You might think that your senses are fairly good at delivering an unbiased assessment of your surroundings, but that’s not quite the case. In fact, what’s going on in your brain subtly affects how your senses perceive the world around you. A new study confirming this finds that hungry people are able to see words relating to food more clearly than those who aren’t hungry. This effect occurs immediately, during the act of perception and long before the higher thinking parts of the brain could get involved.
French researchers told student participants to arrive at the study lab at noon, after three or four hours of not eating. They then told the participants there was a delay; some were held for just ten minutes, while others had a whole hour in which to get lunch, thus dividing volunteers into the hungry and the sated. After the delay, the participants were asked to identify words flashing on a screen at 1/300th of a second each. After each word, researchers asked the study participants to choose the word they had seen and how bright it was. One-quarter of the words had been related to food. Each word had appeared too briefly for the participant to really read it, yet the hungry people reliably were better at identifying food-related words and had seen them as brighter. Because the word appearance was too brief for higher level processing (i.e. reading) to happen, the researchers concluded that the difference had occurred at the level of perception itself.
“This is something great to me, that humans can really perceive what they need or what they strive for, to know that our brain can really be at the disposal of our motives and needs,” [study director Rémi] Radel says. “There is something inside us that selects information in the world to make life easier.”
Our brains unconsciously allocate resources according to need, so it makes sense that the brain of a hungry person would be extra-perceptive when it comes to food. Try as we might, we will never be completely unbiased beings. Deep below our awareness, brain processes chug along unbeknownst to us. And that’s a good thing, the result of eons of evolution helping to fine-tune our brains and our bodies for survival.