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Marlene Cohen @marlenecohen.bsky.social · 15d

Thank you! Your work was definitely the inspiration for a lot of this.

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Marlene Cohen @marlenecohen.bsky.social · 15d

Thanks, Hannah!

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Marlene Cohen @marlenecohen.bsky.social · 15d

Ha! My student was the one who realized we should cite your paper. Maybe she should earn a second PhD in history...

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Marlene Cohen @marlenecohen.bsky.social · 15d

Thank you, especially for the laugh!

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Marlene Cohen @marlenecohen.bsky.social · 15d

We are excited about potential applications of this work, from artificial intelligence to translational efforts to fix memory disorders. This highlights a central value of our field: using curiosity-driven science for broad impact. We’d love your feedback! doi.org/10.1101/2025.09.22.677855 /end

Neuronal signatures of successful one-shot memory in mid-level visual cortex

High-capacity, one-shot visual recognition memory challenges theories of learning and neural coding because it requires rapid, robust, and durable representations. Most studies have focused on the hip...

doi.org

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Marlene Cohen @marlenecohen.bsky.social · 15d

This is the first chapter of Grace’s thesis, and there is so much more to come. She is something special, and I am going to thoroughly enjoy seeing her take our field by storm. 9/

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Marlene Cohen @marlenecohen.bsky.social · 15d

These findings show that the building blocks of fast, high-capacity memory are present in mid-level visual cortex. Take-home: cognition is distributed. And stay tuned: Grace’s next papers will explore mechanisms by which these signals interact with the larger network and are disrupted in disease. 8/

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Marlene Cohen @marlenecohen.bsky.social · 15d

We also found faster response dynamics to familiar images, consistent with pattern completion. This means that after the first couple of image fragments, V4 already signaled the whole image (but only during successful memory). The hippocampus does this, but we were surprised to see it in V4. 🤯 7/

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Marlene Cohen @marlenecohen.bsky.social · 15d

We found all of these neuronal signatures in V4. But the only ones that reliably predicted behavior were related to how consistent population responses were during memory encoding and retrieval. More consistent responses = greater memory success. 6/

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Marlene Cohen @marlenecohen.bsky.social · 15d

We looked for proposed neuronal signatures of memory, including:
• magnitude coding
• repetition suppression
• sparse coding
• population response consistency (=similar responses to novel and familiar images) 5/

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Marlene Cohen @marlenecohen.bsky.social · 15d

Grace and awesome staff scientist Cheng Xue tested whether area V4 contains the signals that could support recognition memory. Their task revealed images bit by bit. This allowed us to analyze dynamics and increased difficulty so we could compare neuronal responses on correct vs error trials. 4/

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Marlene Cohen @marlenecohen.bsky.social · 15d

Most previous studies have focused on hippocampus and higher cortical areas. But behavioral work shows that memorability depends on visual features and recognition memory distinguishes even semantically similar images. Seems like a job for mid-level visual cortex. 3/

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Marlene Cohen @marlenecohen.bsky.social · 15d

When she was a rotation student, Grace DiRisio pointed out that visual recognition memory challenges all our neural coding theories because of its remarkable capacity. Linear codes work for low capacity functions e.g. discrimination & attention. Memory for thousands of images is another story. 2/

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Marlene Cohen @marlenecohen.bsky.social · 15d

New preprint! How can you remember an image you saw once, even after seeing thousands of them? We find a role for humble mid-level visual cortex in high-capacity, one-shot learning. doi.org/10.1101/2025.09.22.677855 🧵🧪1/

Neuronal signatures of successful one-shot memory in mid-level visual cortex

High-capacity, one-shot visual recognition memory challenges theories of learning and neural coding because it requires rapid, robust, and durable representations. Most studies have focused on the hip...

doi.org

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

We are grateful for sustained federal funding (mostly NIH for us), which is the only thing that makes it possible to work on a problem for decades. This work will translate to people: it suggests targeted treatments for disorders that affect cognition & also correlated variability. Coming soon! /end

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

First author Ramanujan Srinath demonstrated some of the things that make him a great scientist: he thinks deeply & creatively, brings together many forms of evidence & people, and is determined and innovative. He is on the job market this year and will run an incredible lab – don’t miss out! 5/

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

Ramanujan Srinath collected & analyzed many data sets including Amy Ni’s, Yunlong (Draco) Xu & Brent Doiron modeled, & Doug did a causal experiment. The key is: when noise and signal come from the same circuit (they must!), then smart, flexible decisions have a strong relationship with noise. 4/

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

@ramanujan-s.bsky.social and a fantastic team of coauthors figured out a resolution: we propose that correlated variability isn’t noise that corrupts a signal or something to ignore. It reflects the activity in the population that is read out to guide behavior. 3/

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

Hmm: Correlated variability in sensory neurons (how much responses fluctuate together) is related to behavior: it’s modulated by attention, learning, & motivation and related to individual decisions. But because it's low-D, in theory its effect on behavior should be small. What’s up with that? 2/

a husky puppy is laying on the floor with its tongue out and wearing a blue collar .

ALT: a husky puppy is laying on the floor with its tongue out and wearing a blue collar .

media.tenor.com

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Marlene Cohen @marlenecohen.bsky.social · Aug 15

One of the joys of being a scientist is the ability to think about a problem for a long time. Our new preprint solves a mystery that has been bugging me since I was a graduate student (which was, ahem, a while ago). 🧪🧠🧵1/
www.biorxiv.org/content/10.1...

Guided by Noise: Correlated Variability Channels Task-Relevant Information in Sensory Neurons

Shared trial-to-trial variability across sensory neurons is reliably reduced when perceptual performance improves, yet this variability is low-dimensional, so it could be ignored by an optimal readout...

www.biorxiv.org

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Marlene Cohen @marlenecohen.bsky.social · Aug 8

And I am so, so happy for you.

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Marlene Cohen @marlenecohen.bsky.social · Aug 8

I’m in!

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Marlene Cohen @marlenecohen.bsky.social · Aug 8

And I’m sorry about my bad autocorrect, I know it’s Tucson and not Houston! I will have to convince you to invite me to visit sometime and educate me about Arizona 😊

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Marlene Cohen @marlenecohen.bsky.social · Aug 8

Awesome, thank you!

Marlene Cohen @marlenecohen.bsky.social · Aug 8

Exciting! Are you going there or are you in Houston? Do you happen to know if there will be an NHP facility in Phoenix? (asking for a couple of wonderful postdocs I know)

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