but not a lot. It’s as scientifically accurate to say, “This MSNBC is going straight to my amygdala,” as it is to say, “This ice cream is going straight to my thighs.” Only, now we actually have more information and more accurate research about how ice cream actually affects your thighs.
Let’s start with some acknowledgement that our brains are not exactly like the digestive and endocrine systems. Direct comparisons tend to be ridiculous: the rules for how our minds store and process information are different from how our bodies store and process food. Food consumption has immediate effects: drink an extraordinary amount of water, and you may get a fatal case of water intoxication. The same is not true for information; few people have died directly from reading too much
Cognitive processing does, however, cause physiological changes just like our food does—only not in the same way. Up until a few years ago, it was thought that the human brain became fixed at some point during early childhood. Now science has shown that this isn’t the case; our brains constantly adapt and change their physiological structure. Every time we learn something (according to neuroscientists), it results in a physiological change in the brain.
This phenomenon is called
“Let us assume that the persistence or repetition of a reverberatory activity (or “trace”) tends to induce lasting cellular changes that add to its stability.… When an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased.” [44]
The human brain is constantly adapting to experiences and the choices the mind makes. In London, taxi drivers must pass a comprehensive exam known as “The Knowledge,” which requires them to instantly create routes for passengers without the use of a GPS or a map. It’s considered the world’s most comprehensive taxi driver’s test, and it takes up to four years to prepare for and pass it.
According to scientists at the University College London, this is why London cab drivers have a differently shaped hippocampus than “regular” people.[45] The hippocampus is important to the brain’s ability to move short-term memories to long-term memory and to help with spatial navigation, the skills the cab drivers in London need the most. As a cab driver exercises this part of the brain more, the brain adjusts and lends more neurons to the region. When that happens, old circuits are replaced by new ones.
That’s one example of how doing things changes the physical composition of the brain. What about just reading something? Could something with a lower cognitive load—like watching your favorite television program— alter your brain’s structure?
The answer is likely
They even found a correlation between the neuron that fired off when a picture was viewed of the common landmark or celebrity, and the string of letters representing the corresponding name. In other words: a picture of the Sydney Opera House fired off the same neuron that seeing the string “Sydney Opera” did.
But that’s about memory. What about beliefs?
Dr. Ryota Kanai and some colleagues at the University College London Institute of Cognitive Neuroscience took self-described liberals and conservatives and studied their brains via fMRI (functional magnetic resonance imaging). They found something remarkable: the liberal brains had structural differences in the anterior cingulate cortex—the region of the brain responsible for empathy and conflict monitoring.[47] Conservative brain structures, by contrast, had enlarged right amygdali—the part of the brain responsible for picking up threatening facial expressions and responding to threatening situations aggressively.
The science is admittedly sketchy. Kanai’s test group was rather limited— just a small group of students. It also doesn’t explicitly prove that environmental factors had anything to do with the increased sizes of the respective brain regions; this could be genetic.
That said, I contacted Kanai and asked him if these differences in brain region sizes could be the result of media consumption and other environmental factors. Here’s what he had to say:
“From our study, it’s hard to resolve the chicken or the egg causality of brain structure and political orientation. I think this needs to be further explored with additional empirical work. As you suggested, exposure to politically tinged information could have influenced people’s political opinions, and it would be very interesting to see if such changes are reflected in brain structure. This is an empirical question we have to answer by more experiments.”
I also contacted another respected neuroscientist in the field, Dr. Marco Iacoboni at UCLA, to see what he had to say:
“I think it’s plausible, although unprovable at this stage. I mean, any decision we make is based on neurophysiological activity, it doesn’t come from the gods. If people, on average, become more or less liberal, in some way something must have happened in their brain. The tricky issue is the chain of causes and effects.”
Whether or not media consumption could physically alter your brain to be more partisan is unknown. But what’s known is that whenever you learn something new, the result is a physiological change in the body—just like whenever you eat. Another similarity is that we’re not in direct control over what changes get made to our brains, and where.
Search Frenzy
Back in 1954, psychologist James Olds found that if he allowed a rat to pull a lever and administer a shock to its own lateral hypothalamus, a shock that produced intense pleasure, the rat would keep pressing the lever, over and over again, until it died. He found that “the control exercised over the animal’s behavior by means of this reward is extreme, possibly exceeding that exercised by any other reward previously used in animal experimentation.”[48] This launched the study of brain stimulation reinforcement, which has been shown to exist in all species tested, including humans. At the heart of brain stimulus reinforcement is a neurotransmitter called
Dopamine makes us seek, which causes us to receive more dopamine, which causes us to seek more.[49] That jolt you feel when you get a new email in your inbox, or hear the sound of your cell phone’s ding? That’s dopamine, and it puts you in a frenzy. This used to be helpful: our dopamine systems helped us, as a species, to find resources, acquire knowledge, and innovate. But in an age of abundance, there are new consequences.
Dopamine receptors often put us in a loop. With all the inputs available to us today—all the various places where notifications come about: our email boxes, our text messages, our various social network feeds, and blogs to read—our brains throw us into a runaway loop in which we’re not able to focus on a given task at hand. Rather, we keep pursuing new dopamine reinforcement from the deluge of notifications headed our way.
We got this way because of evolution. We’re wired to seek. For thousands of years, those that sought
