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“What we see seems like what we have just seen”: a new SISSA study

16 May 2023
To optimize its performance, our brain “builds reality, it doesn’t mirror it”, researchers say

Things are not always as they appear: what we see seems like what we have just seen, a new SISSA study says. For example, compared to the actual size, an object might seem bigger if it is preceded by the presentation of a big object, and smaller if preceded by a small one. This visual perceptual bias is thus associated with early visual-evoked brain activity and is driven by a trace of past information kept by neural populations at the very basic levels of visual analysis in the brain. The result of what we see, in short, is a kind of average that the brain makes between what is happening in front of our eyes and what has already happened.

This is the evidence that has emerged from research just published in Journal of Neuroscience. The new investigation confirms an intriguing scientific issue already explored by neuroscience: what we perceive is often not a faithful representation of what reaches our senses, but a distorted representation of the external world.

According to research authors, Michele Fornaciai, Irene Togoli and Domenica Bueti from Scuola internazionale Superiore di Studi Avanzati (SISSA), this phenomenon is due to the discrepancy between the limited brain computational resources and the plethora of stimuli bombarding our senses. This “bias” reflect the brain’s need to find regularities in the external world, making it more predictable and easier to deal with.

Image: Florian Roost from Unsplah