Sam Gershman
@gershbrain
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Professor, Department of Psychology and Center for Brain Science, Harvard University
Cambridge, MA
Joined July 2016
I love this project, which feels like it opens many doors.
Looking for a distraction (for some reason)? May I interest you in this cool new paper on "Blending simulation and abstraction for physical reasoning"? (by Sosa, Gershman, and me) paper link: https://t.co/tmEgPkopqB OSF: https://t.co/MQe25Kas0d
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Great opportunity here!!
I'm hiring a postdoc to work with me on problems related to meta-learning and probabilistic representation learning in the brain. Perks: i) the amazing research community at @bcm_neurosci and @RiceNeuro. ii) Houston food is DELICIOUS (and cheap) https://t.co/vAHS2Ny4Jd
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My impression is that there is a cultural barrier where systems neuroscientists overlook the relevance of non-invasive brain imaging to test certain hypotheses, simply because it's not directly measuring spikes.
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My point is that it's too simplistic to think that measuring spiking activity is always a more "direct" way of testing hypotheses about the relationship between neural activity and information processing.
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It's also possible that the patterns are encoded in a distributed way across thousands of neurons. To test that hypothesis, you might need methods like 2 photon imaging.
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In some cases, what matters for information processing is inter-area communication, which is not something that is measured in most ephys studies, but can be accessed with fMRI (again, I'm not arguing that's true in the case of imagery).
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Ephys will only sample a relatively small number of neurons at the same time. It won't find patterns that are only visible when you aggregate many neurons. It's conceivable that methods like fMRI could detect such patterns (I'm not arguing that's true in the case of imagery).
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Let's take the hypothesis that sensory neurons are activated during mental imagery. There are trade-offs in using different methods to address this question. And it depends a lot on how you think about the relevant neural activity.
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I think my point here has been misunderstood by most commentators. Obviously I agree that ephys is a more direct measure of spiking activity. Let me try to clarify...
Papers that report neuronal recordings sometimes say that they provide "direct" evidence for neural encoding of something, in contrast to "indirect" methods such as non-invasive brain imaging. I don't really understand this. What makes one "direct" and the other "indirect"?
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Is the alternative hypothesis that something other than neural activity is generating the non-invasive brain signals? Or is the qualifier "direct" simply a rhetorical flourish?
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Papers that report neuronal recordings sometimes say that they provide "direct" evidence for neural encoding of something, in contrast to "indirect" methods such as non-invasive brain imaging. I don't really understand this. What makes one "direct" and the other "indirect"?
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Please don't tell me about perceptrons, neocognitrons, or TD learning. These aren't good examples, for reasons I go into here: https://t.co/6M04CYYdfD
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I'm mainly interested in examples where neuroscientists make a correct ex ante prediction that some brain fact will improve performance when incorporated into an AI system (without changing other things). Ex post explanations in terms of neuroscience are less convincing.
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I'd like to teach a paper which shows how a fact about the brain materially improved an AI system in a way that is unlikely to have been figured out by engineering alone. I haven't been able to find a single example of this. Suggestions welcome.
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What are the most compelling real-world applications of cognitive science? I'm looking for empirical papers (not opinions/reviews).
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we've finally updated our 2⃣ year old preprint on action chunking as (conditional) policy compression! this was a lesson in perseverance and not giving up on your ideas...work with @gershbrain & @AnnHuang42 ✨ (1/3)
osf.io
Many skills in our everyday lives are learned by sequencing actions towards a desired goal. The action sequence can become a ``chunk'' when individual actions are grouped together and executed as one...
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I advised a physics student and I kept worrying that the physics police would burst in to take her away because she wasn’t doing “real” physics. But I realized that if it’s interesting to physicists, it’s physics.
I feel like the critique that the physics Nobel is going to computer science misunderstands the culture of physics. They aren’t ceding the prize to cs, they’re claiming it as a branch of physics
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[Please retweet!] My paper, 'Cognitive Representations of Social Relationships and their Developmental Origins" has been accepted at Behavioral and Brain Sciences! I'm thrilled to be able to engage with people's commentary! Please consider writing one!
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If you're interested in the future of scholarly publishing, check out this panel discussion (open to the public): https://t.co/umpgjsGN6w
libcal.library.harvard.edu
In celebration of International Open Access Week 2024, please join us for a conversation with Open Mind, MIT Press, MIT Libraries, and Harvard Library. Although a young journal in...
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(5') If you are invited to review and you don't have time, please just decline! Don't leave the invitation hanging, because this just slows down the whole process.
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