{"id":7516,"date":"2016-03-21T21:24:56","date_gmt":"2016-03-22T01:24:56","guid":{"rendered":"https:\/\/sites.bu.edu\/ombs\/?p=7516"},"modified":"2016-03-21T21:25:05","modified_gmt":"2016-03-22T01:25:05","slug":"what-we-think-we-see-why-the-real-world-is-confusing","status":"publish","type":"post","link":"https:\/\/sites.bu.edu\/ombs\/2016\/03\/21\/what-we-think-we-see-why-the-real-world-is-confusing\/","title":{"rendered":"What We Think We See – Why the Real World is Confusing"},"content":{"rendered":"

\"Eye-Benders-Shutterstock1\"<\/a><\/p>\n

Most of us rely on our eyes in order to help us interact with the world on a daily basis. Yet the visual system often distorts what we see, so what we think we see is actually an altered reality.\u00a0 According to Dr. Mareschal, as quoted in an article published in Proceedings of the National Academy of Science<\/i>, \u201c[i]n fact a lot of it is distortion, and it is occurring in the early processing of the brain, before consciousness takes over. Our [researchers from the University of Sydney\u2019s School of Psychology and The Vision Centre] work shows that the cells of the primary visual cortex create small distortions, which then pass on to the higher level of the brain, to interpret as best it can\u2026And we found that even the higher brain cannot always correct for them, as it doesn\u2019t in fact know they are illusions.\u201d<\/p>\n

In agreement with previously discovered results, Dr. Mareschal and her colleague Professor Clifford found that these illusions were occurring during early processing in the brain, prior to consciousness.\u00a0 They then went on to be the first labs to report being able to connect the origin of the tilt illusion to the cells of the primary visual cortex, a highly specialized region in the occipital lobe of the brain.\u00a0 Let me take this chance to explain what the tilt illusion is.\u00a0 Take a look at this image before reading on:<\/p>\n

\"Screen<\/a>\u00a0Via Journal of Vision<\/a><\/p>\n

What direction do the lines of the inner circle appear to be rotated in: clockwise, counterclockwise, or not at all?\u00a0 Notice how the lines in the inner circle appear to be tilted counterclockwise.\u00a0 Here\u2019s the catch though: they\u2019re actually vertical.<\/p>\n

\"Screen<\/a><\/p>\n

Why is this?\u00a0 According to Mareschal and Clifford, the brain looks to the surroundings for contextual information in order to determine the pattern and alignment of an image.\u00a0 Therefore, because the lines in the outer circle are tilted clockwise and because the lines in the inner circle are tilted away from those of the outer circle, the brain concludes that they must be sloped counterclockwise, while the truth is they are simply vertical.<\/p>\n

Here is an example of how our brain utilizes context clues to help us form images in our brain: What are these broken pieces a part of?<\/p>\n

\"Screen<\/a>\u00a0Via Ink Covered Optical Illusions<\/a><\/p>\n

Can you see it now?<\/p>\n

\"Screen\u00a0Via Ink Covered Optical Illusions<\/a><\/p>\n

The only thing that changed between the first picture and the second picture is the presence of the spilled ink.\u00a0 In the first image, there is too much empty space for the brain to piece together the image because the missing pieces of the image and the background are both white.\u00a0 However, in the second image, the black ink connects the pieces of the image, allowing our brain to put them together into a familiar object – the letter B.\u00a0 Here, we use the presence of contextual clues to trick our brains into recognizing the image.<\/p>\n

Here is a final example of how our brain can be tricked by contextual information: Is square A or square B darker?<\/p>\n

\"Screen<\/a>\u00a0Via mit.edu<\/a><\/p>\n

Trick question!\u00a0 The two squares are actually the same shade of grey, despite the fact that they appear different.\u00a0 We are able to see this by connecting the two squares with grey strips of the same shade throughout.<\/p>\n

\"Screen<\/a>\u00a0Via mit.edu<\/a><\/p>\n

In order to explain this, we need to discuss the successes demonstrated by our visual system as well as the failures while interpreting this image.\u00a0 Notice that square A is supposedly a dark checker and square B is a light one.\u00a0 Due to the arrangement of squares on a checkerboard, lighter checkers will be surrounded by darker checkers and, likewise, darker checkers will be surrounded by lighter ones.\u00a0 Despite the presence of the shadow, ultimately making all of the checkers within the shadow a \u201cdarker shade of paint,\u201d square B is still surrounded by darker tiles.\u00a0 This contextual information cues our brain to recognizes B as a light checker and A as a dark one, although we have now proven that they are actually the same shade of grey.<\/p>\n

So to summarize: \u201cAll I know is that I know nothing\u201d ~ Socrates<\/p>\n

~Alexa Aaronson<\/p>\n

Sources:<\/p>\n

How Your Eyes Deceive You<\/a><\/span><\/p>\n

Why Does the Illusion Work?<\/a><\/span><\/p>\n

Ink Covered Optical Illusion<\/a><\/span><\/p>\n

Professor Gavornik\u2019s Principles of Neuroscience Lectures – Thanks!<\/p>\n

Image Source:<\/p>\n

Wired<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Most of us rely on our eyes in order to help us interact with the world on a daily basis. Yet the visual system often distorts what we see, so what we think we see is actually an altered reality.\u00a0 According to Dr. Mareschal, as quoted in an article published in Proceedings of the National […]<\/p>\n","protected":false},"author":9559,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/posts\/7516"}],"collection":[{"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/users\/9559"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/comments?post=7516"}],"version-history":[{"count":1,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/posts\/7516\/revisions"}],"predecessor-version":[{"id":7524,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/posts\/7516\/revisions\/7524"}],"wp:attachment":[{"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/media?parent=7516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/categories?post=7516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.bu.edu\/ombs\/wp-json\/wp\/v2\/tags?post=7516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}