Can Hallucinations Teach Us About the Brain’s Inner Workings? 

A few of the human brain’s functions are as fascinating as hallucinations. Our ability to produce seemingly real sights and sounds that are illusions is stunning — especially because they can happen without external causes. However, since they’re the result of complex biochemistry, hallucinations are essentially produced by our brain’s inner workings. And considering how much of the brain is still a mystery to us, it’s easy to wonder — can we learn something about the brain from hallucinations?  

Researchers around the globe have been asking themselves the same thing for ages, especially since we’ve become aware of mental health issues. With that in mind, let’s see what hallucinations can teach us about how our brain perceives reality — and the times it fails to do so properly! 

Understanding Hallucinations in the Brain’s Inner Workings 

To the average layman, hallucinations are nothing more than another symptom of mental illness. While that may be true in most cases, these illusions can tell us much about how our brains work.  

It’s also a common misconception that hallucinations are only visual. Sight is only one of our five senses, and there’s a type of hallucination for each of them. This includes: 

• Tactile 

• Gustatory 

• Olfactory 

• Auditory  

• Visual 

Yes, given the right conditions, we can even hallucinate taste and touch. That’s why hallucinations are also called “phantom sensations” — in other words, stimuli observable by our senses without any external causes.  

Unfortunately, hallucinations are indeed mostly symptoms of a psychotic or a neurocognitive illness — including dementia and schizophrenia.  

Even when hallucinations are the result of a mental disorder, they still hold valuable insights. For instance, people suffering from schizophrenia often experience vivid sensory illusions. Examining these patients has told us a lot about the human brain. Specifically, how the smallest imbalance in our brain’s perceptive functions can drastically alter the patient’s view of reality.  

Of course, patients suffering from mental illnesses like schizophrenia require more than scientific insights for effective care. Specialized schizophrenia treatment centers provide comprehensive support, addressing both the symptoms and underlying causes of the condition. 

Besides mental disorders, hallucinations can also be caused by psychedelic drugs, the most famous among them being DMT and LSD.  

What Are Hallucinations In Practice? 

A quick Google search will tell you that there are countless definitions of hallucinations. However, the one coined by the neurologist Oliver Sacks may move us closer to a technical understanding of how our brain constructs these illusions. 

To paraphrase Sacks, illusions are sensory stimuli that seemingly stem from external reality — without any actual external reality. In simpler terms, he defines hallucinations as perceptions of things that aren’t really there.  

In practice, we understand that hallucinations are brain anomalies. Sights and sounds that happen due to irregular brain activity. However, to understand why they happen, we must first understand how our brain perceives reality — even when it’s doing so correctly.  

When we smell or see something in the real world, our brain’s inner workings aren’t actually perceiving these senses per se. Instead, it uses our sensory input to create an approximation — a model that’s most likely a real representation of what we’re encountering in the real world.  

Notice how “most likely” is doing much of the heavy lifting here. When our brains function properly, we get an accurate representation of reality. But when there’s any kind of neurological abnormality, the brain can create these models incorrectly.  

In that case, we stray from a normal perception of the world. And we experience these “mistakes” as hallucinations — perceptions of stuff that isn’t there. Any divergence from regular brain activity can cause these mistakes. For instance, our brain can incorrectly build models as a result of: 

• Various mental illnesses 

• Injuries or strokes 

• Different drugs 

Hallucinations and Drugs 

As we’ve mentioned above, mental illnesses and traumatic brain injuries aren’t the only things that can cause hallucinations. People have been experimenting with drug-induced hallucinations since the dawn of mankind. Some remote tribes still use potent drugs from natural sources to create complex sensory illusions. 

In many cases, members of these tribes ingest psychedelic compounds that, in their words, allow them to communicate with spirits. In reality, this just shows us how our brain uses our life experiences and beliefs to fill in the blanks when necessary.  

While we don’t know this for sure, anecdotal evidence suggests that illusions are often connected to our thoughts, memories, and other parts of our subconscious. This would explain why so many hallucinations are presented as religious experiences — usually in tune with the religion of the person experiencing them.  

In Mexico, the mountain tribe of Huichol claims they can speak to the spirits of ancestors and animals. Of course, they’re assisted by a locally grown cactus with psychedelic properties. This peyote cactus, when ingested raw, can cause vivid hallucinations because it contains a compound called mescaline.  

This tribe is far from an exception, especially in the Americas. Various local peoples have taken psychedelics during religious occasions and for recreational purposes for centuries. Today, most millennials will have likely heard of the powerful ayahuasca — an insanely potent drink with hallucinogenic properties. Many people who have taken it describe their brain chemistry as being permanently changed by the drug.  

Hallucinations and Religious Rituals 

You may rightly ask — why have so many cultures, in different eras and on different continents, used psychedelics in their religious rituals? Most likely, the drugs were used to produce feelings of spirituality. And more importantly, powerful hallucinations that people didn’t perceive as illusions could quickly be explained as the presence of a supernatural deity.  

Naturally, taking drugs to induce religious hallucinations isn’t advisable, and an immediate drug detox is necessary if you’ve already done so.  

Wrapping Up 

Injuries, drug use, and different neurological disorders can cause hallucinations. While experimenting with hallucinations can give us valuable insights into the brain’s inner workings — inducing them intentionally is never advised outside of a scientific environment. If you’re experiencing hallucinations without taking drugs, it’s always advisable to seek help from a qualified healthcare professional. The sooner you discover the cause of this symptom, the sooner your healthcare provider will be able to recommend adequate therapy.