by Benjamin Plackett
“I’m showing you slices of the brain,” Joy Hirsch, the Director of fMRI Research at Columbia University Medical Center tells me. More specifically, she’s talking about some images of an fMRI brain scan she took while her subject was watching a video sequence. “Every possible visual area is just going nuts,” she adds. What does this mean?
It shows that the human brain is anything but inactive when it’s watching television. Instead, a multitude of different cortexes and lobes are lighting up and working with each other to enable us, the viewer, to relate to the images flickering before our eyes and keep up with the subtleties of the plotline – to say nothing of the complexities in the incessantly twisting storylines of the likes of "The Americans" or "Homeland".
Hirsch uses high tech fMRI machines, or Functional Magnetic Resonance Imaging, in her labs at Columbia and Yale to measure the brain’s activity in her participants when they’re watching video clips. The fMRIs work by tracking blood flow into and between the many different expanses of the brain. The more blood, the more activity, which suggests that particular area of the brain is responsible for whatever activity is happening at the time of the scan – or so goes the theory.
Her research indicates that following the storyline of an edited film clip that depicts a visual action requires a complex and coordinated effort across multiple brain areas. You might feel brain dead at the end of the workday when you plonk yourself in front of the TV and blissfully zone out with a beer and a favorite show, but Hirsch says that couldn’t be further from the truth.
In one of her studies, Hirsch suspects she might have pinned down the specific neural regions that are responsible for helping us to keep track of the storyline. She identified a “distributed cortical network” that’s only activated when the participant is shown a normal video sequence with a narrative flow – and crucially, not by random video shots or scrambled images. “There’s a whole network of activity that goes on to interpret these narratives. What we observed was this enormous activity in the right hemisphere, that’s the visual area,” says Hirsch. This system of collaborating cerebral constituencies consists of the "extrastriate, inferotemporal, parietal, posterior cingulate, and frontal areas,” which again are all predominant in the right hemisphere.
The right side of our noggin is also involved with producing an emotional response, says Hirsch, which might explain how we can become so emotionally invested in particular characters. In addition to these areas, Hirsch says that there’s also a substantive amount of blood flow to the “short term memory areas, where [the subject is] remembering what had just happened in the video sequence and is connecting what is currently happening. I like to think of it as the visual narrative.”
It’s worth noting that for this particular research, Hirsch was only using fairly simple video sequences with an absence of any sound to simplify matters, which she thinks–stressing that she has no evidence– that without sound the brain is more active because there’s more inferring needed to make sense of what’s happening. Interestingly, Hirsch says that “you don’t see a whole lot of variation,” between study participants. The same regions of the brain seem to be stimulated scan after scan, which grants a consistency to her results.
Research similar to that of Hirsch’s labs – looking into the brain’s engagement with video clips – has even piqued interest in the marketing and advertising worlds, where they could potentially use techniques to produce infomercials and commercials that mesh with the way our brains perceive, digest and understand moving images. Many have scrutinized the scientific vigor of fMRI brain scans with less than kind eyes, most notably for the controversial (and hyped) suggestion that the technology could be used as a lie detector, possibly even in a court of law one day.
Hirsch says it’s a fashionable trend for other scientists to bash her method, yet it remains true that for all the technique’s revolutionary applications, it’s also still a burgeoning and somewhat rudimentary science often dismissed as ‘best guess science’. “It’s offensive to people who do incredible brain imaging in a field in which people have done decades of research to get us where we are. It incites provocation. Yes, of course, people who have done traditional research are threatened by us,” retorts Hirsh, “but they needn’t be, fMRI doesn’t exclude other sciences.”
Returning to the first “brain slice” she mentioned, Hirsch says, “In this person, the posterior cingulate gyrus is active.” This particular subject was watching a simple video montage of some boys playing outdoors when a bee nest suddenly falls from the tree causing the kids to run away. “This person is relating to someone in the sequence,” she says, because the middle part of his brain is active – “the part of the brain used for self reference.” Hirsch speculates that maybe the participant had a similar experience when he was young and- whether consciously or subconsciously – his brain is recalling and relating what happened all those years ago."