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Qihong (Q) Lu

@qlu.bsky.social
1.4K followers 669 following 65 posts

Computational models of learning and memory Assistant Professor in Neuroscience @ CityU Hong Kong Postdoc with Daphna Shohamy & Stefano Fusi @ Columbia PhD with Ken Norman & Uri Hasson @ Princeton qlulab.github.io/website

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Qihong (Q) Lu @qlu.bsky.social · 08/06/2025
had so much fun hanging out with Uri in Hong Kong 😆
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Qihong (Q) Lu @qlu.bsky.social · 26/05/2025
I’d like to share some slides and code for a “Memory Model 101 workshop” I gave recently, which has some minimal examples to illustrate the Rumelhart network & catastrophic interference :) slides: shorturl.at/q2iKq code (with colab support!): github.com/qihongl/demo...
hidden state representation during training
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Qihong (Q) Lu @qlu.bsky.social · 08/05/2025
City U of HK is a great university and an English-speaking environment! More generally, HK is very English-friendly (I use English there, too) and a fun place to live! (2/5)
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Qihong (Q) Lu @qlu.bsky.social · 07/05/2024
In simulation 2, the model had to learn 12 classification tasks that varied along a ring manifold. Models with EM learned the ring. Again, models without EM suffered from excessive representation drift, which hindered learning.
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Qihong (Q) Lu @qlu.bsky.social · 07/05/2024
… this is because encoding and retrieving TRs in EM can reduce representation drift, which facilitates learning. Without EM, “good representation” for the ongoing task is often non-unique, leading to unnecessary TR drift – change in TRs after performance converges.
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Qihong (Q) Lu @qlu.bsky.social · 07/05/2024
In simulation 1, the model had to learn 8 sequence prediction tasks that varied along 3 independent feature dimensions. Models with EM learned to represent the 3 dims in abstract format (Bernardi 2020)...
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Qihong (Q) Lu @qlu.bsky.social · 07/05/2024
We developed an NN model augmented with a task representation (TR) layer and an episodic memory (EM) buffer. It uses EM to retrieve and encode TRs, so when it searches for a TR online (Giallanza 2023; Hummos 2022), it can retrieve previously used TRs from EM.  1/n
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
The latent causes inferred by LCNet captured the ground truth event structure, and the inferred event boundaries were correlated with human judgments, as was previously found using SEM2.0, a variant of SEM modified to account for this dataset (Bezdek et al., 2022b). (12/N)
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
Finally, we used LCNet to process naturalistic video data of daily events (Bezdek et al., 2022a). LCNet was trained to predict “what would happen next” (i.e., the next frame of the video). (11/N)
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
In Simulation 2, LCNet was able to account for data showing that humans were better at learning event schemas in a blocked training curriculum compared to an interleaved curriculum (Beukers et al., 2023), a pattern that standard neural network models can't explain. (8/N)
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
In simulation 1, we found that LCNet was able to extract and reuse the shared structure across contexts (e.g., learning a new related task was faster) and overcome catastrophic interference. (7/N)
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
To address this limitation, we proposed the Latent Cause Network (LCNet), which uses a single neural network shared across all latent causes... (5/N)
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Qihong (Q) Lu @qlu.bsky.social · 15/12/2023
In this paper, we are interested in event processing – a form of continual learning where an intelligent agent has to learn about the properties of different contexts, and the context changes are not (necessarily) signaled explicitly to the agent. (2/N)
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