Does the levitation illusion depend on the view seen or the scene viewed?
Bibliographic record
Abstract
The levitation illusion is an example of a visual reorientation illusion (VRI) in which observers continue to feel upright while slowly tilted onto their backs in a room that tilts with them, remaining aligned with their body axis (Howard & Hu 2001, Perception 30: 583). Objects such as a ball hanging in the room appear to levitate. Similar VRIs are very significant in unusual environments such as microgravity. We assessed the effectiveness of different fields of view (FOV) on creating the levitation illusion in York University's Tumbling Room. We varied FOV from unrestricted to approximately 15°x15° in a counterbalanced design. The content of the visual scene was controlled by viewing at twice the distance with half the FOV. Free viewing was compared to head fixed. Responses were categorized as ‘full’, ‘confused’ or ‘no effect’. The majority of supine observers experienced the levitation illusion with unrestricted viewing. The effectiveness reduced systematically with reduction of FOV. Doubling the viewing distance revealed that this was not an effect of FOV per se but rather of the visibility of polarized visual features. A field of e.g. 30°x60° was equally effective at inducing a VRI as a 15°x30° field viewed from twice the distance. The incidence of VRIs was enhanced when subjects were allowed to move the head indicating that the features do not have to be visible all at once. We conclude that VRIs, such as the levitation illusion depend critically on what can be seen but are not critically affected by the FOV.
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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 | 0.001 | 0.012 |
| 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 | 0.002 |
| Scholarly communication | 0.001 | 0.003 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".