Michael Beyeler
LightNews LightNews
banner
mbeyeler.bsky.social
Michael Beyeler
@mbeyeler.bsky.social
1.1K followers 430 following 440 posts
👁️🧠🖥️🧪🤖 Associate Professor in @ucsb-cs.bsky.social and Psychological & Brain Sciences at @ucsantabarbara.bsky.social. PI of @bionicvisionlab.org.
#BionicVision #Blindness #LowVision #VisionScience #CompNeuro #NeuroTech #NeuroAI
Posts Replies Media Videos
mbeyeler.bsky.social
And here’s the kicker: 🚨

If you try to predict perception from stimulation parameters alone, you’re basically at chance.

But if you use neural responses, suddenly you can decode detection, brightness, and color with high accuracy.
Three bar charts show how well different models predict perception of detection, brightness, and color. Using only the stimulation parameters performs worst. Including brain activity recordings—especially pre-stimulus activity—makes predictions much better across all three perceptual outcomes.
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
We pushed further: Could we make V1 produce new, arbitrary activity patterns?

Yes ... but control breaks down the farther you stray from the brain’s natural manifold.

Still, our methods required lower currents and evoked more stable percepts.
Figure showing the ability of different methods to reproduce target neural activity patterns and the limits of generating synthetic responses. Left: A target neural response (bottom-up heatmap) is compared to recorded responses produced by linear, inverse neural network, and gradient optimization methods. In this example, the inverse neural network gives the closest match (MSE 0.74) compared to linear (MSE 1.44) and gradient (MSE 1.49). Center: A bar plot of mean squared error across all methods shows inverse NN and gradient consistently outperform linear and dictionary approaches. Right: A scatterplot shows that prediction error increases with distance from the neural manifold; synthetic targets (red) have higher error than natural targets (blue), illustrating that the system best reproduces responses within the brain’s natural activity space.
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
Prediction is only step 1. We then inverted the forward model with 2 strategies:

1️⃣ Gradient-based optimizer (precise, but slow)
2️⃣ Inverse neural net (fast, real-time)

Both shaped neural responses far better than conventional 1-to-1 mapping
Figure comparing methods for shaping neural activity to match a desired target response. Left: the target response is shown as a heatmap. Three methods—linear, inverse neural network, and gradient optimization—produce different stimulation patterns (top row) and recorded neural responses (bottom row). Gradient optimization and the inverse neural network yield recorded responses that more closely match the target, with much lower error (MSE 0.35 and 0.50) than the linear method (MSE 3.28). Right: a bar plot of mean squared error across methods shows both gradient and inverse NN outperform linear, dictionary, and 1-to-1 mapping, approaching the consistency of replaying the original stimulus.
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
We trained a deep neural network (“forward model”) to predict neural responses from stimulation and baseline brain state.

💡 Key insight: accounting for pre-stimulus activity drastically improved predictions across sessions.

This makes the model robust to day-to-day drift.
Figure comparing predicted and true neural responses to electrical stimulation. Left panels show two example stimulation patterns (top), predicted neural responses by the forward neural network (middle), and the actual recorded responses (bottom). The predicted responses closely match the true responses. Right panels show bar plots comparing model performance across methods. The forward neural network (last bar) achieves the lowest error (MSE) and highest explained variance (R²), significantly outperforming dictionary-based, linear, and 1-to-1 mapping approaches.
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
Many in #BionicVision have tried to map stimulation → perception, but cortical responses are nonlinear and drift day to day.

So we turned to 🧠 data: >6,000 stim-response pairs over 4 months in a blind volunteer, letting a model learn the rules from the data.
Diagram of the experimental setup for measuring electrically evoked neural activity. A stimulation pattern is chosen across electrodes on a Utah array (left). Selected electrodes deliver 167 ms trains of 50 pulses at 300 Hz (middle left), sent via stimulator and amplifier into the visual cortex of a participant (middle). Neural signals are recorded before and after stimulation across all channels, producing multi-unit activity traces (MUAe). The difference between pre- and post-stimulation activity (ΔMUAe) is computed (middle right) and visualized as a heatmap across electrodes, showing localized increases in neural responses (right).
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
👁️🧠 New preprint: We demonstrate the first data-driven neural control framework for a visual cortical implant in a blind human!

TL;DR Deep learning lets us synthesize efficient stimulation patterns that reliably evoke percepts, outperforming conventional calibration.

www.biorxiv.org/content/10.1...
Diagram showing three ways to control brain activity with a visual prosthesis. The goal is to match a desired pattern of brain responses. One method uses a simple one-to-one mapping, another uses an inverse neural network, and a third uses gradient optimization. Each method produces a stimulation pattern, which is tested in both computer simulations and in the brain of a blind participant with an implant. The figure shows that the neural network and gradient methods reproduce the target brain activity more accurately than the simple mapping.
September 27, 2025 at 2:52 AM
mbeyeler.bsky.social
Excited to share that I’ve been promoted to Associate Professor with tenure at UCSB!

Grateful to my mentors, students, and funders who shaped this journey and to @ucsantabarbara.bsky.social for giving the Bionic Vision Lab a home!

Full post: www.linkedin.com/posts/michae...
Epic collage of Bionic Vision Lab activities. From top to bottom, left to right: A) Up-to-date group picture B) BVL at Dr. Beyeler's Plous Award celebration (2025) C) BVL at The Eye & The Chip (2023) D/F) Dr. Aiwen Xu and Justin Kasowski getting hooded at the UCSB commencement ceremony E) BVL logo cake created by Tori LeVier G) Dr. Beyeler with symposium speakers at Optica FVM (2023) H, I, M, N) Students presenting conference posters/talks J) Participant scanning a food item (ominous pizza study) K) Galen Pogoncheff in VR L) Argus II user drawing a phosphene O) Prof. Beyeler demoing BionicVisionXR P) First lab hike (ca. 2021) Q) Statue for winner of the Mac'n'Cheese competition (ca. 2022) R) BVL at Club Vision S) Students drifting off into the sunset on a floating couch after a hard day's work
August 2, 2025 at 6:12 PM
mbeyeler.bsky.social
Coming up: Jacob Granley on whether V1 maintains working memory via spiking activity. Prior evidence from fMRI and LFPs - now, rare intracortical recordings in a blind human offer a chance to test it directly. 👁️ #VSS2025

🕥 Sun 10:45pm · Talk Room 1
🧠 www.visionsciences.org/presentation...
Schematic illustrating the phosphenes elicited by an intracortical prosthesis. A 96-channel Utah array is shown, stimulated with biphasic pulse trains. An arrow points to drawings of visual percepts elicited by electrical stimulation Jacob Granley headshot
May 18, 2025 at 12:26 PM
mbeyeler.bsky.social
Our @bionicvisionlab.org is at #VSS2025 with 2 talks and a poster!

First up is PhD Candidate Byron A. Johnson:

Fri, 4:30pm, Talk Room 1: Differential Effects of Peripheral and Central Vision Loss on Scene Perception and Eye Movement Patterns

www.visionsciences.org/presentation...
Example stimulus from Byron's image dataset: an unobscured version (left) depicting a man on a bike approaching a woman trying to cross the bike lane; a simulation of peripheral vision loss (center), where the woman is clearly visible but the man on the bike is obscured; and a simulation of central vision loss (right), where the man on the bike is apparent but the woman is obscured Byron Johnson headshot
May 16, 2025 at 7:27 PM
mbeyeler.bsky.social
Not usually one to post personal pics, but let’s take a break from doomscrolling, yeah?

Some joyful moments from the Plous Award Ceremony: Honored to give the lecture, receive the framed award & celebrate with the people who made it all possible!

@bionicvisionlab.org @ucsantabarbara.bsky.social
Michael Beyeler smiles while receiving the framed Plous Award at UC Santa Barbara. College of Letters & Science's Dean Shelly Gable presents the award in front of a slide thanking collaborators and funders, with photos of colleagues and logos from NIH and the Institute for Collaborative Biotechnologies. The audience watches the moment from their seats. The lecture hall of Mosher Alumni House is packed as Prof. Beyeler gets started with his lecture titled "Learning to See Again: Building a Smarter Bionic Eye" Michael Beyeler stands with members of the Bionic Vision Lab in front of a congratulatory banner celebrating his 2024–25 UCSB Plous Award. Everyone is smiling, with some holding drinks, and Michael is holding his young son. The group is gathered outdoors under string lights, with tall eucalyptus trees in the background.
April 17, 2025 at 4:16 PM
mbeyeler.bsky.social
It sounded like too much fun not to try it myself
A vibrant depiction of a multifaceted life. The foreground shows a scientist sitting at a computer, working on futuristic visualizations related to bionic vision. Nearby, a cozy corner features a piano as the centerpiece, with a guitar leaning beside it. In the background, an outdoor scene blends mountains, a beach, and trees in vibrant autumn colors. A family moment is captured with a father, mother, and two sons enjoying time together. A bookshelf filled with science and technology books hints at intellectual pursuits. Subtle references to The Hitchhiker’s Guide to the Galaxy, including a Marvin figure and Deep Thought object, add a personal touch. The overall mood is warm, intellectual, and family-oriented.
November 23, 2024 at 6:21 AM
mbeyeler.bsky.social
Excited to be featured in the @unity Sentis sizzle reel!
https://youtu.be/okSYmGrPBDE?feature=shared

We simulate #BionicEye vision using neuro-inspired #AI models embedded in #VR, which are computationally heavy. But with Sentis we can run them in real-time to update based on head...
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
Just found out we made it into @DailyMailUK!

Except they "borrowed" a slide of mine and @NLM_NIH footage w/ @byebyedarkness, crediting it to SecondSight & calling it Nintendo-like graphics as @elonmusk said🤣@neuralink must deal with this all the...
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
Tori LeVier @tori_levier:
- Colville-Dearborn Memorial Award, College of Letters & Science
- Morgan Award for Research Promise, @UCSBpsych

Tori's a force of nature & we'll miss her dearly!! Can't wait to see all the things she'll achieve in @mollycrockett's lab @PsychPrinceton
November 9, 2024 at 8:51 PM
mbeyeler.bsky.social
It's a joy to see our talented students recognized. This year, 3 students from the @bionicvisionlab earned departmental & college-wide awards @ucsantabarbara:

@galenpogo: Outstanding TA Award, @ucsbcs

Galen is working on AI alignment & is currently interning with @RealityLabs
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
I'm thrilled to announce the first PhD graduates from the Bionic Vision Lab:

- @JustinKasowski (DYNS): Founder & CEO at RealmVR
- Aiwen Xu (@ucsbcs): Joining @SnowflakeDB this summer

It's been a pleasure working with you, and I can't wait to see your future achievements!
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
Exciting news 99% confirmed by the @VSSMtg President: History has been made at #VSS2024! 🚀✨

@lnadolskis proudly took the stage as the first #blind researcher to present at VSS, detailing our @Cortivis work on stimulus-selective activity in human V1

@EqualitySci
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
After a bit of drama behind the scenes (of the interview - it's meta drama!👻), our interview with Dr. Brian Burg is back up!

How did it come to the acquisition of @PixiumVision by Science Corporation? What will happen to the existing PRIMA...
November 9, 2024 at 8:57 PM
mbeyeler.bsky.social
With @maxhodak_'s Science Corporation acquiring @PixiumVision's IP & assets, there is a path forward for the #Prima technology.

How did it get to this? What will happen next?

Exclusive interview with Dr. Brian Burg (former Director of R&D at...
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
My students @tori_levier and Lily Turkstra recently got a chance to sit down with Prof. @greggsuaning, who shared his journey with Bionic Vision Australia, from humble beginnings with makeshift components to pioneering cutting-edge visual...
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
💡Postdoc in visual/computational neuroscience (#NeuroAI) 💡

Come help us figure out how the mouse brain processes visual information during active exploration to support navigation: bionicvisionlab.org/join

#PhDone #compneuro #neuroscience #AcademicChatter
This image features a panoramic view of the University of California, Santa Barbara (UCSB) during twilight. The sky is a gradient of colors, from a warm pink and orange near the horizon, blending into a deep blue as it extends upward. The campus is seen against this backdrop, with lights from buildings providing a gentle contrast to the dimming sky. Prominently, there's a tall, narrow tower with lights that could be windows or decorative elements, standing out against the sky. Trees and other vegetation are scattered throughout the campus, adding a touch of greenery. In the distance, a calm ocean can be seen, and further back, a faint outline of mountains or large hills on the horizon completes the serene landscape. The banner "UC SANTA BARBARA" is superimposed at the top of the image, identifying the location.
January 10, 2024 at 5:41 PM
mbeyeler.bsky.social
🚨Postdoc in visual/computational neuroscience (#NeuroAI) 🚨

Come help us figure out how the mouse brain processes visual information during active exploration to support navigation:
https://bionicvisionlab.org/join

#PhDone #AcademicTwitter #AcademicChatter #neurotwitter
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
What does it take for people with visual impairment to pursue a career in science?

Hear from Prof. Gordon Legge @UMNews about his decorated career, shifting paradigms of vision science, and the potential & limitations of #BionicEye...
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
And that’s a wrap: 2 platform presentations, 4 posters, and a #VR demo at #TEATC23 @HenryFordHealth ! We had a great time presenting our recent findings and discussing the potential & limitations of #BionicEye technology with leaders in the field
November 9, 2024 at 8:46 PM
mbeyeler.bsky.social
Intrigued that some neurons lacked pronounced visual RFs, we analyzed the influence of behavioral state on the predicted neuronal response (saliency map).

We found that only 25% of model neurons were purely visual - all others were driven by multiple behavioral variables!
November 9, 2024 at 9:33 PM