Brain-imaging study reveals curiosity as it emerges
In a first, researchers link people’s subjective feelings of curiosity to the way their brains physically represent it
You look up into the clear blue sky and see something you can’t quite identify. Is it a balloon? A plane? A UFO? You’re curious, right?
A research team based at Columbia’s Zuckerman Institute has for the first time witnessed what is happening in the human brain when feelings of curiosity like this arise. In a study published in the Journal of Neuroscience, the scientists revealed brain areas that appear to assess the degree of uncertainty in visually ambiguous situations, giving rise to subjective feelings of curiosity.
“Curiosity has deep biological origins,” said corresponding author Jacqueline Gottlieb, PhD, a principal investigator at the Zuckerman Institute. The primary evolutionary benefit of curiosity, she added, is to encourage living things to explore their world in ways that help them survive.
“What distinguishes human curiosity is that it drives us to explore much more broadly than other animals, and often just because we want to find things out, not because we are seeking a material reward or survival benefit,” said Dr. Gottlieb, who is also a professor of neuroscience at Columbia’s Vagelos College of Physicians and Surgeons. “This leads to a lot of our creativity.”
Joining Dr. Gottlieb on the research were Michael Cohanpour, PhD, a former graduate student at Columbia (now a data scientist with dsm-firmenich), and Mariam Aly, PhD, also previously at Columbia and now an acting associate professor of psychology at the University of California, Berkeley.
In the study, researchers employed a noninvasive, widely used technology to measure changes in the blood-oxygen levels in the brains of 32 volunteers. Called functional magnetic resonance imaging, or fMRI, the technology enabled the scientists to record how much oxygen different parts of the subjects’ brains consumed as they viewed images. The more oxygen a brain region consumes, the more active it is.
To unveil those brain areas involved in curiosity, the research team presented participants with special images known as texforms. These are images of objects, such as a walrus, frog, tank or hat, that have been distorted to various degrees to make them more or less difficult to recognize.
The researchers asked participants to rate their confidence and curiosity about each texform, and found that the two ratings were inversely related. The more confident subjects were that they knew what the texform depicts, the less curious they were about it. Conversely, the less confident subjects were that they could guess what the texform was, the more curious they were about it.
Using fMRI, the researchers then viewed what was happening in the brain as the subjects were presented with texforms. The brain-scan data showed high activity in the occipitotemporal cortex (OTC), a region located just above your ears, which has long been known to be involved in vision and in recognizing categories of objects. Based on previous studies, the researchers expected that when they presented participants with clear images, this brain region would show distinct activity patterns for animate and inanimate objects. “You can think of each pattern as a ‘barcode’ identifying the texform category,” Dr. Gottlied said.
The researchers used these patterns to develop a measure, which they dubbed “OTC uncertainty,” of how uncertain this cortical area was about the category of a distorted texform. They showed that, when subjects were less curious about a texform, their OTC activity corresponded to only one barcode, as if it clearly identified whether the image belonged to the animate or the inanimate category. In contrast, when subjects were more curious, their OTC had characteristics of both barcodes, as if it could not clearly identify the image category.