Curiosity has its own neural signal: Brain separates valuable information from water rewards in mice

Researchers at Columbia University, Harvard Medical School, and Johns Hopkins University have developed a new experimental method to study curiosity and the drive for knowledge in mice. This approach, detailed in a paper published in Nature Neuroscience, reveals how the brain values information independently of physical rewards.

The study's lead author, Jennifer J. Bussell, explains that understanding the neural basis of our desire for knowledge is crucial. Previous research suggested that brain reward centers respond to information as if it were a reward, but the exact way the brain represents and values information remained unclear.

To investigate this, the researchers created a paradigm using thirsty mice presented with two holes. One hole rewarded mice with a water puff upon nose probing, while the other provided water without offering information. A third hole, with an odor, directed mice to either the information or non-information hole. Mice learned to prefer the information-providing hole, even if it contained less water, indicating a preference for knowledge over physical rewards.

Using miniaturized microendoscopes, the team observed neural activity in the orbitofrontal cortex (OFC), a brain region involved in reward evaluation. Approximately 20% of OFC neurons showed different activity patterns when mice expected information versus no information. The magnitude of this activity difference correlated with the time mice had knowledge of the reward outcome.

These findings suggest the mouse brain processes curiosity and reward differently, with separate neural representations. Further studies using this paradigm could clarify the differences between these two drives. The researchers plan to explore curiosity and knowledge-seeking behavior further, with the ultimate goal of applying their findings to human understanding.