Eric Garr
@garrface.bsky.social
Postdoc @ Johns Hopkins. Behavior, brains, biking, bagels.
ericgarr.com
ericgarr.com
Pinned
Eric Garr
@garrface.bsky.social
· Aug 5
Modeling hidden cognitive states reveals acute and chronic effects of fentanyl on decision-making
The cognitive mechanisms underlying behavior are often dynamic, shifting gradually or abruptly over time scales spanning years, to weeks, to minutes. Whether drug-induced changes in learning and decis...
www.biorxiv.org
I’m excited to share my latest paper, in which we used latent state modeling to reveal how fentanyl shapes decision-making dynamics in rats.
Here’s a summary of what we found (thread).
www.biorxiv.org/content/10.1...
Here’s a summary of what we found (thread).
www.biorxiv.org/content/10.1...
Reposted by Eric Garr
Can humans & animals really use internal maps to take shortcuts?
Tolman famously said yes - based largely on his Sunburst maze.
Our new review & meta-analysis suggests evidence is far weaker than you might think.
🧵👇 doi.org/10.1111/ejn....
@uofgpsychneuro.bsky.social @ejneuroscience.bsky.social
Tolman famously said yes - based largely on his Sunburst maze.
Our new review & meta-analysis suggests evidence is far weaker than you might think.
🧵👇 doi.org/10.1111/ejn....
@uofgpsychneuro.bsky.social @ejneuroscience.bsky.social
Tolman's Sunburst Maze 80 Years on: A Meta‐Analysis Reveals Poor Replicability and Little Evidence for Shortcutting
In 1946, Tolman et al. reported that rats could take a novel shortcut to a goal after training on an indirect route, supporting the Cognitive Map theory. However, a review of subsequent Sunburst maze...
doi.org
January 5, 2026 at 7:52 PM
Can humans & animals really use internal maps to take shortcuts?
Tolman famously said yes - based largely on his Sunburst maze.
Our new review & meta-analysis suggests evidence is far weaker than you might think.
🧵👇 doi.org/10.1111/ejn....
@uofgpsychneuro.bsky.social @ejneuroscience.bsky.social
Tolman famously said yes - based largely on his Sunburst maze.
Our new review & meta-analysis suggests evidence is far weaker than you might think.
🧵👇 doi.org/10.1111/ejn....
@uofgpsychneuro.bsky.social @ejneuroscience.bsky.social
Reposted by Eric Garr
I don't think you non-science people realize what it takes to get a grant funded by NIH. Started experiments in Sept 2021 to generate 3 new mouse mutants to model human disease. Prelim dara shows they have relevant disease phenotypes worthy of study. Need a small grant first to characterize /1
January 2, 2026 at 3:19 AM
I don't think you non-science people realize what it takes to get a grant funded by NIH. Started experiments in Sept 2021 to generate 3 new mouse mutants to model human disease. Prelim dara shows they have relevant disease phenotypes worthy of study. Need a small grant first to characterize /1
Reposted by Eric Garr
Excited to share latest study from the lab by an amazing RA, Dylan Flink.
We solved a small (important) puzzle while in the trenches of a larger (wavy 🌊) puzzle.
www.biorxiv.org/content/10.6...
🧵...
We solved a small (important) puzzle while in the trenches of a larger (wavy 🌊) puzzle.
www.biorxiv.org/content/10.6...
🧵...
Dual cholinergic mechanisms for sculpting striatal dopamine in vivo
Striatal dopamine (DA) and acetylcholine constitute a computationally powerful neuromodulatory dyad that orchestrates action selection, motivational vigor, and reward learning. Striatal cholinergic in...
www.biorxiv.org
December 30, 2025 at 5:47 AM
Excited to share latest study from the lab by an amazing RA, Dylan Flink.
We solved a small (important) puzzle while in the trenches of a larger (wavy 🌊) puzzle.
www.biorxiv.org/content/10.6...
🧵...
We solved a small (important) puzzle while in the trenches of a larger (wavy 🌊) puzzle.
www.biorxiv.org/content/10.6...
🧵...
Reposted by Eric Garr
Sleep dependent consolidation and replay that doesn’t require the hippocampus?
Very beautiful work by Marcus Stephenson-Jones’ lab on sleep driven sequential skill consolidation in the striatum.
www.biorxiv.org/content/10.1...
Very beautiful work by Marcus Stephenson-Jones’ lab on sleep driven sequential skill consolidation in the striatum.
www.biorxiv.org/content/10.1...
www.biorxiv.org
December 22, 2025 at 11:59 AM
Sleep dependent consolidation and replay that doesn’t require the hippocampus?
Very beautiful work by Marcus Stephenson-Jones’ lab on sleep driven sequential skill consolidation in the striatum.
www.biorxiv.org/content/10.1...
Very beautiful work by Marcus Stephenson-Jones’ lab on sleep driven sequential skill consolidation in the striatum.
www.biorxiv.org/content/10.1...
Reposted by Eric Garr
🚨New Kutlu Lab preprint! Excited to share our latest work led by Oyku Dinckol and Noah Wenger.
🔗 www.biorxiv.org/content/10.6...
We find that ACh shapes DLS neural ensembles for outcome learning but is biased toward signaling threats over rewards 👇
🔗 www.biorxiv.org/content/10.6...
We find that ACh shapes DLS neural ensembles for outcome learning but is biased toward signaling threats over rewards 👇
Dorsolateral striatal acetylcholine reorganizes neural ensembles to anticipate threat
Adaptive behavior requires flexible encoding of emotional valence. Although striatal acetylcholine (ACh) signaling is critical for reinforcement learning, its contribution to aversive learning has rem...
www.biorxiv.org
December 13, 2025 at 2:24 PM
🚨New Kutlu Lab preprint! Excited to share our latest work led by Oyku Dinckol and Noah Wenger.
🔗 www.biorxiv.org/content/10.6...
We find that ACh shapes DLS neural ensembles for outcome learning but is biased toward signaling threats over rewards 👇
🔗 www.biorxiv.org/content/10.6...
We find that ACh shapes DLS neural ensembles for outcome learning but is biased toward signaling threats over rewards 👇
Reposted by Eric Garr
22% fewer NIH grants
December 2, 2025 at 3:28 PM
22% fewer NIH grants
Reposted by Eric Garr
Nature Sci Rep publishes incoherent AI slop. eLife publishes a paper which the reviewers didn't agree with, making all the comments and responses public with thoughtful commentary. One of these journals got delisted by Web of Science for quality concerns from not doing peer review. Guess which one?
November 27, 2025 at 1:35 PM
Nature Sci Rep publishes incoherent AI slop. eLife publishes a paper which the reviewers didn't agree with, making all the comments and responses public with thoughtful commentary. One of these journals got delisted by Web of Science for quality concerns from not doing peer review. Guess which one?
Reposted by Eric Garr
So excited to see our latest paper out today in @natcomms.nature.com! Studies led by the amazing @margestelzner.bsky.social www.nature.com/articles/s41.... VTA GABA neurons have a unique role in economic decision making - they integrate reward seeking motivation and the current cost of seeking
Ventral tegmental area GABA neurons integrate positive and negative valence - Nature Communications
The role of ventral tegmental area GABA neurons in behavior is unclear. Here, authors show that VTA GABA but not dopamine neurons integrate positive and negative valence to encode motivational conflic...
www.nature.com
November 24, 2025 at 4:18 PM
So excited to see our latest paper out today in @natcomms.nature.com! Studies led by the amazing @margestelzner.bsky.social www.nature.com/articles/s41.... VTA GABA neurons have a unique role in economic decision making - they integrate reward seeking motivation and the current cost of seeking
Reposted by Eric Garr
If you're at SfN on Monday, come by poster board II10 to see how fentanyl changes cell type-specific encoding of choice outcomes in the striatum to influence decision-making phenotypes. Looking forward to seeing some cool science and supporting SfN during these difficult times!
November 13, 2025 at 6:05 PM
If you're at SfN on Monday, come by poster board II10 to see how fentanyl changes cell type-specific encoding of choice outcomes in the striatum to influence decision-making phenotypes. Looking forward to seeing some cool science and supporting SfN during these difficult times!
If you're at SfN on Monday, come by poster board II10 to see how fentanyl changes cell type-specific encoding of choice outcomes in the striatum to influence decision-making phenotypes. Looking forward to seeing some cool science and supporting SfN during these difficult times!
November 13, 2025 at 6:05 PM
If you're at SfN on Monday, come by poster board II10 to see how fentanyl changes cell type-specific encoding of choice outcomes in the striatum to influence decision-making phenotypes. Looking forward to seeing some cool science and supporting SfN during these difficult times!
Reposted by Eric Garr
Delighted to see this finally out: rdcu.be/eO9oW
We tested whether brief striatal dopamine release events influence the vigor of skilled movements. Despite popular belief, we did not find any evidence linking rapid dopamine dynamics to motor vigor on a moment-by-moment basis.
We tested whether brief striatal dopamine release events influence the vigor of skilled movements. Despite popular belief, we did not find any evidence linking rapid dopamine dynamics to motor vigor on a moment-by-moment basis.
Subsecond dopamine fluctuations do not specify the vigor of ongoing actions
Nature Neuroscience - Liu and colleagues show that the vigor (that is, speed and amplitude) of dexterous movements is not controlled by ongoing fluctuations in extracellular dopamine within the...
rdcu.be
November 10, 2025 at 3:43 PM
Delighted to see this finally out: rdcu.be/eO9oW
We tested whether brief striatal dopamine release events influence the vigor of skilled movements. Despite popular belief, we did not find any evidence linking rapid dopamine dynamics to motor vigor on a moment-by-moment basis.
We tested whether brief striatal dopamine release events influence the vigor of skilled movements. Despite popular belief, we did not find any evidence linking rapid dopamine dynamics to motor vigor on a moment-by-moment basis.
Reposted by Eric Garr
VTA dopamine neuron activity produces spatially organized value representations https://www.biorxiv.org/content/10.1101/2025.11.04.685995v1
November 6, 2025 at 7:16 PM
VTA dopamine neuron activity produces spatially organized value representations https://www.biorxiv.org/content/10.1101/2025.11.04.685995v1
Reposted by Eric Garr
Nature suggests you use their "Manuscript Adviser" bot to get advice before submitting
I uploaded the classic Watson & Crick paper about DNA structure, and the Adviser had this to say about one of the greatest paper endings of the century:
I uploaded the classic Watson & Crick paper about DNA structure, and the Adviser had this to say about one of the greatest paper endings of the century:
November 3, 2025 at 1:55 PM
Nature suggests you use their "Manuscript Adviser" bot to get advice before submitting
I uploaded the classic Watson & Crick paper about DNA structure, and the Adviser had this to say about one of the greatest paper endings of the century:
I uploaded the classic Watson & Crick paper about DNA structure, and the Adviser had this to say about one of the greatest paper endings of the century:
I first heard Jack DeJohnette as part of the Keith Jarrett trio when I was ~14. I didn’t like his drumming and thought it sounded sloppy. For whatever reason, it clicked with me much later. Here’s a 🔥 clip I discovered recently. RIP JD
youtu.be/a3CZHr5uiNM?...
youtu.be/a3CZHr5uiNM?...
Jack DeJohnette, Pat Metheny, Herbie Hancock and Dave Holland - Shadow Dance (live)
YouTube video by SafaJah
youtu.be
October 27, 2025 at 10:01 PM
I first heard Jack DeJohnette as part of the Keith Jarrett trio when I was ~14. I didn’t like his drumming and thought it sounded sloppy. For whatever reason, it clicked with me much later. Here’s a 🔥 clip I discovered recently. RIP JD
youtu.be/a3CZHr5uiNM?...
youtu.be/a3CZHr5uiNM?...
Reposted by Eric Garr
Some great consideration of differences in learning and performance during blocking (the sine qua non of PE phenomena) in sign vs goal trackers here: www.sciencedirect.com/science/arti...
Behavioral determinants in the expression of the Kamin blocking effect: Implications for associative learning theory
Associative learning makes important contributions to our behavior and decisions. The Kamin blocking effect is an associative learning phenomenon that…
www.sciencedirect.com
October 15, 2025 at 9:19 PM
Some great consideration of differences in learning and performance during blocking (the sine qua non of PE phenomena) in sign vs goal trackers here: www.sciencedirect.com/science/arti...
Reposted by Eric Garr
Nice preprint from Veronica Alvarez's group on cortically-evoked DA mediated by ACh! I We observed something quite similar in birds, and interesting to see the sensory/prefrontal distinction
Cholinergic-dependent dopamine signals in mouse dorsal striatum are regulated by frontal but not sensory cortices
Everyday decisions depend on linking sensory stimuli with actions and outcomes. The striatum supports these sensorimotor associations through dopamine-dependent plasticity. Thus, the timing and magnit...
www.biorxiv.org
October 14, 2025 at 7:29 PM
Nice preprint from Veronica Alvarez's group on cortically-evoked DA mediated by ACh! I We observed something quite similar in birds, and interesting to see the sensory/prefrontal distinction
Reposted by Eric Garr
We have an open NIH-funded postdoc position in the lab to study circuit and neurochemical mechanisms of cognitive and motivational deficits in opioid withdrawal. Apply here: recruit.ap.uci.edu/JPF09885 or message/email for more information.
Postdoctoral Scholars - Ostlund Laboratory - Anesthesiology & Perioperative Care
University of California, Irvine is hiring. Apply now!
recruit.ap.uci.edu
October 3, 2025 at 5:41 PM
We have an open NIH-funded postdoc position in the lab to study circuit and neurochemical mechanisms of cognitive and motivational deficits in opioid withdrawal. Apply here: recruit.ap.uci.edu/JPF09885 or message/email for more information.
Reposted by Eric Garr
I'm recruiting a PhD student to study how enkephalins affect cognitive processing in the rodent frontal cortex. The project uses pharmacology, multi-electrode recordings, and fiber photometry, and is funded by NIDA. Please share with trainees applying this cycle. Thanks!
October 3, 2025 at 3:43 PM
I'm recruiting a PhD student to study how enkephalins affect cognitive processing in the rodent frontal cortex. The project uses pharmacology, multi-electrode recordings, and fiber photometry, and is funded by NIDA. Please share with trainees applying this cycle. Thanks!
Reposted by Eric Garr
This may be the most important paper ever published about NIH funded research.
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
What if NIH had been 40% smaller?
Replaying history with less NIH funding shows widespread impacts on drug-linked research
www.science.org
September 25, 2025 at 9:20 PM
This may be the most important paper ever published about NIH funded research.
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Eric Garr
A mechanistic theory of planning in prefrontal cortex https://www.biorxiv.org/content/10.1101/2025.09.23.677709v1
September 24, 2025 at 8:15 AM
A mechanistic theory of planning in prefrontal cortex https://www.biorxiv.org/content/10.1101/2025.09.23.677709v1
Reposted by Eric Garr
Today 1-2 pm CST bit.ly/3VOJrcy
Join us!
Join us!
Our next speaker is my friend @garrface.bsky.social , who will discuss my favorite topic: Mesolimbic DA --> Causal Learning!
Tune in on Monday 9/22 from 1-2pm CST bit.ly/3VOJrcy
Tune in on Monday 9/22 from 1-2pm CST bit.ly/3VOJrcy
September 22, 2025 at 2:40 PM
Today 1-2 pm CST bit.ly/3VOJrcy
Join us!
Join us!
Reposted by Eric Garr
🚨Our preprint is online!🚨
www.biorxiv.org/content/10.1...
How do #dopamine neurons perform the key calculations in reinforcement #learning?
Read on to find out more! 🧵
www.biorxiv.org/content/10.1...
How do #dopamine neurons perform the key calculations in reinforcement #learning?
Read on to find out more! 🧵
September 19, 2025 at 1:05 PM
🚨Our preprint is online!🚨
www.biorxiv.org/content/10.1...
How do #dopamine neurons perform the key calculations in reinforcement #learning?
Read on to find out more! 🧵
www.biorxiv.org/content/10.1...
How do #dopamine neurons perform the key calculations in reinforcement #learning?
Read on to find out more! 🧵
Reposted by Eric Garr
This article is truly impressive, both for the significance of its findings and the enormous amount of work it represents!
Briefly, it demonstrates that the gut-brain vagal axis exerts a considerable influence on dopamine-dependent reward-related processes...
1/n
www.biorxiv.org/content/10.1...
Briefly, it demonstrates that the gut-brain vagal axis exerts a considerable influence on dopamine-dependent reward-related processes...
1/n
www.biorxiv.org/content/10.1...
September 18, 2025 at 10:03 AM
This article is truly impressive, both for the significance of its findings and the enormous amount of work it represents!
Briefly, it demonstrates that the gut-brain vagal axis exerts a considerable influence on dopamine-dependent reward-related processes...
1/n
www.biorxiv.org/content/10.1...
Briefly, it demonstrates that the gut-brain vagal axis exerts a considerable influence on dopamine-dependent reward-related processes...
1/n
www.biorxiv.org/content/10.1...
Reposted by Eric Garr
How does the brain decide? 🧠
Our new @nature.com paper shows that neural activity switches from an 'evidence gathering' to a 'commitment' state at a precise moment we call nTc.
After nTc, new evidence is ignored, revealing a neural marker for the instant when the mind is made up.
rdcu.be/eGUrv
Our new @nature.com paper shows that neural activity switches from an 'evidence gathering' to a 'commitment' state at a precise moment we call nTc.
After nTc, new evidence is ignored, revealing a neural marker for the instant when the mind is made up.
rdcu.be/eGUrv
Transitions in dynamical regime and neural mode during perceptual decisions - Nature
Simultaneous recordings were made of hundreds of neurons in the rat frontal cortex and striatum, showing that decision commitment involves a rapid, coordinated transition in dynamical regime and neura...
www.nature.com
September 17, 2025 at 8:12 PM
How does the brain decide? 🧠
Our new @nature.com paper shows that neural activity switches from an 'evidence gathering' to a 'commitment' state at a precise moment we call nTc.
After nTc, new evidence is ignored, revealing a neural marker for the instant when the mind is made up.
rdcu.be/eGUrv
Our new @nature.com paper shows that neural activity switches from an 'evidence gathering' to a 'commitment' state at a precise moment we call nTc.
After nTc, new evidence is ignored, revealing a neural marker for the instant when the mind is made up.
rdcu.be/eGUrv