Sztuka, I. M., Becker, M., & Kühn, S. (2025). Neural representations underlying psychological responses to natural and artificial features in indoor architecture. Journal of Environmental Psychology, 103, 102553.

 What They Did

The researchers recruited adults for a study on psychological responses to indoor scenes. The scenes were categorized by natural or artificial style and by function: commercial, educational, etc.; these prior categorizations were not revealed to the participants. The researchers also evaluated each image for visual features such as hue, saturation, brightness, edge density, etc.

 Each participant completed three tasks: undergoing fMRI while observing a randomized, sequential display of scene images; spatially arranging some of the images on a screen according to their perceived similarity; and rating each image by how much they liked it, how natural it appeared, how much they would want to be in the scene, and how much it evoked feelings of relaxation as opposed to stress. The researchers found that individuals were fairly consistent in their own ratings but that ratings of the same image by different participants were not consistent. They found no correlation between the ratings participants gave the images and the prior categorizations of the scenes.

The researchers spatially arranged all the images based on the combined participant responses. The previously-assigned categories of natural and artificial could be distinguished but did not directly map to a single linear dimension. Rather, the images seemed to be arranged in one dimension by a combination of edge density, saturation, and brightness, with the other dimension not well determined by the measured variables. Finally, the fMRI results showed differences in brain activity, primarily in the visual system, in response to simple visual features but not previously-assigned categories.

 

Further Exploration

Even though the results did not support the hypothesis that people would identify more natural indoor architectural styles and rate them more highly, I found this article really interesting. I wonder if the results have more to do with the images used than with the underlying hypothesis.

The article provides examples of the natural and artificial style images for each category, and those words don’t really describe how I’d distinguish them. In general, I’d say the ones labeled natural have more curves and somewhat more color. The artificial ones are all stark whites and right angles. In most cases, I prefer the ones labeled natural, but I wouldn’t say they look more natural as much as that the ones labeled artificial look cold and boring.

Part of the reason none of them feel natural for me is that there are no plants. This was intentional on the part of the researchers; they wanted to focus on other characteristics that generate a sense of naturalness, not on literal exposure to vegetation. Similarly, there are no rocks: no boulders or pebbles or sand. For me, being in nature really means being in contact with nonhuman life and with the raw elements. There are other traits that affect whether indoor spaces are comfortable (including being able to see plants and rocks) but they will never be natural per se. Whether natural is correlated with comfortable for me probably depends on a whole lot of factors, but that’s a rabbit hole for another day!

Image credit: Public domain, contributor listed as "Vincent"

https://commons.wikimedia.org/wiki/File:Wageningen_University_-_Building_Lumen.JPG