Probing the cortical circuit basis of perception



Cortical activity underpins perception. This activity is often sparse, with a minority of neurons responding to specific stimuli. How do sparse groups of neurons influence perception and behavior? How does cortical computation impact perception? We use the mouse whisker system to tackle these questions.

Cortical correlates of perception

Large-scale recording of cortical activity in animals performing controlled behaviors allows us to identify populations that may underpin perception. Such correlative experiments are an essential prerequisite to experiments that probe circuit computation and the perceptual role of specific populations.

Computation in cortical circuits

Recurrence is a defining feature of cortical circuitry, and is believed to underpin many computations. We use perturbation in conjunction with network models to probe how recurrence among specific populations influences cortical computation.

Perceptual role of cortical populations

Identifying the cortical populations that correlate with perception is not enough to establish causality. We use focal perturbation to understand how specific populations of neurons contribute to behavior.


Quantitative behavior

Combining high speed videography with modern image processing techniques allows for precise measurement of the behavioral state of the animal. Tasks are designed so that even subtle changes in the animal's behavior can be detected.

Two-photon calcium imaging

Two-photon microscopy using modern calcium indicators allows us to record the activity of thousands of cortical neurons during behavior. Neurons can be tracked over months, allowing us to study how cortical dynamics evolve over time.

Automated analysis pipelines

Our experiments depend on rapid turnaround of terabyte-scale datasets. We are developing pipelines to process data acquired during calcium imaging and behavioral videography, and to relate neural activity to behavior.

Focal perturbation

Neurons encoding particular features are often intermingled with other neuron types. Approaches like multiphoton ablation, microlesions, and two-photon optogenetics allow us to test the hypotheses originating from our large scale mapping experiments.



Representational drift in barrel cortex is receptive field dependent (preprint)

Ahmed A, Voelcker B, Peron SP

2023, BioRxiv


Sparse and distributed cortical populations mediate sensorimotor integration (preprint)

Pancholi R, Sun-Yan A, Laughton M, Peron SP

2023, BioRxiv


Cortical circuitry mediating inter-areal touch signal amplification

Ryan L, Sun-Yan A, Laughton M, Peron SP

2023, Cell Reports


Learning in a sensory cortical microstimulation task is associated with elevated representational stability

Pancholi R, Ryan L, Peron SP

2023, Nature Communications


Microstimulation of sensory cortex engages natural sensory representations

Pancholi R, Sun-Yan A, Peron SP

2023, Current Biology


Columnar lesions in barrel cortex persistently degrade object location discrimination performance

Ryan L, Laughton M, Sun-Yan A, Costello S, Pancholi R, Peron SP

2022, eNeuro


Transformation of primary sensory cortical representations from layer 4 to layer 2

Voelcker B, Pancholi R, Peron SP

2022, Nature Communications


Recurrent interactions in local cortical circuits

Peron SP, Pancholi R, Voelcker B, Wittenbach JD, Olafsdottier FH, Freeman J, Svoboda K

2020, Nature


Comprehensive imaging of cortical networks

Peron SP, Chen TW, Svoboda K

2015, Curr. Opinion Neurobiology


A cellular resolution map of barrel cortex activity during tactile behavior

Peron SP, Freeman J, Iyer V, Guo C, Svoboda K

2015, Neuron


Complete list of publications, PubMed


Simon Peron, PhD

Principal Investigator

Simon earned his PhD with Fabrizio Gabbiani at Baylor College of Medicine, studying single neuron computation in the context of insect vision. He did his postdoctoral work with Karel Svoboda at Janelia Farm, working on mechanisms of cortical processing in the behaving mouse using two-photon microscopy.

Ravi Pancholi

Graduate (MD/PhD) Student

Ravi joined the lab in 2018. Ravi employs optical microstimulation to study the neural basis of perception.

Lauren Ryan

Graduate Student

Lauren joined the lab in 2019. Lauren's work focuses on the role sensory cortex plays in behavior.

Alisha Ahmed

Graduate Student

Alisha joined the lab in 2022. Alisha is interested in representational drift in vibrissal sensorimotor cortices.

Maya Laughton

Research Technician

Maya joined the lab in 2021. Maya is our master animal wrangler.

Andrew Sun-Yan

Research Technician

Andrew joined the lab in 2021.



We are actively recruiting post-docs and PhD candidates. If you are interested in our ongoing projects, please get in touch!

Perceptual role of cortex

Cortical activity has long been known to contribute to perception: nearly a century ago, Penfield and colleagues demonstrated that direct stimulation of somatosensory cortex could evoke natural touch sensations. How do the neurons in the mouse vibrissal cortical areas influence the perception of touch? We recently demonstrated that a single cortical barrel containing approximately 10,000 neurons is crucial to object localization but not detection behaviors. We now seek to use cellular-resolution perturbation to determine if much smaller populations - 50 to 100 neurons - actually underpin localization behaviors. We seek candidates interested in how cortical activity results in specific percepts.

Computations in cortical circuits

Cortex performs a range of computations that ultimately influence behavior. Understanding these computations requires careful measurement of neural activity combined with precise perturbation of circuit elements. We use a range of techniques, including volumetric calcium imaging, multiphoton ablation, and optogenetic approaches to asses how barrel cortex transforms sensory inputs. Building on recent work that revealed increasing receptive field complexity in the most superficial layers of barrel cortex, we seek candidates interested in designing experiments to probe the way in which specific functional classes of excitatory pyramidal neurons interact to produce these receptive fields.

Dynamics of recurrent network formation

Barrel cortex contains groups of touch-sensitive neurons that are recurrently coupled, allowing for computations such as amplification and pattern completion. How do these recurrent networks emerge, and what rules govern their formation? We recently developed an optical microstimulation paradigm that allows us to generate such recurrent networks artificially in mice that then use the evoked activity to drive behavior. We seek candidates interested in building on this work to probe the rules governing recurrent network plasticity in vivo.


Peron Lab

Center for Neural Science

New York University

4 Washington Place, Rm. 809

New York, NY 10003