Getting A Sense Of Time

Cognitive researchers at IIITH uncover novel insights into time perception that seem to refute the popular Theory of Magnitude. 

It is said that in order to fend off persisting questions from the press, Einstein came up with a tongue-in-cheek explanation of his famous theory of relativity: When you sit with a nice girl for two hours you think it’s only a minute, but when you sit on a hot stove for a minute you think it’s two hours. That’s relativity. This concept of time, which seems to fly when one is happy and at other times seem to drag on, has often been the subject of much research. At the Cognitive Science lab in IIITH,  Prof. Bapi Raju and Ph.D researcher Anuj Shukla have been investigating about how people experience time. “There’s ‘clock’ time or time as given by a clock and then there’s the subjective experience of time. The two are not always in sync with each other, “ says Prof. Bapi.

Prof Bapi Raju

He explains that while psychologists have always been interested in exploring the way time is experienced subjectively, there is also curiosity about whether there is an internal conversion of metrics that converts magnitudes such as space, time and number into a common magnitude system. It was in fact Vincent Walsh, Professor of Human Brain Research, UCL, England who first proposed that time, numbers and space are converted into a common currency, and by virtue of being processed in the same brain regionMalaytigershop influence each other. In order to test this, the IIITH researchers set out to investigate if the presence of numbers affects and distorts one’s experience of time.

Numbers And Time Estimation
A series of experiments were conducted to record subjects’ judgement of duration in the presence of positive and negative numbers. Like they hypothesized, the researchers found that when a large positive number such as 9 was presented, time was overestimated. Similarly, in the presence of a small number such as 1, time was underestimated. However in the case of negative numbers, the magnitude effect was missing. They expected time to be overestimated in the presence of the number -1 and underestimated in the presence of -9 but observed contrary findings. “The relation of number to magnitude is straight forward in the case of positive numbers and processing is much faster and automatic in nature. For negative numbers, the relation between numbers and their magnitude is reciprocal in nature and that affects judgement of time,” says Anuj. It also indicated that while sensitivity to different numbers was not affected, it was attention of the subjects that was at play and affecting accuracy. With these behaviour studies, the researchers suggest that there is the possibility of other brain areas involved in automaticity processing of tasks such as those described above. According to Anuj, “Neuro-imaging studies can help where we can directly probe if there are brain areas that are activated during these kinds of tasks. If they are activated, then probably we can discount the possibility of the common magnitude system.”

Anuj Shukla

Similar Other Studies
It was the hypothesis of a common magnitude representation system in the brain that first led the researchers to investigate if there is indeed crosstalk in the brain and to probe it further. “One of the first experiments we conducted was on numbers in the presence of very small durations such as milliseconds and seconds. We found that numerical magnitude affected duration judgement only in the millisecond range and not for the second durations. So that sort of hinted to us that there may be a chink in the armour for this theory that proposes a common currency for magnitude,” says Prof. Bapi. With the publication of the papers titled Attention Mediates The Influence Of Numerical Magnitude On Temporal Processing in the journal Scientific Reports (Springer Nature) and Numerical Magnitude Affects Accuracy But Not Precision Of Temporal Judgements in the Frontiers In Human Neuroscience, the team then focused on cross modal interactions of magnitude. “We noticed that most of the work in literature has been done only in the visual domain. So our knowledge about the common magnitude processing or the theory of magnitude is limited to this unimodal setting,” explains Prof. Bapi.

In a yet-to-be-published paper, they found that in a crossmodal setting (where there are both visual and auditory stimuli in the form of numbers as well as a sound tone), numbers affect the duration judgement, especially when subjects were asked to recall the number later. “We concluded that common magnitude systems operate only in the unimodal setting whereas when it comes to crossmodal, all information needs to be integrated and that integration is taking place in the memory,” says Anuj.

Real-Life Implications
For Prof. Bapi, the study of time perception assumes significance in the light of the fact that one’s experience of the ‘self’ is in time. “Time is what connects you with the past, the present and with the future. So in that sense it is a very fundamental feature of what makes us ourselves,” he says, adding, “Anything that is distorting or influencing time ought to be understood in a more fundamental way.” According to the professor, one of the speculative ways this could be useful is, if it were possible to train people to experience a given duration as longer than it really is. ”For instance, if you are able to experience half a second as 2 seconds, it is possible that it can give you an advantage as an athlete or a sportsperson where split second decisions matter, in terms of being able to react accordingly,” he muses. Since time and an understanding of the self are intrinsically linked, the researchers future work is cut out in the direction of investigating how time facilitates the experience of the self.

 

 

Sarita Chebbi is a minimalist runner, practising yogi and baker of all things whole-wheat, and sugar-free. Currently re-learning her ABC’s…the one that goes: A for algorithm, B for Bayesian, C for convolutional (neural network)….

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