Cortical state and natural movie responses in cat visual cortex
Bibliographic record
Abstract
Abstract How does cortical state affect neural responses to naturalistic stimuli, and is it analogous between anesthetized and awake animals? We recorded spikes and local field potential (LFP) from all layers of isoflurane-anesthetized cat primary visual cortex (V1) while repeatedly presenting wide-field natural scene movie clips. Spiking responses of single units were remarkably precise, reliable and sparse, with lognormally distributed mean firing rates. Many units had distinct barcode-like firing patterns, with features as little as 10 ms wide. LFP-derived cortical state switched spontaneously between synchronized (1/ f ) and desynchronized (broadband). Surprisingly, responses were more precise, reliable and sparse during the synchronized than desynchronized state. Because the desynchronized state under anesthesia is thought to correspond to attending periods in awake animals, during which responses are enhanced, our results complicate the analogy between cortical states in anesthetized and awake animals. The presenceof orientation maps in cat V1 may explain contrary reports in anesthetized rodents, and predicts a similar result in anesthetized ferret and primate V1. Significance Statement Global brain activity changes spontaneously over time and can be characterized along a spectrum from slow synchronized activity, to fast desynchronized activity. This spectrum is similar in awake, asleep and anesthetized animals, but is its effect on neural responses the same in all cases? Here we show that neural responses to natural movies in anesthetized cat visual cortex are more precise during synchronized activity. This is contrary to reports in anesthetized rodents, which we suggest may be due to greater columnar organization in cat visual cortex. Since this is also contrary to enhanced responses and behavioural performance during attention, when activity is desynchronized, our results suggest that similar brain states in awake and anesthetized animals may not be functionally analogous.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".