Fast visual learning of competitive neuronal assemblies revealed using two novel technologies: Moculus (Virtual Reality) and Atlas (Fast 3d  Microscopy)

Thursday, August 25, 2022 at 11:00am

Singleton Auditorium, 46-3002 43 Vassar Street, Cambridge MA

Talk title: "Fast visual learning of competitive neuronal assemblies revealed using two novel technologies: Moculus (Virtual Reality) and Atlas (Fast 3d  Microscopy)””

Speaker: Balázs Rózsa, MD, PhD, Director of the BrainVisionCenter in Budapest Hungary

Thursday 8/25 at 11am 

In person: 46-3189

Pizza will be served after the talk

Zoom link: 

Password: 523142

Hosts: Gregg Heller and Mriganka Sur

Contact: Gregg Heller (



The time scale of visual learning is protracted in rodents, which can interfere with the readout of the underlying network mechanisms. Here we report a head-mounted, bidirectional display (Moculus) for small head-fixed animals which covers the entire visual-field, allows binocular depth-perception, and provides a fully immersive experience. This naturalistic and controllable behavioural environment combined with a treadmill and fast 3D acousto-optical imaging (Atlas) revealed fast visual learning in tens of minutes mediated by competing neuronal representations of the visual cues. Before learning, visual cues presented simultaneously in the VR are represented by a sparse code in the V1 region of the cortex. During learning, all neuronal assemblies initially grow in parallel before before the reinforcement-associated cue dominates the network representation and control cues return to normal sparse coding.  


The technical portion of this talk will also highlight acousto-optical microscopy technology that allows random access point scanning in all 3 dimensions (x,y AND z) which was used for the network imaging in this work. The following applications of this technology will also be shown, all possible with ROIs distributed across a spatial volume in 3D: 

Photostimulation with single cell specificity while simultaneously imaging population activity for all optical interrogation Voltage imaging in-vivo (with simultaneous calcium imaging also shown)  3D image stabilization/motion correction in behaving mice 



Species studied:                           Mouse

Brain Areas studied:                    Visual Cortex

Neural Phenomena:                     Network Ensembles 

Behavior:         Associative cue learning in virtual reality

data type :                                     2P Calcium Imaging of somatic activity

Lab Website:

Relevant Publications:

Using 3D Optical Photostimulation Induced Artificial Perception to Investigate Neuronal Ensembles Coding Visual Information. Rozsa, ... and Katana, Optics and the Brain, 2021 

Cortex-wide fast activation of VIP-expressing inhibitory neurons by reward and punishment. Szadai, ... and Rozsa, Bioarxiv, 2022

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Department of Brain and Cognitive Sciences (BCS)
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