The visual system. That is what this week’s lecture and exercise session attempted to teach us about. The visual system is interesting in the sense, that it is the way through which us animals can infer the most information of the “real world” surrounding us. Yet, it has plenty of limits and it thus “fails” us in many situations. This becomes especially evident in 2D-images, as our brain seems to be used to interpreting the 3D-world, where moving around can give more information of the “actual” situation.
I watched a neuroscience discussion video, where Dale Purves, who is Geller Professor of Neurobiology Emeritus in the Duke Institute for Brain Sciences, Jean-François Gariépy and some others discuss the function and evolution of the visual system. Dale Purves held an opinion that we should not, in fact, talk about our visual system “failing” us, because the term itself is misleading. It is true that we cannot see the outside world as it is “in reality” – whatever it may mean – but the mechanism we perceive it is always the same. If there are no errors in the mechanisms, then we should not call it a failure.
One of the discussion participants held a Bayesian view of what happens in the visual post-processing: in our brain, we have a model of the world, and every time we see something which differs from the model, we either change the model or become convinced that what we are seeing is somehow false information. To me, this sounds intuitively very convincing. Professor Purves, however, was skeptical towards this perspective, as there is “no evidence” for this actually happening on the level of neural circuits.
To me, all this discussion highlights an important point: it matters, how we talk about things, what kind of vocabulary we use. It matters, because the way we talk about things automatically shapes and limits our understanding of the concepts discussed. It may be that we miss the actual nature and mechanism of the phenomenon we are investigating, just because we intuitively feel that it should work in such and such way. Especially now, that the subject matter is our own brain, we are prone to get mislead by our intuition. Therefore, we should be careful with the language.