Neuroplasticity: The Changing Brain

From memory and rationality to mood and mental stamina, the mind’s cognitive abilities are constantly being exercised. While the brain was previously considered immutable in its ability to make connections, the newest research highlights the phenomenon of neuroplasticity, the ability of the brain to rewire itself even after reaching maturity.1 With this discovery, the adage “You can’t teach an old dog new tricks” no longer rings true where the brain is concerned. Companies and research facilities have begun to harness the brain’s neuroplastic potential, giving rise to a new superhero figure in society: the brain trainer. The developing field of brain training focuses on improving brain-fitness by using the principles of neuroplasticity, with the goal to forge connections between neurons through repeated sensory practices and responses to specific stimuli.

Misconceptions about neuroplasticity, such as the belief that the adult brain is unalterable, are based on misunderstandings about the critical period, a portion of time when the brain is most plastic. This period consists of three stages: the precritical phase, the critical phase, and the closure of the critical phase.1 In the precritical phase, neuronal circuits begin to form, making connections among the brain’s neurons; this phase occurs at a young age and is not based on identifiable visual experiences. However, the critical phase is triggered by specific visual experiences rather than by a constant environment.1 In the closure phase, the same array of information is processed with a lower degree of plasticity, triggering phenotypic effects such as memory-loss and slower information-intake which are commonly associated with aging.

The societal implications of the potential applications of plasticity research are nearly infinite. The potential of harnessing the brain’s ability to repurpose neurons to serve new functions opens countless new doors for a number of medical possibilities. Some potential possibilities include strengthening core mental abilities, preventing age-induced cognitive decline, improving memory in autistic patients, repairing body functions that are inactive due to brain damage, and explaining medical phenomena such as the phantom limb.2

Harnessing the science of plasticity for general public use, brain trainers are able to mold the brain by developing exercises targeted towards strengthening a certain mental faculty, be it attention span, memory, or quick thinking. Brain trainers, hired by organizations including Lumosity, Cogmed, LearningRX, and Posit Science, seek to raise IQ and overall mental stamina by creating exercises that test speed, accuracy, focus, and memory. 3 With these drills, they aim to repurpose neurons to the weaker faculties of the brain, developing a training regimen tailored to each user’s cognitive needs or deficiencies. The brain training is targeted towards not only those who wish to increase their mental strength, but also those who desire to stop the cognitive decline augmented by aging. Cognitive regression is a result of fewer “active learning” hours and focused activities, therefore creating the association between the adult brain and the development of only a certain amount of mental faculties at a time. These factors contribute to the so-called “downward spiral” of mental regression.4 Brain-trainers battle these symptoms of age by creating opportunities for active learning through computerized games that become progressively harder as the player masters each stage of play.

Advances in neurological research have revealed that along with stimulating the ordinary brain, learning-induced neuroplasticity may be useful in the verbal memory development of Schizophrenic patients as well. Impaired verbal memory and the inability to decode emotional subtext, both characteristics of Schizophrenia, can be remediated through intensive auditory training.5 As the training program progresses, the temporal transitions, which are the distinguishing factors of sound, present in the computer-generated auditory training become less exaggerated so as to provide a challenge to the user as he or she improves. The process exercises the brain to rewire neurons to focused skills such as verbal memory or constantly developing skills such as emotion detection in speech.6

The alarmingly strong presence of ischemic injuries (problems due to blood flow obstruction or nerve damage) has made neurological treatments after stroke or other cerebral ischemia increasingly prevalent.7 While the long-term effects of ischemic and nervous injuries may not be completely eliminated, the capacity to use neurorehabilitation to form physical connections between two previously separated neurons contributes to the rehabilitation of the patient’s mental function after the injury. The neurons’ ability to make these connections increases the efficiency of the neurotransmissions, allowing the brain to regain control of bodily functions that were previously inactive.1

In addition to aiding in mental rehabilitation, research in the field of neuroplasticity may also help patients with physical injuries deal with the pain of the aftermath of an amputation. In one such  phenomenon referred to as phantom limb pain, a person’s mind has the illusion that he or she can feel the pain in an amputated limb,8 occurring when the area of the brain that corresponds to the removed limb remains activated to give the sensation of pain despite the loss of the limb, hence the feeling of a “phantom limb.” Despite its significance in the medical and neurological world, the phantom limb is only one of many medical phenomena explained by the concepts of neuroplasticity. For example, the discovery provides proof of the hearsay associated with visual degradation in humans and other species. According to modern myth, the blind have other heightened senses; as research has proved, this is far more than legend.9 Neurons from the occipital lobe, the most posterior area of the brain customarily used for processing vision, are repurposed to augment the blind person’s auditory capabilities, a tendency that develops naturally over time without the need for brain-training or conditioning.

The discovery of cortical repurposing has given birth to the quickly developing field of brain training. With a world of medical, scientific, and practical possibilities for society, the concept of neuroplasticity has proven to be integral to our new understanding of the brain and a large step towards the resolution of brain damage and abnormalities.

References:

1. Maino, Dominick. “Neuroplasticity: Teaching an Old Brain New Tricks.Review of Optometry. 2009: 1-6.
2. “Neuroplasticity.Brightstar Learning. 2012.
3. Han, James. “Motor learning and neuroplasticity in humans.University College London, Faculty of Science. 2009:1-2.
4. Mahncke et al. “Memory enhancement in healthy older adults using a brain plasticity-based training program: A randomized, controlled study.” Proceedings of the National Academy of Sciences of the United States of America. 2006: 103(33):1.
5. Fisher, Melissa; Holland, Christine; Merzenich, Michael; Vinogradov, Sophia. “Using Neuroplasticity-Based Auditory Training to Improve Verbal Memory in Schizophrenia.” The American Journal of Psychiatry. 2009: 166(7):1-2.
6. Fisher, Melissa; Holland, Christine; Subramaniam, Karuna; Vinogradov, Sophia. “Neuroplasticity-Based Cognitive Training in Schizophrenia: An Interim Report on the Effects 6 Months Later.” Schizophrenia Bulletin, Oxford Journals. 2010; 36(4):1-3.
7. Di Filippo et al. “Plasticity and repair in the post-ischemic brain.” Neuropharmacology. 2008; 55:1.
8. Ramachandran, V.S. & Hirstein, William. “The perception of phantom limb.” Brain. 1998: 121:1-8.
9. “Neuroplasticity.” San Diego State University, Psychology Dept. 2010.

Vasudha Rengarajan is a student at The Harker School. Follow The Triple Helix Online on Twitter and join us on Facebook.

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