Live from the Biggest Science Conference in the World: How Imagination Works

By Jennifer Barone | February 17, 2008 4:52 pm

Psychologists and neuroscientists got together today for a dive into the imaginitive mind. What parts of our brains allow us to experience the past, the future, and the perspective of others? What goes on in our brains during those processes?

Eleanor Maguire of University College London has been working with patients with amnesia. Her recent findings show that people with brain damage that prevents them from remembering past experiences also have trouble imagining fictitious future experiences. This suggests that the same brain area–the hippocampus–plays a role both in replaying the past and conceiving the future. Brain imaging studies yield similar results: there seems to be a “scene-setting” network of brain regions that gets activated whenever we mentally transport ourselves to another time and/or place, and then depending on the specifics of what we’re thinking about, other parts of the brain may join the fray (for example, there seem to be a few parts of the brain, including the medial prefrontal cortex, that are involved in recalling real events that actually happened, but that don’t get activated in fictitious settings). Maguire wonders if core scene-setting network may also be behind mind-wandering and daydreaming.

Daniel Gilbert of Harvard spoke about the discrepancies between the way we imagine future experiences and how we actually feel when they happen. Researchers have already found that people regularly overestimate the intensity of pleasure or pain they’ll feel when experiencing a future event (going out for ice cream is not going to be as great as you think, and having a root canal won’t actually be the end of the world). Gilbert’s research is now explaining why we make these errors. He hypothesizes that comparisons to alternatives play a big role in how we predict we’ll feel about future events, but once we’re actually engaged in experiencing them, our attention is focused away from other possibilities and on the task at hand.

To test this, he studied a group of college students eating potato chips. (I, for one, must admit that I had nearly written off the potato chip as a source of insight into the human psyche, but science is full of surprises.) Participants rated the thought of eating potato chips as really great compared to sardines, but less appealing when compared to chocolate. In predicting how much they’d like eating chips, they forecasted that they’d enjoy them more after being forced to down a sardine, or less if they had just had some chocolate. But when actually munching on the chips, that was the only thing that mattered: regardless of whether they’d been eating chocolate or sardines beforehand, the chips were rated exactly the same.

Gilbert hypothesizes that this difference between prediction and experience comes from a change in attention: when you’re not stuffing chips in your face, you have plenty of brain resources to devote to thinking about how much you’d rather be eating chocolate (or how glad you are that you’re not eating sardines). But when you’re actually eating chips, the whole greasy, salty, crunchy, noisy affair is absorbing your attention, distracting you from other options. A further test backed up the importance of attention: when required to eat potato chips in slow motion, leaving lots of time to think about other options, the alternatives once again began to play a role in the experience. Super-slowly-eaten potato chips were rated lower following chocolate and higher after sardines, showing the same relationships seen in students’ original forecasts.

Gilbert pointed to other instances of errors in “hedonic” (pleasure/pain) prediction. In one case, he looked at student responses to receiving a test score. When asked in advance, test-takers say they’ll be extra excited about a getting back a test if they do better than they expect, or extra horrible if they fall short of their own expectations. But when papers are actually passed around and students are asked about their feelings, the experience drowns out comparisons to prior expectations: students who get As are all equally happy, whether they expected an A or a D, and the poor scorers are equally unhappy no matter how they had predicted they’d perform.

For better or worse, it seems, actually doing something diminishes our ability to compare it to alternatives. As Gilbert puts it, “The roads we don’t take in life disappear much more quickly than we think they do.”

While there are some situations where the difference between our predictions and our experiences could cause trouble, I can definitely see a value to a habit-of-brain that forces us to focus on the present rather than constantly second-guessing ourselves. If we kept weighing every alternative once we’d started down a path, we’d all be constantly paralyzed by wondering if we’ve made the right call. So if you’re agonizing over a job offer, a move, a purchase, or a relationship, know that despite all your calculus and comparisons, once you make your decision, you’ll be so busy experiencing it that you’ll hardly have a chance to look back.


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