Brain imag(in)ing the make believe

I seldom get worked up over the fate of fictional characters. That said, I joined millions in horror as the infamous Red Wedding (or “Rains of Castarmere”) finally unfolded on screen in last week’s Game of Thrones. Having read the books, I’ve waited for the *spoilers/youknowwhat* with a mixture of dread and anticipation. When it finally came, it felt like my heart was ripped out, trampled and shredded into bits all over again.

Once sucked into a good story, we experience the entire rainbow of emotions alongside the protagonist. Why are stories SO emotionally powerful?

Neuroscientists have long known that stories activate parts of our brains associated with language and comprehension. However, the brain doesn’t stop at just “understanding” - it seems to “recreate” the story, in terms of neuronal activation. Reading about someone grasping, for example, strongly activates parts of the primary motor cortex representing hand movement (in fact, this area lights up even when non-literal phrases like “grasping at straws” are said, albeit to a weaker extent). This activation is fairly specific to the body part used; reading about “scratching an itch” won’t activate cortexes involved in foot motion. Neuronal “re-imagining” encompasses all senses: words describing scents (like “perfume”, “coffee”) lights up the olfactory cortex, as if the brain is trying to smell, while those that suggest touch activate tactile-processing circuits.

So are we also trying to recreate emotions during story time?

Our brains certainly respond to emotionally charged words, even when they’re presented in isolation of a story context. A central region involved is the amygdala, an almond-shaped structure deep within the brain that processes both fear and pleasure. Neuroimaging studies tell us words like “torture” or “happy” increase blood flow to the amygdala and stimulate the release of dopamine, while more neutral words (“pencil”) do not. This happens even when we’re not consciously processing the word. In a 2005 study, researchers flashed a string of words at epilepsy patients while recording from their brains. The words disappeared so quickly that the patients couldn’t say what they were – however, their amygdala still activated in response to “intense” words.

But stories are not a string of emotionally charged words. Gasps and shudders are evoked by a rollercoaster of chilling scenarios, often without any direct mention of words describing emotional states (for example, “I can hear his footsteps coming closer…” is pretty creepy, but each single word is completely innocuous). This high-level of understanding requires us to fully place ourselves into others’ thoughts and feelings, to experience the storyline from the characters’ point of views.

Theory of mind: I think that you're thinking this and that of me. Source: http://genealogyreligion.net/

In a 2011 meta-analysis of 86 fMRI studies, researchers found that neuronal networks involved in story comprehension overlapped remarkably with those used for social interactions, especially those where we try to infer the thoughts, motivations and emotions of others. This ability to reflect on other’s mental processes is called “theory-of-mind”, and many researchers propose that this ability allows us to experience fiction as if it’s reality. Many studies show that we tend to treat fictional characters like “real people”: the mere presence of them can relieve feelings of loneliness and isolation. However, story comprehension and theory-of-mind only partially share the same neuronal circuits, and we don’t know if those overlapping circuits are sufficient to produce a similar feeling of empathy. Based on imaging studies alone, it’s far too early to conclude that our ability to experience emotions from stories stem from our understanding of other human beings and social interactions (although I do see the appeal of this hypothesis).

What we do know is that we can get so worked up over a story that our bodies respond as if in stress. In a 2011 neuroimaging study, researchers played a recording of “The Ugly Duckling” while monitoring the subjects’ heart rate changes and brain blood flow with fMRI. (For those who didn’t grow up on fairy tales, “The Ugly Duckling” tells the story of a shunned duckling that eventually blooms into a beautiful swam.) They found that intense parts of the narrative, including both woeful and joyous segments, significantly increased heart rate and perspiration. At the same time, a whole network of brain circuits –including the amygdala and areas involved in auditory processing- lit up like fireworks. These networks are usually involved in simple auditory fear conditioning, where you learn to associate pain or terror with something completely innocuous (circus music, anyone?). This tells us that as complicated as stories are, emotional processing of narratives may utilize a very basic, evolutionarily conserved circuitry that may produce a physical response.

Emotional narratives trigger strong activation in the amygdala, temporal lobe, thalamus (network linked to emotional processing of sound stimuli) and other cortical regions, including language areas and motor cortices.

A general, sweeping conclusion is then stories trigger a basic emotional processing system in our brain. The more intense the narrative, the more this circuit activates, and the more we generate a physical arousal (no, not that kind) response to the story. Of course, emotions often don’t come from stories per se, but from memories triggered by the narrative. A story of betrayal, for example, would be much more emotionally challenging to someone who has suffered dishonesty before. I would love to see research on the interaction between our autobiographical memories and fictional literature in the future.

In the meantime, I'm eagerly looking forward to the new Game of Thrones season. It's going to be satisfying.

Bonus video:

Mikkel Wallentin, Andreas Højlund Nielsen, Peter Vuust, Anders Dohn, Andreas Roepstorff, & Torben Ellegaard Lund (2011). Amygdala and heart rate variability responses from listening to emotionally intense parts of a story Neuroimage, 58, 963-973 DOI: 10.1016/j.neuroimage.2011.06.077
Mar RA (2011). The neural bases of social cognition and story comprehension. Annual review of psychology, 62, 103-34 PMID: 21126178