Kathy Garcia

Kathy Garcia

@gkathy.bsky.social

Computational Cognitive Science PhD at Johns Hopkins with Leyla Isik | BS @Stanford| | 🔗 https://garciakathy.github.io/ |

143 followers221 following23 posts

Kathy Garcia reposted

Kathy Garcia reposted

Excited about this new work led by @gkathy.bsky.social: Human similarity judgments reveal fine-grained representations of dynamic social scenes osf.io/preprints/ps... 🧵👇

osf.ioHuman similarity judgments reveal fine-grained representations of dynamic social scenesHow does the human mind organize dynamic social scenes? Existing accounts rely on pre-defined social-affective or action-based taxonomies, yet whether humans use these dimensions to structure their re...
Kathy Garcia@gkathy.bsky.social

What dimensions organize how we see social interactions? We learn them from 53,000+ human judgments of naturalistic social clips. They explain 2× the variance of pre-labeled annotations & better predict visual cortex, EBA, and pSTS New preprint w @lisik.bsky.social 🧵 osf.io/preprints/ps...

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Interestingly, these same learned dimensions do a much better job at predicting fMRI neural responses (N=4; McMahon et al 2023) in the every participant, including EBA, ventral temporal cortex, and pSTS

Takeaway: People seem to represent social scenes as fine-grained representations that prior accounts might not fully capture And social-affective information may matter more in lateral "visual" cortex than prior action-based accounts assume

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The top 11 dimensions are interpretable and stable across 20 retrained models. Many combine who is involved with what they're doing: conversation, caregiving, infant play, cooking & eating, children dancing. Labels: contrastive analysis of human-written captions.

We also find broad semantic categories split: Infant caregiving and infant play involve the same kinds of people and settings; the 13 annotations describe them near-identically Yet judgments split them into separate dimensions (only 3 of their top-20 videos overlap)

For the behavioral task, we had over 232 people watch 3 sec clips of two-person interactions and pick the odd one out. Which would you pick? From their choices, a sparse embedding model (SPoSE; Zheng et al. 2019, Hebart et al. 2020) learns 40 sparse dimensions.

On held-out judgments, we find the learned dimensions explain twice the variance of the prelabeled annotations (scene, bodies, actions, social-affective): r² = .25 vs 40 learned dimensions: r² = .51

Kathy Garcia reposted

Kathy Garcia reposted

We're hiring! 2 postdocs + 3 PhD students to join InfantNeuroAI at Trinity College Dublin: awake infant fMRI & OPM-MEG, plus computational models of how infants learn. Aims: understand infant visual cognition, infant neuroimaging methods, more energy-efficient learning 🧵 www.cusacklab.org/vacancies

Kathy Garcia reposted

🦀New preprint! (w/ @najoung.bsky.social)🦞 Is grammaticality a major organizing principle of NLM representations? We show that many NLMs exhibit abstract rep. separation for grammaticality. We believe this work addresses debates about confounds in measuring model gram. knowledge. [1/10]

Kathy Garcia reposted

Excited to share that I’m at #NeurIPS2025 this year! 🧠 I’ll be presenting my work at UniReps on Social Tokens where we explore how to inject socially relevant visual features into language models to improve social reasoning and alignment. If you’re around, come say hi Feel free to DM for a chat! ☕️

Kathy Garcia reposted

Check out this new preprint led by @gkathy.bsky.social showing how a new fine-tuning scheme using human similarity judgements can improve existing video models, making them more human-aligned on different social tasks! arxiv.org/abs/2510.01502

Kathy Garcia@gkathy.bsky.social

🚨New preprint w/ @lisik.bsky.social! Aligning Video Models with Human Social Judgments via Behavior-Guided Fine-Tuning We introduce a ~49k triplet social video dataset, uncover a modality gap (language > video), and close via novel behavior-guided fine-tuning. 🔗 arxiv.org/abs/2510.01502

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In follow-up experiments we show this model generalizes better to novel social tasks, and avoids catastrophic forgetting by preserving baseline on action recognition tasks.

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Hybrid fine-tuning substantially increases match to human judgment on held-out videos and surpasses the best language model baseline. The hybrid loss > triplet-only loss and > RSA-only loss.

After fine-tuning, the video model explains both captures more shared variance with language models AND captures more unique variance in human judgments, indicating it learned both language-like semantics and additional visual social nuances.

Despite the task being purely visual, caption embeddings from a language model predict human similarity better than any pretrained video model (e.g., mpnet-base-v2 > TimeSformer-base).

We fine-tune a video transformer with a novel hybrid objective function = Triplet loss (local constraints) + RSA Loss (global Pearson-correlation over pairwise distances), which captures both local and global similarity structure. We use Low Rank Adaptation to reduce the number of trainable params.

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📹 While most model features (like architecture or training objective) did not affect performance, we saw a big advantage for video versus image models along the lateral stream. But no model tested could predict anterior lateral stream responses well. [5/6]

🚀 Together, this work highlights a major gap in AI's ability to match human social vision, and underscores the importance of developing AI models in dynamic social contexts [6/6]

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🔍 Unlike visual scene features and ventral stream responses, vision models struggled to match human action and social interaction ratings, and did a poor job of predicting brain responses along the recently proposed lateral stream, specialized for social perception. [4/6]

🎥 Real-world vision is dynamic, involving complex social interactions. Current AI models provide a good match to humans in static scene vision, but how do they fare with dynamic, social stimuli? 🤔 We set out to explore this! [2/6]

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