The persistence of global form (Part I): Stimulus inversion influences V1 fMRI activity
Bibliographic record
Abstract
The human visual system uses feedforward and feedback mechanisms to achieve and maintain the figure-ground segregation of global form. One way to study figure-ground segregation is to measure the visual persistence of global form, a type of short-term perceptual memory. Studies of persistence have shown that figure-ground segregation is maintained by the visual system for up to a few seconds following the removal of perceptual binding cues that originally led to segregation. Previous studies showed persistence-related fMRI activity in human lateral occipital cortex, but failed to show persistence-related fMRI activity in V1. If persistence were observed in V1 it would suggest that feedback from high-level visual areas influence the participation of V1 in the persistence of global form. We presented observers with outlines of faces and animals that were camouflaged until they moved; these figures were either upright or inverted. We found that both upright and inverted figures persisted for up to several seconds (measured behaviorally) after they stopped moving, but that upright figures persisted longer than inverted versions of the same stimuli. We measured persistence-related fMRI activity in several occipito-temporal regions of interest (ROIs): object-selective lateral occipital cortex (LO); face-selective occipital cortex (OFA) and the fusiform face area (FFA); and several early visual ROIs (V1, V2, V3, V4v). We observed an effect of inversion on persistence in all of our ROIs, including V1. Our findings suggest that V1 fMRI activity is influenced by the orientation of an object, even though upright and inverted versions of the same figure contain equivalent low-level stimulus information. We propose that LO and other higher-tier visual areas—including the OFA and the FFA—are part of a recurrent processing network, and that these areas facilitate visual processing in V1 via feedback. We further investigate this possibility in Part II.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.002 | 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".