Assignment 1: Explain Brain Basics
For EDF 6646: Learning, Instructional Design, and Cognitive Neuroscience
By Richard Thripp
University of Central Florida
May 21, 2017
Magenetoencephalography (MEG) is a new type of non-invasive brain scan that detects brain activity via the associated magnetic fields (MEG Community, 2010b; PBS, n.d.). Although strictly speaking it is not an “imaging” technique, it nevertheless provides time-sensitive data about the activity of groups of neurons, and can be combined with functional magnetic-resonance imaging for spatial information (Rees, 2011). MEG is very expensive—not only does one MEG device costs millions of dollars and weigh approximately eight tons (PBS, n.d.), but it must be placed in a room with carefully designed, comprehensive magnetic shielding. Magnetic fields emitted by the brain are so faint that the earth’s magnetic field itself is 100 million times more powerful (MEG Community, 2010b). Consequently, it is unsurprising that few MEG machines exist—in the entire state of Florida, the only MEG machine is at the Florida Hospital for Children in Orlando (Florida Hospital, n.d.; MEG Community, 2010a).
An MEG device principally includes a helmet with about 300 sensors that use superconducting coils cooled with liquid helium to –452° F. This array is able to detect signals from the brain to an accuracy of less than 1/1000 of a second, which was unheard of with prior technologies (MEG Community, 2010b). Thus, it can detect, in real time, both spontaneous brain activity and activity from an evoked response such as visual or auditory stimuli. MEG is valuable for both medical treatments (e.g., epilepsy; Florida Hospital, n.d.) and research (e.g., cognition; Freeman, Ahlfors, & Menon, 2009). On its own, it may provide more accurate “source localization” than electroencephalography (EEG), meaning that the source of brain activity can be isolated to within a general region of the brain (MEG Community, 2010b). However, while EEG has a much higher latency, it also has specific uses that make it complementary to MEG (Sharon, Hämäläinen, Tootell, Halgren, & Belliveau, 2007), and in fact, MEG, EEG, and fMRI can be used in concert to give a more accurate spatial and temporal depiction of brain activity, and perhaps even to determine the antecedents of cognition (Freeman et al., 2009), albeit with significant challenges and costs.
Security, Lie Detection, and Privacy
Rees (2011) explains that the desire for neuroimaging to allow humans to “detect covert mental states or deception” (p. 17) is strong. Despite the many problems and limitations associated with current techniques, a prevailing assumption that these will be overcome via technical means is apparent. While the polygraph is an unreliable approach to lie detection that relies on skin conductance rather than neuroimaging, neuroimaging techniques themselves are also quite susceptible to countermeasures—individuals may deceive such attempts at detecting deception with practice or training. While present attempts to deploy neuroimaging and related techniques for lie detection, predicting recidivism, and determining criminal intent are lacking in rigor and validity (Rees, 2011), the privacy implications of deploying such technologies to improve human–computer interactions are plainly evident (Fairclough, 2009). Data about neurophysiological states can be used to make computers more responsive and useful, but can also be leveraged to spy on or manipulate individual users, as well as to analyze users in aggregate without their consent. Therefore, Fairclough (2009) suggests that users should be given a great deal of control over the information collected, and should also be required to opt-in to such data collection with written consent.
How Much of the Brain Can One Develop Without?
Amazingly, anomalies in brain development can be compensated for by neuroplasticity, to the extent that such individuals may have a semblance of normalcy in adulthood. For example, Herkewitz (2014) summarizes the story of Michelle Mack, who was missing almost half of her brain at birth, yet graduated high school and is now in her 40s living a satisfying life. Another case described by Yu, Jiang, Sun, and Zhang (2015) involves a woman who has no cerebellum, and yet did not discover this until a hospital visit at Age 24. While according to her mother she could not speak intelligibly until Age 6 nor walk until Age 7, in her hospital visit she presented no signs of aphasia and only mild to moderately impaired speech, and she is married and gave birth to a daughter without incident. Finally, the case of Trevor Waltrip, a boy born with severe hydranencephaly whereby he developed with only a brainstem but no brain, is highly unusual because he lived to Age 12, although blind and unable to speak (Madden, 2014). Typically, children with this condition die shortly after birth. However, although there are many popular news articles with Waltrip’s story online (www.google.com/search?q=Trevor+Judge+Waltrip), it may be dubious because there appear to be no references to it in academic literature. Nevertheless, there are many other cases that demonstrate the brain’s plasticity particularly in childhood, but also to a less extreme degree in adulthood. Therefore, it has become clearly inaccurate to characterize the brain as a machine that can only deteriorate—the brain can also adapt to physical damage, and, of potentially greater importance, cognitive performance may be improved or regained through rehabilitation in a manner reminiscent of physical rehabilitation (Doidge, 2009).
Doidge, N. (2009). The brain: How it can change, develop and improve [Video file]. Retrieved from http://www.youtube.com/watch?v=tFbm3jL7CDI
Fairclough, S. H. (2009). Fundamentals of physiological computing. Interacting With Computers, 21, 133–145. http://doi.org/10.1016/j.intcom.2008.10.011
Florida Hospital. (n.d.). MEG: Advanced neuroimaging at Florida Hospital for Children. Retrieved from https://www.floridahospital.com/children/neuroscience/epilepsy/MEG
Freeman, W. J., Ahlfors, S. P., & Menon, V. (2009). Combining fMRI with EEG and MEG in order to relate patterns of brain activity to cognition. International Journal of Psychophysiology, 73, 43–52. http://doi.org/10.1016/j.ijpsycho.2008.12.019
Herkewitz, W. (2014). How much of the brain can a person do without? Retrieved from http://www.popularmechanics.com/science/health/a13017/how-much-of-the-brain-can-a-person-do-without-17223085/
Madden, N. (2014, September). Keithville boy born without brain dies at 12. Retrieved from http://www.ksla.com/story/26405843/keithville-boy-born-without-brain-dies-at-12
MEG Community. (2010a). Groups and jobs page. Retrieved from http://megcommunity.org/groups-jobs/groups
MEG Community. (2010b). What is MEG? Retrieved from http://megcommunity.org/what-is-meg
PBS. (n.d.). Scanning the brain: Magenetoencephalography. Retrieved from http://www.pbs.org/wnet/brain/scanning/meg.html
Rees, G. (2011, January). The scope and limits of neural imaging. In C. Blakemore et al. (Eds.), Brain Waves Module 1: Neuroscience, society, and policy (pp. 5–18).
Sharon, D., Hämäläinen, M. S., Tootell, R. B. H., Halgren, E., & Belliveau, J. W. (2007). The advantage of combining MEG and EEG: comparison to fMRI in focally stimulated visual cortex. NeuroImage, 36, 1225–1235. http://doi.org/10.1016/j.neuroimage.2007.03.066
Yu, F., Jiang, Q.-J., Sun., X.-Y., & Zhang, R.-W. (2015). Letter to the editor: A new case of complete primary cerebellar agenesis: Clinical and imaging findings in a living patient. Brain, 138(6), 1–5. http://doi.org/10.1093/brain/awu239