Whether you believe that time marches forward, or that you can put the past behind you, is influenced by your visual development, recent research spotted by BPS Research Digest finds. Published in the Journal of Experimental Psychology: General, the small study found that blind research participants did not conceive of the past as being behind them and the future in front, as most sighted participants did.

To test this phenomenon, Italian researchers recruited 17 blind people, all of whom had lost their sight before their second birthday and had no visual memories, and 17 sighted people (who wore blindfolds) to take part in the experiment. Each had to categorize words that referred to the past or the future by pressing keys on a computer keyboard. In one test, they had to press the key in the forward position whenever they heard a word related to the future, and the key behind their resting position if it related to the past. In the second test, the two were reversed, so the forward key represented the past and the one behind represented the future.

In the final phase, participants had to answer a questionnaire regarding events in their past and future—between one day and three years in each direction—and how close they perceived those events to be.

The results showed that sighted volunteers had an easier time with the key-pressing task if the future was linked to the forward direction and the past linked to the backward direction, but blind volunteers had no implicit association of the future happening ahead of them and the past behind. And in the questionnaire, sighted people perceived the future as being closer than the past, while the blind people perceived them as equally distant.

The study suggests that our concept of time as related to the body's movement in space depends on how our vision develops. It also shows the importance of using a diverse sample in psychology studies. Studies on the psychological links between time and space that don’t test any blind volunteers would suggest that everyone associates the future with forward movement, when, in fact, a significant portion of the world population may not.

[h/t BPS Research Digest]