and is also evaluated via term paper that reviews and synthesizes recent empirical work and possibly proposes a new hypothesis. As a GSI, I helped students understand the materials in the context of theory and data, and guided each student to read and assimilate recent articles in the field and to tie the recent findings to the class materials. This four-credit course includes lectures, discussion, demonstrations, in-class experiments, and practice on problem-solving exercises.

Awards and Honors

Clyde Hamilton Coombs Scholarship, University of Michigan, 2009.
Rackham Graduate Student Research Grant, University of Michigan, 2008.
Korea Honor Scholarship, Embassy of the Republic of Korea in the U.S.A., 2007.
Information and Telecommunication National Scholarship, Republic of Korea, 2004.
Kwanjeong Educational Foundation Scholarship (declined), 2004.
Korea Science and Engineering Foundation Scholarship (declined), 2004.
Graduated with Honors, Seoul National University, 2004.
Army Commendation Medal, Secretary of the Army, U.S.A., 2003.
University Fellowship (full tuition waiver), Seoul National University, 2000, 2003.

Professional Membership

Student Member, Society for Neuroscience (since May 2008)
Student Member, Cognitive Neuroscience Society (since Feb 2008)
Student Member, Society for Mathematical Psychology (since May 2007)

Professional Experience

I was a Research Scientist from September 2005 to August 2006 at the Intelligence and Interaction Research Center at the Korea Institute of Science and Technology. Although I was there for a relatively short time, I initiated a project called the Generic Interaction Methods and worked with great people with various different backgrounds to design a simple ubiquitous control method for home electronics and appliances.

Between my undergraduate graduation and my new life at CMU, I worked as a research intern for a short time (Jan 2004 ~ Apr 2004) at Accenture Korea, a business consulting firm. I was assigned to part of a business strategy project, and I mainly researched and analyzed financial data of pharmaceutical companies and venture capitals.

I served 26 months of military service in the Republic of Korea Army from November 2000 to Jan 2003. As a KATUSA (Korean Augmentation to the United States Army), I was assigned to the 17th Aviation Brigade, 8th US Army. I worked as a tactical air traffic controller and participated in major military exercises. As a tactical unit, my section spent a lot of times up at the mountain tops setting up tents, camouflage, antennas, and talking to aircrafts. I sometimes miss sleeping with my rifle on a military cot, but I wouldn't necessarily want to go back to those times.

Personal

Photography

Photography is one big part of my life. I often like to explore busy streets with my rangefinder and enjoy taking street photos. The reason that I favor street photos is that they are not staged. I like things that are pure and natural. When you look around people, buildings, cars, and many other things on the street, you will notice that every single thing exists to serve its own purpose and in fact nothing is artificial, yet together they form an amazingly wonderful scene with many stories. Good street photos are very self-restrained and unartificial, yet they convey an extremely interesting story worth a thousand words. For instance, when you look at some pieces of my favorite photographers like Henri Cartier-Bresson or Robert Frank, you will feel that interesting and meaningful stories behind a critical moment of an unstaged scenery coming to you.

With a hope that one day I will open my own photography exhibition, my rangefinder and I are waiting on critical moments of our everyday lives. Here are some of my photographs, but more can be found at my personal web gallery (as well as foodlery; see below) joonkoo.com.

Food

Eating is another big joy of my life. People often ask me how I am able to control my weight while I am overly fond of food. Although I may not eat a lot, I really enjoy tasting well-prepared fresh food. I usually like simple food made of pure, natural ingredients. You will be able to tell this from my two favorite dishes which are boiled fresh shrimp (this is actually a Chinese dish) and steamed homemade tofu. But I basically like any kind of food that I can taste the freshness and richness of each of the ingredients. I should say I am quite picky on restaurants, since I like to have Jajangmyon (a Korean dish of bean-paste noodles) at one restaurant which serves one of the best Jajangmyon in Seoul but average Tangsooyook, while I like to eat Tangsooyook (a Korean style sweet and sour pork) at another place which has the best Tangsooyook but mediocre Jajangmyon. This is very much like eating soup at one restaurant and bread at another.

Spending most of my childhood and high school years in the greater Chinese region, I am very accustomed to various styles of Chinese food. Steamed grouper, Dongpo Rou, and dimsum dishes are a few of my favorites. I am also very fond of Japanese ramen - especially Hakata style dontoksu ramen. Its richness of broth is incomparable to any other soup dishes, and I wish I could have a chance to visit Hakata and eat the genuine Hakata style ramen. Although my favorite bread depends on occasions, but my all-time favorite is fresh Italian ciabatta. There are so many other foods that I like and want to introduce here, but I will have definitely have no space for all that. I keep a list of recommended restaurants in my personal web foodlery (as well as gallery; see above) joonkoo.com, but unfortunately the list is currently limited to restaurants in Korea only.

Language

Korean is my native language, but I learned to speak Chinese (Mandarin) and English when I was growing up in various different cities including Taipei, Hong Kong, and Beijing. I had formal education in English at English speaking schools such as International School of Beijing, and I learned colloquial Chinese outside of school. As I rarely speak Chinese these days, I am unfortunately losing it, but I should keep it up so that I can order some authentic dishes in Chinese restaurants!