A research team at the Zuckerman Institute at Columbia University in the United States has witnessed for the first time what happens in the human brain when feelings of curiosity arise. In the study, published in the journal Neuroscience on July 5, the scientists revealed the brain regions that appear to assess the degree of uncertainty in ambiguous visual scenes, leading to feelings of curiosity.
“Curiosity has deep biological roots,” says Dr. Jacqueline Gottlieb, principal investigator at the Zuckerman Institute, professor of neurology at Columbia University College of Physicians and Surgeons, and lead author of the study.
The main benefit of curiosity, she explained, is that it encourages organisms to explore the world around them in ways that help them survive. What distinguishes human curiosity, according to Dr. Gottlieb, is that it “drives us to explore much more widely than other animals, often simply because we want to know things, not because we are seeking material reward or some benefit, which leads to creativity.”
Trust and curiosity.. an inverse relationship
To uncover the brain regions involved in feelings of curiosity, the research team presented participants with pictures of objects such as a seahorse, a frog, a tank, or a hat, and distorted them to varying degrees to make them more or less clear.
The researchers asked participants to rate their confidence and curiosity about each picture, and found that the two ratings were inversely related: the more confident participants were that they knew what was in the picture, the less curious they were about it. Conversely, the less confident they were that they could guess what the picture was, the more curious they were about it.
What happens when we feel curious?
In the study, researchers used a non-invasive technique called functional magnetic resonance imaging (fMRI), which is widely used to measure changes in oxygen levels in the brains of 32 volunteers. This allowed scientists to record how much oxygen different parts of the participants’ brains were consuming while they viewed images. It is known that consuming more oxygen in a particular area of the brain means that that area is more active.
Brain scan data showed high activity in the occipitotemporal cortex, an area above the ears that has long been known to be involved in vision and recognizing object categories.
The researchers expected, based on what they knew from previous studies, that when they presented participants with vivid images, this area would show distinct patterns of activity in the brain for living and nonliving objects. “You can think of each pattern as a barcode that defines the category of the image,” Dr. Gottlieb said.
The researchers used these patterns to develop a tool to measure the uncertainty in this cortical region about the category of the blurred image. When participants were less curious about the image, the occipitotemporal cortex activity indicated a single barcode-like symbol, as if it clearly identified whether the image belonged to the animate or inanimate category. In contrast, when participants were more curious, the occipitotemporal cortex showed features of both symbols, as if it could not clearly identify the image category.
Two areas in the front of the brain were also activated when viewing the scrambled images: the anterior cingulate cortex, which previous studies have indicated is involved in gathering information, and the ventral prefrontal cortex, which is involved in monitoring a person’s self-perceptions of value and confidence in different situations.
In the new study, both regions were more active when participants reported being more confident in knowing what was in the picture, and therefore less curious to see the clear image.
Curiosity and depression
“This is the first time we can link subjective feeling to curiosity about how your brain represents this information,” says Dr. Gottlieb.
The findings, according to Dr. Gottlieb, could have diagnostic and even therapeutic implications for those suffering from depression, apathy or anhedonia, conditions often marked by a lack of curiosity.
“Curiosity involves a kind of enthusiasm and a willingness to expend energy and it is self-motivated, which means that no one is pushing you to be curious, you are just curious based on the hope that something good will come of it when you learn, and these are just some of the amazing things about curiosity,” Dr. Gottlieb says.