Xinyi Christine Zhang
As sentient beings, humans receive and respond to sensory information from their environment. To explain, and attach reality to this sensory input, the human mind formulates beliefs that provide an understanding of external experiences. These social beliefs, after formation, are stored in a subconscious neural network that shapes people’s personal view on reality. They become a filter that environmental sensory information must pass before the sensory input reaches their consciousness. In part, this is how a person’s preality (personal reality) is created.
When the brain evaluates new sensory input, the sensory input is filtered through the person’s set of belief systems stored throughout his brain. During this automatic filtering effect, the insula in the brain determines the valence to the belief. The assigned valence is an unconscious decision on whether or not the current news is relevant to their existing set of beliefs. The Reticular Activating System (RAS) is involved with linking the subconscious mind with the conscious mind and also has the purpose of filtering out sensory information to only those important to one’s belief system. The RAS has nuclei in the upper and middle brainstem as well as in the posterior aspect of the hypothalamus, with many neuronal circuits that project into the cerebral cortex (Arguinchona et al., 2021).
Other parts of the brain also contribute to the formation of beliefs. For example, the precuneus has been shown to activate during false belief reasoning and visual perspective taking (Schurz et al., 2013). The medial prefrontal cortex and right temporoparietal junction (TPJ) are involved in updating probabilistic beliefs and play a role in cognitive theory of mind (Mengotti et al., 2017). Theory of mind pertains to trying to understand the mental states of others. The right TPJ also directs the brain’s attention to unexpected stimuli (Krall et al., 2015). The posterior superior temporal sulcus, which is near the right TPJ, is extremely sensitive to biological movement and plays functions in detecting the intentions behind social actions (Shultz et al., 2011).
Neural pathways transmit messages throughout the brain which result in the continuous formation of new synaptic connections. This polishes the existing belief. There are unique neural pathways responsible for any thought that a person is conscious of in his mind. The more the neural pathway associated with the belief system is used (increased neural network activity), the stronger it becomes. Beliefs are formed through the reinforcement of these neural networks, and eventually become part of people’s subconscious reservoir of neural networks.
The lack of awareness newborns have does not prevent them from receiving (or experiencing) the abundant environmental sensory input available to them. For example, babies possess the thalamocortical pathway that allows them to receive visual cues such as their parents’ movements.
The preality of newborns likely changes on virtually a second-to-second time scale. This is because of the rapid synapse formation and neurogenesis in their brains. This renders them highly impressionable, allowing them to build on their neural pathways with each passing stimulus. In fact, in newborns, the cerebral cortex can form more than one million synapses per second, which is known as exuberant synaptogenesis (Brain Architecture, https://developingchild.harvard.edu/science/key-concepts/brain-architecture/). The large growth of the hippocampus after three months enables babies to grow their recognition memory. As a result, the environment (i.e. sensory input) that people grow up in becomes the foundation for developing their core values and beliefs. These beliefs shape every aspect of a person’s daily life as they mature into adults behaviorally and emotionally. Even the physiological responses evoke when the belief system is used in filtering new information. Thus, different experiences shape a vast array of diverse beliefs across people in the world, creating a heterogeneous array of global personalities. Political stances or nuances in how language is interpreted may be influenced by the social constructs and general environment in which one was raised. Even though these beliefs are often subconscious, once these beliefs are instilled, they create an intricate system of beliefs that the brain can draw on in the face of new or old environmental stimuli.
Each person’s beliefs have varying degrees of strength, with some that they can easily let go of after receiving new information, and others that they firmly hold on to. When people’s short-term beliefs are altered, the midbrain and the striatum become more active due to the release of the neurotransmitter dopamine (Nour et al., 2018). This activity participates in the brain’s filtering of sensory information which may or may not change their beliefs.
By definition, beliefs are assumed to be true, or veridical. This is particularly true for strongly-held beliefs which contribute to a person’s perception of reality. In an effort to maintain this “reality”, the mind constantly seeks out evidence to reinforce its current beliefs while shutting out opposing perspectives; this is known as confirmation bias. Because these beliefs are so deeply rooted in the subconscious, it is extremely difficult to recognize harmful beliefs and change them.
When strongly-held beliefs are challenged, there is increased activation in the amygdala and the insula cortex (Kaplan et al., 2016). The amygdala is an area of the brain that is responsible for processing threatening stimuli and activating the fight-or-flight response, whereas the insula contributes to the assessment of sensory stimuli to influence how humans experience events emotionally. These brain regions help to explain why a person becomes defensive and emotional when their beliefs are challenged, and also helps explain why beliefs that are challenged become stronger in one’s mind. The strength of a belief increases when environmental sensory input causes the neurons creating the strong belief system to fire, yet maintain the neural network’s intrinsic connections to the strongly held belief.
Though beliefs exist subconsciously in our mind, they have the power to create observable physiological effects. The human body is able to reflect one’s beliefs through biochemical changes. A widely scientifically documented example of this phenomenon is the placebo effect: studies have shown that when participants believe that a mock medication will improve their illnesses, their symptoms may be drastically reduced. For instance, following heart surgery, patients who believed that the outcome of the surgery would be positive had improved long-term outcomes (Rief et al., 2017). On the opposite end of the spectrum, negative beliefs manifest in the form of the “nocebo”, a phenomenon in which a mock medication that participants believe will worsen their symptoms may actually cause a negative effect on their physiology.
One study demonstrated the effects of both the nocebo and the placebo: When participants were led to believe that they would develop altitude headaches, it led to the increasing prostaglandin synthesis, which intensified their pain. When participants believed that an administered placebo medication would alleviate their symptoms, the increased levels of prostaglandin were reversed and the pain subsided (Wager et al., 2015). Thus, the steadfastness of beliefs may result in both positive and uncomfortable consequences for one’s body.
Beliefs can also have a profound impact on cortical thickness. Miller et al. (2014) have demonstrated that people with strong religious beliefs have increased cortical thickness in the parietal lobe and precuneus (Miller et al., 2014). On the other hand, those with more severe depressive symptoms had thinner cortices in the parietal lobes. Given that people with more severe depressive symptoms had thinner cortices, Miller et al. have proposed that this cortical thickening may offer some protection against depressive illness.
Given that positive beliefs may result in beneficial effects, it is of one’s personal benefit and interest to alter one’s thinking to promote more optimistic thinking. People’s minds are responsible for formulating their beliefs, which in turn affects how they view the world and even their physical state or intrinsic biology may be changed according to beliefs being challenged. By believing more empowering thoughts, people may actually be able to change their preality and intrinsic biology.
References
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Center on the Developing Child at Harvard University. 2021. Brain Architecture. [online] Available at: <https://developingchild.harvard.edu/science/key-concepts/brain-architecture/> [Accessed 31 October 2021].
Disruption of the Right Temporoparietal Junction Impairs Probabilistic Belief Updating
Paola Mengotti, Pascasie L. Dombert, Gereon R. Fink, Simone Vossel Journal of Neuroscience 31 May 2017, 37 (22) 5419-5428; DOI: 10.1523/JNEUROSCI.3683-16.2017
Kaplan, J., Gimbel, S. & Harris, S. Neural correlates of maintaining one’s political beliefs in the face of counterevidence. Sci Rep 6, 39589 (2016). https://doi.org/10.1038/srep39589
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I am grateful to Navneeth Murali for his helpful suggestions. This blog has been approved by Dr. Charles Pidgeon.
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