Principal Investigator

Dobromir (Doby) Rahnev, Ph.D.



Research Interests: Perceptual decision making, prefrontal cortex, metacognition, computational models of cognition

About me: I enjoy soccer, hiking, juggling, and math puzzles.


Marshall Green


E-mail: [at] outlook [dot] com

Research Interests: I am interested in perceptual decision-making and metacognition. To study these topics, I combine psychophysics and computational modeling to test and develop theories of perception. My recent work has been focused on motion and orientation perception, summary statistics, and visual confidence.

About me: I earned my Ph.D. in Cognitive Science from Mississippi State University where I researched visual perception and visual working memory. I am married to a wonderful woman named Jenn, who is a talented graphic designer. My hobbies include playing violin, cooking, photography, and hiking.

Yi Gao



Research Interests: I am interested in understanding human visual perception, including various visual effects such as adaptation, perceptual learning and ensemble coding. I am also interested in how other sensory modalities interact with vision.

About me: I like playing Werewolf games and Catan. I also love watching professional gamers playing PUBG Esports.

Medha Shekhar



Research Interests: I study how humans make perceptual and confidence judgements using a combination of behavioural experiments and computational modelling. Currently, I am working on testing CNNs on perceptual tasks to understand how their behaviour and internal representations compare to humans.

About me: I love to read and collect all kinds of books, especially fiction. I also enjoy running and watching horror movies.

Graduate Students

Sean Zheng



Research Interests: I am interested in how people become aware of themselves and the external environment. I am also interested in how people metacognitively monitor and control their own decision-making processes. I would like to use behavioural experiments, multimodal neuroimaging methods and computational models to answer these questions of interests.

About me: I love coffee, reading, Lego, stand-up comedy, Peanuts (comic), Japanese TV dramas, and Arsenal football club.

Nadia Haddara



Research Interests: I am interested in the neural mechanisms underlying emotion-cognition interactions, specifically the influence of fear and threat-predictive environmental cues on how we perceive, attend to, and learn about meaningful associations. My current projects use functional neuroimaging (fMRI) to examine the impact of threat-related information on perceptual decision-making in the brain using a Pavlovian conditioning paradigm. I also have an interest in factors that modulate people’s basic visual perception and metacognition (i.e. the ability to reflect on and evaluate one’s behavior).

About me: I am an avid horseback rider who also enjoys running, reading any neuroscience book or fantasy trilogy I can get my hands on, and playing board games or just spending time with family and friends.

Kai Xue



Research Interests: I am interested in how visual system is able to perceive information and make decisions. I want to integrate computational modeling, neuroimaging techniques, and behavioral experimentation to understand how visual system understands and reasons actions.

About me: I play the piano and the flute. For sports, I play table tennis.

Herrick Fung



Research Interests: I’m fascinated by the binding problem of visual perception and consciousness, as well as the neural mechanisms underlying subjective experiences. In my previous studies, I delved into understanding the attentional mechanism and binding processes involved in human face recognition and ensemble processing. Currently, my focus is on projects aiming at enhancing metacognition and how various stimulus properties impact perceptual accuracy and confidence.

About me: I have a strong preference for indoor activities, primarily because I tend to sweat a lot. Among my favourites are playing and composing music, diving into textbooks (which cultivated my interest in cognitive neuroscience at the very beginning), and solving Rubik’s cube and Sudoku.

Undergraduate Research Assistants

Girish Jayakumar


Research Interests: I am deeply involved in bridging machine learning, autonomous systems, and human-computer interaction to enhance real-world applications and decision-making processes. Currently, I am focused on the resilience of neural networks against adversarial attacks. My project investigates the robustness of RTNet, a newly developed ANN that generates stochastic decisions and human-like response time (RT) distributions, and its capabilities compared to standard neural networks.

About me: I am a computer science student at Georgia Tech with concentrations in Intelligence and HCI. Over the years, I have visited over 20 national parks, and I enjoy hiking and engaging in outdoor activities. In my spare time, I love to exercise, read, watch movies, play tennis and racquetball, and volunteer to help Atlanta-based nonprofits.

Sophie Michelsen


Research Interests: Computational neuroscience, convolutional neural networks, neural modeling, and metacognition.

About me: I love reading, hiking, spending time with friends and family, and cheering on the Liverpool football club. I also love playing Ultimate frisbee, and I've been getting more into running and lifting!

Ananya Jain


Research Interests: Artificial Neural Networks. As part of my current project at the lab, I am working on training a convolutional neural network to learn quantity estimation tasks on perceptual data like length of a line or number of dots in a grid.

About me: I am a second-year student at Georgia Tech studying computer science with a specialization in artificial intelligence and human computer interaction. I love hiking, sailing, astronomy, and photography!

Sruthi Medepalli


Research Interests: I’m fascinated by computational neuroscience, and how we model decision-making processes in the brain through neural networks. I’m currently developing an ANN to mimic the performance of human subjects on a color numerosity task while analyzing which method of generating confidence in machines most accurately aligns with human thought processes.

About me: I’m a first-year computer science major at Georgia Tech with a concentration in intelligence and people. I enjoy watching and reading thrillers, listening to all kinds of music, and running!

Nola Pickering


Research Interests: I am interested in using machine learning as a tool for understanding biological systems, especially toward modeling complex processes like vision. I am currently working on developing a CNN model in order to analyze its performance on multi-choice tasks in the context of developing a baseline for similar testing in human perception and decision-making.

About me: I am a second-year math major at Georgia Tech planning on a concentration in probability and statistics. I love to play rugby, powerlift, show friends my favorite horror movies and TV shows, watch indie game let's plays, and bake new treats.

Sarayu Ayyalasomayajula


Research Interests: I am interested in perceptual decision-making and understanding human visual perception. Currently, I'm working on a project using transcranial magnetic stimulation (TMS) to identify how the motor cortex influences response bias.

About me: I'm a second-year Neuroscience major at Georgia Tech on the pre-med track. I enjoy playing tennis competitively, reading, and traveling!

Michaela Bocheva

E-mail: mbocheva02 [at] gmail [dot] com

Research Interests: I use various psychophysical and computational approaches to study perceptual representations as a statistical inference problem. My interests include efficient coding, probabilistic perception, and perceptual uncertainty at the sensory and decision levels.

About me: I enjoy reading, oil painting, theater, films, and MMORPG games.

Lab Alumni

  Ji Won Bang: Postdoc (2015-2017). Next position: postdoc at New York University.

  Jiwon Yeon: Ph.D. student (2016-2021). Next position: postdoc at Stanford University.

  Medha Shekhar: Ph.D. student (2016-2021). Next position: postdoc at University College London.

  Farshad Rafiei: Ph.D. student (2016-2022). Next position: machine learning scientist at IQVIA.

  Samuel Goldstein: Ph.D. student (2020-2022). Next position: data scientist at World Wide Technology.

  Johan Nakuci: Postdoc (2020-2023). Next position: Postdoctoral Fellow at Army Research Laboratory (ARL).