Suppose you were sitting at home relaxing on a sofa with your dog, when suddenly your
visual image of the dog gave way to a bowl of noodles.
Now suppose the sofa changed too.
Suppose everything in your visual field changed instantaneously.
At the turn of the twentieth century, exactly this started happening – first to a few thousand people,
and then to millions of people all over the world.
Articles from the time describe the vivid impressions the first films produced,
yet early cinemagoers took little note of cuts – which, on the face of it,
are discontinuous with ordinary experience in the most literal sense possible.
Consider that our visual systems evolved over hundreds of millions of years,
while film editing has only been around for a bit over 100.
Modern action films can have long sequences where there’s a cut every second or so.
Still, audiences assimilate them on more or less the first try.
What’s going on here?
First, although we don’t think of our visual experience as being chopped up
like a Christopher Nolan fight sequence, it actually is.
For one thing, we blink.
Blinks happen every couple of seconds, blinding us for about a quarter of a second.
Our eyes also make jolting movements called saccades two to three times a second,
each of which takes a little less than a tenth of a second.
Our brains have a nifty mechanism that turns down the gain during saccades so that we ignore
the bad information coming in while our eyeballs jerk.
Between blinks and saccades, we’re functionally blind about a third of our waking life.
Worse yet, our eyes are recording a lot less of the world than we realise.
Much of our visual information is drawn from the high-resolution center of our visual fields.
If you hold your thumbs together at arm’s length, their width just about covers that high-resolution area.
Try it.
Your thumbs should appear sharp and detailed.
If you concentrate on an object out in the periphery, you’ll realise it’s pretty fuzzy.
We feel like we have a continuous representation of the visual details of our world,
but what our visual system really delivers is a sequence of patchy pictures – a jittery music video
rather than a smooth camera pan.
Our brains do a lot of work to fill in the gaps, which can produce some pretty fascinating
errors of perception and memory.
In 1997, two Cornell graduate students constructed a short film, where at each cut,
all sorts of objects were altered.
Viewers were oblivious.
In Hollywood, script editors work furiously to keep these sorts of inconsistencies out of movies,
but they’re by no means perfect.
The fact that they're are so hard to detect gives us an important hint about how our brains handle cuts:
We’re continuously knitting together successive glimpses to construct
a coherent representation of the world.
Take this famous scene from The Wizard of Oz.
To understand the action, we probably need a representation of the Munchkins scattering,
Glinda and Dorothy startled, and the Wicked Witch of the West emerging from the plume of smoke.
Do we need to track where each Munchkin is running?
Not really.
Are we confused when the lollipop Dorothy's holding disappears between cuts?
Probably not.
Our visual systems are optimised to highlight the information that is important for our
comprehension of the activity.
If the current shot has stuff that is inconsistent with what was in the last shot,
we tend to go with what we currently see.
That makes good evolutionary sense, doesn’t it?
If your memory conflicts with what’s in front of your eyeballs, chances are your memory’s at fault.
So we seem to have a good story about why our heads don’t explode when we watch movies.
It’s not that we’ve learned how to deal with cuts.
It’s certainly not that our brains have evolved biologically to deal with film.
Film cuts work because they exploit the ways our visual systems evolved to work in the real world.
Which isn’t to say that filmmaking techniques can’t mess with our heads.
Maybe you’ve heard about the 1997 episode of Pokemon that caused widespread seizures
when it first aired in Japan.
Rapid, extreme color and light changes are very unusual in nature and our brains aren’t well-equipped for them.
Or, maybe you’re one of the people who fled screenings of "Cloverfield" or "Gravity"
with your hands over your mouth.
Lots of camera motion can make you nauseous because it produces a conflict between your eyes,
which tell your brain that you are moving, and your inner ears, which tell your brain that you are sitting still.
These rare cases where film production does become jarring show why so much of the time
commercial film editing feels unobtrusive.
It’s because directors and editors construct the shots and transitions to support the way
we usually look around the world.
When the editing fits the way our visual systems evolved to work, it renders itself invisible.
And when it doesn’t?
The editor is usually making a deliberate stylistic choice to alter our perspective
or draw our attention to something.
Or in some cases, maybe just mess with us.