Time perception is a field of study within psychology and neuroscience that refers to the subjective experience of time, which is measured by someone's own perception of the duration of the indefinite and continuous unfolding of events. The perceived time interval between two successive events is referred to as perceived duration. Another person's perception of time cannot be directly experienced or understood, but it can be objectively studied and inferred through a number of scientific experiments. Time perception is a construction of the brain that is manipulable and distortable under certain circumstances. These temporal illusions help to expose the underlying neural mechanisms of time perception.
Pioneering work, emphasizing species-specific differences, was conducted by Karl Ernst von Baer.[citation needed] Experimental work began under the influence of the psycho-physical notions ofGustav Theodor Fechner with studies of the relationship between perceived and measured time.
- The strength model of time memory. This posits a memory trace that persists over time, by which one might judge the age of a memory (and therefore how long ago the event remembered occurred) from the strength of the trace. This conflicts with the fact that memories of recent events may fade more quickly than more distant memories.
- The inference model suggests the time of an event is inferred from information about relations between the event in question and other events whose date or time is known.
Another theory involves the brain's subconscious tallying of "pulses" during a specific interval, forming a biological stopwatch. This theory alleges that the brain can run multiple biological stopwatches at one time depending on the type of task one is involved in. The location of these pulses and what these pulses actually consist of is unclear.[4] This model is only a metaphor and does not stand up in terms of brain physiology or anatomy.[5]
Changes with aging[edit]
Psychologists have found that the subjective perception of the passing of time tends to speed up with increasing age in humans. This often causes people to increasingly underestimate a given interval of time as they age. This fact can likely be attributed to a variety of age-related changes in the aging brain, such as the lowering in dopaminergic levels with older age; however, the details are still being debated.[38][39][40]In an experimental study involving a group of subjects aged between 19 and 24 and a group between 60 and 80, the participants' abilities to estimate 3 minutes of time were compared. The study found that an average of 3 minutes and 3 seconds passed when participants in the younger group estimated that 3 minutes had passed, whereas the older group's estimate for when 3 minutes had passed came after an average of 3 minutes and 40 seconds.[41][42]
Very young children literally "live in time" before gaining an awareness of its passing. A child will first experience the passing of time when he or she can subjectively perceive and reflect on the unfolding of a collection of events. A child's awareness of time develops during childhood when the child's attention and short-term memory capacities form—this developmental process is thought to be dependent on the slow maturation of the prefrontal cortex and hippocampus.[5][43]
The common explanation is that most external and internal experiences are new for young children while most experiences are repetitive for adults. Children have to be extremely engaged (i.e., dedicate many neural resources or much brain power) in the present moment because they must constantly reconfigure their mental models of the world to assimilate it and properly behave within it. On the contrary, adults may fall into mental habits and external routines that they rarely step outside of. When an adult frequently experiences this overstimulation of the same stimuli, their brain renders it "invisible" because the brain has already sufficiently and effectively mapped those stimuli; this phenomenon is known as neural adaptation. Thus, the brain will record less densely rich memories during these frequent periods of disengagement from the present moment.[45] Consequently, the subjective perception of time often passes by at a faster rate with age.