Marvin Maechler, PhD

I'm honored to receive the Penn AI Fellowship with support from @upenndddi.bsky.social! The fellowship supports my research on computational models of perception and cognitive bias. Specifically, we want to understand when and why both brains and AI systems are susceptible to cognitive biases.

One way of interpreting perception is to say "given the neural activity in my sensory system, what is the most likely cause of this activity". Doing that involves a very sophisticated world model, which this hypothetical car would also have to have.

I think this really undersells what the human sensory apparatus achieves (I acknowledge that I might be biased because of what I study). Seeing is more than just pointing your eyes at something.

It’s not a, it’s b

A paper we started working on SEVEN YEARS ago got accepted for publication this week 🎉

The problem is less cute but more clear when it is rephrased as: "You are a doctor caring for five patients who need a different organ each. They will die if no organ donors are found. Would you kill a healthy nurse to harvest the needed organs?".

very excited to share some of the final bits of work from my PhD! 🎉 we find that phasic DA in the accumbens simultaneously tracks persistent motivation towards reward cues in addition to new learning (but maybe not RPE?!) in sign-tracking rats. check out the preprint below!

a little girl is crying while holding her fist in the air and the word exciting is on the bottom . ALT: a little girl is crying while holding her fist in the air and the word exciting is on the bottom .

Huge congrats to Gio Lab postdoc Dr @ericastownsend.bsky.social on her poster award at Temple’s Department of Neural Sciences Research Day!

What platform can we use to play this with you guys?

#JNeurosci: A functional MRI study from @maechlermarvin.bsky.social‬ et al. identify brain regions that might be the source of hemifield-specific capacity limits in attentional tracking of multiple moving objects.
vist.ly/3n7a9wt

I have to thank a lot of people for their help with this, but for this post I will limit myself to my dissertation committee: @violastoermer.bsky.social @rolfslab.bsky.social @carolinerobertson.bsky.social and Peter Tse, who were incredibly supportive and provided guidance throughout this process.

Our research challenges previous explanations of hemispatial neglect and enhances our understanding of how the brain manages spatial attention and mental effort. Additionally, we identify regions that might be the source of hemifield-specific capacity limits in attentional tracking.

We show that the load-dependent responses differ between earlier visual areas, which prefer targets on the contralateral side, and later areas that respond to targets anywhere in the visual field.

Our findings reveal brain areas where effort-driven increases in activity are dependent on the visual hemifield where targets are tracked.

We investigated how attentional effort impacts brain activity. Effort (the number of targets in a multiple-object tracking task) parametrically drives activity in the attention system.

Hemifield Specificity of Attention Response Functions during Multiple-Object Tracking The difficulty of tracking multiple moving objects among identical distractors increases with the number of tracked targets. Previous research has shown that the number of targets tracked (i.e., load)...

I am excited to announce (belatedly) that my dissertation’s final chapter has been published in the Journal of Neuroscience! doi.org/10.1523/JNEU...