The reality of perception is at the heart of human consciousness.  All of what we think we know tends to break down as we try to understand why we know it.  What really is reality?  The term is often used to describe all that is, ever has been, and ever will be.  Reality is what truly exists, not regarding what is or can be observed.  But the word itself has origin in the latin word relits which means "having inherited."  Reality as we know it can only exist from what we inherit as stimuli.  Therefore an interesting gap is bridged between perception and reality.  An apple inside a refrigerator is black, but outside in the sunlight it is red.  The reality of the apple did not change, but our perception of that apple changed our reality.   Perception has the ability to affect our world in such a way that it becomes warped from its physical state.  This has a profound impact on temporally-extended stimuli.

In the context of our perception, time takes on two unique roles.  First, there is the explicit embodiment of mental-time travel.  We are able to look back into our past through memory and extrapolate data into the future to be used as a predictive model.  But this character of our perception is not skilled in the recollection or interpretation of time as it is on the clock.  It understands the distance of time, but interprets it  as a narratives—moments are recorded as episodic, semantic, or procedural data rather than as quantitative data in the manner of clocktime.

Empirical data supports this theory.  An experiment was conducted to test the effect of time on the perception of pain.  Subjects were first asked to place a hand in water at 14^o Celsius for sixty seconds.  After seven minutes the subject repeated the experiment, however after sixty seconds the temperature of the water was raised one degree for an additional thirty seconds.  Each participant was asked after another seven minutes which trial they would like to repeat as an exact replica of itself.  An overwhelming majority wished to have the longer trial repeated—submitted themselves to thirty-seconds of unnecessary discomfort.  Memory was able to recall that the second trial ended with less discomfort than the first, much more easily than it was able to recognize the difference in time.  As stated earlier, mental-time travel is able to recall how long ago an event occurred, but is more concerned with the experiences of that event rather than the time.

The second character of the perception of time is the embodiment of implicit-time awareness.  Like any computer system, our brains work to an internal clock.  This clock allows us to adjust for time variability in the reception of light and sound, causes us to create a pattern out of randomly flashing lights when music is being played, and ultimately allows us to more effectively perceive our reality.  However this internal clock-time, which I will refer to using the greek Chronos, does not explain the entire experience  of implicit-time awareness nor can it explain a perceptual moment.

The Greek word Kairos describes the subjectively felt-time of any moment.  It can be described similarly to the concept of superposition in quantum mechanics.  The instance of time itself is indeterminate as what is perceived can hold a range of values between a fixed moment in the past and anticipated moment in the future.  A perceptual moment is illusory. When new stimuli is received by the brain, it is affected by the states of each neuron at the time of reception.  The past is equally important in defining a moment as is the set of stimuli of the moment itself.  Similarly, your past experiences and the state of the present also affect the analysis of any current stimuli as your subconsciously calculate a prediction of the future.  Therefore, any given moment of time is impacted by memory and anticipation and the perception of it is altered accordingly.

The instantaneous recollection of memory and derived anticipation are as fluid as neuralplasticity.   Not every set of stimuli in amoment will utilize the same amount of time in short-term memory and future extrapolation and therefore the actual experience of time itself is can shrink and grow.  There are two factors involved in the dynamics of perceived time.  The first is the realization of true time.  Watching a clock reverts the qualitative perception to its objective state and causes experienced time to progress slowly.  In the concept of the figure above, the focus on the clock removes any need to anticipate and creates a bland short-term memory that is not needed to be recollected.  A lack of stimuli can have a similar effect.  Being "bored" causes both anticipation and memory to shrink and isolate a moment.  Time seems to slow done when there is a distinct set of experienced moments.  You could think about it as thought it takes more of these smaller blocks of time in order to fill a given period.

The second factor in the dynamics of novel experiences.  The brain is unable to anticipate the instant future while riding a new roller coaster or free falling for the first time.  It's memory of the experience is also limited.  Kairos slows during new experiences. Conversely, much practiced activities have the effect of speeding up time.  As anticipation and memory swell, time begins to blend together.  The third hour of driving a car is faster than the second hour on a long road trip.  Entering a state of cognitive flow while participating in a much practiced hobby turns off the entire perception of recollection and anticipation in a manner of speaker.  Time truly does fly while having fun.

This may be an answer for why our brains are so addicted to narratives.  New experiences create a longer life than objective time.  In fact, a man who dies at thirty after traveling the world experiencing new cultures, trying new activities, and focusing on the living rather than life may actually live a longer experienced life than someone who dies much older after a monotonous forty years of routine.  You only live once, so at the very least get the most out of your perception.

 

References:

Kahneman, Daniel. Thinking Fast and Slow. New York: Farrar, Straus and Giroux, 2011. Print