Scientists at the National Eye Institute (NEI) have found that neurons in the superior colliculus are key players in allowing us to detect visual objects and events. This structure doesn’t help us recognize what the specific object or event is; instead, it’s the part of the brain that decides something is there at all.
In this study researchers used an “accumulator threshold model” to study how neuronal activity in the superior colliculus relates to behavior. By comparing brain activity recorded from the right and left superior colliculi at the same time, the researchers were able to predict whether an animal was seeing an event. The findings were published today in the journal Nature Neuroscience.
This new study shows that process of deciding that an object is present or that an event has occurred in the visual field – is handled by the superior colliculus. The process of deciding to take an action (a behavior, like avoiding a chair) based on information received from the senses (like visual information) is known as “perceptual decision-making”. Most research into perceptual decision-making – in humans, non-human primates, or in other animals – uses mathematical models to describe a relationship between a stimulus shown to an animal (like moving dots, changes in color, or appearance of objects) and the animal’s behavior. But because visual information processing in the brain is highly complex, scientists have struggled to demonstrate that these mathematical models accurately mimic a biological process happening in the brain during decision-making.
Citation: James P. Herman, Leor N. Katz, and Richard J. Krauzlis. “Midbrain Activity Can Explain Perceptual Decisions during an Attention Task.” Nature Neuroscience 21, no. 12 (2018): 1651-655. doi:10.1038/s41593-018-0271-5.