Graphic by Eilidh McNaughton By Ellie PinkertonFor centuries scientists have struggled to explain the inner workings and physiological mechanisms of human behavior and in fact, up until recent decades, have only been able to hypothesize complex behaviors using a relatively superficial functional understanding of the brain. Modern methods at a molecular level have brought us a deeper understanding of the neural circuitry that modulates higher-order human functions that span from attention, to decision-making, and addiction. When one thinks of the manipulation of behavior in today’s day and age, we often think of this behavioral control through antisocial means, like individuals telling lies in order to emotionally manipulate someone. For instance, fear and intimidation is a strong persuasion tactic in politics to create a hostile sense of ‘other,’ toward non-supporters, which consolidates a sense of polarity. (If you want to see more about this polar divide, specifically in America, read this blog here). The future of behavioral control has the potential to shy away from this perception, however, as while our understanding of complex behavioral traits is continually expanding, one thing that expands with it is our ability to predict and control outcomes through our observation and modulation of brain activity. Optogenetics is an upcoming, recently discovered field of neuroscience that has the capacity to modulate complex behaviors. This method elicits electrical current in specific neurons, or brain cells, due to the exposure of light stimuli via an optrode* activating specific light-sensitive channels that have been genetically modified to be expressed within an animal brain. This technique allows the identification and precise temporal modulation of neurophysiological targets, like neurons contributing to circuitry involved in complex behaviors of addiction, fear response, and much more. A study by Tsai et al. (2009) showed that optogenetic activation of dopaminergic† neurons in a phasic, high frequency in the ventral tegmental area (VTA), a brain region mediating reward-seeking behavior that is intimately involved with drug addiction, was able to elicit conditioned place preference (CPP) without a tangible stimulus. In other words, the activation of a specific neuronal subtype in the VTA directly persuaded the behavior of a mouse to show preference to an environment that they were previously conditioned to associate with the photo-activation of their reward pathway, despite there not being an addictive stimulus to co-associate. Similar studies have been done toward the reduction of fear conditioning by deactivation in the amygdala, an area of the brain dedicated to emotional response. This could provide therapeutics for psychological disorders attributed to hyper-alert emotional arousal states like in anxiety disorder, PTSD, or OCD to name a few. Neural implants have also been suggested as a means of modulating brain activity to effectively ‘brain-hack,’ as Elon Musk has claimed regarding his company Neuralink’s implant. These implants connect directly to the brain’s physiology and fire electrical impulses in a specific pattern at important functional regions, like areas of the frontal cortex or the amygdala. Neuralink’s implant is by no means cutting-edge technology, however, as implants at the level of one thousand electrodes have been previously used in experimentation in neuroscience. In fact, using the phrase ‘neural implant’ broadly, such a product can already be seen in therapeutic use. For instance, there is an implanted pacemaker able to connect to the vagus nerve and control its activation for the minimization of epileptic seizures. The novelty of Neuralink, however, is that they are suggesting these implants could become the ‘interface to connect humans and computers,’ and while Neuralink’s benefit has been implicated in the control of human behavior and disease, it has even been said to modulate complex cognitive processes like nostalgia, consciousness, and attention. To some scientists, however, this feels like a computer scientists’ day-dream towards something that is not very likely to occur in the near future. The burden of these revolutionary new methods, like optogenetics and neural implants, comes at a heavy price, however, as with this innovation also comes ethical controversies that must be given forethought. Without acknowledging the potential implications that these scientific discoveries have on equality, ethics, and the environment, we are sure to fall into similar moral dilemmas posed by past breakthroughs that blur the line between therapeutic intervention and human modification, like the discovery of CRISPR-Cas9, a technique capable for genetic manipulation. It’s important to note, however, that there are currently extreme limitations in the methods proposed previously, and that the human application of these methods are far from immediate. But it is nevertheless necessary to acknowledge the potential that they could have for the future. The modulation of behavior; It’s something that has been of interest to the human population since the first lie was ever told, or maybe just since an article of Cosmopolitan magazine was first entitled ‘How to Tell if He’s Gaslighting You.’ Regardless, is the future of neuroscience permitting us to go so far as to biologically controlling the precise details of individual behavior? And more importantly, is that humane? Perhaps these are questions that only time will tell… * Optrodes are optical micro-electrodes that transmit light while evoking and recording induced electrical activity in the brain † Dopaminergic neurons are a specific neural cells type that are believed to control processes ranging from movement to drug addiction Deisseroth, K. (2014). Circuit dynamics of adaptive and maladaptive behaviour. Nature. 505, 309–317. DOI: 10.1038/nature12982.
Tsai, H. C., Zhang, F., Adamantidis, A., Stuber, G. D., Bonci, A., De Lecea, L., & Deisseroth, K. (2009). Phasic firing in dopaminergic neurons is sufficient for behavioral conditioning. Science, 324(5930), 1080-1084. DOI: 10.1126/science.1168878. https://theconversation.com/neuralink-brain-hacking-is-exceptionally-hard-no-matter-what-elon-musk-says-145711 https://www.epilepsy.com/learn/treating-seizures-and-epilepsy/devices/vagus-nerve-stimulation-vns https://neuralink.com/
2 Comments
Stewart Pinkerton
1/29/2021 15:19:20
Very nice read. I like your perspective of multiple “sides.”
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Sue pinkerton
1/29/2021 16:46:54
As a past "psych" major, I'm very impressed!! The BIG question really is "how moral is a procedure " Keep up the good work Ellie, Gramma
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