Reality bites: How your brain makes sense of reality

Neural processes work together to create our idea of everything — a consciousness that perceives reality.

All that we know is based on what our brain allows us to experience. So is our perception of reality fundamentally real or rather, a copy of reality limited by what our nervous system will allow?

From an idealist perspective, philosophy lecturer Dr. Anders Kraal said some may sympathize with the idea that “everything that is called natural sciences is actually about how the human mind encounters the world, rather than simply the world.”

“We don’t have access to [the] external. We only have phenomena as they are experienced by the mind,” said Kraal, referencing a point of view reminiscent of philosophers Immanuel Kant and Gottfried Wilhelm Leibniz.

Philosophers have long debated the nature of reality. But thankfully, science can help armchair philosophers and brain aficionados alike better understand these centuries-old questions — and hopefully add some neuroscience to your daily existential crisis.

What makes our reality?

To understand our reality, it is valuable to parse our knowledge down to exemplary theories and mechanisms driving our perception.

Evolutionary theory can be used to understand why we experience our perceptual world, otherwise known as the umwelt, according to Dr. Lawrence Ward, a professor in psychology, a member of the Djavad Mowafagian Centre for Brain Health and principal investigator of the Psychophysics and Cognitive Neuroscience Laboratory.

The umwelt is determined by our sensory systems and differs between species, explained Ward. It is believed to have been adapted around the specific information an organism needs to survive and thrive in its niches, which refers to the role an organism plays in its environment.

“The [perceivable information] that an animal or a person has are extremely niche relevant and in fact, are quite limited based on the niche,” said Ward.

As we perceive the world, our brain is actually constructing multiple different realities, according to Dr. James Enns, professor in psychology, Distinguished University Scholar at UBC and principal investigator of the UBC Vision Lab.

At any given time the brain is processing two separate visual streams: vision for perception processes information for the purpose of perceiving things, while vision for action processes information for the execution of movements. Evidence also suggests vision for action is important for the overall perception of a scene and the ability to sense where our bodies are in space.

“The brain is constructing multiple realities, and somehow magically, it coordinates them so that most of the time we have the seamless conscious experience,” Enns said.

These two streams work together to make sense of our visual space, according to Enns. The brain does this without us even realizing it.

According to Dr. Paul Gabias, associate professor in psychology at UBC Okanagan, the brain does not construct reality, but rather extracts reality.

He argues framing reality as something to be extracted places a greater emphasis on the entire network of perception rather than individual senses or even the brain itself. According to Gabias, without its perceptual systems, the brain “can’t do anything.”

As a blind man and an expert on visual perception, Gabias emphasized the importance of a holistic approach to perception.

“Let’s say blind and sighted people do live in the same world and extract information from that world,” he said. “We really ought to construct a theory of perception that allows us to be able to say that … the information blind people get is equivalent to the information that sighted people get.”

From integrating multiple realities to perceiving information relevant to our niche, the mechanisms and theories driving perception remain an essential area of research and topic of study for UBC experts.

“I know perception is miraculous, but we have to try to explain things in ways that make it seem perhaps less miraculous,” Gabias said.

What’s in a mind

Mechanisms governing our perception give insight into how we process reality but fail to address why we experience a conscious understanding of our reality, as opposed to merely responding to it. This is known as the hard problem of consciousness.

“None of those [neurological and adaptive] mechanisms entail that we should have experience. They all entail that we can control our behaviour and do the right things to persist in an environment but it doesn’t mean that we have to experience that persisting,” said Ward.

In other words, the hard problem questions the experience of “qualia or phenomenal experiences, such as seeing, hearing, and feeling, and knowing what they are,” according to a review in Neural Networks.

There are multiple models of consciousness, but two of the most prominent are the global workspace and information integration theories.

The global workspace theory argues that core subsystems distributed in the brain communicate information with each other in a “global workspace.” From these intimately connected regions, data is broadcasted to other brain areas and consciousness is born. Global workspace theory assumes sensory input is sequentially converted into conscious output.

In contrast, information integration theory considers consciousness “an intrinsic property of the right kind of cognitive network,” according to an article in Quanta Magazine. Unlike global workspace theory, information integration theory asserts that the network can feed back on itself to drive conscious thoughts in a phenomenon known as “causal power.” The more causal power in a network, the more conscious it supposedly is.

According to Ward, there are a dozen other theories and they are all shrouded in heavy debate. Earlier this year, he published an article in Frontiers in Human Neuroscience where he posited that consciousness is derived from an electromagnetic field generated by the brain’s electrical activity.

The thalamus is also believed to play a crucial role in consciousness, as it acts as a ‘master switch box’ in the brain, where the overwhelming majority of sensory inputs are organized and then sent to the appropriate brain regions for further processing.

Studies support connections between the thalamus and the cortex as important for modifying states of consciousness. Beyond the thalamus, functional magnetic resonance imaging has also been used to characterize brain patterns in conscious and minimally conscious people to reveal distinct patterns in the brain for consciousness.

Researchers are continuing to develop strategies to put these different models to the test. But for now, the hard problem of consciousness remains a topic of heated debate.

Chicken soup for the existential soul

It appears that neuroscience might support Kraal’s idealist perspective “where what we could consider empirical reality is actually our mind processing external phenomena,” he said.

Philosophers and scientists will undoubtedly continue to ponder questions about reality for years to come.

In the meantime, Ward offers words of comfort for existentialists to consider — a commentary grounded in an appreciation for interconnectedness, between the circuits in our brains, the niches we occupy and reality itself.

“I would argue reality creates us. Reality is there, and it’s sending information to us constantly about itself — and we are part of it,” he said.

This article is part of The Ubyssey's neuroscience supplement, Big Brain Time. Pick up our latest print issue on campus to read the full supplement.