Nav: Home

Time maps: How our brain perceives time

March 22, 2019

What happens in our brain when we listen to the rhythmic pace of a song or when, at the traffic light, the light is red and we are trembling awaiting the green? How do we perceive such an abstract feature of the world? For the first time in humans, an imaging study shows that in a specific area of the brain, the so-called "supplementary motor area (SMA)", a time map exists. The study, conducted by the team led by SISSA Professor Domenica Bueti and published in PLOS Biology, shows that distinct portions of the SMA, a region of the cerebral cortex important for both motor preparation and time perception--respond preferentially to different durations. The portions of the SMA responding to similar durations are in close spatial proximity on the cortical surface according to an anterior-to-posterior spatial gradient. The most anterior portions of SMA are greatly active for the shortest duration (200 ms), while the most posterior bits are active for the longest duration (3 sec), the intermediate durations led to the activation of the cortex between those extremes. These novel findings, which are the result of a collaborative effort between SISSA and research institutions in Japan, Switzerland and the Netherlands, are important to gain insights on the computational architecture underlying time perception and they also open up new perspectives to the study of temporal cognition.

The representation of time

"Topography i.e., the fact that neurons processing similar stimulus properties occupy neighbouring positions on the nervous system, is an encoding mechanism widely used in the brain to represent sensory and motor information. For example, there is a body map in our primary somatosensory cortex. In this map, the portions of the cortex receiving tactile information from the hand and the wrist are neighbours compared to those receiving information from the toe" says Domenica Bueti, coordinator of the research whose leading author is the Greek researcher Foteini Protopapa: "our findings show that a topographic representation exists also for something immaterial like time". Previous studies conducted in humans and other animals have shown the involvement of SMA in time perception. However none of those previous works clarified how temporal information is represented in this area.

"With our work we show that in SMA time is represented via topography and duration tuning. The first, as we said earlier, refers to the fact that the portions of SMA responding to similar durations are in close spatial proximity on the cortical surface". The second is duration tuning: "our results show that different portions of SMA respond preferentially to certain durations in a way that the response is greater for the preferred duration and become progressively weaker for durations far from the preferred one. Moreover, we show that temporal maps are linked to perception: i.e., the better the map in SMA, the more accurate and precise is duration perception. This is how SMA represents time".

A cutting-edge study

The research was conducted with functional magnetic resonance imaging (fMRI) at ultra-high field i.e., 7 Tesla, available at the Ecole Polytechnique Federale of Lausanne. During the study, two groups of healthy volunteers carried out a temporal discrimination task of visual stimuli i.e., two images displayed in sequence on a computer screen for durations ranging from 200 milliseconds up to 3 seconds. Each volunteer had to decide which of the two images was presented for longer time. While the volunteers carried out the task, their cerebral activity was recorded through fMRI.

"It was an extremely complex study, which took a long time to carry out and, besides SISSA, it involved researchers from Osaka University, Sussex University, the Ecole Polytechnique Federale of Lausanne, the Royal Academy for Arts and Sciences of Amsterdam, Lausanne University and Araya Inc. of Tokyo" explains Domenica Bueti.

Perceiving time: innate or acquired phenomenon?

Many interesting and fascinating questions arise from these original findings. Domenica Bueti explains: "We have now to understand what is the time that has been mapped in SMA: is it the physical or the perceived time? Does the map change as the perceived duration changes? Does the map change if an observer perceives a stimulus, which was physically displayed on the screen for one second, as either longer (for example a second and a half) or shorter (for example, 800 milliseconds)? And, are there maps at birth? Or are they the by-product of experience and education? These are important and fascinating questions we would like to investigate with our future research".
-end-


Scuola Internazionale Superiore di Studi Avanzati

Related Brain Articles:

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.
Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.
An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.
Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.
Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.
Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.
Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.
BRAIN Initiative tool may transform how scientists study brain structure and function
Researchers have developed a high-tech support system that can keep a large mammalian brain from rapidly decomposing in the hours after death, enabling study of certain molecular and cellular functions.
Wiring diagram of the brain provides a clearer picture of brain scan data
In a study published today in the journal BRAIN, neuroscientists led by Michael D.
Blue Brain Project releases first-ever digital 3D brain cell atlas
The Blue Brain Cell Atlas is like ''going from hand-drawn maps to Google Earth'' -- providing previously unavailable information on major cell types, numbers and positions in all 737 brain regions.
More Brain News and Brain Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.