Samuel Hewitt, PhD
@samuelhewitt.bsky.social
Machine Learning Engineer at Limbic
Building AI therapy
Previously, Max Planck Centre for Computational Psychiatry @ UCL
Building AI therapy
Previously, Max Planck Centre for Computational Psychiatry @ UCL
Pinned
Day-to-day fluctuations in motivation drive effort-based decision-making | PNAS
Internal states like motivation fluctuate substantially over time. However, studies
of the neurocomputational mechanims of motivated behavior have ...
doi.org
A little bby from my PhD is published!
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
Here here !! Well done CPSY
🔥💥📣 Excited to announce a new policy at the Computational Psychiatry (CPSY) journal @cpsyjournal.bsky.social. Starting from April 2025, CPSY will compensate reviewers for their time and effort invested in reviewing manuscripts. w/ @drrickadams.bsky.social
cpsyjournal.org/articles/10....
cpsyjournal.org/articles/10....
One Small Step Towards Fixing a Broken System | Computational Psychiatry
cpsyjournal.org
May 15, 2025 at 5:55 PM
Here here !! Well done CPSY
Reposted by Samuel Hewitt, PhD
#OCD is a understudied disorder, meaning that we know way too little about the underlying (brain) processes.
We have thus built the Brain Explorer app www.brainexplorer.net where everyone can easily contribute to understanding OCD.
#MentalHealthAwareness @tueneurocampus.bsky.social @ucl.ac.uk
We have thus built the Brain Explorer app www.brainexplorer.net where everyone can easily contribute to understanding OCD.
#MentalHealthAwareness @tueneurocampus.bsky.social @ucl.ac.uk
Brain Explorer - Test your brain power
The brain explorer app for Apple and Android tests your brain functions and helps researchers to understand the brain. Explore your brain power and how brain functions are important for mental health.
www.brainexplorer.net
May 14, 2025 at 11:45 AM
#OCD is a understudied disorder, meaning that we know way too little about the underlying (brain) processes.
We have thus built the Brain Explorer app www.brainexplorer.net where everyone can easily contribute to understanding OCD.
#MentalHealthAwareness @tueneurocampus.bsky.social @ucl.ac.uk
We have thus built the Brain Explorer app www.brainexplorer.net where everyone can easily contribute to understanding OCD.
#MentalHealthAwareness @tueneurocampus.bsky.social @ucl.ac.uk
Hey cognitive scientists
I asked lovable.dev to make me a 2-arm bandit RL task
2 prompts and 3 minutes later
🤯🤯🤯🤯
Play it:
preview--cosmic-bandit-quest.lovable.app
Think of the hours and grad student tears saved 😅
Yes lovable I accept your sponsorship terms
I asked lovable.dev to make me a 2-arm bandit RL task
2 prompts and 3 minutes later
🤯🤯🤯🤯
Play it:
preview--cosmic-bandit-quest.lovable.app
Think of the hours and grad student tears saved 😅
Yes lovable I accept your sponsorship terms
April 9, 2025 at 7:41 PM
Hey cognitive scientists
I asked lovable.dev to make me a 2-arm bandit RL task
2 prompts and 3 minutes later
🤯🤯🤯🤯
Play it:
preview--cosmic-bandit-quest.lovable.app
Think of the hours and grad student tears saved 😅
Yes lovable I accept your sponsorship terms
I asked lovable.dev to make me a 2-arm bandit RL task
2 prompts and 3 minutes later
🤯🤯🤯🤯
Play it:
preview--cosmic-bandit-quest.lovable.app
Think of the hours and grad student tears saved 😅
Yes lovable I accept your sponsorship terms
Reposted by Samuel Hewitt, PhD
“Motivation drives changes in the subjective value of reward both in the moment and in the future.”
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
Day-to-day fluctuations in motivation drive effort-based decision-making | PNAS
Internal states like motivation fluctuate substantially over time. However, studies
of the neurocomputational mechanims of motivated behavior have ...
www.pnas.org
March 25, 2025 at 5:45 PM
“Motivation drives changes in the subjective value of reward both in the moment and in the future.”
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
Reposted by Samuel Hewitt, PhD
In life, 3 things are certain: death, taxes, and decision-making variability🧠. Our review tinyurl.com/4dcwafc4 explores how computational models 💻 explain variability, their limits, and recent advances. A thread🧵👇
@redmondoconnell.bsky.social @neuromurphy.bsky.social Mark Bellgrove (not on Bluesky)
@redmondoconnell.bsky.social @neuromurphy.bsky.social Mark Bellgrove (not on Bluesky)
Disentangling sources of variability in decision-making - Nature Reviews Neuroscience
Identifying the psychological and neurobiological processes underpinning intra-individual variations in choice behaviour presents a formidable challenge. In this Review, Duffy et al. discuss how algor...
www.nature.com
March 24, 2025 at 12:29 PM
In life, 3 things are certain: death, taxes, and decision-making variability🧠. Our review tinyurl.com/4dcwafc4 explores how computational models 💻 explain variability, their limits, and recent advances. A thread🧵👇
@redmondoconnell.bsky.social @neuromurphy.bsky.social Mark Bellgrove (not on Bluesky)
@redmondoconnell.bsky.social @neuromurphy.bsky.social Mark Bellgrove (not on Bluesky)
When I began my PhD, there was a major disconnect between my own lived experience and the way researchers probed mental health-behaviour links.
I hope this work inspires others to use new designs to appreciate the complexity of human beings and their experiences.
link.growkudos.com/1f5ss3bn1ts
I hope this work inspires others to use new designs to appreciate the complexity of human beings and their experiences.
link.growkudos.com/1f5ss3bn1ts
March 20, 2025 at 10:39 AM
When I began my PhD, there was a major disconnect between my own lived experience and the way researchers probed mental health-behaviour links.
I hope this work inspires others to use new designs to appreciate the complexity of human beings and their experiences.
link.growkudos.com/1f5ss3bn1ts
I hope this work inspires others to use new designs to appreciate the complexity of human beings and their experiences.
link.growkudos.com/1f5ss3bn1ts
Reposted by Samuel Hewitt, PhD
This is a great study, if I may say. We have had a lot of data showing correlations between subjective assessments and behaviour between individuals. With this study, we are starting to see how they interact over days within individuals. Congratulations @samuelhewitt.bsky.social!
A little bby from my PhD is published!
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
Day-to-day fluctuations in motivation drive effort-based decision-making | PNAS
Internal states like motivation fluctuate substantially over time. However, studies
of the neurocomputational mechanims of motivated behavior have ...
doi.org
March 18, 2025 at 5:51 PM
This is a great study, if I may say. We have had a lot of data showing correlations between subjective assessments and behaviour between individuals. With this study, we are starting to see how they interact over days within individuals. Congratulations @samuelhewitt.bsky.social!
A little bby from my PhD is published!
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
Day-to-day fluctuations in motivation drive effort-based decision-making | PNAS
Internal states like motivation fluctuate substantially over time. However, studies
of the neurocomputational mechanims of motivated behavior have ...
doi.org
March 18, 2025 at 11:23 AM
A little bby from my PhD is published!
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
we did a complex study to answer a simple Q:
do day-to-day feelings impact choices?
A: Yes. When feeling motivated (independent of other stable or unstable feelings) choices changed because rewards seemed greater.
open access link:
doi.org/10.1073/pnas...
Reposted by Samuel Hewitt, PhD
3.5 year PhD studentship in cognitive computational neuroscience open in my MSN lab, @thechbh.bsky.social, co-supervised with @selmalugtmeijer.bsky.social & @simonlittle.bsky.social. Deadline 23rd March. Only open to UK candidates. More details here: www.findaphd.com/phds/project...
Pls repost
Pls repost
https://findaphd.com/phds/project/p…
February 20, 2025 at 4:07 PM
3.5 year PhD studentship in cognitive computational neuroscience open in my MSN lab, @thechbh.bsky.social, co-supervised with @selmalugtmeijer.bsky.social & @simonlittle.bsky.social. Deadline 23rd March. Only open to UK candidates. More details here: www.findaphd.com/phds/project...
Pls repost
Pls repost
I cannot deny photo evidence...!
Nothing further, your honour😍
It's a wrap, finished, terminado....
thank you V V much, especially to my mentors for all the support @thepsychologist.bsky.social, Prof Essi Viding, @olijrobinson.bsky.social and especially @tobiasuhauser.bsky.social
Nothing further, your honour😍
It's a wrap, finished, terminado....
thank you V V much, especially to my mentors for all the support @thepsychologist.bsky.social, Prof Essi Viding, @olijrobinson.bsky.social and especially @tobiasuhauser.bsky.social
Huge congratulations to Dr Sam Hewitt @samuelhewitt.bsky.social for passing his PhD viva today without corrections!🥳🕺🏼🚀
Big thanks to Tali Sharot and @brainapps.bsky.social for being the examiners! 🙏🙏🙏
Some of the papers are dropping soon - stay tuned! @imagingneuroucl.bsky.social #proudsupervisor
Big thanks to Tali Sharot and @brainapps.bsky.social for being the examiners! 🙏🙏🙏
Some of the papers are dropping soon - stay tuned! @imagingneuroucl.bsky.social #proudsupervisor
February 12, 2025 at 3:57 PM
I cannot deny photo evidence...!
Nothing further, your honour😍
It's a wrap, finished, terminado....
thank you V V much, especially to my mentors for all the support @thepsychologist.bsky.social, Prof Essi Viding, @olijrobinson.bsky.social and especially @tobiasuhauser.bsky.social
Nothing further, your honour😍
It's a wrap, finished, terminado....
thank you V V much, especially to my mentors for all the support @thepsychologist.bsky.social, Prof Essi Viding, @olijrobinson.bsky.social and especially @tobiasuhauser.bsky.social
Reposted by Samuel Hewitt, PhD
In the beginning there were starter packs, then came the cull
a woman is looking at her phone and the word unfollow is on the bottom
Alt: a woman is looking at her phone and smugly clicking unfollow
media.tenor.com
December 17, 2024 at 10:49 AM
In the beginning there were starter packs, then came the cull
I'm sick of GPT4 telling me I'm absolutely right. I'm not here for validation from a cyborg.
Tell me about all the mistakes I made !
Tell me about all the mistakes I made !
December 5, 2024 at 11:32 AM
I'm sick of GPT4 telling me I'm absolutely right. I'm not here for validation from a cyborg.
Tell me about all the mistakes I made !
Tell me about all the mistakes I made !
Reposted by Samuel Hewitt, PhD
Funded PhD (UK students only). Interested in a PhD working in the MSN lab, co-supervised by Dr. Romy Froemer? Topic is flexible around themes of motivation and decision-making, using techniques such as computational modelling, brain imaging, or brain stimulation. www.findaphd.com/phds/project...
The Computational and Neural Dynamics of Human Motivation and Cognitive Control at University of Birmingham on FindAPhD.com
PhD Project - The Computational and Neural Dynamics of Human Motivation and Cognitive Control at University of Birmingham, listed on FindAPhD.com
www.findaphd.com
November 20, 2024 at 5:11 PM
Funded PhD (UK students only). Interested in a PhD working in the MSN lab, co-supervised by Dr. Romy Froemer? Topic is flexible around themes of motivation and decision-making, using techniques such as computational modelling, brain imaging, or brain stimulation. www.findaphd.com/phds/project...
Reposted by Samuel Hewitt, PhD
Valerie Thomas (1943) is an African American badass scientist.
She invented the illusion transmitter in 1980.
She helped develop the digital media formats that image processing systems used in NASA's Landsat program.
Her [very cool!] NASA photo next to a stack of computer tapes, 1979.
#WomenInSTEM 🧪
She invented the illusion transmitter in 1980.
She helped develop the digital media formats that image processing systems used in NASA's Landsat program.
Her [very cool!] NASA photo next to a stack of computer tapes, 1979.
#WomenInSTEM 🧪
November 21, 2024 at 8:33 PM
Valerie Thomas (1943) is an African American badass scientist.
She invented the illusion transmitter in 1980.
She helped develop the digital media formats that image processing systems used in NASA's Landsat program.
Her [very cool!] NASA photo next to a stack of computer tapes, 1979.
#WomenInSTEM 🧪
She invented the illusion transmitter in 1980.
She helped develop the digital media formats that image processing systems used in NASA's Landsat program.
Her [very cool!] NASA photo next to a stack of computer tapes, 1979.
#WomenInSTEM 🧪
Reposted by Samuel Hewitt, PhD
Early intervention for depression for young people.
This week we're presenting findings from the BESST trial - Brief Educational Workshops in Secondary Schools.
Watch the videos in this THREAD or sign up to join our webinar on Friday: www.eventbrite.co.uk/e/early-inte...
#BESSTtrial #Depression
This week we're presenting findings from the BESST trial - Brief Educational Workshops in Secondary Schools.
Watch the videos in this THREAD or sign up to join our webinar on Friday: www.eventbrite.co.uk/e/early-inte...
#BESSTtrial #Depression
Early intervention for depression for young people
Join our free webinar to hear results from the BESST trial and ideas about how we might implement DISCOVER nationally.
www.eventbrite.co.uk
November 27, 2024 at 12:45 PM
Early intervention for depression for young people.
This week we're presenting findings from the BESST trial - Brief Educational Workshops in Secondary Schools.
Watch the videos in this THREAD or sign up to join our webinar on Friday: www.eventbrite.co.uk/e/early-inte...
#BESSTtrial #Depression
This week we're presenting findings from the BESST trial - Brief Educational Workshops in Secondary Schools.
Watch the videos in this THREAD or sign up to join our webinar on Friday: www.eventbrite.co.uk/e/early-inte...
#BESSTtrial #Depression
Reposted by Samuel Hewitt, PhD
JOB ALERT: We are recruiting a research assistant in the Imagine Reality Lab to work on a project using MEG decoding to distinguish between different theories of consciousness 🧠 Get in touch if you have any questions about the role's scientific details. Please share!
www.ucl.ac.uk/work-at-ucl/...
www.ucl.ac.uk/work-at-ucl/...
UCL – University College London
UCL is consistently ranked as one of the top ten universities in the world (QS World University Rankings 2010-2022) and is No.2 in the UK for research power (Research Excellence Framework 2021).
www.ucl.ac.uk
November 22, 2024 at 2:15 PM
JOB ALERT: We are recruiting a research assistant in the Imagine Reality Lab to work on a project using MEG decoding to distinguish between different theories of consciousness 🧠 Get in touch if you have any questions about the role's scientific details. Please share!
www.ucl.ac.uk/work-at-ucl/...
www.ucl.ac.uk/work-at-ucl/...
Reposted by Samuel Hewitt, PhD
Leeds has a fully funded scholarship program for undergraduate and Masters study for Gaza students.
**Tell Everyone**
www.leeds.ac.uk/masters-scho...
**Tell Everyone**
www.leeds.ac.uk/masters-scho...
Gazan Humanitarian Scholarship
We offer scholarships for citizens of Gaza who have been displaced as a result of the ongoing conflict in the region and are living in a different country (outside of the UK).
www.leeds.ac.uk
November 21, 2024 at 10:42 PM
Leeds has a fully funded scholarship program for undergraduate and Masters study for Gaza students.
**Tell Everyone**
www.leeds.ac.uk/masters-scho...
**Tell Everyone**
www.leeds.ac.uk/masters-scho...
Finally, an app to help dodge shit
Some good news for river and sea campaigners in England
National sewage spill map to help swimmers dodge pollution in real time
@thetimes.com Clean it Up campaign has been calling for this
www.thetimes.com/uk/environme...
National sewage spill map to help swimmers dodge pollution in real time
@thetimes.com Clean it Up campaign has been calling for this
www.thetimes.com/uk/environme...
National sewage spill map to help swimmers dodge pollution in real time
Live data will show when storm overflows are releasing raw sewage into English waterways, after calls by The Times Clean It Up campaign for transparency
www.thetimes.com
November 22, 2024 at 8:33 AM
Finally, an app to help dodge shit
Reposted by Samuel Hewitt, PhD
Optogenetic vipassana! 🌬️
A top-down slow breathing circuit that alleviates negative affect in mice www.nature.com/articles/s41... in @natureportfolio.bsky.social #neuroscience #psychscisky
A top-down slow breathing circuit that alleviates negative affect in mice - Nature Neuroscience
Jhang et al. identify a prefrontal–pontomedullary pathway that slows breathing and reduces anxiety in mice, where the pontine reticular nucleus converts excitatory prefrontal inputs into inhibitory si...
www.nature.com
November 22, 2024 at 5:51 AM
Optogenetic vipassana! 🌬️
Reposted by Samuel Hewitt, PhD
This place is getting seriously good; and this is better than good, just magnificent.
My old boss did a lot of stupid things, like, proper crazy stuff, but the funniest was when he was on the roof of our shop and looked like he was about to leap the 6-foot gap to the roof of the neighbouring building.
I shouted, "Jim, don't be stupid, there's no way you'll make that jump!"
I shouted, "Jim, don't be stupid, there's no way you'll make that jump!"
November 17, 2024 at 1:59 PM
This place is getting seriously good; and this is better than good, just magnificent.
Reposted by Samuel Hewitt, PhD
First post here: our latest paper on insight-like learning dynamics (and the factors causing them) in humans and ANNs journals.plos.org/ploscompbiol... published last month in PLoS Comp Bio. with @nicoschuck.bsky.social @summerfieldlab.bsky.social @saxelab.bsky.social Paul Muhle-Karbe and Léo Touzo
Abrupt and spontaneous strategy switches emerge in simple regularised neural networks
Author summary Insights, or aha-moments, are a remarkable phenomenon in human cognition that is unique in a number of ways: they are accompanied by a powerful subjective experience, occur abruptly aft...
journals.plos.org
November 14, 2024 at 12:27 PM
First post here: our latest paper on insight-like learning dynamics (and the factors causing them) in humans and ANNs journals.plos.org/ploscompbiol... published last month in PLoS Comp Bio. with @nicoschuck.bsky.social @summerfieldlab.bsky.social @saxelab.bsky.social Paul Muhle-Karbe and Léo Touzo
Amazing work identifying a key factor which drives indecisiveness. A rare combination of smartphone behaviour (general population), patients with clinical obsessive-compulsive and anxiety disorders and imaging...! In one study 😱💥
New preprint from my postdoc with @tobiasuhauser.bsky.social at the MPC!
TL;DR: there is a strong recency bias in information gathering and it is attenuated in people on the #OCD spectrum - a possible mechanism for #indecisiveness 🤔
Paper here: www.biorxiv.org/content/10.1...
Thread below...
TL;DR: there is a strong recency bias in information gathering and it is attenuated in people on the #OCD spectrum - a possible mechanism for #indecisiveness 🤔
Paper here: www.biorxiv.org/content/10.1...
Thread below...
Indecision and recency-weighted evidence integration in non-clinical and clinical settings
Biases in information gathering are common in the general population and can reach pathological extremes in paralysing indecisiveness, as in obsessive-compulsive disorder (OCD). Here, we adopt a new p...
www.biorxiv.org
November 14, 2024 at 2:51 PM
Amazing work identifying a key factor which drives indecisiveness. A rare combination of smartphone behaviour (general population), patients with clinical obsessive-compulsive and anxiety disorders and imaging...! In one study 😱💥
I wish people would stop mentioning that place and that guy. Let's be present in the beautiful new world
November 13, 2024 at 12:01 PM
I wish people would stop mentioning that place and that guy. Let's be present in the beautiful new world