Applied group independent component analysis (ICA)  EDUCATION                                                                                                                                                                      

 

M.S. in Cognitive Science and Engineering                                                                                                        Mar 2016 - Feb 2018

   Thesis: Voxel-wise mapping of functional magnetic resonance imaging in impression formation

   Brain Cognition Laboratory of Memory and Decision-Making

   Interdepartmental Cognitive Science Program, Yonsei University, Seoul, South Korea

   Advisor: Sanghoon Han, Ph.D.

   Total GPA 4.18/4.3

 

B.A. in Psychology                                                                                                                                                 Mar 2011- Aug 2015

   Department of Psychology, Korea University, Seoul, South Korea

B.S. in Brain and Cognitive Sciences

   College of Information and Communications, Korea University, Seoul, South Korea

  

   Dual Major, Total GPA 4.06/4.5, Upper Division GPA 4.16/4.5

 

Exchange Student Program                                                                                                                                 July 2013 - Dec 2013

   Department of Psychology, Macquarie University, Sydney, Australia

 

 

 

 

ACADEMIC POSITION & EXPERIENCE                                                                                                                   

  

Post-Master’s Research Associate                                                                                                                           Feb 2018 – Present

   Brain Cognition Laboratory of Memory and Decision-Making

   Interdepartmental Cognitive Science Program, Yonsei University

   Principal Investigator: Sanghoon Han, Ph.D.

  

Research Associate                                                                                                                                                   Mar 2016 – Present

   Integrated Neurocognitive Functional Imaging Center,

   Yonsei University Severance Hospital

   Principal Investigator: Seung-Koo Lee, M.D., Ph.D.

 

Senior Researcher                                                                                                                                                 Mar 2016 – Feb 2018

   Team Quantumlabs

• a start-up company developing a new transcranial direct current stimulation (tDCS) device

• tDCS device evaluation via psychological experiments and fMRI data analysis

 

Administrative Assistant                                                                                                                                     Mar 2016 – Aug 2016

   Institute of Human Behavior

   Department of Psychology, Yonsei University

 

   Brain Korea 21+                                                                                                                                                   Jun 2017 – Feb 2018

   National Research Foundation (NRF) of Korea

 

Undergraduate Research Assistant                                                                                                                   April 2015 – Feb 2016

   Cognitive Neuroscience of Memory and Decision-Making Lab.

   Department of Psychology, Yonsei University

   Advisor: Sanghoon Han, Ph.D.

 

Undergraduate Research Assistant                                                                                                                  Nov 2014 – April 2015

   Laboratory of Social Decision Neuroscience

   Department of Psychology, Korea University

   Advisor: Hackjin Kim, Ph.D.

• involved in conducting an EEG hyperscanning experiment

 

 

 

 

HONORS                                                                                                                                                                            

 

Dean’s Honors

   Department of Psychology, Korea University

        2014, Fall Semester (GPA 4.25/4.5)

        2014, Spring Semester (GPA 4.25/4.5)

        2013, Spring Semester (GPA 4.0/4.5)

        2011, Fall Semester (GPA 4.11/4.5)

        2011, Spring Semester (GPA 4.37/4.5)

 

 

 

 

AWARDS                                                                                                                                                                             

 

Certificate of Merit, Best Thesis Award                                                                                                                             May 29, 2018

   Yonsei University

   Thesis: Voxel-wise mapping of functional magnetic resonance imaging in impression formation

    

Grand Prize, Interdisciplinary Research Initiative Award                                                                                                    Sept 1, 2017

   Institute of Convergence Science (ICONS), Yonsei University

   Collaborated with Department of Electrical and Electronic Engineering

   Thesis: Development of resolution enhancement technique for functional magnetic resonance imaging

              based on the deep learning algorithm

 

First Runner-Up, Yonsei Start-Up Challenge                                                                                                                      Aug 19, 2016

   Department of Computer Science, Yonsei University

   As a main researcher of a start-up company, Team Quantumlabs

   In pursuit of developing a new portable tDCS device

 

 

 

 

SCHOLARSHIP                                                                                                                                                                 

  

Full Tuition Merit Scholarship for Graduate Program (approximately $20,000)                                                                 2016 – 2017

   Kwanjeong Educational Foundation

   The largest educational foundation in Asia (http://en.ikef.or.kr)

    

Research Assistant Scholarship                                                                                                                                    2016, 2 semesters

   Interdepartmental Cognitive Science Program, Yonsei University

 

Brain Korea 21+ Scholarship for Graduate Student                                                                                                            2016 – 2017 

   National Research Foundation (NRF) of Korea

            

 

 

 

PUBLICATIONS                                                                                                                                                                

    

PUBLISHED

 

Ahn, J., Kim H., Park, J., & Han, S. (in press) Interactivity of neural representations for perceiving shared social memory, Korean   

   Journal of the Science of Emotion and Sensibility, 21(3)

 

Ahn, J., Lee, J., Han, J. H., Kang, M. S., & Han, S. (2018) Group analysis data representing the effects of frontopolar transcranial       direct current stimulation on the default mode network. Data in brief, 20, 1309-1313.  https://doi.org/10.1016/j.dib.2018.08.164

 

 

IN PREPARATION

 

Writing Manuscript Completed

 

Ahn, J., Nah, Y., & Han, S. Voxel-wise mapping of functional magnetic resonance imaging in impression formation

 

Min, S., Jun, S., Ahn, J., Lee, J., Lee, S-K., Park, S.H., & Han, S. Intrinsic functional connectivity in emotion regulation network is     altered in emotional laborers

 

Lee, J., Lee, H-J., Ahn, J., Min,S., Lee, S-K., & Han, S. Exploring the optimal high-resolution echo planar imaging protocols to           reduce susceptibility-related BOLD signal dropout

 

Writing Manuscript

 

Ahn, J., Nah, Y., & Han, S. Functional connectivity patterns predict the relationship of task difficulty expectation and subsequent       decision-making

 

Ahn, J., Jun, S., Min, S., Lee, J., Lee, S-K., Park, S.H., & Han, S. Altered emotional attention and brain functional connectivity       

   networks of emotional laborers

 

Data Analysis Completed

 

Ahn, J., Lee, J., Han, J. H., Kang, M. S., & Han, S. Altered intrinsic functional connectivity networks after frontopolar transcranial     direct current stimulation

 

 

 

 

CONFERENCE POSTER PRESENTATIONS                                                                                                               

                     

Ahn, J., Jun, S., Lee, J., Min, S., Lee, S-K., Park, S.H., & Han, S. (Nov 3, 2018) Exploring the impact of emotional labor on social    attention and brain connectivity patterns, Society for Neuroscience 2018 Annual Conference, San Diego, USA

 

Min, S., Jun, S., Ahn, J., Lee, J., Lee, S-K., Park, S.H., & Han, S. (Nov 3, 2018) Intrinsic functional connectivity in emotion       

  regulation network is altered in emotion laborers, Society for Neuroscience 2018 Annual Conference, San Diego, USA

 

Lee, J., Lee, H-J., Ahn, J., Lee, S-K., Han, S. (June 19-21, 2018) Exploring the high-resolution EPI fMRI protocol to reduce

  susceptibility-related BOLD signal dropout, The Organization for Human Brain Mapping 2018 Annual Meeting, Singapore 

 

Ahn, J., Han, J.H., Kang, M.S., & Han, S. (Nov 11, 2017) Frontopolar transcranial direct current stimulation changes intrinsic

  functional connectivity networks during resting-state fMRI, Society for Neuroscience 2017 Annual Conference, Washington DC,    USA

 

Ahn, J., Nah, Y., & Han, S. (Nov 16, 2016) Voxel-wise Mapping of the Cingulate Cortex in Impression Formation, Society for   

  Neuroscience 2016 Annual Conference, San Diego, USA

 

Ahn, J., Nah, Y., & Han, S. (April 3, 2016) Patterns of Functional Connectivity during Preparation Periods Can Predict the

  Tendency to Give Up in Following Decision-Making, Cognitive Neuroscience Society 2016 Annual Conference, New York, USA

 

 

 

 

RESEARCH INTERESTS                                                                                                                                                

 

1. Human Decision-Making Process and Large-Scale Functional Connectivity Network

• Social decision-making

• Neuroeconomics: modeling and decoding value calculation processes

• Neural mechanism of morality: non-economic prosocial behaviors and altruistic behaviors

• Effects of motivation and emotion on decision-making

• Neuromarketing: mechanisms of persuasion and predicting consumer behaviors

 

2. How Humans Influence & Communicate with Each Other

• Neural dynamics of media influence, message propagation, and persuasion

• Human relationship, social interaction, and communication in the digital age

• Intergroup conflicts, stereotypes in intergroup communication, and theory of mind

 

3. Neural Biomarkers in Decision-Making Deficits

• Impulsivity, aggression, antisocial behaviors, criminality, and the nature vs. nurture problem

• Decision-making in clinical groups

• Treatment effects of neurostimulation such as transcranial direct current stimulation (tDCS), Transcranial Magnetic Stimulation (TMS), and Deep Brain Stimulation (DBS)

 

4. Protocol Optimization to Enhance Data Quality of Various Neuroimaging Techniques 

• functional Magnetic Resonance Imaging (fMRI), functional Near-Infrared Spectroscopy (fNIRS), Diffusion Tensor Imaging (DTI), Positron Emission Tomography (PET), and Electroencephalogram (EEG)

 

 

 

 

RESEARCH PROJECTS INVOLVED                                                                                                                           

 

Neural Mechanisms of Social Cognition and Decision-Making

1.  Large-Scale Functional Connectivity Network Underlying Common Sense Perception (Behavior & fMRI study) 

• Investigated the neural mechanism underlying the process of judging whether a certain behavior or knowledge is common sense or not

• Incorporated two different decision contexts involving different cultural perspectives for making common sense judgments to account for the social variability of the judgments

• Demonstrated that common sense judgment requires integrated neural involvements of a general memory retrieval network and social-affective regions, which include the amygdala, ventromedial prefrontal cortex, medial temporal lobe, angular gyrus, and hippocampus

 

     2. Predicting the Effects of Task Difficulty Expectation on Subsequent Decision-Making (Behavior & fMRI study)

• Investigated whether functional connectivity patterns during task preparation can predict the effects of task difficulty expectation on subsequent decision-making

• Demonstrated that participants tend to easily give up solving simple problems when the preceding cue indicates the subsequent problem will be “HARD” notwithstanding the cue is presented randomly

• Classified participants who were largely affected by task difficulty expectation and participants who were not, using functional connectivity multivariate pattern analysis (fcMVPA) and support vector machine algorithm

• Currently working on decoding motivation and predicting subsequent decisions (giving up or not) using activation patterns during task preparation periods

 

     3. Voxel-wise Mapping of fMRI in Impression Anchoring and Adjustment (Behavior & fMRI study)

• Performed voxel-wise mapping of fMRI data when impression anchoring or adjustment occurs

• Applied Least Squares Single (LSS) analysis and established two simple models representing impression anchoring or adjustment process using sign function

• Functionally parcellated the orbitofrontal cortex, cingulate cortex, amygdala, and fusiform gyrus according to whether a voxel within the region is more involved with first impression anchoring or updating

 

 

Stress from Social Interaction and Alteration of Emotional Attention

    1. Effects of Emotional Labor-Induced Chronic Stress on Emotional Attention  (Behavior & fMRI study)

• Recruited emotional laborers who had been suffered from chronic work-related stress

• Demonstrated emotional laborers take longer to disengage from threatening facial stimuli

• Demonstrated altered emotional attention and functional connectivity networks centering the amygdala, hippocampus, prefrontal cortex, and insula in emotional labor group especially when perceiving threat stimuli

 

 

Development of Novel Treatment Approaches for Clinical Groups

1. Development of a Smartphone Application to Reduce Social Anxiety

• Configured Attentional Bias Modification task as a mobile application

• Currently validating the effects of the application on reducing anxiety level of social anxiety group

 

   2. Development of Virtual Reality (VR) Training Program to Enhance the Cognitive Functions of the Elderly

• Currently developing Activity of Daily Living (ADL) task to enhance the hippocampal functions of the elderly with mild cognitive impairment (MCI)

 

   3. Development of Non-Invasive Alternatives to the Wada Test (Epilepsy Patients Study)

• Currently developing a fMRI memory paradigm and analysis pipeline as an alternative to the traditional Wada test during which one hemisphere of the brain should be anesthetized

 

Effects of Neurostimulation on Intrinsic Functional Networks and Cognition 

  1. Effects of Transcranial Direct Current Stimulation (tDCS) on Default Mode Network (tDCS & fMRI study)

• Investigated whether tDCS with current intensity smaller than 0.5 mA and electrodes smaller than a conventional size can induce alterations of default mode network (DMN)

• Applied group independent component analysis (ICA)

• Demonstrated frontopolar tDCS alters the intrinsic coactivation of regions within default mode network

• Currently exploring the effects and safety of tDCS on enhancing adolescents’ cognitive abilities, such as attentional allocation and memory 

 

 

Optimizing Protocols for High-Resolution fMRI Data and Deep Learning Approach

1. Multiband Echo Planar Imaging (EPI) for fMRI Data Acquisition

• Applying multiband EPI (e.g., factors of 6) to obtain either 1) multiple slices of fMRI data simultaneously with the conventional acquisition time (i.e., TR = 2 sec) to create spatially high-resolution fMRI data (i.e., 1.5 mm isotropic voxel size), or 2) temporally sensitive fMRI data with shortened acquisition time (i.e., TR = 1 sec)

 

   2. Reduction of Blood-Oxygen-Level-Dependent (BOLD) Signal Dropout in High-Resolution fMRI

• Investigated the optimal high-resolution EPI protocols to reduce susceptibility-related BOLD signal dropout

• Demonstrated that a high-resolution protocol with “slice tilt=30°, polarity of phase encoding direction = anterior to posterior (AP)” is optimal to reduce signal dropout except signals of the orbitofrontal cortex survive the most when a protocol with “slice tilt=parallel to anterior and posterior commissure line, polarity of phase encoding direction = AP” is applied.

 

   3. Deep Learning Approach for Converting Low-Resolution fMRI Data into High-Resolution fMRI Data

• Applying deep-learning approach (convolutional neural network, CNN) to convert conventional low-resolution fMRI data (i.e., 3.75 × 3.75 × 4 mm voxel size) into high-resolution data (i.e., 1.5 mm isotropic voxel size) through super-resolution technique without modifying any fMRI acquisition protocols during an actual fMRI scanning period

 

 

 

TRAINING                                                                                                                                                                         

 

Linear Algebra Workshop                                                                                                                                                  October 2018 

  Linear algebra, Machine learning, Python programming

  Department of Communication, Yonsei University

  Prof. Sang Yup Lee

 

Computational Neuroscience Winter School                                                                                                                             Feb 2018

  Korean Society for Computational Neuroscience, Daejeon, South Korea

 

Computational Modeling Seminar                                                                                                                         Spring Semester 2018

  Bayesian modeling, R programming, Stan (mc-stan.org)

  Department of Psychology, Seoul National University, Seoul, South Korea

  Prof. Woo-Young Ahn

  

MRI Safety Training                                                                                                                                                                2015-2017

  Department of Radiology, Yonsei University Severance Hospital, Seoul, South Korea

 

 

 

  

RESEARCH SKILLS                                                                                                                                                        

  

 NEUROIMAGING DATA ANALYSES

     Task-Dependent fMRI Analyses

• General Linear Modeling (GLM)

• Beta-series analysis: Least Squares All (LSA), Least Squares Single (LSS)

• Psychophysiological Interaction (PPI) analysis

• Principal Component Analysis (PCA): task-dependent signal extraction

 

     Brain-Activity Pattern Analyses

• Multivariate Pattern Analysis (MVPA), functional connectivity MVPA, searchlight MVPA

• Representational Similarity Analysis (RSA)

• Machine learning techniques: Support Vector Machine (SVM), Linear Discriminant Analysis (LDA), Convolutional Neural Network (CNN), etc.

• Graph theoretical analysis: centrality analysis

 

     Resting-State fMRI Analyses

• Independent Component Analysis (ICA)

• Regional Homogeneity (ReHo)

• Amplitude of Low Frequency Fluctuations (ALFF), fractional ALFF

• Seed-based functional connectivity

 

    fMRI Data Denoising

• Physiological artifacts removal

• Motion artifacts removal: motion-related independent components, voxel-by-voxel framewise displacement (FD)

 

 

 NEUROIMAGING STATISTICAL TOOLS

    Neuroimaging Software

• Statistical Parametric Mapping 8 (SPM 8), SPM 12

• Group ICA of fMRI Toolbox (GIFT)

• FMRIB Software Library (FSL)

• Analysis of Functional NeuroImages (AFNI)

• FreeSurfer

  

    Resting-State fMRI Software

• Data Processing Assistant for Resting-State fMRI (DPARSF)

• Resting-State fMRI Data Analysis Toolkit (REST)

 

    Machine Learning Tools

• Spider

• Princeton MVPA

• Orange

 

    Connectivity Analysis Tool

• BASCO

  

    Graph Theoretical Analysis Tools

• GraphVar

• Gephi

 

    ROI Analysis Tool

• MarsBar

 

    fMRI Data Denoising Tools

• TAPAS: PhysIO toolbox

• ICA-AROMA

 

 

  NEUROIMAGING VISUALIZATION TOOLS

• Pycortex

• Connectome Workbench

• BrainNet Viewer

• MRIcro / MRIcroN / MRIcroGL

 

  PROGRAMMING

• MATLAB

• R

• Python

• VISUAL BASIC 6.0, Excel Macros (Visual Basic for Applications)

 

  STATISTICS

• SPSS 24

• Excel Solver

• R Stan: Bayesian statistical modeling

 

  OTHERS

• MRI Console (GE, Philips)

  • conversant with fMRI scanning procedure, including modifying scanning protocols and sequences through the console

 

• MRI-Related Products

  • NordicNeuroLab goggles, SyncBox, etc.

 

• Philips Physiologic Monitoring

  • Peripheral Pulse Unit (PPU), Respiration sensor

 

• tDCS Devices

  • neuroConn DC-STIMULATOR MC, foc.us, The Brain Stimulator

 

• Experiment Scripts

  • MATLAB Cogent 2000, Psychophysics Toolbox 3

 

• Visualization Tools

  • Prism

  • Gephi

 

• Talairach Daemon

• Microsoft Office: Word, Excel, Powerpoint

• Adobe Photoshop

 

 

LANGUAGES

• Fluent in English (GRE verbal 164/170, quant 169/170, writing 4.5/6; TOEFL 110/120)

• Fluent in Japanese (JLPT N1)

• Native in Korean

 

 

 

EXTRACURRICULAR ACTIVITIES                                                                                                                            

Korea University SimYeon (Psychology Research Club)                                                                                     Mar 2013 – Aug 2015

 

Kookmin Bank (Intern)                                                                                                                                              July – August 2014

• Worked as a lobby manager and administrative assistant

 

Daham Community Mental Health Center (Volunteer)                                                                                                April – June 2014

• Helped patients with schizophrenia for stress relief

 

Korean Cultural Centre Australia (Intern)                                                                                                                       Sep – Dec 2013

• Worked as a receptionist

• Australian media monitoring, cultural events planning, translation

 

Macquarie University Global Leadership Program                                                                                                         Aug – Oct 2013

• Attended various colloquiums for global leadership skills

 

Korea University Global Leadership Program                                                                                                               Mar – May 2013

• Attended various colloquiums for global leadership skills

 

Hackers Education Group (Volunteer)                                                                                                                              Jan – Feb 2013

• Mentored high school students for career exploration

 

 

 

REFERENCES                                                                                                                                                                  

Sanghoon Han, Ph.D. (ys.sanghoon.han@gmail.com) Department of Psychology, Yonsei University

Hackjin Kim, Ph.D. (hackjinkim@gmail.com) Department of Psychology, Korea University

Young-Hoon Kim, Ph.D. (solagratia72@gmail.com) Department of Psychology, Yonsei University