Human Perception Influenced by Prior Knowledge and Expectations Called Top-Down Control

Prior information impacts how the brain processes what we see, revealed a new study. From the smell of flowers to the taste of wine, our perception is strongly influenced by prior knowledge and expectations, a cognitive process known as ’top-down control’. This cognitive process uses an individual’s thoughts and influences the senses. The study findings support the long-standing theory that the brain does not faithfully represent the environment but rather attempts to predict it based upon prior knowledge. The new study in mouse models found that the brain significantly changed its visual cortex operation modes by implementing top-down processes during learning. First author Hiroshi Makino, postdoctoral researcher at University of California, San Diego School of Medicine, said, "We found that when the mouse assigns a new meaning to a previously neutral visual stimulus, top-down control becomes much more influential in activating the visual cortex. Top-down inputs interact with specific neuron types in the visual cortex to modulate its operation modes."

Makino further added, "In addition to revealing circuit mechanisms underlying these learning-related changes, our findings may have implications in understanding the pathophysiology of psychiatric diseases, such as schizophrenia, that generate abnormal perception."

The study appears online in Nature Neuroscience.

Source-IANS