Neurological Space and Time

Jun 29, 2022

Time is a complicated subject. In comparison to spacetime in physics, both space and time still remain separate coordinates in neuroscience (Llinas, 2017). When it comes to the brain—nothing is more intuitive, yet incredibly complex, than the concept of time. We already know that in order to locate a specific point in space, three values are needed: latitude, longitude, and elevation—whereas only one value is needed to mark an instant in time. Therefore, it is not to say that time is more complicated than space—it is just incredibly hard for the human brain to perceive time. Much harder than it is for it to perceive space (Buonomano, 2017, 8).

All vertebrate animals are tuned to navigate through space by creating internal maps of their surroundings. All of which helps the brain understand the concept of space. Neuroscience has been recording what we call place cells (and grid cells) in the hippocampus for over four decades now. These place cells are what mammals use as highly sophisticated internal maps of space to navigate (Best & White, 1998). Place cells are neurons that fire (generate output) when an animal is located in a specific spot in a room—or in a precise location in space. These place cells then work together and form a network that builds a spatial map of the animal's external world.

You could think of it as a highly sophisticated, yet flexible, GPS system. We were designed to navigate space. We can “see” and “hear” space. Our somatosensory system is not only telling us about the objects position in space, it is also informing us of our own location in space. It allows us to know where each and every one of our own limbs are at a particular point in space (proprioception). The same is not to be said about time. Animals have no direct sensory organs to detect the passage of time. We cannot physically navigate time. The nervous system in animals evolved ways to represent spatial coordinates (up, down, left, right) well before it developed the ability to represent the temporal continuum of past, present, and future (Buonomano, 2017, 9).

One of the most fundamental forms of learning within the animal kingdom is classical conditioning. It is the use of temporal contiguity and order within brain function. This use of classical conditioning captures the essence of Hume’s cause-and-effect law. It is a primordial algorithm that animals use to predict what is going to come next (Buonomano, 2017, 29). Consider how excited a pet dog becomes when you simply grab its leash. The dog has learned, over time, that grabbing the leash leads to going for a walk. Or, consider the house cat learning to emerge in the kitchen from hearing the sound of a can opener. 

These are all predetermined algorithms that are yet very shortsighted forms of learning. Humans have a special ability to complete more complex cognitive tasks, such as understanding the relationship between events separated by hours, days, months, and years. We can conceptualize time in a way that we use in the form of mental time travel. Dean Buonomano, a neuroscientist at UCLA, describes our brain as a time machine of sorts for four interrelated reasons:

1. The brain is a machine that remembers the past in order to predict the future.
2. The brain is a machine that tells time.
3. The brain is a machine that creates the sense of time.
4. The brain allows us to mentally travel back and forth in time.
 

Is this ability unique to humans only? Animals have the ability to tell time by naturally anticipating external events. But, does this imply that animals are thinking of the future? Does this imply that they understand the concept of time?

A clock tells time—it doesn’t understand time.

Written by: Jordan Ettner

References

Best, P. J., & White, A. M. (1998). Hippocampal cellular activity: A brief history of space. NCBI. Retrieved June 29, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC33842/

Buonomano, D. (2017). Your Brain is a Time Machine: The Neuroscience and Physics of Time. W.W. Norton.

Llinas, R. (2017). (PDF) Space and time in the brain | Rodolfo Llinas. Academia.edu. Retrieved June 29, 2022, from https://www.academia.edu/82328471/Space_and_time_in_the_brain?f_ri=61474

Resnick, B. (2019, December 26). Proprioception is our silent “sixth” sense. Neuroscience is just beginning to understand it. Vox. Retrieved June 29, 2022, from https://www.vox.com/the-highlight/2019/11/22/20920762/proprioception-sixth-sense