Brains can recreate detailed scenes from simple line drawing

Simple line drawings that have been with us since prehistoric times - can capture the essence of a beach or a mountain for viewers just as well as a photograph would, a new study has shown.

"Our results suggest that our brains can recreate whole detailed scenes from just a few lines, said Dirk Bernhardt-Walther, lead author of the study and assistant professor of psychology at Ohio State University.

"The representations in our brain for categorising these scenes seem to be a bit more abstract than some may have thought we don't need features such as texture and color to tell a beach from a street scene," he said.

For the study, 10 participants viewed color photographs and line drawings of six categories of scenes -- beaches, city streets, forests, highways, mountains and offices -- while their brains were scanned using functional magnetic resonance imaging (FMRI).

The fMRI images showed the researchers what was going on in several areas of the participants' brains when they viewed the photos and line drawings. The most significant results occurred in the parahippocomal place area (PPA), an area of the brain that scientists know plays an important role in the encoding and recognition of scenes (rather than faces or objects).

Using the data from when participants viewed the color photos, the researchers trained a software-based decoder to tell what type of scene the participants viewed -- a beach, mountain, etc., -- based on the patterns of brain activity in the PPA revealed in the fMRI.

The decoder was far from perfect, but it did better than chance at predicting what scene a person was viewing in a particular fMRI image.

Most importantly, the decoder could do just as well at predicting which scene a person viewed when it was focused on line drawings as it was on photographs. In fact, the decoder did slightly better -- although not significantly so -- at predicting line drawings compared to photographs in the primary visual cortex.

"That suggests the brain uses the same information to decode which scene it is viewing when it is presented with line drawings or photos," he said.

The study appears in the online early edition of the Proceedings of the National Academy of Sciences.