Learning and memory
This complex chemical process helps to form what we think is a primary basis for learning and memory. However, there are many aspects of learning and memory that are yet unexplained. An explanation for episodic memory comes from O’Keefe and Dostrovsky, who observed in 1971 that ‘ Rats with hippocampal damage are reported to be hyperactive in novel environments, ‘ perseverative ’ and resistant to extinction on tasks that they have learned, heedless of drastic changes in their environment, and poor at spatial tasks such as mazes and tasks which require the alteration of responses on successive trials .’ 7 They discovered that the rats’ hippocampi formed a ‘ veritable spatial map ’ 8 in area Cornu Ammonis 1 of the rats’ hippocampi, such that certain neurons within that area become active only when a rat is within a certain part of its environment. The 1 million neurons within that area all individually corresponded to a specific point in the space of the rats’ environment, forming a map, and as the rat explores a new environment, a new map is also formed. If applied to humans, this could offer a suitable explanation for the workings of episodic memory: we simply recall old neuronal maps as we recall episodes. However, this discovery also highlights how complex other animals’ cognition is. Any explanat ions for any truly ‘human’ experiences have yet to be given. It is my own belief that this is likely due to how relatively recently this area of science has emerged compared to more timely disciplines such as mathematics and physics. Additionally, technology such as fMRI scanners only became available since 1990, 9 and it is again, my belief, that the advancement of technology, such as in quantum computing, will result in further discoveries concerning our brains, our cognition and our very natures. Until then, the machinations and workings of other animal brains, let alone ours, still remain a mystery. To quote Lucius Annaeus Seneca, ‘ Time reveals the truth ’ and I certainly believe that it will too reveal the truth about ourselves and answer the age-old qu estion of, ‘What does it mean to be human?’
Additional resources
• https://thebrain.mcgill.ca/flash/a/a_07/a_07_m/a_07_m_tra/a_07_m_tra.html • https://thebrain.mcgill.ca/flash/i/i_07/i_07_m/i_07_m_tra/i_07_m_tra.html • https://thebrain.mcgill.ca/flash/a/a_07/a_07_cl/a_07_cl_tra/a_07_cl_tra.html • https://www.khanacademy.org/test-prep/mcat/organ-systems/neuron-membrane-potentials/a/neuron- action-potentials-the-creation-of-a-brain-signal • https://www.savemyexams.co.uk/a-level/biology/cie/22/revision-notes/15-control--coordination/15-1- control--coordination-in-mammals/15-1-6-transmission-of-nerve-impulses/ • https://www.sciencedirect.com/science/article/pii/S0896627316309576#:~:text=Since%20the%20discov ery%20of%20long,has%20finally%20come%20of%20age. • https://www.news-medical.net/life-sciences/What-is-Neuronal-Plasticity-and-Why-Is-It-Important.aspx
7 O'Kee fe, J. & Dostrovsky, J. (1971) ‘The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely- moving rat’, Brain Research Volume 34.1: 171-175. 8 See https://thebrain.mcgill.ca/flash/a/a_07/a_07_m/a_07_m_tra/a_07_m_tra.html. 9 See https://www.dana.org/article/the-two-faces-of-mri.
51
Made with FlippingBook - Online catalogs