Probing for Reading Times
Summary
This research investigates whether language model (LM) representations encode human reading times, a cognitive signal. Utilizing regularized linear regression on two eye-tracking corpora across five languages (English, Greek, Hebrew, Russian, Turkish), the study compares LM representations from each layer against scalar predictors like surprisal, information value, and logit-lens surprisal. Findings indicate that early LM layers surpass surprisal in predicting early-pass reading measures such as first fixation and gaze duration. This suggests that low-level structural or lexical representations in LMs capture human-like processing signatures, aligning model depth with early temporal stages of human reading. However, for late-pass measures like total reading time, scalar surprisal proves superior. Combining surprisal with early-layer representations also yields performance gains, though the optimal predictor varies significantly by language and eye-tracking measure.
Key takeaway
For NLP Engineers developing models intended to mimic human cognitive processing, you should consider that early-layer representations are more indicative of initial human reading behaviors (e.g., first fixation), while scalar surprisal remains critical for predicting overall reading duration. Integrating both types of predictors could enhance the model's ability to simulate human reading, but you must account for language-specific performance variations.
Key insights
Early LM layers predict early human reading times, while scalar surprisal predicts late reading times.
Principles
- Early LM layers capture low-level processing signatures.
- Model depth aligns with human reading's temporal stages.
Method
Regularized linear regression was used to compare language model representations against scalar predictors on eye-tracking corpora across five languages.
In practice
- Combine surprisal with early-layer representations.
- Consider language-specific predictor variations.
Topics
- Language Model Probing
- Human Reading Times
- Eye-tracking Corpora
- Surprisal Predictors
- Early Layer Representations
Best for: NLP Engineer, AI Scientist, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by Computation and Language.