• Real-world memory and the brain

    How do we construct and retrieve memories of complex real-world episodes? In this research we use realistic stimuli (such as movies and narratives) and behaviors (such as spoken recall) that contain rich natural semantics and unfold continuously across multiple timescales. Employing between-brain temporal and pattern analysis methods, we ask how mnemonic and sensory systems operate together dynamically to create the present moment.

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  • Research

    In the mind, the present moment is a convergence point of two information streams: one, a continuous flow of sensory input from the outside world; and two, a series of elements from our past experiences, i.e., memories. Memories may be triggered by sensory stimuli, they may themselves cue more memories, and they may change the way incoming stimuli are interpreted, all of which become part and parcel of our current experience.

     

    Past information casts an influence across multiple timescales: events that occurred a moment ago, a minute ago, and a day ago may all impact the present. In order to understand how the mind and brain work, we need an account of how memories of past events, across multiple timescales, continuously influence and merge with ongoing perception and behavior.

     

    Studying real memory requires using real stimuli. Scientists often trade realism for control; we use lists or configurations of random items, attempting to isolate selected variables. However, this approach can strip away the very richness and complexity that made memory such a compelling topic in the first place, and cause us to neglect phenomena that emerge only when stimuli are as dynamic and detailed as the real world.

     

    My work aims to understand how we construct and retrieve memories of complex real-world episodes. I use realistic stimuli (such as movies and narratives) and behaviors (such as spoken recall) that contain rich natural semantics and unfold continuously across multiple timescales. Using novel between-brain temporal and pattern analysis methods, I ask how mnemonic and sensory systems operate together dynamically to create the present moment.

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  • Snapshots

    Shared experience, shared memory. Patterns in the brain which emerge during perception are later reactivated during spoken recall, are robustly similar across different individuals, and transform systematically between perception and memory.

    A hierarchy of processing timescales. In order to interpret a continuous stream of input from the world, the brain must integrate information over multiple timescales. We propose that stimulus processing is distributed across a hierarchy of cortical regions, with processing timescales increasing along a gradient from low-level sensory areas (e.g., visual cortex) up to high-level association areas (e.g., default network).

    Under natural conditions, memories can persist in high-order cortex for minutes. It is well known that formation of new episodic memories depends on the hippocampus, but in real- life settings (e.g., conversation), hippocampal amnesics can utilize information from minutes earlier. What neural systems outside the hippocampus support this minutes-long retention? My work using functional MRI in the healthy brain suggests that default network cortical regions can intrinsically retain information for several minutes during continuous, semantically rich natural stimulation.

  • Methods

    Analyses of functional neuroimaging data

    Naturalistic stimuli and behavior

    Collect brain data as people watch movies and listen to stories, and as they describe their memories out loud

    Inter-subject correlation

    Compare activity between the brains of different people, both in the temporal domain and the spatial domain

    Multi-voxel pattern classification

    Identify neural patterns that are specific to certain periods in the stimulus, such as a particular movie scene

    Semantic model construction

    Predict patterns of neural activity given combinations of stimulus features

  • People

    Janice Chen

    Principal Investigator

    Assistant Professor

    Lisa Musz​

    Postdoctoral Research Fellow

    I received my BA in Psychology at Carleton College and my PhD in Psychology at the University of Pennsylvania. My doctoral dissertation investigated how task context modulates item-level neural representations of word meanings.

     

    In my post-doctoral work, I plan to study how information is transformed in the brain across changes in time and representational format, for example from (1) initial encoding to subsequent recollection, and from (2) an observed sequence of audiovisual events to a retrieved and verbalized narrative. I will use a combination of neuroimaging and behavioral methods to address these questions.

    Hongmi Lee

    Postdoctoral Research Fellow

    I received my BA and MA in Psychology at Yonsei University, South Korea. I did my PhD in Cognitive Neuroscience at New York University, where I studied mnemonic content representations in human posterior parietal cortex using functional neuroimaging.

     

    I am broadly interested in how high-level association areas in the brain support complex cognitive functions such as remembering naturalistic events. In my current project, I am studying the relationship between the structure of narratives and neural responses in the default mode network regions during encoding and recall of movies and stories.

    Buddhika Bellana

    Postdoctoral Research Fellow

    I am broadly interested in the ideas of depth of processing, and what it means to deeply engage with incoming information.

     

    My doctoral work at the University of Toronto explored this topic via episodic memory. There, I examined the influence of prior knowledge on our ability to recollect recent experiences, using measures of behaviour and fMRI.

     

    During my post-doc, I will explore depth of processing using narratives. Narratives provide a natural example where we draw upon prior knowledge to contextualize and enrich the concrete details of a story. Using fMRI, I hope to gain insight into 1) the neural systems that can reliably predict moments when we are deeply processing a narrative, and 2) the functional contributions of these neural systems to deep processing.

    Peter Johnson

    Graduate Student

    What does it mean for two people to be thinking about the same thing? Remembering the same event? How does communication allow us to come to shared understandings despite differences in experience? How are these similarities in concepts, memory, and understanding reflected in the brain? I hope to develop a better grasp of the nature and answers to questions like these by taking advantage of the power and flexibility of intersubject fMRI analyses using complex, naturalistic stimuli.

     

    I did my undergraduate work at Princeton University where I landed in Psychology from a background in Computer Science and Philosophy. Past research topics I've worked with include the computational underpinnings of human learning, neural network models of cognition, and the statistical properties of methods in fMRI analysis.

    Savannah Born

    Lab Manager

    I’m a senior Neuroscience major and have been the lab manager for the Chen and Honey labs since the summer of 2019.

     

    I’m currently involved in a project investigating how the sequence of events in stimuli, such as a movie, is connected to later memory of that stimulus. We expect that “central” events that are highly connected with the other events will be the best recalled. From a broader perspective, I’m very interested in researching more about how people learn and ways to optimize learning and memory.

     

    In addition to lab work, I am a part of Experiential Education where I lead whitewater kayaking and sailing trips.

    Katelyn Macholl

    Undergraduate Research Assistant

    I’m a junior Psychology and Molecular & Cellular Biology double major.

     

    I’m interested in learning more about memory outside of traditional research techniques. I love that we can study individuals with real-world stimuli, such as movies or pictures. I’m currently helping on a project in which fMRI participants recall details from a series of images. From this, both similarities and discrepancies among individuals can be noted based on which parts of an image one remembers.

    Edward Halpin

    Undergraduate Research Assistant

    I'm a senior undergrad majoring in Psychology and Writing Seminars. More specifically, I'm interested in social psychology: what causes people to come together and drift apart, and what kind of systematic behaviors can we observe across people in particular situations? I'm currently helping in a project where participants recall a narrative they just watched. I hope to learn more about what makes a narrative memorable so that it could influence my writing.

     

    Outside of the lab, I love to write stories and go running from time to time. Murder mysteries and suspense stories have always been really interesting to me, and I hope to become a novelist someday.

    Elly Yeom

    Undergraduate Research Assistant

    I’m a junior double majoring in Neuroscience and Psychology.

    My broad research interests include human cognition and memory, functional connectivity between different parts of the nervous system, and how they influence humans on day to day basis. Currently, I’m working on a project to test the impact of event structure of movie narrative on people’s later memory of the movie.

    Kenz Wilkinson

    Undergraduate Research Assistant

    I'm senior Neuroscience Major and Psychology minor. I've been involved with the Chen lab since the fall of 2018.

     

    Within Neuroscience, I've chosen cognition as my focus area. I'm deeply interested in why we think the way we do, and further exploring the mind/brain border. My current project involves predictions and the mental models we create to assist those predictions. More specifically, we are looking at which areas of the brain are active during moments of both high and low predictability and why.

     

    Outside of the lab I'm a member of the varsity cross country, basketball, and track and field teams. I also love art and any activity that involves being in the outdoors!

    Amanda Liu

    Undergraduate Research Assistant

    I received my bachelor's degree in Neuroscience with a minor in Psychology.

     

    My research interest involved the study of brain activity with regards to memory and recall. More specifically, we’re currently working on a project that maps the memory of participants recalling a set of ten short stories. We’re looking to analyze the times of memory search, transition periods, and other elements of their responses before matching it up to their fMRI.

     

    A fun fact about me? I love grocery shopping and watching people cook.

    Yoonjin Nah

    Alumni (Graduate Student)

    Yoonjin was interested in the behavioral and neural mechanisms underlying encoding and retrieval processes of real-life experiences. His research focused on understanding how the human mental processes deal with real-life experiences by adopting naturalistic fMRI paradigms, how these systems operate to guide us to both successfully encode and retrieve a multitude of information which contains various contextual factors, and how individual differences have a direct/indirect impact on these processes.

     

    Yoonjin is currently pursuing his dream of becoming a pilot, and will soon become the lab member with the highest-flying career.

    Zoey Zuo

    Alumni (Lab Manager)

    I received my bachelor's degree in Cognitive Science at UCLA, and am now a Clinical Psychology graduate student at the University of Toronto, working with Drs. Zindel Segal and Norman Farb.

     

    I'm working with Janice on a project to investigate whether the long-timescale capability of default network regions depends on interactions with the hippocampus, using fMRI data collected as an amnesic patient and neurotypical controls listened to a 7-minute real-life story. Our results suggest that default network regions are capable of integrating long-timescale information even without contributions from the hippocampus.

    Qingwei Zhang

    Alumni (Undergraduate Research Assistant)

    I received my bachelor's degrees in Psychology and Cognitive Science at JHU.

     

    I’m interested in several psychology topics, including sleep patterns, emotions, relationships, etc, but memory is definitely my favorite. I’m currently involved in a study that looks at whether people’s brain activity differ when they recall temporally specific events that can be targeted to a precise moment in the past, versus when they summarize information that happened over a longer period of time.

  • Positions Available

    Now recruiting!

    Lab Coordinator / Research Assistant

    Research areas: Human learning and memory, brain networks, computational neuroscience

    The Lab Coordinator is responsible for managing and implementing the research activities of the lab. This position is designed as preparation for graduate school. Thus, a large portion of the job is research, along with some administrative tasks. Duties may include: 1) behavioral and fMRI testing of human subjects, 2) experiment design, programming, troubleshooting, and record-keeping, 3) analyses of behavioral and brain data under the guidance of the PI, 4) scheduling and other organizational matters for the lab group.

     

    Requirements: Strong programming skills (MATLAB, Python, or R); bachelor’s degree in neuroscience, psychology, cognitive science, computer science, engineering, or a related field.


    Helpful: Previous research experience in a psych or neuro lab.

     

    A start date in the range of May to September 2019 is preferred.

     

    Previously this position was joint between two labs (Janice Chen and Christopher Honey). The new position could be individual or joint, subject to discussion and the preference of the applicant.

     

    Send cover letter and CV to:

     

    Janice Chen <janice@jhu.edu>
    http://jchenlab.johnshopkins.edu

     

    Christopher Honey <chris.honey@jhu.edu>
    http://honeylab.org

     

    JHU ad: https://jobs.jhu.edu/job/Baltimore-Research-Program-Coordinator-MD-21218/546240300/

     

    note: if you apply via the jhu website, you must also directly contact us by email.