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Douglas Garrett @garrettneuro.bsky.social · Apr 16

Fantastic news Tom, no doubt they are stoked to have you!

Douglas Garrett @garrettneuro.bsky.social · Feb 8

BOLD variability (especially on-task) typically has loads of behaviourally-relevant effects, at within- and between-subject levels. No amount of preprocessing/noise removal can kill those effects in our hands. For example: www.cell.com/neuron/pdf/S...

www.cell.com

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Douglas Garrett @garrettneuro.bsky.social · Feb 8

The majority of variance in BOLD has nothing to do with motion. MeanBOLD and SDBOLD are rarely highly correlated in any dataset I've seen, any ratio of the two (e.g., tSNR) makes interpretations unnecessarily difficult. Could start by linking mean and SD estimates you have separately to behaviour?

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Reposted by Douglas Garrett

Steve Fleming @smfleming.bsky.social · Jan 22

This is happening tomorrow! 😅😅😅

Steve Fleming @smfleming.bsky.social · Dec 19

I'll be talking about all things metacognitive on 23rd Jan in a public lecture at the @royalsociety.org

It's free to attend and will also be broadcast live on the RS YouTube channel (no pressure then 😅)

royalsociety.org/science-even...

How the human brain thinks about itself | Royal Society

Royal Society Francis Crick Prize Lecture by Professor Stephen Fleming.

royalsociety.org

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Douglas Garrett @garrettneuro.bsky.social · Jan 17

Agreed...No doubt film is a major step forward over resting state, and is indeed an engaging task in its own right, especially when behavior is concurrently collected!

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Reposted by Douglas Garrett

Nico Dosenbach @ndosenbach.bsky.social · Jan 2

The brain’s action-mode is created by a dedicated action-mode network (AMN) rdcu.be/d5odm. In the brain’s mode continuum, AMN sits opposite DMN’s default-mode, as yin-yang. AMN might be key in pain, apathy, Parkinson’s. New @natrevneurosci.bsky.social w/ Marc Raichle & @gordonneuro.bsky.social 🧵 ⬇️

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Douglas Garrett @garrettneuro.bsky.social · Jan 16

Thanks a lot Ellie! Film might be logistically easier, but clinical meaningful, disorder-relevant tasks are grossly underutilised in our opinion. Even incredibly short tasks can be highly effective and relatively easy to implement...for example: www.biologicalpsychiatryjournal.com/article/S000...

Moment-to-Moment Brain Signal Variability Reliably Predicts Psychiatric Treatment Outcome

Biomarkers of psychiatric treatment response remain elusive. Functional magnetic resonance imaging (fMRI) has shown promise, but low reliability has limited the utility of typical fMRI measures (e.g.,...

www.biologicalpsychiatryjournal.com

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Reposted by Douglas Garrett

Neuron @cp-neuron.bsky.social · Jan 8

To start off 2025, we are very pleased to introduce a Special Issue on the Neuroscience of Aging, curated by Axel Guskjolen.
We hope you enjoy every single piece of it as much as we do!
www.cell.com/neuron/current

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Douglas Garrett @garrettneuro.bsky.social · Jan 14

PhD student @zoyamooraj.bsky.social et al. with a remarkable vision for the future of the cog neuro of human aging, now live in Neuron: www.cell.com/neuron/fullt....

Task-related function is the future y'all... there can be no substitutes if we want to understand cognitive aging.

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Douglas Garrett @garrettneuro.bsky.social · Jan 14

Curious to hear your take on the structure-function stance as well...no doubt you're one of those trying to do it right. Keep up the great work guy😤

Douglas Garrett @garrettneuro.bsky.social · Jan 14

Outstanding man, congrats!

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Reposted by Douglas Garrett

Center for Lifespan Psychology, MPI for Human Development @lipmpib.bsky.social · Jan 13

New LIP paper out now: Congratulations to colleagues Leo Waschke and Fabian Kamp and co-authors!

Douglas Garrett @garrettneuro.bsky.social · Jan 13

*How* does the hippocampus encode the world around us? Leo Waschke and Fabian Kamp bring the 🔥, showing that single-neuron spiking variability in hippocampus dynamically tracks sensory content during memory formation in humans. Our latest in Nature Communications: www.nature.com/articles/s41...

Single-neuron spiking variability in hippocampus dynamically tracks sensory content during memory formation in humans - Nature Communications

The hippocampus is thought to encode the content of stimuli, but how it does so is unknown. The authors show that when hippocampal spiking variability tracks the abstract building blocks of individual...

www.nature.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

Massive thanks to all co-authors (Waschke, Kamp, van den Elzen, Krishna, Lindenberger, and Rutishauser) and to @lipmpib.bsky.social @mpib-berlin.bsky.social for support of one of the most important projects I have had the pleasure to work on. Cheers!

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

We thus propose that moment-to-moment spiking variability may provide a new window into how the hippocampus constructs memories from the "building blocks" of our sensory world.

a blurred image of a brick wall with a blue sky in the background

ALT: a blurred image of a brick wall with a blue sky in the background

media.tenor.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

Crucially, we show that the more precisely hippocampal spiking variability tracks the composite (late-layer) features that comprise each individual stimulus, the better those stimuli are later remembered up to 30 minutes later. These effects were also *spatially specific* to the hippocampus.

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

Hippocampus spiking entropy was coupled to image features in every.single.subject...with tighter coupling to more composite (late layer) than to simpler (early layer) image features.

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

We used comp. vision models (HMAX & VGG16) to estimate the features of images presented to patients (N = 34) during memory encoding. We then estimated the coupling of hippocampal single-neuron variability (entropy) to image features via within-participant latent correlations.

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

Ok, but what signature of hipp. spiking might track such features? We've shown that the variability of fMRI activity in visual cortex scales with the complexity of visual input (sciencedirect.com/science/arti...). Could this also be the case in the hippocampus during memory formation?

Higher performers upregulate brain signal variability in response to more feature-rich visual input

The extent to which brain responses differ across varying cognitive demands is referred to as “neural differentiation,” and greater neural differentia…

sciencedirect.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

In turn, this permits direct testing of the “sensory feature space” the hippocampus leverages during memory formation.

a man with glasses and a mustache is standing in front of a sign that says sweet .

ALT: a man with glasses and a mustache is standing in front of a sign that says sweet .

media.tenor.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

We argue that the architecture of multi-layer computational vision models can be used to differentiate between simple and composite visual features of any stimulus a participant may encode.

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

More composite features might dominate due to the hippocampus’ hierarchical position and afferent projections, but “simple” features might still be crucial for detailed representations. How can we know?

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

During memory formation, the hippocampus is presumed to represent and conjunct the “content” of stimuli. How does it do this? On which kind of sensory features does the hippocampus rely when memories are formed?

a fat man is wearing a blue and yellow striped shirt .

ALT: a fat man is wearing a blue and yellow striped shirt .

media.tenor.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

*How* does the hippocampus encode the world around us? Leo Waschke and Fabian Kamp bring the 🔥, showing that single-neuron spiking variability in hippocampus dynamically tracks sensory content during memory formation in humans. Our latest in Nature Communications: www.nature.com/articles/s41...

Single-neuron spiking variability in hippocampus dynamically tracks sensory content during memory formation in humans - Nature Communications

The hippocampus is thought to encode the content of stimuli, but how it does so is unknown. The authors show that when hippocampal spiking variability tracks the abstract building blocks of individual...

www.nature.com

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Douglas Garrett @garrettneuro.bsky.social · Jan 13

JEALOUS. Enjoy!

Douglas Garrett @garrettneuro.bsky.social · Jan 7

Absolutely outstanding multi-modal work on uncertainty in the aging brain by @juliankosciessa.bsky.social et al., many years in the making. EEG, fMRI, comp modelling, sub vs. cortical, this one has it all!

Now live in Nature Communications: www.nature.com/articles/s41...

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