After the superhero Daredevil lost his sight, he began to develop reflexes that were akin to superpowers. He had a keen sense of hearing and could quickly react to any opposition. Daredevil's brain began to adapt to no longer receiving visual stimuli. While there are some elements of science fiction, what happened to Daredevil is not far off from what our brains are capable of in real life!
The brain has a fluidity or plasticity that allows it to adapt to even the most traumatic damages, and learn from the most novel experiences.
- What is neural fluidity?
- What are types of neuroplasticity?
- What are examples of neural fluidity?
A Definition of Neural Fluidity
Our brains do not remain the same throughout our lifetimes. The brain is constantly changing and adapting to internal and external changes. This is achieved through neural fluidity or neural plasticity. This refers to the brain's ability to adapt and change its nervous system by reorganizing its functions, structure, or connections.
Neural fluidity is most active during childhood, but it can also continue through life into adulthood. In neural fluidity, new pathways can be formed following novel experiences, or as a result of internal damage. Neural fluidity plays an important role in learning new skills, forming memories, problem-solving, and logic.
Connections Between the Cerebrum and Cerebellum
The process of trial and error is one of the best ways to learn new skills and form new neural pathways. But how does this process look in the brain? The communication between the cerebellum and the cerebrum plays a large role. Only the size of a tennis ball, the cerebellum is small but mighty. It is often referred to as the "little brain", and is situated in the back of the skull just under the cerebrum (the largest part of the brain, which is split into two hemispheres).
The cerebellum is the part of the brain near the brainstem responsible for functions such as movement coordination, balance, processing sensory input, nonverbal learning, memory, and even emotion.
The cerebellum is well connected to the cerebrum and accounts for fifty percent of the neurons in the entire brain. Information from the cerebrum is sent through fibers that synapse onto the granule cells found in the cerebellum. The parallel fibers of those cells then connect to Purkinje cells.
Purkinje cells are neurons with many branches located in the cerebellar cortex. They receive impulses from granule cells.
If any parallel fibers cause an error, it is reported to the cerebellum, and the synapses that led to the error will be weakened. This is the process by which connections in the cerebrum are either strengthened or weakened.
Superfluidity in Psychology
Scientists believed for a long time that the cerebellum was only responsible for motor movements. But recent studies have shown its activity in non-motor processes and learning as well. The cerebrum has two cerebral hemispheres, while the cerebellum has two cerebellar hemispheres. For movement on the right side of the body, for example, the left cerebral hemisphere and the right cerebellar hemisphere coordinate motor skills by working together. Recent studies have found that this interaction also occurs during other cognitive processes such as verbal fluency (Li et al., 2022)1.
When this connection between the four hemispheres of the brain is uninterrupted (left/right cerebral hemispheres and left/right cerebellum hemispheres), the brain reaches a state referred to as superfluidity.
Superfluidity is the frictionless, unhindered communication between the four hemispheres of the brain, achieving peak performance and "flow" of cognitive processes and motor tasks.
This tennis player is "in the zone" and experiencing superfluidity. pexels.comAthletes, writers, and artists often report a state of superfluidity, during which they experience almost a subconscious or 'bottom-up' state of flow while completing their task.
Types of Neuroplasticity
There are two main types of neural plasticity: functional plasticity and structural plasticity.
Functional Plasticity
Functional plasticity can occur during learning, but most often occurs in the instance of a brain injury, such as from an accident or stroke. In this case, the brain looks for other areas to move the functions that were once done by the damaged part of the brain.
Functional plasticity refers to the brain's ability to use other parts of the brain for related or unrelated functions in response to learning or internal damage.
Research done by Pierre Paul Broca on lateral lesions of the brain led to discoveries in a form of neuroplasticity called equipotentiality.
Equipotential is the brain's ability to use the relative opposing region of the brain to improve function, or replace function lost on a damaged part of the brain.
Another form of functional plasticity or fluidity is vicariation. Unlike equipotentiality, vicariation is the theory that other areas of the brain with different functions could substitute for an unrelated damaged part of the brain.
Structural Plasticity
Rather than parts of the brain taking over functions, structural plasticity responds to damage or new learning experiences by improving functions at the synaptic site, within neurons, or within glial cells.
Synaptic Plasticity
In synaptic plasticity or synaptic fluidity, neuronal connections are strengthened through the increase in the number and size of relevant synapses. Receptor density can also be increased.
Synaptic plasticity plays a large role in learning and memory by strengthening neuronal connections. Receptor quantity and density can also increase through a process called long-term potentiation.
New synapses are being created due to structural plasticity. Pixabay.comLong-term potentiation is the process during which more neurotransmitter receptors are added when the postsynaptic neuron is stimulated by the presynaptic neuron.
Through this process, the threshold required for that neuron to start firing is lowered.
Neurogenesis
One of the reasons why neural fluidity is more active during childhood is because neurogenesis is still active. Neurogenesis is the formation of new neurons in the brain. It was long believed that neurogenesis was impossible for the adult brain. However, recent studies have found that neurogenesis can in fact take place in parts of the adult brain including the hippocampus and olfactory bulb (Kumar et al., 2019)2.
Contrary to adding more synapses or receptors, another form of neural fluidity removes synapses and neurons. This is referred to as pruning. While most pruning ends shortly after birth, neurologist Peter Huttenlocher found that pruning actually continues throughout life for synapses. Pruning is just as important for brain development and neural fluidity as neurogenesis or synaptic plasticity.
Examples of Neural Fluidity
There are many examples of neural fluidity that researchers continue to learn more about today, in hopes of improving learning and memory, as well as improving the treatment of brain injuries. Neural fluidity is at play when examining fluid intelligence, the brain activity of the deaf and the blind, treating disease or damages, and finally the treatment of drug abuse.
Fluid Intelligence vs. Crystallized Intelligence
There are two forms of intelligence that the brain engages in: Fluid intelligence and crystallized intelligence.
Crystallized intelligence is the type of intelligence that is acquired through prior experiences or past learning.
Fluid intelligence, on the other hand, is the type of intelligence that, when faced with new experiences or challenges, attempts to reason or problem-solve.
Our fluid intelligence refers to our ability to think creatively as well as adapt to new situations. According to Ferrer et al. (2009)3, fluid intelligence is strongest between the ages of 5-10 and begins to decline during late adulthood. However, crystallized intelligence is simply the accumulation of facts, knowledge, or skills that can easily continue throughout life and even increase (Cattle, 1987)4. However, due to neural fluidity, there are ways to improve fluid intelligence for the adult brain.
Neural Fluidity As a Reaction to Deafness and Blindness
Many researchers have sought to understand how the brain responds to the loss of sight or vision. Due to our brain's neural fluidity, many studies have found that the brain responds to the inactive or damaged areas of the brain by engaging several forms of functional plasticity.
For example, Sadato et al. (1996)5 found that when a blind person begins to read Braille, the brain uses unused areas of the visual cortex to expand that person's sense of touch in their finger. Some studies have found that visual motion detection is enhanced in deaf people who learned sign language prior to any other language (Shiell et al., 2014)6. The part of their temporal lobe that is usually dedicated to hearing searches for signals to process.
Drugs and Alcohol Addiction
Unfortunately, the brain is unable to distinguish between good or bad habits when it is engaging in neural fluidity. When drugs and alcohol are abused, dopamine, the neurotransmitter that is responsible for pleasure, increases in the brain. The brain's neural fluidity responds by increasing and strengthening synaptic connections that are in favor of the addiction. The brain actually changes in addiction. Luckily, however, because of the neural fluidity of the brain, addiction can also be treated by training the brain to not depend on the substance.
Neural Fluidity - Key takeaways
- Neural Fluidity or neural plasticity refers to the brain's ability to adapt and change its nervous system by reorganizing its functions, structure, or connections. It is most active during childhood but can continue throughout life.
- The cerebellum is the part of the brain near the brainstem responsible for functions such as movement coordination, balance, processing sensory input, nonverbal learning, memory, and even emotion. The cerebellum is well connected to the cerebrum and accounts for fifty percent of the neurons in the entire brain.
- Superfluidity is the frictionless, unhindered communication between the four hemispheres of the brain, achieving peak performance and "flow" of cognitive processes and motor tasks.
- Functional plasticity refers to the brain's ability to use other parts of the brain for related or unrelated functions in response to learning or internal damage, while structural plasticity responds to damage or new learning experiences by improving functions at the synaptic site, within neurons, or within glial cells.
- Neurogenesis, the formation of new neurons in the brain, occurs most heavily during early development, but can continue through adulthood in the hippocampus and the olfactory bulb.
References
- Li, Y., Yang, L., Li, L., Xie, Y., & Fang, P. (2022). "The resting-state cerebro-cerebellar function connectivity and associations with verbal working memory performance." Behavioural Brain Research, 417, 113586. https://doi.org/10.1016/j.bbr.2021.113586
- Kumar, A., Pareek, V., Faiq, M. A., Ghosh, S. K., & Kumari, C. (2019). "ADULT NEUROGENESIS IN HUMANS: A Review of Basic Concepts, History, Current Research, and Clinical Implications." Innovations in clinical neuroscience, 16(5-6), 30–37.
- Ferrer, E. (2009). "Fluid reasoning and the developing brain." Frontiers in Neuroscience, 3(1). https://doi.org/10.3389/neuro.01.003.2009
- Cattell, R.B. (1987) "Intelligence: Its Structure, Growth, and Action." Elsevier Science Publishers.
- Sadato, N., Pascual-Leone, A., Grafman, J., Ibañez, V., Deiber, M. P., Dold, G., & Hallett, M. (1996). "Activation of the primary visual cortex by Braille reading in blind subjects." Nature, 380(6574), 526–528. https://doi.org/10.1038/380526a0
- Shiell M.M., Champoux F., Zatorre R.J. (2014). "Enhancement of Visual Motion Detection Thresholds in Early Deaf People." PLOS ONE 9(2): e90498.https://doi.org/10.1371/journal.pone.0090498
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