About

Dr. Cameron Ellis is an Assistant Professor in the Department of Psychology at Stanford University. His research focuses on understanding the developing mind of infants through methods from neuroscience and cognitive science. He leads the Scaffolding of Cognition Team, which investigates fundamental questions about how infants perceive, attend, learn, and remember. His work employs techniques such as functional magnetic resonance imaging (fMRI) with awake, behaving infants to access the cognitive mechanisms underlying early development. Dr. Ellis's research has contributed to understanding the organization of the infant visual cortex, demonstrating that infants aged 5-23 months possess retinotopic maps and visual area boundaries, indicating a greater maturity of the extrastriate cortex than previously thought. Additionally, his studies have shown that the infant hippocampus supports statistical learning from a very young age, with activity related to learning observed around three months old, and that attention mechanisms in infants involve frontal brain regions active during attentional orienting tasks. His work provides insights into early brain development, highlighting the early recruitment of neural circuits involved in perception, memory, and attention, and offers a model for understanding how the mature brain functions through noninvasive neuroimaging techniques.

Research topics

• Computer Science
• Artificial Intelligence
• Neuroscience
• Psychology
• Cognitive psychology
• Biology
• Computational biology

Selected publications

• Functional Magnetic Resonance Imaging in Awake Infants: Insights From More Than 750 Scanning Sessions

  Infancy · 2026-01-01 · 1 citations

  articleOpen access

  Functional magnetic resonance imaging (fMRI) in awake infants has the potential to reveal how the early developing brain gives rise to cognition and behavior. However, awake infant fMRI poses significant methodological challenges that have hampered wider adoption. The present work takes stock after the collection of a substantial amount of awake infant fMRI data across multiple studies from two labs, at Yale University and Massachusetts Institute of Technology (MIT). These data were leveraged to glean insights on participant recruitment, experimental design, and data acquisition that could be useful to consider for future studies. Across 766 fMRI sessions with awake infants aged 1-36 months, the authors explored the factors that influenced how much usable data were obtained per session. The age of an infant predicted whether they would successfully enter the scanner (younger more likely) and, if they did enter, the number of minutes of functional data collected (linear, younger more) and retained after preprocessing with lab-specific protocols or harmonized motion exclusion thresholds (quadratic, 12-24 months more than younger and older). The amount of functional data retained was also influenced by assigned sex (female more), experimental paradigm (movies better than blocks and events), and stimulus content (social better than abstract). There were many differences in the research approach between labs making head-to-head comparisons difficult, but Yale was more likely to get infants into the scanner, MIT collected more data from infants who entered, and the amount of data retained after preprocessing did not differ statistically between labs (9 min). In addition, the authors assessed the value of attempting to collect multiple experiments per session, an approach that yielded more than one usable experiment averaging across all sessions. Although any given scan is unpredictable, these findings support the feasibility of awake infant fMRI and suggest practices to optimize future research.

  PublisherOA PDFDOI

• Functional magnetic resonance imaging in awake infants: Insights from more than 750 scanning sessions

  OSF Preprints (OSF Preprints) · 2026-01-05

  other

  This repository contains the data that support the findings reported in "Functional magnetic resonance imaging in awake infants: Lessons from more than 750 scanning sessions"

  Publisher

• Functional magnetic resonance imaging in awake infants: Insights from more than 750 scanning sessions

  OSF Preprints (OSF Preprints) · 2026-01-05

  other

  This repository contains the data that support the findings reported in "Functional magnetic resonance imaging in awake infants: Lessons from more than 750 scanning sessions"

  Publisher

• Enhanced processing of cartoons in infant visual cortex

  bioRxiv (Cold Spring Harbor Laboratory) · 2026-05-11

  article

  Abstract Developing sensory systems may have heightened sensitivity to exaggerated features that emphasize diagnostic information, as shown by the benefits of infant-directed speech for language acquisition. Here, we examine this sensory exaggeration hypothesis in the visual domain by testing whether cartoons elicit stronger and more consistent neural representations than realistic movies in human infants. We collected fMRI data while 24 awake infants (4–15 months) watched the same 3-minute clip of the opening sequence from the original animated version of The Lion King (1994) and its shot-for-shot remake with photorealistic CGI (2019). A computer vision model confirmed that the movies differed in low-level features while depicting similar high-level content. Consistent with sensory exaggeration, the animated version yielded more reliable neural responses and better decoding of visual features than the CGI version throughout occipital cortex. This effect was not observed in adults nor in higher-order regions in infants and could not be explained by differential head motion or looking time. These results suggest that the developing visual system may be attuned to diagnostic features and that cartoons may (unwittingly) exploit this early neural preference.

  PublisherDOI

• Author response: Movies reveal the fine-grained organization of infant visual cortex

  2025-03-06

  peer-reviewOpen access1st authorCorresponding

  How babies see the world is a mystery. They cannot share their experiences, and adults cannot recall this time. Clever experimental methods are needed to understand sensory processing in babies' brains and how variations from adults could cause them to have different experiences. However, finding ways to study infant brain structure and function has challenged scientists. Babies cannot complete many cognitive tasks used to assess adult brain activity. It can also be difficult to use imaging tools like magnetic resonance imaging (MRI) that require individuals to lay still for extended periods, which can be challenging for infants who are often wiggly and have short attention spans. As a result, many questions remain unanswered about infant brain organization and function. Recent technological advances have made it easier to study infant brain activity. Scientists have developed approaches allowing infants to watch a movie while being comfortably positioned in an MRI machine. Infants and toddlers will often happily watch a film for minutes at a time, enabling scientists to observe how their brains respond to what they see on the screen. Ellis et al. used this approach to assess the organization of the visual system in the brains of 15 infants while they watched movies during functional MRI. The researchers compared the infant scans with scans of adult brains who watched the same film, which revealed that babies’ brain activity is surprisingly structured and similar to that of adults. Moreover, the organization of the adult brain could predict the organization of the infant brain. Ellis et al. show that scanning infants while they watch movies can be a valuable way to study their brain activity. The experiments reveal important similarities in adult and infant visual processing, helping to identify the foundation on which visual development rests. The movie-watching experiments may also provide a model for scientists to study other types of infant perception and cognition. Movies can help scientists compare brain activity in typically developing infants to those with neurodevelopmental conditions, which could one day help clinicians create new avenues for diagnosis or treatment.

  PublisherDOI

• Movies reveal the fine-grained organization of infant visual cortex

  eLife · 2025-01-07

  preprintOpen access1st authorCorresponding

  Studying infant minds with movies is a promising way to increase engagement relative to traditional tasks. However, the spatial specificity and functional significance of movie-evoked activity in infants remains unclear. Here we investigated what movies can reveal about the organization of the infant visual system. We collected fMRI data from 15 awake infants and toddlers aged 5–23 months who attentively watched a movie. The activity evoked by the movie reflected the functional profile of visual areas. Namely, homotopic areas from the two hemispheres responded similarly to the movie, whereas distinct areas responded dissimilarly, especially across dorsal and ventral visual cortex. Moreover, visual maps that typically require time-intensive and complicated retinotopic mapping could be predicted, albeit imprecisely, from movie-evoked activity in both data-driven analyses (i.e., independent components analysis) at the individual level and by using functional alignment into a common low-dimensional embedding to generalize across participants. These results suggest that the infant visual system is already structured to process dynamic, naturalistic information and that fine-grained cortical organization can be discovered from movie data.

  PublisherDOI

• Awake infant fMRI: Insights from more than 750 scanning sessions

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-25 · 1 citations

  preprintOpen access

  Abstract Functional magnetic resonance imaging (fMRI) in awake infants has the potential to reveal how the early developing brain gives rise to cognition and behavior. However, awake infant fMRI poses significant methodological challenges that have hampered wider adoption. The present work takes stock after the collection of a substantial amount of awake infant fMRI data across multiple studies from two labs at different institutions. These data were leveraged to glean insights on participant recruitment, experimental design, and data acquisition that could be useful to consider for future studies. Across 766 fMRI sessions with awake infants aged 1–36 months, the authors explored the factors that influenced how much usable data were obtained per session. The age of an infant predicted whether they would successfully enter the scanner (younger more likely) and, if they did enter, the number of minutes of functional data collected (linear, younger more) and retained after preprocessing with lab-specific protocols or harmonized motion exclusion thresholds (quadratic, 12–24 months more than younger and older). The amount of functional data retained was also influenced by assigned sex (female more), experimental paradigm (movies better than blocks and events), and stimulus content (social better than abstract). There were many differences in the research approach between labs making head-to-head comparisons difficult, but Yale was more likely to get infants into the scanner, MIT collected more data from infants who entered, and the amount of data retained after preprocessing did not differ statistically between labs (9 minutes). In addition, the authors assessed the value of attempting to collect multiple experiments per session, an approach that yielded more than one usable experiment averaging across all sessions. Although any given scan is unpredictable, these findings support the feasibility of awake infant fMRI and suggest practices to optimize future research.

  PublisherOA PDFDOI

• Author response: Movies reveal the fine-grained organization of infant visual cortex

  2025-01-07

  peer-reviewOpen access1st authorCorresponding

  Studying infant minds with movies is a promising way to increase engagement relative to traditional tasks. However, the spatial specificity and functional significance of movie-evoked activity in infants remains unclear. Here we investigated what movies can reveal about the organization of the infant visual system. We collected fMRI data from 15 awake infants and toddlers aged 5–23 months who attentively watched a movie. The activity evoked by the movie reflected the functional profile of visual areas. Namely, homotopic areas from the two hemispheres responded similarly to the movie, whereas distinct areas responded dissimilarly, especially across dorsal and ventral visual cortex. Moreover, visual maps that typically require time-intensive and complicated retinotopic mapping could be predicted, albeit imprecisely, from movie-evoked activity in both data-driven analyses (i.e., independent components analysis) at the individual level and by using functional alignment into a common low-dimensional embedding to generalize across participants. These results suggest that the infant visual system is already structured to process dynamic, naturalistic information and that fine-grained cortical organization can be discovered from movie data.

  PublisherDOI

• Profiling brain morphology for autism spectrum disorder with two cross-culture large-scale consortia

  Communications Biology · 2025-08-05 · 3 citations

  articleOpen access

  We explore neurodevelopmental heterogeneity in Autism Spectrum Disorder (ASD) through normative modeling of cross-cultural cohorts. By leveraging large-scale datasets from Autism Brain Imaging Data Exchange (ABIDE) and China Autism Brain Imaging Consortium (CABIC), our model identifies two ASD subgroups with distinct brain morphological abnormalities: subgroup “L” is characterized by generally smaller brain region volumes and higher rates of abnormality, while subgroup “H” exhibits larger volumes with less pronounced deviations in specific areas. Key areas, such as the isthmus cingulate and transverse temporal gyrus, were identified as critical for subgroup differentiation and ASD trait correlations. In subgroup H, the regional volume of the isthmus cingulate cortex showed a direct correlation with individuals’ autistic mannerisms, potentially corresponding to its slower post-peak volumetric declines during development. These findings offer insights into the biological mechanisms underlying ASD and support the advancement of subgroup-driven precision clinical practices. Using the lifespan brain chart and two large-scale cross-cultural consortia (ABIDE and CABIC), we disentangle the heterogeneity of brain morphology in ASD into two structural impairment pathways that could disrupt sensory to association functions.

  PublisherOA PDFDOI

• Hippocampal encoding of memories in human infants

  Science · 2025-03-20 · 39 citations

  article

  Humans lack memories for specific events from the first few years of life. We investigated the mechanistic basis of this infantile amnesia by scanning the brains of awake infants with functional magnetic resonance imaging while they performed a subsequent memory task. Greater activity in the hippocampus during the viewing of previously unseen photographs was related to later memory-based looking behavior beginning around 1 year of age, suggesting that the capacity to encode individual memories comes online during infancy. The availability of encoding mechanisms for episodic memory during a period of human life that is later lost from our autobiographical record implies that postencoding mechanisms, whereby memories from infancy become inaccessible for retrieval, may be more responsible for infantile amnesia.

  PublisherDOI

Frequent coauthors

• Nicholas B. Turk‐Browne

  Yale University

  96 shared

• Tristan S. Yates

  Yale University

  78 shared

• Michael Arcaro

  California University of Pennsylvania

  57 shared

• Léo Paly

  16 shared

• Gaël Chételat

  Université de Caen Normandie

  16 shared

• Marion Delarue

  16 shared

• Lena J. Skalaban

  Temple University

  15 shared

• Jonathan D. Cohen

  Princeton University

  14 shared

Labs

• Vice Provost for Student AffairsPI

Education

• B.S.

  Auckland University

  2013

• M.A.

  Princeton University

  2017

• Ph.D.

  Yale University

  2021

Awards & honors

• FLUX Dissertation Prize (2021)
• James Grossman Dissertation Prize (2021)
• William Kessen Teaching Award (2019)