Holly Dobbing, Year 2
Your brain is capable of retrieving memories from when you were five years old, of contemplating the meaning of life, and making countless decisions every single day. But is your brain – or any brain for that matter – able to understand itself?
The human brain contains 86 billion neurons and each of them forms thousands of connections (Voytek 2013). Think of the brain as a huge network of motorways, each with hundreds of other motorways and roundabouts all branching off and leading to more. This unfathomable complexity of the brain makes it the focus of high-level research around the world. Notably, Barak Obama’s BRAIN Initiative. The BRAIN (Brain Research through Advancing Innovative Neurotechnologies) Initiative was launched in April 2013 in an attempt to give scientists better understanding of ‘how we think and how we learn and how we remember’ (Insel, Landis et al. 2013). The aim of the project: to map the neurons in the brain, build a dynamic picture of activity within the brain whilst completing different tasks, and establish different circuits that act in response to various stimuli (Insel, Landis et al. 2013). It was thought that this initiative would ultimately give way to better diagnosis, prevention, and treatment of brain disorders, such as Alzheimer’s disease, Parkinson’s disease, autism, and schizophrenia. Thus, hospitals could reallocate the funds previously spent on treating individuals with these brain disorders to different specialties (Obama 2013).
Still, we must appreciate how much we already do know about the brain. For instance, we know a lot about how the brain ages. Physiological, structural and molecular changes occur in the brain as we age, causing it to change in size, function and vasculature (Peters 2006). Ageing causes our brains to shrink in volume, particularly in the frontal cortex (Peters 2006) which is responsible for managing perceptions, behaviours, memories and goal setting (Loveday 2017). In fact, our brains decrease in volume at approximately 5% every 10 years after the age of 40 (Svennerholm, Boström et al. 1997). However, the most identifiable change associated with ageing of the brain is the decline in memory function (Peters 2006). Memory skills such as the ability to remember names and dates, recall a list of words, or an experience from decades ago, all deteriorate with age (Foster 2006). This is perhaps due to the decrease in size of the prefrontal cortex, which plays a role in managing memories (Loveday 2017).
We also know how the brain can regulate stress. This organ is key in acknowledging, coping with and recovering from physical and social stresses (McEwen and Gianaros 2010). Initially, a wide variety of complex brain mechanisms are utilised to determine whether an event is a real or potential threat, and these mechanisms differ depending on whether the threat is physical or psychological (Godoy, Rossignoli et al. 2018). This initiates a rapid response within the brain, that leads to activation of the immune system and suppression of the digestive systems, among other widespread changes, so that the body is prepared to deal with the stressor (Godoy, Rossignoli et al. 2018).
We have also gained understanding of how speech is produced and understood. Speech production and processing in the brain is extremely complex; there are multiple networks involved, with significant asymmetry between the left and right hemispheres (Scott 2019). The rostral auditory fields in the brain are key in understanding speech – playing a vital role in recognition of patterns of speech, filtering unnecessary (or background) noise away and identifying the ‘talker’, and are particularly sensitive to intonation and pitch cues (Scott 2019). It is the procedural memory, however, that is key in forming speech – using previously heard sentences as a grammatical framework to form more coherent and articulate sentences (Branan 2009).
So, if the brain is capable of all these complex processes, is it possible for the brain to understand itself? Philosophers would argue that ‘a system can only ever understand another system that is less complex than itself’ (Loveday 2017) which establishes a paradox: the brain cannot understand itself, unless it is more complex than itself. But surely the brain is only equally as complex? Furthermore, to fully understand it, we would have to be able to test every hypothesis made about the brain to an appropriate extent. There are a few issues with this: (a) thousands of experiments would be required to prove or disprove any hypotheses sufficiently; (b) thousands of hypotheses would be required to understand the very intricate details of every function, mechanism and network in the brain; and (c) many of these experiments would require live tissue or a live participant, for example, to study how the brain reacts to different stimuli, which could prove neither possible nor ethical in all circumstances. However, it is still possible to grasp basic processes in the brain using scientific and mathematical modelling. Researchers at the University of Leicester, UK, have studied mathematical tools to aid in the analysis, simulation and modelling of behaviour in the brain (Ivan Turkin 2007). Furthermore, the analysis of brains donated by deceased volunteers gives way for additional learning about the function of the brain – even allowing scientists to decipher a map of its networks. Scientists at Yale University (USA) have been able to culture active cells from entirely dead brain tissue, potentially providing a way to restore activity to dead brain cells (Shaer 2019). This would provide a new platform to study activity within the brain in an experimental yet ethical way.
I believe, eventually, we will be able to understand the brain, perhaps not in its entirety, but at least the principal functions of its networks and mechanisms associated with them. Medical science is advancing rapidly each day: new drugs are being developed, and new treatment methods formed. How can we not have faith that we will one day be able to understand the very thing that makes us us – the brain?
References
Branan, N. (2009). “How Does the Brain Form Sentences.” Scientific American Mind.
Foster, T. C. (2006). “Biological Markers of Age-Related Memory Deficits: Treatment of Senescent Physiology.” CNS Drugs 20(2): 153-166.
Godoy, L. D., et al. (2018). “A Comprehensive Overview on Stress Neurobiology: Basic Concepts and Clinical Implications.” Frontiers in Behavioral Neuroscience 12(127).
Insel, T. R., et al. (2013). “The NIH BRAIN Initiative.” Science 340(6133): 687.
Ivan Turkin, A. G., David Fairhurst, Alexey Semyanov, Cees van Leeuwan, Inseon Song, Henk Nijmeijer, Erik Steur (2007). “Mathematical Modelling of Brain.” University of Leicester.
Loveday, C. (2017). The Secret World of the Brain. London, SevenOaks.
McEwen, B. S. and P. J. Gianaros (2010). “Central role of the brain in stress and adaptation: links to socioeconomic status, health, and disease.” Annals of the New York Academy of Sciences 1186: 190-222.
Obama, B. (2013). “Remarks by the President on the BRAIN Initiative and American Innovation.” from https://obamawhitehouse.archives.gov/the-press-office/2013/04/02/remarks-president-brain-initiative-and-american-innovation.
Peters, R. (2006). “Ageing and the brain.” Postgraduate medical journal 82(964): 84-88.
Scott, S. K. (2019). “From speech and talkers to the social world: The neural processing of human spoken language.” Science 366(6461): 58-62.
Shaer, M. (2019). Scientists Are Giving Dead Brains New Life. What Could Go Wrong? The New York Times Magazine.
Svennerholm, L., et al. (1997). “Changes in weight and compositions of major membrane components of human brain during the span of adult human life of Swedes.” Acta neuropathologica 94(4): 345-352.
Voytek, B. (2013). “Are There Really as Many Neurons in the Human Brain as Stars in the Milky Way?” Scitable by Nature Education https://www.nature.com/scitable/blog/brain-metrics/are_there_really_as_many/2020.
THE WORSLEY TIMES 