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Time perception is a field of study within psychology and neuroscience. It refers to the sense of time, which differs from other senses since time cannot be directly perceived but must be reconstructed by the brain. Humans can perceive relatively short periods of time, in the order of milliseconds, and also durations that are a significant fraction of a lifetime. Human perception of duration is subjective and variable. Some researchers attempt to categorize people by how they differ in their perception of time (see "Personality characteristics" below).
Pioneering work, emphasizing species-specific differences, was done by Karl Ernst von Baer. Experimental work began under the influence of the psycho-physical notions of Gustav Theodor Fechner with studies of the relationship between perceived and measured time. Work with animals conducted by Jakob von Uexküll included measurement of length of momentum in snails.
William J. Friedman also contrasted two theories for a sense of time:
Although the sense of time is not associated with a specific sensory system, the work of psychologists and neuroscientists indicates that human brains do have a system governing the perception of time composed of a highly distributed system involving the cerebral cortex, cerebellum and basal ganglia. One particular component, the suprachiasmatic nucleus, is responsible for the circadian (or daily) rhythm, while other cell clusters appear to be capable of shorter-range (ultradian) timekeeping.
Experiments have shown that rats can successfully estimate intervals of time around 40 seconds despite having their cortex entirely removed, which suggests it is a low level (subcortical) process.
The specious present is the time duration wherein a state of consciousness is experienced as being in the present. The term was first introduced by the philosopher E. R. Clay. and developed by William James. A version of the concept was used by Edmund Husserl in his works and discussed further by Francisco Varela based on the writings of Husserl, Heidegger, and Merleau-Ponty. The experienced present is an interval; it is not a momentary instant except 'speciously'.
The concept was further developed by William James. James defined the specious present to be "the prototype of all conceived times... the short duration of which we are immediately and incessantly sensible". C. D. Broad in "Scientific Thought" (1930) further elaborated on the concept of the specious present, and considered that the Specious Present may be considered as the temporal equivalent of a sensory datum.
Psychologists assert that time seems to go faster with age, but the literature on this age-related perception of time remains controversial. One day to an eleven-year-old would be approximately 1/4,000 of their life, while one day to a 55-year-old would be approximately 1/20,000 of their life. This is perhaps why a day would appear much longer to a young child than to an adult. In an experiment comparing a group of subjects aged between 19 and 24 and a group between 60 and 80 asked to estimate when they thought 3 minutes had passed, it was found that the younger group's estimate was on average 3 minutes and 3 seconds, while the older group averaged 3 minutes and 40 seconds, indicating a change in the perception of time with age. People tend to recall recent events as occurring further back in time (backward telescoping) and distant events occurring more recently (forward telescoping).
While the difference in age between an older and a younger person always remains the same, the ratio between the two ages decreases exponentially over time. For example, if a 27-year-old woman gives birth to a child, the ratio between their ages at the first day is about 10,000 to one. After a year, this decreases quite dramatically to only 28 to one. A decade later, the ratio is about 3.5 to one, and if the mother is alive at age 90, it is down to 1.4 to one. Regardless of the numerical difference in age, over time a younger person "catches up" to an older person by the power of two. (This can be proved mathematically by taking the partial derivative of the older person P1 divided by the younger person P2.)
It has been proposed that the subjective experience of time changes with age due to changes in the individual's biological makeup. The apparent speeding up of time as we grow older is depicted in the Time's Paces poem of Henry Twells as modified by Guy Pentreath: "For when I was a babe and wept and slept, Time crept."
A temporal illusion is a distortion in sensory perception caused when the time between the occurrence of two or more events is very short (typically less than a second). In such cases a person may misperceive the temporal order of the events. The kappa effect is a form of temporal illusion verifiable by experiment whereby time intervals between visual events are perceived as relatively longer or shorter depending on the relative spatial positions of the events. In other words, the perception of temporal intervals appears to be directly affected, in these cases, by the perception of spatial intervals. The Kappa effect can be displayed when considering a journey made in two parts that take an equal amount of time. Between these two parts, the journey that covers more distance will appear to take longer than the journey covering less distance, even though they take an equal amount of time.
Psychoactive drugs can alter the judgement of time. Some – such as entheogens – may also dramatically alter a person's temporal judgement. Substances such as LSD, psilocybin, and mescaline may affect our time perception. At higher doses time may appear to slow down, stop, speed up, go backwards or even seem out of sequence. In 1955, British MP Christopher Mayhew took mescaline hydrochloride in an experiment under the guidance of his friend, Dr Humphry Osmond. On the BBC documentary The Beyond Within, he described that half a dozen times during the experiment, he had "a period of time that didn't end for me".
Stimulants can lead both humans and rats to overestimate time intervals, while depressants can have the opposite effect. The level of activity in the brain of neurotransmitters such as dopamine and norepinephrine may be the reason for this.
Hypnosis and emotional state can affect the perception of time. Researchers from the University of Texas Health Science Center at Houston and Baylor College of Medicine found that although retrospective time estimations after a bungee jump were slower than the actual duration, there was no evidence for a slowing of time perception during the event. However, this experiment has been extensively critiqued.[unreliable source?]
Along with other perceptual abnormalities, it has been noted by psychologists that schizophrenia patients have an altered sense of time. This was first described in psychology by Minkowski in 1927. Many schizophrenic patients stop perceiving time as a flow of causally linked events. It has been suggested that there is a delay in time perception in schizophrenic patients compared to normal subjects.
These defects in time perception may play a part in the hallucinations and delusions experienced by schizophrenic patients according to some studies. According to an article titled Altered Subjective Time of Events in Schizophrenia, in the Journal of Nervous and Mental Disease in 2005 (Volume 193(5), May 2005), researchers suggest that "abnormal timing judgment leads to a deficit in action attribution and action perception."
Some researchers aim to explain the differences between people in the way they relate to the time they have to perform different tasks. They claim that time perception is influenced by both internal-personal characteristics and by external-environmental factors. Some theorists suggest that time perception is categorized by two axes: "time perspective" and "time urgency" and these ideas have been used in occupational psychology settings. These axes typically create four personalities that differ in their personal characteristics and the way they deal with tasks.
Time perspective can be affected by genetics, culture, religion, arise from education, family, past employment, and so on. As it is well known, the timeline axis moves between past, present and future, which is also the way the time perspective axis is organised. People with a present perspective of time have a tendency to believe that the actions in the present do not significantly affect the future. That is, these people do not think that an action performed in the present will increase the probability of a future outcome. People with this perspective tend to use the phrase "why do today what can be done tomorrow?" Individuals with personality characteristics of present time perspective tend to think that it is unnecessary to make future plans. These individuals also tend to take risks and act impulsively. People with future perspective tend to believe that an action performed in the present increases the probability of a future outcome. These people are very goal-oriented, with high capacity to infer future results, usually prepare task lists, use a calendar, and tend to wear a watch. When a team is assembled from the majority of future time perspective people, the team tends to be more "flexible" and tends to make more changes in strategic thinking than teams with more present time perception individuals. Such an individual will delay his or her performances to the very last moment, which can at times lead to inability to meet deadlines. When such a person belongs to a work team, he/she makes the team less focused strategically, being late in submitting tasks and acting impulsively.
Time urgency relates to the need for quick response or action, to achieve a particular goal (or non existence of this feeling). It can be described as an axis ranging from high to low.
The two dimensions described above produce four types of personalities, that can be described as follows:
Organizers have high time urgency and future time perspective and are characterized by high awareness of time, scheduling tasks and activities and high achievement striving.
Crammers have high time urgency and present time perspective and are characterized by high awareness of time, needing to exert control over deadlines, competitiveness, high achievement striving and impatience.
Relators have low time urgency and present time perspective and are characterized by attending little to deadlines or passage of time, taking risks, acting impulsively, focusing on present tasks and focusing on relations with others.
Visioners have low time urgency and future time perspective and are characterized by attending little to deadlines or passage of time, taking risks, acting impulsively and focusing on future goals.
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