Ingmar de Vries

The Human Brain as a Dynamic Mixture of Expert Models in Video Understanding The human brain is the most efficient and versatile system for processing dynamic visual input. By comparing representations from deep video models to brain activity, we can gain insights into mechani...

📢 New preprint, together with @sargechris.bsky.social!

Building on @sargechris.bsky.social's previous work, we benchmark 100+ image and video models 🤖 on brain representational alignment, this time to EEG data of humans 🧠 watching videos! 🧵⬇️

www.biorxiv.org/content/10.1...

These findings reveal how low- and high-level priors jointly shape predictive neural processing of observed biological motion.

Main dynamic RSA results. Region of interest (ROI)-based analysis, with dRSA regression weights illustrated as latency plots. The three viewing conditions are displayed in rows with normal on top (A), inverted in the middle (B), and temporally scrambled at the bottom (C). Different stimulus models are displayed in columns with pixelwise motion reflecting optical flow vector direction in each pixel, and body motion reflecting 3D motion of 13 kinematic markers placed on the dancer. (D) Individual-participant peak magnitude in normal versus inverted condition. A dot in the upper left or lower right triangle indicates a larger peak magnitude in the inverted or normal condition, respectively. The red dot reflects the participant average. (E) Same as (D) but for normal versus scrambled condition (n = 37). ** p < 0.01, *** p < 0.001. Results indicate that predictive representation for high-level view-invariant body motion is selectively attenuated with top-down inversion, indicating that such high-level prediction relies on holistic priors. Instead, temporal scrambling attenuates all predictive representation, indicating that view-dependent body and pixelwise motion prediction rely on kinematics priors.

Disrupting holistic priors by turning videos upside down selectively reduced high-level view-invariant motion predictions. Instead, disrupting kinematics priors by temporal scrambling eliminated all motion prediction, with neural activity merely reacting to, rather than predicting, visual input.

Under normal viewing conditions, neural representations were indeed predictive and followed an inverse hierarchy: high-level viewpoint-invariant body motion representations were visible before representations of viewpoint-dependent body motion and low-level visual features (Figure below).

We investigated this by comparing the dynamic representational geometry of human magnetoencephalography (MEG) activity and observed biological motion stimuli by means of dynamic representational similarity analysis (dRSA).

Biological motion perception is an essential skill that allows us to quickly infer how others move. While this is often cast as inherently predictive process, it remains unclear to what extent different priors shape neural processing of biological motion.

New Preprint alert ❗

Holistic and kinematics priors enable predictive neural representations during biological motion perception

With: @predictivebrain.bsky.social and
@moritzwurm.bsky.social

At: doi.org/10.1101/2025...

🧠🧠🧠
@cimecunitrento.bsky.social
will soon open an MEG lab manager position!
The ideal candidate is a previous postdoc/phd student with MEG experience and a title in physics, engineering, neuroscience, or psychology.
Please spread the word and reach out to me if you are interested!

🧠🧠🧠 @cimecunitrento.bsky.social will soon open an MEG lab manager position!
The ideal candidate is a previous postdoc/phd student with MEG experience and a title in physics, engineering, neuroscience, or psychology.
Please spread the word and reach out to me if you are interested!

Frontiers | Disruptions in serotonin- and kynurenine pathway metabolism in post-COVID: biomarkers and treatment This opinion article attempts to connect knowledge about post-Covid syndrome (PCS) gained in neuropsychiatry and immunology. It discusses some misunderstandi...

PCP’s can prescribe SSRIs quite easily. As long as they build up the SSRIs very slowly and switch to another SSRI if there are too many side effects.
If you find it useful, please spread this article.

Kind regards, Carla Rus, MD, neuropsychiatrist

doi.org/10.3389/fneu...

Frontiers | Disruptions in serotonin- and kynurenine pathway metabolism in post-COVID: biomarkers and treatment This opinion article attempts to connect knowledge about post-Covid syndrome (PCS) gained in neuropsychiatry and immunology. It discusses some misunderstandi...

New interesting opinion article about post covid by my mum!
doi.org/10.3389/fneu...