A longstanding question in cognitive science is how the brain represents time. Unlike with vision, hearing, touch, taste, and smell, there is no external input that our brain can use to keep track of time (in the absence of clocks). Instead we have only the memory of how events are ordered in time. How is it then that we represent and think about that which has no concrete representation?
Many scientists have noticed that the language of time is shared with the language of space. People commonly refer to events moving forward, having long conversations or short meetings, and or to time moving quickly or slowly. Graphic depictions of time are also organized spatially. Clocks represent time as traveling circuitously around a disc, calenders represent time as a table, and time-lines represent time as flowing from one direction to another. This has made researchers wonder if time the representation of time using space is simply a matter of visual and conversational convenience or if it extends to how time’s representation in the brain.
One of the leading researchers in this field is Lera Boroditsky of Stanford University. She argues that the pattern of spatial metaphors is asymmetrical since we use space to represent space much more than we use time to represent space. This gives grounds for the hypothesis that perhaps representations of time recycle, in a sense, the existing mechanisms originally meant to represent space. She has performed a number of studies that have largely confirmed that hypothesis. She has done this through the use of temporal ordering tasks, in which participants organize images representing steps in a process into a logical order, and by 3D ordering tasks in which has participants indicate the spatial direction that they imagine preceding or following events to occur (for example, “If today is right here, where is tomorrow?”).
She has found that subjects that speak several different native languages tend to perceive time as traveling in the same direction in which their language is written, relative to which direction their body is positioned. English speakers tend to represent time as moving from their left to right, coincident with the way that English is written. Hebrew and Arabic speakers, on the other hand, represent time as moving from right to left, coincident with direction in which those languages are written. Likewise, Mandarin was traditionally written from the top of the page to the bottom, and Boroditsky has found that Mandarin speakers tend to represent time as moving downwards.
Some other patterns have been noted, as well. Among speakers of Aymara, an indigenous language spoken in the Andes, the past is thought of as being in front them and the future is behind, which is really a more accurate way to think time since we can only see what has already occurred. As Raphael Núñez and Eve Sweetser have shown speakers of Aymara also gesture towards the front when talking about the past and behind them when talking about the future.
She has also had subjects participate in a set of interesting non-linguistic computer experiments which have shown, in short, that the length of a line can serve as a distractor when participants are asked to replicate the duration of its presentation, but the duration of the line’s presentation does not serve as a distractor when they are asked to replicate its length. The participants were not sure beforehand which aspect they would be asked to replicate, so they had to be ready to replicate either one afterwards. From this experiment, and five other variations published in the same report, Boroditsky and the lead author of the paper, Daniel Casasanto, concluded that the spatial information interfered with the temporal elements, and not vice versa, because the spatial representations of time became distorted by the spatial information while both were being processed by the same mechanisms for spatial cognition.
The remote Australian Aboriginal community of Pormpuraaw, located on the western side of the Cape York peninsula in Queensland, northern Australia, offered an interesting way to further test the hypothesis that people represent time by using their spatial cognition. Unlike all of the groups previously tested by Boroditsky’s group, the Pormpuraawans rarely use relative spatial relationships (left, right, in front of, behind, etc.). Instead, they extensively use absolute directions (north, south, southeast, etc.) to represent spatial relationships on all scales, including the spatial relationships between objects (“Can you please hand me the jug to the southwest of your cup”). This trait is shared by as many as one third of the world’s languages from various geographical settings.
To function in societies whose languages use absolute rather than relative directions, it is essential that its speakers always stay oriented. Among speakers of the Kuuk Thaayorre, one of the several native languages rooted of Pormpuraaw, a person greets another by asking, “Where are you going?” One would look quite foolish if they set off southwards after answering “A long way to the north.” Having a permanent and near perfect internal representation of one’s direction is known as “dead reckoning.” With it, people perform extremely well not only in their familiar settings, but also in new settings, including within the interiors of complex buildings.
In addition, none of the several distinct languages in the area are written, so it is unlikely that they will follow the pattern set by English, Hebrew, and Mandarin speakers in which time flows in the same direction that their languages are written.
How then might the Pormpuraawans represent time? To find out, Boroditsky’s research team traveled to Pormpuraaw and carried out a set of experiments.
First, using a translator to conduct the experiments in their native languages, they asked people to lay out six to twelve sets of images, one set at a time, in temporal order on the ground or on a table, depending on the circumstances in which someone agreed to do their task. One of these sets of images, for example, showed four photographs of Boroditsky’s father in childhood, as a teenager, as an adult, and in his elder years. Halfway through each set of trials, or in some cases on a different day, depending on the conditions, they had the participant complete the rest of the trials after rotating either 90º or 180º, telling them that it was necessary so that they might find a better angle for the video camera.
They found that the Pormpuraawan participants tended to arrange they cards as progressing from east to west, even after being rotated. Each Pormpuraawan participant was matched to a Stanford participant as a control, in that they were initially facing the same direction as the Pormpuraawan and were rotated the same way. Unsurprisingly, none of the Stanford students arranged their cards east to west, except by chance; all of them ordered theirs from left to right.
In the second part of the experiment, one of the researchers presented a Pormpuraawan with a dot either on the ground or on paper. They then were asked questions such as, “If this dot is today, where is tomorrow?” Similarly to the first part of the experiment, the participants tended to arrange time from east to west. None of the Stanford students did the same except by chance.
Lastly, they had the participants point in the four cardinal directions, considering them correct if they were within 60º of the target direction (or within 30º in either of direction of the target). Every Pormpuraawan was correct, coming instead within 20º (or 10º in either direction) in every case.
According to Boroditsky and Alice Gaby, the U.C., Berkeley linguist who did her doctoral dissertation on the grammar of Kuuk Thaayorre and who co-authored the paper, absolute directions are not used metaphorically in the Pormpuraawan languages for time. However, they do seem to factor into how it is represented. It is likely that the east-west direction has its importance because of the sun’s trajectory. The Pormpuraawans also gesture along the east-west axis when talking about time, pointing to the east for past events and the west for the future.
This experiment provides further evidence that people use their representations of space to represent time. One possible concern is that the Pormpuraawans realized early on what was expected of them by the scientists and made sure that they followed through. Ethnographies are full of examples of how a few facts about a researcher told to a few people can rapidly become known by entire communities, including people that live miles away. If the scientists repeatedly were asking people about their dead reckoning and how they thought about time, it would not take long for the Pormpuraawans to deduce how they were ‘supposed’ to be responding.
It is refreshing, however, to find studies that use cross-cultural methods to investigate cognition. They are much too rare, which is an unfortunate state of affairs as traditional cultural practices are rapidly being erased by modernization. The data are disappearing with every generation, and this kind of study is important for making use of that rare resource before it is gone.