{"id":84,"date":"2015-09-26T21:12:59","date_gmt":"2015-09-26T21:12:59","guid":{"rendered":"http:\/\/blog.richmond.edu\/cognitiveneurod\/?p=84"},"modified":"2015-09-26T21:14:09","modified_gmt":"2015-09-26T21:14:09","slug":"decoding-visual-illusions-what-you-see-is-not-always-the-truth","status":"publish","type":"post","link":"https:\/\/blog.richmond.edu\/cognitiveneurod\/2015\/09\/26\/decoding-visual-illusions-what-you-see-is-not-always-the-truth\/","title":{"rendered":"Decoding Visual Illusions: What You See is Not Always the Truth"},"content":{"rendered":"

\"big-eye\"<\/a><\/p>\n

So seeing is believing right? \u00a0Think again\u2026<\/p><\/blockquote>\n

The whole concept behind visual illusions is that our minds make assumptions about the sensory information we perceive. \u00a0A visual illusion occurs when our minds perceive an image that is different from the objective reality. \u00a0This may happen for a variety of reasons such as over stimulation of the brain and eyes or the brain and eyes making unconscious inferences. \u00a0The bottom line is that what we see isn\u2019t always necessarily the truth\u2026<\/p>\n

\"\"<\/p>\n

This visual illusion is called the Hermann Grid. Notice how the black dots are coming and going and each individual dot will become white when you focus on it.<\/p>\n

Let\u2019s take a look at the Hermann Grid, a classic example of visual illusions that deals with contrast and colors.\u00a0 Why are the black dots coming and going?\u00a0 Why does any particular dot become white when you focus on it?<\/p>\n

Visual sensory information is accepted by light receptive cones and rods.\u00a0 The receptors pass the information down through intermediary cells, such as retinal ganglion cells.\u00a0 However, here\u2019s the twist: there are 125 million receptors in the retina and only one million retinal ganglion cells.\u00a0 Therefore, before any information reaches the brain, all visual input is being compressed at a ratio of 125 to 1.\u00a0 No wonder the \u201cimage\u201d your light receptors receive is not the same \u201cimage\u201d your brain receives.<\/p>\n

Lateral Inhibition<\/h3>\n

The retinal ganglion gathers stimuli from a small area of light receptors.\u00a0 Many ganglion cells then pass along the average of this stimuli.\u00a0 However, lateral inhibition cells are a bit more complex.\u00a0 For lateral inhibition cells, stimuli from the center of the receptive field is \u201cpositive\u201d and stimuli from the edges of the receptive field is \u201cnegative.\u201d\u00a0 This becomes useful when the eyes are presented with edges because edges are where high contrast meet low contrast.\u00a0 In the case of the Hermann Grid, the white dot in the middle is a \u201cpositive\u201d stimulus but the surrounding white creates an even bigger \u201cnegative\u201d stimulus.\u00a0 Therefore, the middle white dot is perceived as white when we focus on it and the surrounding white lines are perceived as grey.\u00a0 .<\/p>\n

We can conclude from this that what we see may not be the truth.\u00a0 Would it be too much of a stretch to take this lesson learned from visual illusions and apply it to our daily lives?\u00a0 For example, if we catch a glimpse of our new crush talking to a girl or a guy we often jump to conclusions that he or she likes that person more than us.\u00a0 But this may not be true, in fact often times that it is not the case.\u00a0 As visual illusions teach us, seeing should not be believing.<\/p>\n

Here is a list of optic illusions<\/a> if you are interested in looking at a few more! Clicking on the name of the illusion will explain how the illusion works. Enjoy!<\/p>\n

References:<\/h4>\n
Eustis, D. (n.d.). Contrast Effects. Retrieved September 25, 2015, from http:\/\/cs.brown.edu\/~deus\/courses\/optical\/Contrast1.htm <\/small><\/div>\n
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Lateral Inhibition. (2015). Retrieved September 25, 2015, from http:\/\/www.indiana.edu\/~p1013447\/dictionary\/lat_i.htm<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

So seeing is believing right? \u00a0Think again\u2026 The whole concept behind visual illusions is that our minds make assumptions about the sensory information we perceive. \u00a0A visual illusion occurs when our minds perceive an image that is different from the … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2288,"featured_media":88,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-84","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"jetpack_featured_media_url":"https:\/\/blog.richmond.edu\/cognitiveneurod\/files\/2015\/09\/big-eye.png","_links":{"self":[{"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/posts\/84","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/users\/2288"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/comments?post=84"}],"version-history":[{"count":0,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/posts\/84\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/media\/88"}],"wp:attachment":[{"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/media?parent=84"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/categories?post=84"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.richmond.edu\/cognitiveneurod\/wp-json\/wp\/v2\/tags?post=84"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}