What We See Seems Like What We Have Just Seen
hubie writes:
To optimize its performance, our brain "builds reality, it doesn't mirror it" [PDF]:
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.
[...] 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.
[...] What the scientists observed is that the participants' perception was indeed distorted by past images. The research authors confirm: "A group of objects was judged, for instance, larger or more numerous than it was in reality depending on whether the participant previously saw a large or a more numerous sets of items". Importantly, "the EEG signals revealed that neurons in the visual part of the brain - the "occipital" cortex - kept a trace of the past visual images. And the greater this trace in brain activity was, the stronger the perceptual bias measured in participants".
[...] This research also tells us something more about how our brain works. Domenica Bueti, last author of the research, explains: "We often think that our brain works mirroring reality, but this is not true: on the contrary, it "builds" reality, it is a creator of reality. This is because it receives too many inputs from the external world, and it must find a good method of processing them in an effective way. According to our research, the knowledge of the world influences our perception, from which we can also say that perception is partially based on our expectations. What we have already experienced, in some ways, influences the way we will perceive future events. This is a very stimulating issue, not only a scientific perspective, but also from a philosophical point of view.
Journal Reference:
Michele Fornaciai, Irene Togoli and Domenica Bueti, Perceptual History Biases Are Predicted by Early Visual-Evoked Activity [open], J. Neurosci. 24 May 2023, 43 (21) 3860-3875; DOI: https://doi.org/10.1523/JNEUROSCI.1451-22.2023
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