(photo of JHU's Peabody Library, where we wish we held our lab meetings)

The PERCEPTION & MIND LAB investigates how we see, how we think, and especially how seeing and thinking interact to produce sophisticated behavior. We are located in the Department of Psychological and Brain Sciences at Johns Hopkins University, and we are also affiliated with the cross-departmental Vision Sciences Group. This page contains information about who we are and what we do.


  • Congratulations to lab members Austin Baker and Jorge Morales on winning the poster prize from the Society for Philosophy and Psychology! Austin and Jorge were honored for their project on gender stereotypes and perception, titled "'You're my doctor?': Social stereotypes impair recognition of incidental visual features". And they did it in style. (July 2019)

  • Congratulations to several lab members who are moving on to exciting new positions and opportunities! Visiting graduate student Austin Baker will return to the Rutgers Center for Cognitive Science as a Postdoctoral Assistant Professor, where she will continue her research at the intersection of philosophy and cognitive science (and hopefully still collaborate with us!). Lab undergrad Zhenglong Zhou is off to the University of Pennsylvania to begin his PhD in their Department of Psychology. Lab manager Jose Rivera-Aparicio is heading back to Puerto Rico as a law student at the University of Puerto Rico. And Isabel Won, a sophomore in the lab, was one of 13 people selected from 760 applications (!) for a summer internship at Stanford's Center for the Study of Language and Information. Congratulations to everyone on these exciting new positions! (April 2019)

  • The lab is earning some air miles! Earlier this academic year, Chenxiao Guan won a travel award to attend the Object Perception, Attention, and Memory meeting (aka OPAM) in New Orleans, for her talk on representations of "possibility" in perception. Zekun Sun then earned an Elsevier / Vision Research Travel Award from the Vision Sciences Society, to present her work on how verbal descriptions of images encode their perceived complexity. Next, Alon Hafri won an NEI Postdoctoral Travel Grant to tell VSS attendees how "a phone in a basket looks like a knife in a cup" (curious? join us in Fla.!). And last but not least, Isabel Won earned an undergraduate travel grant from our own Department of Psychological and Brain Sciences, to support her impossibly cool VSS presentation titled "Impossible integration of size and weight". As of this update, it is unknown what spoils Chenxiao, Zekun, Alon, and Isabel will claim. ✈️ (April 2019)

  • There's some fun media surrounding our new work (led by lab undergrad Zhenglong Zhou) on how humans perceive adversarial images! Here at JHU, The Hub produced a story and video about the project, which includes a little game to give you a sense of the experience our subjects had. Another great piece is over at VentureBeat, which wrote a long and well-informed article about the paper. There was also some great discussion on the "AI with AI" Podcast. And believe it or not, there was a surprisingly well-informed and insightful discussion about our project on Reddit! We'll let you find that on your own... (April 2019)

  • Lab postdoc Jorge Morales was just named a Provost's Postdoctoral Fellow! Jorge's work and promise were singled out by the Office of the Provost, which has honored him with a special funding award to support his work here at JHU. Congratulations to Jorge on this well-deserved recognition! (March 2019)

  • We've just posted our first-ever preprint! From an exciting new project led by lab undergraduate Zhenglong Zhou, on how humans perceive "adversarial images" that fool convolutional neural nets. You can read the full paper at the link above, and you can also find a summary of the work in a recent news article over at New Scientist. (September 2018)

  • Chaz spoke to the Wall Street Journal about the lab's exciting new work on the perception of complexity carpets.
    (August 2018)

  • Lab postdoc Jorge Morales appeared on the Consciousness Live YouTube series to speak about his doctoral work on "mental strength". Check it out! (August 2018)

  • Congratulations to several lab members on some exciting awards and prizes! Pat Little won a STAR Award to fund his research in the lab this summer; Isabel Won earned a summer internship in the Laboratory for Child Development here at JHU; Zhenglong Zhou won a DURA Award to start a new project on human and machine vision; and Chaz won a Dean's Teaching Award from the Krieger School of Arts & Sciences, as well as the Glushko Prize from the Cognitive Science Society. Congratulations to all! Now, back to work. (May 2018)

  • The lab is very excited to be working with the Science of Learning Institute on a new project exploring 'rationality' in learning. (July 2017)

  • Congratulations to lab undergraduate J.J. Valenti on winning a Provost's Undergraduate Research Award! J.J. will be working in the lab this coming academic year on 'reflexive' processing in intuitive physics. (March 2017)

  • We have a website! This is it. It has a cool web address: http://perception.jhu.edu. (August 2016)

  • It's official! In Summer 2017, we're starting up our new lab in the Department of Psychological and Brain Sciences at Johns Hopkins University. (March 2016)


Principal Investigator

Chaz Firestone [personal webpage]
Assistant Professor of Psychological and Brain Sciences

Chaz is interested in the nature of seeing, thinking, and the relation between the two. He came to Hopkins after completing his graduate work in the Department of Psychology at Yale; before that, he spent some time as a graduate student in philosophy at Brown, where he was also an undergraduate. When he's not trying to figure out how we see and think, Chaz likes to grapple, eat ceviche, and set spurious world records for fastest circumnavigation of the globe on foot.

Postdoctoral Fellows

Alon Hafri [personal webpage]
Postdoctoral Fellow (also in the Bonner Lab)

Alon studies how language encodes the structure of scenes (e.g., which objects are in, on, above, below, or behind others), and how this reflects the perceptual processes that extract such information. He earned his PhD at Penn, working with Russell Epstein and John Trueswell on dyadic event representation (who did what to whom?). Alon makes his own beer and soup, and performs in an annual Purim play as the beloved Vashti — who, like Alon himself, makes a lasting impression.

Jorge Morales [personal webpage]
Postdoctoral Fellow

Jorge is interested in the strength or intensity of conscious states — that aspect of experience shared by strong desires, awful pains, sublime musical experiences, and vivid visual images. He earned a PhD in philosophy from Columbia, where he led a double life in Hakwan Lau's Consciousness & Metacognition lab researching attention and metacognition using psychophysics and fMRI. Jorge takes photographs — more here — and makes cocktails (sometimes together).

Graduate Students

Austin Baker
Visiting Graduate Student (2018/2019 Academic Year)

Austin studies the overlap of perception and social cognition; specifically, how our worldview impacts perceptual and cognitive judgments, and how this sheds light on pervasive types of bias and irrationality. She's visiting from Rutgers University, where she's getting a philosophy PhD and is affiliated with the Center for Cognitive Science. Austin has worked in a congressional office, been a community organizer, and worked to make academia more inclusive. She likes 80s and 90s cult sci-fi.

Chenxiao Guan
Graduate Student (co-advised by Jonathan Flombaum)

Chenxiao is interested in connections between what we see and what we can create, including how we perceive objects that we can use (e.g., graspable tools) and objects that can interact with each other to make something new (e.g., jigsaw puzzle pieces). She comes to us from the University of Rochester, where she studied affordances in the CAOs Lab with Brad Mahon, and took advanced math courses for fun. Chenxiao is also a skilled ATV pilot, and is rumored to be in a band.

Zekun Sun
Graduate Student

Zekun is exploring the perception of complexity — how and why some objects look informationally dense, and others look informationally sparse. Her previous work at the Chinese Academy of Sciences explored visual attention to painful images (such as a hammer hitting a hand), including one study in which she inflicted actual pain on her subjects by attaching a contact-heat thermode to their arms. For this reason, we don't mess with Zekun.

Graduate Affiliates

Cara Maritz
Graduate Student in Philosophy

Cara is interested in how perception interacts with language and skill acquisition, and how development and learning together explain our cognitive abilities. She studied (and made) art before completing a graduate diploma at the University of Melbourne in both philosophy and psychology. Cara spends her leisure time reinforcing the stereotype that philosophers have their ‘heads in the clouds’, as an amateur photographer of the night sky (here of the 2012 transit of Venus).

Qian Yu
Graduate Student in the Halberda lab

Qian studies how we remember what we see, and how remembering is or isn't like seeing. While working as a translator of popular books (incl. Steve Jobs by Walter Isaacson!), she read some psychology books and became fascinated by how the mind works. So, she joined Ying-Yi Hong's Culture Lab at the Chinese University of Hong Kong, and explored the Uncanny Valley phenomenon. Qian gives you two lab members for the price of one, since she is rarely seen without her cat, Pipi.

Lab Manager

Jose Rivera-Aparicio
Lab Manager

Jose claims to be interested in interactions between language and perception, but his latest project is about beer, so who knows. He approached Chaz after a talk with a fantastic resume and even better questions, so Chaz responded by offering him a job. Jose's previous work in Mariko Moher's Early Childhood Cognition Lab at Williams College explored how the mind prioritizes different features (e.g. color vs. shape) in sorting objects; now Jose sorts things here in the lab.


Axel Delano Fabiano Bax (really)
Research Assistant

Axel is a sophomore studying psychology and English. He's using a laser cutter and Raspberry Pi to run our lab's first "real world" vision experiment, on first-person representation in perception. Axel cooks and gives admissions tours, and is somehow also a professional futsal player. Really: He plays for the Baltimore Kings, and once competed for a national championship with a broken wrist. Here are his sick highlights. By a 10-1 lab vote, Axel has the coolest name in cognitive science.

Patrick Little
Research Assistant (now also lab manager for the Halberda lab)

Pat was a member of the Class of 2019, until he graduated early this last December and is now living his best life. He became our lab's first member when he worked with us in Summer 2017; lucky for us, he came back the next year too with a Summer Training And Research Award. Here in the lab, Pat turns viral memes into science. Pat also is a skilled listener: He led the peer listening group A Place To Talk, and he subscribes to more podcasts than Chaz has heard of.

Isabel Won
Research Assistant

Isabel is a sophomore studying psychology and cognitive science. She is the resident 3D-printing expert in the lab, where she is working on a mind-bending illusion of weight perception. Isabel enjoys music and writing, and was inspired to pursue psychology by Oliver Sacks’ book, Musicophilia. Isabel is a member of the Hopkins Symphony Orchestra, and has been playing the cello since age six. Here she is performing Haydn's Cello Concerto No. 2 in her home state of New Jersey.

Zhenglong Zhou
Research Assistant

Zhenglong is a senior studying cognitive science and math. He spent a summer working with Jay McClelland on computational models of numerical cognition; in our lab, he's exploring how similar the human mind is to certain machine-learning systems that approximate its performance, by asking how humans perceive images designed for machines. Zhenglong plays funky jazz guitar and is now Chaz's go-to source for jazz fusion recommendations.

Perception is how we make contact with the world around us. How does this core process interface with the rest of the mind?

Our lab approaches this and other questions using the tools of vision science. Much of our work uses computer-based psychophysical experimentation, but we also explore these questions using larger real-world environments, computational models, 3D-printed stimuli, studies of brain-damaged patients, and even some unusual 'field work' (including experiments run in New York City's Times Square!).

A central research interest in the lab is how perception is 'smarter' and richer than we often give it credit for, often influencing — or even incorporating — surprisingly sophisticated processing that you might typically associate with higher-level cognition. For example, we've recently become interested in how our minds generate physical intuitions about the world (e.g., how we determine that a pile of rocks will topple over or stay upright). In one recent project, we have explored how basic representations of an object's shape can reach all the way up to our higher-level judgments about how that object will behave in physically rich scenarios, creating illusions of balance whereby objects that look hopelessly unstable may in fact balance perfectly (or vice versa).

We have also engaged with core questions about the underlying 'format' of what we see. Just as the format of a digital file constrains how it can be used (consider how a .doc file is useful for different purposes than a .pdf), the way our minds encode and represent information constrains how that information can be used by other processes. We have explored the format of perceptual representations by taking objects and shapes as a case study. Using new paradigms the lab has developed, we have found surprisingly direct evidence that the mind represents objects much as an architect might represent a building — in the format of a 'blueprint' or 'skeleton' that explains why objects look and behave as they do.

The lab also has a deep interest in foundational questions about the nature of perception. In particular, we have explored the ways in which higher-level factors such as language, desire, emotion, and action can — and cannot — influence what we see. Our work on this long-standing question in cognitive science has suggested that vision is not simply another kind of cognition, but rather is a truly distinct, 'encapsulated' process in the mind.

For a list of lab publications, see here.


Some of our recent work explores illusions of balance.

Click this shape, anywhere you like!

Machines think this is a starfish.
Do you?

Join Us

We will be considering graduate students for the 2019-2020 application cycle. There are also opportunities for undergraduate research assistants. More generally, we are always looking for talented and enthusiastic additions to our team. If you're interested in joining the lab, please send an e-mail to Chaz Firestone. Please also check out our opportunities page to learn more about the positions currently available in the lab.