Fixating picture boundaries does not eliminate boundary extension: Implications for scene representation

Abstract

Observers frequently remember seeing more of a scene than was shown (boundary extension). Does this reflect a lack of eye fixations to the boundary region? Single-object photographs were presented for 14–15 s each. Main objects were either whole or slightly cropped by one boundary, creating a salient marker of boundary placement. All participants expected a memory test, but only half were informed that boundary memory would be tested. Participants in both conditions made multiple fixations to the boundary region and the cropped region during study. Demonstrating the importance of these regions, test-informed participants fixated them sooner, longer, and more frequently. Boundary ratings (Experiment 1) and border adjustment tasks (Experiments 2–4) revealed boundary extension in both conditions. The error was reduced, but not eliminated, in the test-informed condition. Surprisingly, test knowledge and multiple fixations to the salient cropped region, during study and at test, were insufficient to overcome boundary extension on the cropped side. Results are discussed within a traditional visual-centric framework versus a multisource model of scene perception.

Keywords:

• Scene perception
• Eye movements
• Spatial layout
• Visual memory
• Boundary extension

This research was supported by NIMH (National Institute of Mental Health) Grant RO1MH54688. We thank Brittni S. Briggs, Lea Gartenmayer, and Shanna Delaney for their valuable assistance in collecting data.

Notes

¹Participants sat in rows; visual angles ranged from approximately 30° (width) × 20° (height) in the back row to 9° (width) × 6° (height) in the front row. In subsequent studies with similar design, visual angles fell inside this range (e.g., Intraub & Bodamer, 1993, based on seating, visual angles ranged from 20° × 13° for participants in front row and 9° × 6° for those in the back row, and in Gagnier, Intraub, Oliva, & Wolfe, 2011, participants were each seated at an individual monitor, and approximate visual angle was 15° × 10°).