CRASH! A deafening roar and the cinema screen explodes with light. The scene is certainly startling, but is this movie stirring up the right emotional reactions deep down? Rather than ask your opinion, it's now possible to cut out the middleman and go straight to your brain for the verdict.
This new approach, known as neurocinematics, is beginning to make itself felt in movie-making and could one day help regulatory bodies implement appropriate age restrictions on films.
Neurocinematics is a term coined by Uri Hasson at Princeton University, who was among the first to investigate how the brain responds to movies using an fMRI brain scanner.
His team looked at the similarity in the brain responses of a group of viewers to different types of films. When volunteers watched a section of Alfred Hitchcock's Bang! You're Dead, for example, they found that about 65 per cent of the frontal cortex - the part of the brain involved in attention and perception - was responding in the same way in all the viewers. Only 18 per cent of the cortex showed a similar response when the participants watched more free-form footage, of sitcom Curb Your Enthusiasm (Projections, DOI: 10.3167/proj.2008.020102). The level of correlation between people indicates how much control the director has over the audience's experience, Hasson claims.
Not all film-makers will be aiming for the highest levels of correlation among the audience, however. "Greater correlation doesn't mean the movie is better," Hasson notes. Some film-makers aim for the opposite - to leave the movie open to interpretation.
Hasson's team also analysed the effects of scrambling the order of individual scenes. The group looked at correlations in patterns of brain activity across a group of people watching either a regular version of a film or one composed of the same shots shuffled around.
A coherent scene structure was needed to achieve the highest correlation of activity between viewers in parts of the brain involved in extracting meaning (The Journal of Neuroscience, vol 28, p 2539). A similar technique could help a film editor work out how effective different edits are for an audience's understanding of a film.
Phil Carlsen and Devon Hubbard at neuromarketing company MindSign in San Diego, California, are also using fMRI to see how active different parts of a viewer's brain are during a screening (see diagram). Among other things, knowing which areas are activated when you see your leading lady or man could inform future casting decisions. "You can see which area of the brain is activated when you see Ben Stiller's face," says Carlsen.
He reckons his company can also identify what the brain of a captivated viewer looks like, depending on the aim of the scene. As a general rule, an "engaged" brain will have high levels of activity in areas involved in processing sound and images. And if a person is watching a good horror movie, for example, you'd expect to see more activity in the amygdala - the part of the brain that responds to threats. On the other hand, a scene which inspires compassion will activate the insula, says Carlsen. "If you look at a cute puppy we see activation of the insula," he says. "But if that puppy's head explodes, the amygdala's activity increases and activity in the insula drops."
Another key area is the ventromedial prefrontal cortex - part of the brain thought to be involved in self-awareness. "That's a very specific area that we feel should 'light up' if the goal of your movie is to connect with people," says Carlsen. He says this is because it is involved with linking what's happening on the screen with your personal feelings.
Brain scans can also aid modern film technologies: Carlsen and Hubbard scanned volunteers' brains while they watched scenes from the movie Avatar in either 2D or 3D. When the viewers used old-fashioned red and blue 3D glasses, their brain scans suggested they were less engaged in the film than when modern polarised glasses were used. 3D movie-makers seem to be on to a good thing though - 3D scenes increased general brain activation compared with 2D, says Carlsen.
Neurocinematics has the potential to revolutionise the way films are made, says Ron Wright of neuromarketing firm Sands Research. "It's definitely impacting television production and commercials, so it is logical that it will pass into film."
That may be a boon for directors of big-budget movies: "We can't replace the film-maker, but we can measure the impact of what he did," says Hasson.
MindSign is already in the business of improving movie scenes and trailers using neurocinematics. Remember the latest Harry Potter movie trailer? That might be because MindSign helped to develop the most brain-engaging version possible to tempt you to the cinema. The team showed potential trailers to a group of individuals to identify which version caused the greatest brain activity, and flagged scenes that were interpreted as dull by apparently disinterested brains.
This technology could also be used to change the way ratings are assigned to movies. When Carlsen's colleagues at MindSign showed R-rated and General Audience-rated trailers (equivalent to the UK's 15 and U ratings, respectively) to a group of adults while scanning their brains, they noted levels of activity in areas involved in disgust were the same - and sometimes higher - when watching the General Audience trailers. The team hopes to discuss the results with the Motion Picture Association of America, which rates movies in the US.
While commercial firms are keeping details of the technology confidential, the arena is growing fast: "The US Advertising Research Foundation is pulling together regulatory standards and a quality consult," says Wright. "The field is becoming more serious.
"Hunting the "buy button"
Brain scans aren't only aiding movie-makers, they can help advertisers too. The elusive mental "buy button" - the brain activity seen in a person poised to purchase - is the ultimate goal of neuromarketing.
"Nobody has seen it, but everybody wants it," says Phil Carlsen at MindSign, a California-based neuromarketing firm. "They want to identify a specific area that goes 'Ding! I want to buy this!'."
Carlsen reckons he's hot on the trail. His team has used an fMRI scanner to track brain activity in people while they shop at online stores Amazon and iTunes. The group watched the participants' brain activity in real time as they bought items ranging from songs to sofas.
"What we've noticed is that it's not about a specific area, but a specific pattern of activity," Carlsen says.
Their findings are currently under wraps, as they may have commercial importance - the idea being that advertisements could be tailored to trigger this activity and persuade consumers to part with their cash.
However, Ron Wright, president of neuromarketing company Sands Research, based in El Paso, Texas, thinks the search for the buy button is probably futile: "There are too many variables," he says. There's this apprehension that neuromarketing is going to be able to control buying habits, but it's not the case, he says.
Neuromarketing consultant Roger Dooley agrees. "I do not believe there is a buy button, or that we will ever find some sort of magic spot that will allow us to accurately predict whether someone will purchase a product or not. That's simply fiction."
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