Psychedelics are Helping Experts Understand the Brain

In addition to learning about Mental diagnoses, psychedelics could teach us more about the brain's primary functions

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Research about psychedelics took off in the 1950s but was discontinued by the 1970s for a few reasons, including tighter pharmaceutical regulations and the “failure of controlled clinical trials to live up to the claims of psychedelic advocates.” Though interest slowly renewed in the 1990s when researchers started cautiously studying how drugs like psilocybin mushrooms, LSD, and MDMA might help experts better understand psychiatric conditions.

Interest in psychedelics and their relationship with the human brain has only grown more popular over the decades since. These days, it’s a booming field of study with a growing pile of remarkable research results. Experts are learning more about how to treat various psychological conditions, yes, but they’re also discovering more about how the brain functions.

Predictive Processing

The brain function of particular interest to experts is known as predictive processing. German physicist and physician Hermann von Helmholtz suggested predictive processing as a hypothesis way back in the 1860s. He proposed one of the brain’s primary functions is to guess about the causes of sensory information at any given moment.

Simply speaking, he suggested that by using prior knowledge, the brain attempts to make sense of the bombardment of sensory information it receives every moment of the day. Whatever conclusion the brain decides on creates our perceptions of the world.

For example, when you hear a sound, your brain searches through all of the sounds you’ve heard, looking for a match. Let’s say the sound came from a text message before. Then your brain will assume the noise you just heard is also a text, and that sound becomes associated with receiving a text from then on. This would be why when you change the noise your phone makes for text notifications, it takes a little bit before you register the new sound rather than expecting the old one.

However, the more ambiguous the sensory input, the more the brain relies on our previous experiences to make sense of it. An example of this is are optical illusions, like the one below that you’ve probably seen before. When looking at the image, you can see two different things — a vase or two faces looking at each other.

Image Source: WikiCommons

The image itself doesn’t change, nor does its sensory input, but how you perceive it does. This means the brain is an active contributor to our perceptions. In other words, rather than being a passive machine simply collecting information from our senses, the brain actively sorts through the data and creates hypotheses to explain it all.

Considering this, Helmholtz argued that our perceptions must be based on our brain using prior knowledge to predict what we see-touch-taste-smell-hear. Today, Helmholtz’s hypothesis, now known as predictive processing, is a widespread assumption for how the brain works.

If it’s true, researchers believe they can use psychedelics to intentionally disrupt these predictions and better understand neuropsychological conditions that cause altered perceptions of reality, such as psychosis.