How are the clocks in our heads generated? Time is an abstract concept on which today’s society is completely dependent; it provides structure in the chaos of everyday life. Humanity has a certain compulsion to carve the days into minute-size fragments and in order to do so we are constantly surrounded by clocks and other time-telling-devices. However, even if we get rid of the clock strapped to our wrists, we cannot escape the one in our heads. The human brain keeps time, from milliseconds to the long ticking of hours, days and years. When having fun our brain seems to make time fly, whereas boring situations seem to last forever. How is this biological clock generated? And does our inner clock really speed up when having fun and slow down in boring situations?

For many years, psychologists thought that humans and animals kept time with a biological version of a stopwatch. They assumed that somewhere in the brain, a regular series of pulses was being generated. When the brain needed to time some event, a gate opened and the pulses moved into some kind of counting device. Psychologists argued that these pulses were counted by some device, and some experiences could speed up the flow of pulses or slow it down (Zimmer, 2008). If our brains really did work that way, we ought to do a better job of estimating long periods of time than short ones as pulses could cancel their errors out over the long run. Unfortunately, that’s not the case and as we estimate longer stretches of time, the range of errors gets bigger as well.

Dean Buonomano, a neuroscientist at UCLA, argues that in order to perceive time in fractions of a second, our brains tell time with help from reverberating signals of neurons. When throwing a rock in the water, ripples will appear. When hearing or seeing something, neurons will get triggered and fire certain ripples as well. When something else occurs, these ripples have not yet settled down and with these ripples the passed time can be counted. Time is basically encoded in the way neurons behave (Zimmer, 2008). If Buonomano turns out to be right, he will have explained only our fastest time telling, because after half a second, the brain’s ripples dissipate. On the scale of seconds to hours, the brain must use some other strategy.

Warren Meck of Duke University argues that the brain measures long stretches of time by producing pulses. But, unlike former assumptions, the brain does not then count the pulses in the way a clock does. Instead, Meck suspects, the answer lie in our medium spiny neurons. Every neuron is linked to about 30,000 other neurons throughout the cortex. Certain neurons come from regions that handle vision, others that handle perception, and so on. By receiving so many signals from all over the brain, some faster than others, a unique pattern of signals occurs. When the tone is over, the medium spiny neuron can simply “listen” to the pattern and read it to tell how much time has passed (Bandettini, 2005).

Conclusively, we can state that our brain does not have some biological stopwatch which generates series of pulses in a faster or slowing counting device. By reading a certain pattern of different neuron signals, our medium spiny neuron can tell how much time has passed. Our biological clocks never change its pace, time never flies, time never slows down; it’s just a psychological perception. Time is a constant property of nature. If we are having fun then it is our state of mind in which we are tension free and relaxed and therefore we are paying less attention to other things. When we are bored thousands of ideas come in our mind and due to this psychological factor we start thinking that time has slowed down. So time's speed can never change, but our mind's acceptance for certain things changes. As people say “a watched pot never boils”, so get out there, focus on something else and your water will cook in a second.

References

Zimmer, C. (2008). How the brain controls time. Discover Magazine, august issue; published online July 12, 2008.

Bandettini, P. Hyde, J. (2005). Time course EPI of human brain function during task activation. Wiley, online library.

Biswal, B. (1992). Time-frequency analysis of functional EPI time-course series, in Proc., SMRM, 12th Annual Meeting, New York.