Why objects in images may appear closer—or farther—than they actually are

Why images may appear closer—or farther—than they actually are
The study relied on two databases, Google Open Images (SOI) and the Scene Understanding Database (SUN), which categorized images using object- and scene-oriented words. Credit: Wilma Bainbridge

When people remember images, they fill in the edges with details they didn't actually see. That's the idea behind the boundary extension, a term which has become widely accepted in psychology classes, textbooks and test-prep flashcards.

But what if the concept isn't quite accurate?

A University of Chicago psychologist has discovered new evidence that challenges the decades-old understanding of the memory error as a universal phenomenon. Published in the journal Current Biology, the study proposes that boundary contraction may be just as common as —and that whether something appears zoomed in or out depends on the properties of the image itself.

"In a way, we're debunking this very strong claim that has been made in psychology over the last 30 years," said Asst. Prof. Wilma Bainbridge, the study's lead author and an expert on the perception and memorability of images.

The finding is important, she added, because boundary extension has been used to make other claims about the nature of the brain, such as the function of the hippocampus.

Bainbridge co-authored the study with Chris Baker, a principal investigator at the National Institute of Mental Health. Testing 2,000 participants, they found that although images of objects caused boundary extension, images of full scenes were more likely to produce boundary contraction. That is, a person may see a close-up photo of an apple and fill in details that were not actually present. But if they see a football field, they may be more likely to remove details—zooming in, or contracting, the actual image.

In a previous study, Bainbridge and Baker showed participants various images and asked them to draw copies. They were "perplexed" when boundary extension did not occur as often as they had expected.

To further investigate those results, they conducted an online experiment using a broad set of 1,000 and 2,000 participants. Participants would see an image, see a scrambled image and then see the original image again.

Even though the was identical to the first, the researchers found that people would indicate it being farther or closer according to its visual properties (object-based vs. scene-based).

Bainbridge said the results highlight the need for psychologists to revisit even long-held assumptions, as well as the potential pitfalls of drawing larger inferences from limited data sets.

Past replications of boundary extension, she suggested, could have been skewed in part by narrow data sets that repeated the use of certain image types.

"Anecdotally, I've spoken with many people who have thought about looking at boundary —but then they aren't able to replicate the effects, so they give up and they set aside the data," she said.


Explore further

Psychology researchers extend knowledge of visual misperception

More information: Wilma A. Bainbridge et al. Boundaries Extend and Contract in Scene Memory Depending on Image Properties, Current Biology (2020). DOI: 10.1016/j.cub.2019.12.004

Wilma A. Bainbridge et al. Drawings of real-world scenes during free recall reveal detailed object and spatial information in memory, Nature Communications (2018). DOI: 10.1038/s41467-018-07830-6

Citation: Why objects in images may appear closer—or farther—than they actually are (2020, February 28) retrieved 27 November 2020 from https://medicalxpress.com/news/2020-02-images-closeror-fartherthan.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
193 shares

Feedback to editors

User comments