{"id":614,"date":"2021-04-16T12:00:00","date_gmt":"2021-04-16T16:00:00","guid":{"rendered":"https:\/\/anyonecanscience.com\/?p=614"},"modified":"2021-04-15T19:38:46","modified_gmt":"2021-04-15T23:38:46","slug":"a-controlled-hallucination-part-1-the-problem-with-perception","status":"publish","type":"post","link":"https:\/\/anyonecanscience.com\/index.php\/2021\/04\/16\/a-controlled-hallucination-part-1-the-problem-with-perception\/","title":{"rendered":"A Controlled Hallucination: Part 1\u2014The Problem with Perception"},"content":{"rendered":"\n

Now that we understand a little bit about the complicated architecture of the brain<\/a>, we can finally start to appreciate the beautiful complexity of the world it creates. Everything we see, hear, smell, taste, and touch is filtered through the lens of the brain, refracted through our thoughts and past experiences, and reconfigured to create our unique perception of reality. Because of this complicated system of translating sensation to perception, we never really interface directly with reality. Most of the time, the image that perception creates is fairly accurate\u2014or at least we mostly agree on it. But like any complicated system, there are holes and pitfalls in perception that can alter the way we view the world and how we communicate our reality with others. Each of us is locked inside our own controlled hallucination that may or may not be representative of reality.<\/p>\n\n\n\n

One of the reasons why perception is so complicated is that it is so interconnected. No sensation happens in a vacuum. A seemingly simple sensation like the taste of something sweet gets tangled up with the object\u2019s smell, what it looks like, the texture of it on your tongue, and the sound it makes when you bite down. All of those complex sensations inform how you perceive the object\u2019s taste, along with sensations from the ambient environment. The brain integrates this complex web of sensory information and attempts to organize it into a complete experience of the world. This data-driven, computational form of perception is called bottom-up processing<\/a>. Bottom-up processing is the more rational side of perception, building reality up from individual sensory inputs.<\/p>\n\n\n\n

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The brain performs bottom-up processing of raw sensory data to build a perception of reality.<\/figcaption><\/figure><\/div>\n\n\n\n

Taste<\/a> is actually a great example of how massive amounts of different sensory stimuli converge to create perception. Your sense of taste is intimately connected with your sense of smell\u2014to the point that foods tend to taste bland when you can\u2019t smell them. While taste as a sensation comes from the interaction of chemicals on your tongue, the experience of flavor is a holistic experience that relies on the taste, smell, look, sound, and feel of the food you are eating. Additionally, your perception of smell is closely tied with memory<\/a>, and the emotions evoked by certain memories associated with a smell can bleed into your experience of flavor. So eating something your mother made you as a child may evoke fond nostalgia that makes the food taste even better. Or eating something that you ate during a stomach flu ten years ago may make you feel disgusted or nauseous even if the food is perfectly well prepared. This added layer of complexity is one of the reasons why taste is such a subjective experience. <\/p>\n\n\n\n

As if the constant integration of millions of sensations isn\u2019t complicated enough, perception also simultaneously goes the other direction. While your brain is rapidly sorting through and computing sensory information, it also uses its existing experience to predict the outcome. This form of perception, called top-down processing<\/a>, utilizes knowledge, memory, and context to impose the most likely reality onto the data provided. Top-down processing is the reason why humans tend to perceive patterns in sensory data even when none exist\u2014our brains try to impose a sense of order onto reality to make the computation easier. Evolutionarily, top-down processing meant the difference between staring dumbly at a shadow in the forest while trying to determine what it could be versus booking it in the other direction because whatever it is, it\u2019s probably not friendly. While this type of processing is necessary in order to quickly understand reality, its reliance on assumption and pattern matching can easily lead to misperception.<\/p>\n\n\n