“Cracking the Neural Code” is the topic I will briefly tackle. I selected the topic because I am in the process of editing a children’s book I wrote, and it presents some information associated with the neural code. I need to internalize the concepts associated with the code and other scientific concepts, and communicate them effectively to my readers.
By definition, the neural code is the representation of specific stimuli or experiences by the firing of neurons. (Goldstein, E. Bruce 2011) So our retina contains neurons called rods and cones, which contain light receptors that harness electromagnetic or light energy, then convert the light energy into electrical signals or action potentials that travel to the brain. “Action potentials facilitate neural communication and cognition.” (Koch and Marcus) So when we see a tree, for an example, we might see it from the perspective of an artist’s rendering in terms of how he or she envisions and perceives the world.
Cracking the neural code entails ‘mapping’ the brain and understanding how the brain communicates with itself. (Koch and Marcus) Therefore, mapping is key to a comprehensive understanding of the regions of the brain, their function(s) in terms of cognition, and relationships with one another. In addition, “neurons are not connected to one another indiscriminately, but form connections with specific neurons.” (Goldstein, Bruce. E). Therefore, this neural circuitry is the navigational feature necessary for brain mapping.
I was fascinated with a code that seems to define me, and which structures a relationship between a physiological process (neuron firing) and “translating the firing of neurons into mental events such as thoughts and emotions. Mapping efforts are based on this concept.” (Lieff, Jon M.D.)
My blog will address (1) why the code is hard to crack, (2) how discovery of a code advances real-world applications in the diagnosis of brain disorders, and (3) the neural codes for faces and long-term memory.
Cracking the code presents an unprecedented challenge because the human brain has 86 billion neurons linked by something on the order of a quadrillion synaptic connections. While we are awake, the action potential rate is 100 trillion per second. (Koch and Marcus)
The impact of and interest in cracking such a code has real-world applications in terms of diagnosing brain disorders. “Neuroscientists can compare differences in ordinary brains vs. the brains of people with disorders such as autism, Alzheimer’s disease, and schizophrenia as a result of seeing the brain in action, including its flaws.” (Zimmer, Carl 2014) The beauty of such applications is the alleviation of the suffering, stigma, and social and economic impacts of the disorders.
Cracking the code will lead to technological advances in the field of optogenetics. Instead of accepting a form of blindness caused by “optical degenerative disorders, such as retinitis pigmentosa,” optogenetics will use a virus gene, injected into the eyeball, to modify the light-sensing retinal cells of the eye. “A camera mounted on glasses would pulse beams of light into the retina and trigger electrical activity in the genetically modified cells, which would directly stimulate the next set of neurons in the signal path—restoring sight.” (Koch and Marcus)
In terms of the neural code for faces, the brain can selectively wire relatively small groups of neurons that represent (code for) something or someone of perceived value. “Recordings from microelectrodes implanted deep inside the brains of epileptic patients revealed single neurons that responded to extremely specific stimuli such as different pictures of actress Jennifer Aniston.” (Koch and Marcus)
Long-term memory is also a brain representation and uses an alternate form of coding. Instead of spikes associated with action potential, long-term memory is encoded by neural re-wiring and re-sculpting of the synapses. (Cooney, Elizabeth)
Re-sculpting is the result of microglia, the brain’s immune cell, which seeks out and destroys debris such as “idle” synapses, “allowing for more precise brain wiring.” (Cooney, Elizabeth)
Cracking the neural code even incrementally suggests a new technological road map that leads to a destination of advanced diagnosis and radical treatment of diseases such as Alzheimer’s. The code will partner with neuroengineers in their quest to, for example, enhance cognition in terms of memories as a result of brain implants. The neural code is a powerful tool and collaborator that needs to be understood, revealed, and its information applied to brain disorders that impede cognitive functioning.
Zimmer, Carl. “The Glow of Memory-Courtesy University of Southern California. Secrets of the Brain. The New Science of the Brain. National Geographic. Volume 225- No. 2. Copyright 2014 National Geographic Society. Pg. 39. web 27 June 2016.
Goldstein, Bruce E. “Glossary.” Cognitive Psychology Connecting Mind, Research, and Everyday Experience. 3rd Edition. Wadsworth Cengage Learning. Copyright 2011, 2008. pg. 402.
Zimmer, Carl. “Secrets of the Brain.” The New Science of the Brain. National Geographic. Volume 225- No. 2. Copyright 2014 National Geographic Society. Pp. 38, 39. web 27 June 2016.
Lieff, Jon, M.D. “Complexity in Searching for the Neural Code.” Searching for the Mind. 12 May 2013. Copyright Jon Lieff 2011. web. 27 June 2016. n.pg.
Koch, Cristof. Gary Marcus. “Cracking the Brain’s Code.” MIT Technology Review. Biomedicine. 17 June 2014. © 2016. web 27 June 2016. n.pg.
Cooney, Elizabeth. “Synaptic Sculpting Investigating Microglia.” Harvard Medical School. Home/News/Harvard Medicine/Voices/Synaptic Sculpting. © 2016 by the President and Fellows of Harvard College. web 27 June 2016. n.d., n. pg.