In
psychology
Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ...
and
neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions, and its disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, ...
, time perception or chronoception is the subjective experience, or sense, of
time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
, which is measured by someone's own perception of the duration of the indefinite and unfolding of events. The perceived time interval between two successive events is referred to as perceived duration. Though directly experiencing or understanding another person's perception of time is not possible, perception can be objectively studied and
inferred
Inferences are steps in logical reasoning, moving from premises to logical consequences; etymologically, the word ''infer'' means to "carry forward". Inference is theoretically traditionally divided into deduction and induction, a distinction ...
through a number of scientific experiments. Some temporal illusions help to expose the underlying neural mechanisms of time perception.
The
ancient Greeks
Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically re ...
recognized the difference between chronological time (
chronos
Chronos (; ; , Modern Greek: ), also spelled Chronus, is a personification of time in Greek mythology, who is also discussed in pre-Socratic philosophy and later literature.
Chronos is frequently confused with, or perhaps consciously identified ...
) and subjective time (
kairos
''Kairos'' () is an ancient Greek language, Greek word meaning 'the right or critical moment'. In modern Greek, ''kairos'' also means 'weather' or 'time'.
It is one of two words that the ancient Greeks had for 'time'; the other being (). ...
).
Pioneering work on time perception, emphasizing species-specific differences, was conducted by
Karl Ernst von Baer
Karl Ernst Ritter von Baer Edler von Huthorn (; – ) was a Baltic German scientist and explorer. Baer was a naturalist, biologist, geologist, meteorologist, geographer, and is considered a, or the, founding father of embryology. He was a m ...
.
Theories
Time perception is typically categorized in three distinct ranges, because different ranges of duration are processed in different areas of the brain:
* Sub-second timing or millisecond timing
* Interval timing or seconds-to-minutes timing
* Circadian timing
There are many theories and computational models for time perception mechanisms in the brain. William J. Friedman (1993) contrasted two theories of the sense of 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 hypothesis involves the brain's subconscious tallying of "pulses" during a specific interval, forming a biological stopwatch. This theory proposes that the brain can run multiple biological stopwatches independently depending on the type of tasks being tracked. The source and nature of the pulses is unclear. They are as yet a metaphor whose correspondence to brain anatomy or physiology is unknown.
Philosophical perspectives
The ''
specious present'' is the time duration wherein a state of
consciousness
Consciousness, at its simplest, is awareness of a state or object, either internal to oneself or in one's external environment. However, its nature has led to millennia of analyses, explanations, and debate among philosophers, scientists, an ...
is experienced as being in the
present
The present is the period of time that is occurring now. The present is contrasted with the past, the period of time that has already occurred; and the future, the period of time that has yet to occur.
It is sometimes represented as a hyperplan ...
.
The term was first introduced by the philosopher E. R. Clay in 1882 (E. Robert Kelly),
and was further developed by
William James
William James (January 11, 1842 – August 26, 1910) was an American philosopher and psychologist. The first educator to offer a psychology course in the United States, he is considered to be one of the leading thinkers of the late 19th c ...
.
James defined the specious present to be "the prototype of all conceived times... the short duration of which we are immediately and incessantly sensible". In "Scientific Thought" (1930),
C. D. Broad
Charlie Dunbar Broad (30 December 1887 – 11 March 1971), usually cited as C. D. Broad, was an English philosopher who worked on epistemology, history of philosophy, philosophy of science, and ethics, as well as the philosophical aspects ...
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.
A version of the concept was used by
Edmund Husserl
Edmund Gustav Albrecht Husserl (; 8 April 1859 – 27 April 1938) was an Austrian-German philosopher and mathematician who established the school of Phenomenology (philosophy), phenomenology.
In his early work, he elaborated critiques of histori ...
in his works and discussed further by
Francisco Varela
Francisco Javier Varela García (September 7, 1946 – May 28, 2001) was a Chilean biologist, philosopher, cybernetician, and neuroscientist who, together with his mentor Humberto Maturana, is best known for introducing the concept of autopoie ...
based on the writings of Husserl,
Heidegger
Martin Heidegger (; 26 September 1889 – 26 May 1976) was a German philosopher known for contributions to phenomenology, hermeneutics, and existentialism. His work covers a range of topics including metaphysics, art, and language.
In April ...
, and
Merleau-Ponty
Maurice Jean Jacques Merleau-Ponty. ( ; ; 14 March 1908 – 3 May 1961) was a French phenomenological philosopher, strongly influenced by Edmund Husserl and Martin Heidegger. The constitution of meaning in human experience was his main interest ...
.
Although the perception of time is not associated with a specific sensory system,
psychologist
A psychologist is a professional who practices psychology and studies mental states, perceptual, cognitive, emotional, and social processes and behavior. Their work often involves the experimentation, observation, and explanation, interpretatio ...
s and
neuroscientist
A neuroscientist (or neurobiologist) is a scientist specializing in neuroscience that deals with the anatomy and function of neurons, Biological neural network, neural circuits, and glia, and their Behavior, behavioral, biological, and psycholo ...
s suggest that humans do have a system, or several complementary systems, governing the
perception
Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous syste ...
of
time
Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
. Time perception is handled by a highly distributed system involving the
cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...
,
cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...
and
basal ganglia
The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...
.
One particular component, the
suprachiasmatic nucleus
The suprachiasmatic nucleus or nuclei (SCN) is a small region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for regulating sleep cycles in animals. Reception of light inputs from photosensitive r ...
, is responsible for the
circadian (or daily) rhythm, while other cell clusters appear to be capable of shorter (
ultradian) timekeeping. There is some evidence that very short (millisecond) durations are processed by dedicated neurons in early sensory parts of the brain.
Warren Meck
Warren H. Meck (17 November 1956 – 21 January 2020) was an American Professor of Psychology and Neuroscience at Duke University. He is known for his interest in interval-timing mechanisms and subjective time perception.
Education
Meck began hi ...
devised a physiological model for measuring the passage of time. He found the representation of time to be generated by the oscillatory activity of cells in the upper cortex. The frequency of these cells' activity is detected by cells in the
dorsal striatum
The striatum (: striata) or corpus striatum is a cluster of interconnected nuclei that make up the largest structure of the subcortical basal ganglia. The striatum is a critical component of the motor and reward systems; receives glutamater ...
at the base of the
forebrain
In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the rostral (forward-most) portion of the brain. The forebrain controls body temperature, reproductive functions, eating, sleeping, and the display of emotions.
Ve ...
. His model separated explicit timing and implicit timing. Explicit timing is used in estimating the duration of a
stimulus. Implicit timing is used to gauge the amount of time separating one from an impending event that is expected to occur in the near future. These two estimations of time do not involve the same neuroanatomical areas. For example, implicit timing often occurs to achieve a motor task, involving the
cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...
, left
parietal cortex
The parietal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The parietal lobe is positioned above the temporal lobe and behind the frontal lobe and central sulcus.
The parietal lobe integrates sensory informa ...
, and left
premotor cortex
The premotor cortex is an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex. It occupies part of Brodmann's area 6. It has been studied mainly in primates, including monkeys and human ...
. Explicit timing often involves the supplementary motor area and the right prefrontal cortex.
Two visual stimuli, inside someone's
field of view
The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to elec ...
, can be successfully regarded as simultaneous up to five milliseconds.
In the popular essay "Brain Time",
David Eagleman
David Eagleman (born April 25, 1971) is an American neuroscientist, author, and science communicator. He teaches neuroscience at Stanford University and was CEO and co-founder of Neosensory, a now-defunct company that developed devices for senso ...
explains that different types of sensory information (auditory, tactile, visual, etc.) are processed at different speeds by different neural architectures. The brain must learn how to overcome these speed disparities if it is to create a temporally unified representation of the external world:
Experiments have shown that rats can successfully estimate a time interval of approximately 40 seconds, despite having their
cortex
Cortex or cortical may refer to:
Biology
* Cortex (anatomy), the outermost layer of an organ
** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain''
*** Motor cortex, the regions of the cerebral cortex i ...
entirely removed.
This suggests that time estimation may be a low-level process.
Ecological perspectives
In recent history,
ecologists
This is a list of notable ecologists.
A-D
* John Aber (United States)
* Aziz Ab'Saber (Brazil)
* Charles Christopher Adams (United States)
* Warder Clyde Allee (United States)
* Herbert G. Andrewartha (Australia)
* Sarah Martha Baker ( ...
and
psychologist
A psychologist is a professional who practices psychology and studies mental states, perceptual, cognitive, emotional, and social processes and behavior. Their work often involves the experimentation, observation, and explanation, interpretatio ...
s have been interested in whether and how time is perceived by non-human
animals
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a ...
, as well as which
functional purposes are served by the ability to perceive time. Studies have demonstrated that many
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of animals, including both
vertebrates
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
and
invertebrates
Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...
, have
cognitive
Cognition is the "mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...
abilities that allow them to estimate and compare time intervals and durations in a similar way to
humans
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
.
There is
empirical evidence
Empirical evidence is evidence obtained through sense experience or experimental procedure. It is of central importance to the sciences and plays a role in various other fields, like epistemology and law.
There is no general agreement on how the ...
that
metabolic rate
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...
has an impact on animals' ability to perceive time. In general, it is true within and across
taxa
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...
that animals of smaller size (such as
flies
Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...
), which have a fast metabolic rate, experience time more slowly than animals of larger size, which have a slow metabolic rate. Researchers suppose that this could be the reason why small-bodied animals are generally better at perceiving time on a small scale, and why they are more
agile than larger animals.
Time perception in vertebrates
Examples in fish
In a lab experiment,
goldfish
The goldfish (''Carassius auratus'') is a freshwater fish in the family Cyprinidae of the order Cypriniformes. It is commonly kept as a pet in indoor aquariums, and is one of the most popular aquarium fish. Goldfish released into the w ...
were
conditioned to receive a
light
Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...
stimulus followed shortly by an
aversive
In psychology, aversives are suffering, unpleasant Stimulus (physiology), stimuli that induce changes in behavior via negative reinforcement or positive punishment (psychology), punishment. By applying an aversive immediately before or after a be ...
electric shock
An electrical injury (electric injury) or electrical shock (electric shock) is damage sustained to the skin or internal organs on direct contact with an electric current.
The injury depends on the Current density, density of the current, tissu ...
, with a constant time interval between the two stimuli. Test subjects showed an increase in general activity around the time of the electric shock. This response persisted in further trials in which the light stimulus was kept but the electric shock was removed. This suggests that goldfish are able to perceive time intervals and to initiate an avoidance response at the time when they expect the distressing stimulus to happen.
In two separate studies,
golden shiner
The golden shiner (''Notemigonus crysoleucas'') is a species of freshwater ray-finned fish belonging to the family Leuciscidae. This fish occurs in Eastern North America. It is the sole member of its genus. Commonly used as a bait fish, it is pr ...
s and
dwarf inanga
The dwarf inanga (''Galaxias gracilis'') is a galaxiid of the genus '' Galaxias'', found in the North Island of New Zealand.
It is a landlocked galaxiid present in only eleven lakes on the west coast of the North Island within of Dargaville
...
s demonstrated the ability to associate the availability of food sources to specific locations and times of day, called
time-place learning. In contrast, when tested for time-place learning based on
predation risk, inangas were unable to associate
spatiotemporal patterns to the presence or absence of predators.
In June 2022, researchers reported in ''
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics ...
'' that
salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...
s were demonstrating
counter-intuitive responses to the
arrow of time
An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers ca ...
in how their eyes perceived different stimuli.
Examples in birds
When presented with the choice between obtaining food at regular intervals (with a fixed delay between feedings) or at stochastic intervals (with a variable delay between feedings),
starlings can discriminate between the two types of intervals and consistently prefer getting food at variable intervals. This is true whether the total amount of food is the same for both options or if the total amount of food is unpredictable in the variable option. This suggests that starlings have an inclination for risk-prone behavior.
Pigeons are able to discriminate between different times of day and show
time-place learning. After training, lab subjects were successfully able to peck specific keys at different times of day (morning or afternoon) in exchange for food, even after their sleep/wake cycle was artificially shifted. This suggests that to discriminate between different times of day, pigeons can use an internal timer (or
circadian timer) that is independent of
external cues. However, a more recent study on time-place learning in pigeons suggests that for a similar task, test subjects will switch to a non-circadian timing mechanism when possible to save
energy resources
World energy resources are the estimated maximum capacity for energy production given all available resources on Earth. They can be divided by type into fossil fuel, nuclear fuel and renewable resources.
Fossil fuel
Remaining reserves of fo ...
. Experimental tests revealed that pigeons are also able to discriminate between cues of various durations (on the order of seconds), but that they are less accurate when timing
auditory cues than when timing
visual cues.
Examples in mammals
A study on privately owned dogs revealed that
dogs
The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers ...
are able to perceive durations ranging from minutes to several hours differently. Dogs reacted with increasing intensity to the return of their owners when they were left alone for longer durations, regardless of the owners' behavior.
After being trained with food
reinforcement
In Behaviorism, behavioral psychology, reinforcement refers to consequences that increase the likelihood of an organism's future behavior, typically in the presence of a particular ''Antecedent (behavioral psychology), antecedent stimulus''. Fo ...
, female
wild boars are able to correctly estimate time intervals of days by asking for food at the end of each interval, but they are unable to accurately estimate time intervals of minutes with the same training method.
When trained with
positive reinforcement
Positive is a property of positivity and may refer to:
Mathematics and science
* Positive formula, a logical formula not containing negation
* Positive number, a number that is greater than 0
* Plus sign, the sign "+" used to indicate a posit ...
,
rats
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), '' Bandicota'' (bandicoot ...
can learn to respond to a signal of a certain duration, but not to signals of shorter or longer durations, which demonstrates that they can discriminate between different durations. Rats have demonstrated time-place learning, and can also learn to infer correct timing for a specific task by following an order of events, suggesting that they might be able to use an ordinal timing mechanism. Like pigeons, rats are thought to have the ability to use a circadian timing mechanism for discriminating time of day.
Time perception in invertebrates

When returning to the
hive with
nectar
Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...
,
forager honey bees
A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the ...
need to know the current ratio of nectar-collecting to nectar-processing rates in the colony. To do so, they estimate the time it takes them to find a food-storer bee, which will unload the
forage
Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...
and store it. The longer it takes them to find one, the busier the food-storer bees are, and therefore the higher the nectar-collecting rate of the colony. Forager bees also assess the quality of nectar by comparing the length of time it takes to unload the
forage
Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...
: a longer unloading time indicates higher quality nectar. They compare their own unloading time to the unloading time of other foragers present in the hive, and adjust their
recruiting behavior accordingly. For instance, honey bees reduce the duration of their
waggle dance
Waggle dance is a term used in beekeeping and ethology for a particular figure-eight dance of the honey bee. By performing this dance, successful foragers can share information about the direction and distance to patches of flowers yielding ne ...
if they judge their own yield to be inferior. Scientists have demonstrated that
anesthesia
Anesthesia (American English) or anaesthesia (British English) is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prev ...
disrupts the
circadian clock
A circadian clock, or circadian oscillator, also known as one’s internal alarm clock is a biochemical oscillator that cycles with a stable phase and is synchronized with solar time.
Such a clock's ''in vivo'' period is necessarily almost exact ...
and impairs the time perception of honey bees, as observed in humans. Experiments revealed that a six-hour-long
general anesthesia
General anaesthesia (UK) or general anesthesia (US) is medically induced loss of consciousness that renders a patient unarousable even by painful stimuli. It is achieved through medications, which can be injected or inhaled, often with an analgesi ...
significantly delayed the start of the foraging behaviour of honeybees if induced during daytime, but not if induced during nighttime.
Bumble bees can be successfully trained to respond to a
stimulus after a certain time interval has elapsed (usually several seconds after the start signal). Studies have shown that they can also learn to simultaneously time multiple interval durations.
In a single study, colonies from three species of
ants
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...
from the genus ''
Myrmica
''Myrmica'' is a genus of ants within the subfamily Myrmicinae. It is widespread throughout the temperate regions of the Holarctic realm, Holarctic and high mountains in Southeast Asia.
The genus consists of around 200 known species and additio ...
'' were trained to associate feeding sessions with different times. The trainings lasted several days, where each day the feeding time was delayed by 20 minutes compared to the previous day. In all three species, at the end of the training, most individuals were present at the feeding spot at the correct expected times, suggesting that ants are able to estimate the time running, keep in memory the expected feeding time and to act anticipatively.
Temporal illusions
A temporal illusion is a distortion in the perception of time. For example:
* estimating ''time intervals'', e.g., "When did you last see your primary care physician?";
* estimating ''time duration'', e.g., "How long were you waiting at the doctor's office?"; and
* judging the ''simultaneity of events ''(see below for examples).
Some main types of temporal illusions are as follows:
*''
Telescoping effect
In cognitive psychology, the telescoping effect (or telescoping bias) refers to the temporal displacement of an event whereby people perceive recent events as being more remote than they are and distant events as being more recent than they are. Th ...
'': People tend to recall recent events as occurring further back in time than they actually did (backward telescoping) and distant events as occurring more recently than they actually did (forward telescoping).
*''
Vierordt's law'': Shorter intervals tend to be overestimated while longer intervals tend to be underestimated
*Time intervals associated with more changes may be perceived as longer than intervals with fewer changes
*Perceived temporal length of a given task may shorten with greater motivation
*Perceived temporal length of a given task may stretch when broken up or interrupted
*Auditory stimuli may appear to last longer than visual stimuli
*Time durations may appear longer with greater stimulus intensity (e.g., auditory loudness or pitch)
*Simultaneity judgments can be manipulated by repeated exposure to non-simultaneous stimuli
Kappa effect
The ''
Kappa effect'' or ''perceptual time dilation'' is a form of temporal illusion verifiable by experiment.
The temporal duration between a sequence of consecutive stimuli is thought to be relatively longer or shorter than its actual elapsed time, due to the spatial/auditory/tactile separation between each consecutive stimuli. The kappa effect can be displayed when considering a journey made in two parts that each take an equal amount of time. When mentally comparing these two sub-journeys, the part that covers more ''distance'' may appear to take longer than the part covering less distance, even though they take an equal amount of time.
Eye movements and chronostasis
The perception of space and time undergoes distortions during rapid saccadic eye movements.
''
Chronostasis'' is a type of temporal illusion in which the first impression following the introduction of a new event or task demand to the brain appears to be extended in time.
For example, chronostasis temporarily occurs when fixating on a target stimulus, immediately following a
saccade
In vision science, a saccade ( ; ; ) is a quick, simultaneous movement of both Eye movement (sensory), eyes between two or more phases of focal points in the same direction. In contrast, in Smooth pursuit, smooth-pursuit movements, the eyes mov ...
(e.g., quick
eye movement
Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms (e.g. primates, rodents, flies, birds, fish, cats, crabs, octopus) to fixate, inspect and track visual objects of inte ...
). This elicits an overestimation in the temporal duration for which that target stimulus (i.e., postsaccadic stimulus) was perceived. This effect can extend apparent durations by up to 500 ms and is consistent with the idea that the visual system models events prior to perception. The most well-known version of this illusion is known as the stopped-clock illusion, wherein a subject's first impression of the second-hand movement of an analog clock, subsequent to one's directed attention (i.e., saccade) to the clock, is the perception of a slower-than-normal second-hand movement rate (the second-hand of the clock may seemingly temporarily freeze in place after initially looking at it).
The occurrence of chronostasis extends beyond the visual domain into the
auditory and
tactile domains. In the auditory domain, chronostasis and duration overestimation occur when observing auditory stimuli. One common example is a frequent occurrence when making telephone calls. If, while listening to the phone's dial tone, research subjects move the phone from one ear to the other, the length of time between rings appears longer. In the tactile domain, chronostasis has persisted in research subjects as they reach for and grasp objects. After grasping a new object, subjects overestimate the time in which their hand has been in contact with this object.
Flash-lag effect
In an experiment, participants were told to stare at an "x" symbol on a computer screen whereby a moving blue doughnut-like ring repeatedly circled the fixed "x" point. Occasionally, the ring would display a white flash for a split second that physically overlapped the ring's interior. However, when asked what was perceived, participants responded that they saw the white flash lagging behind the center of the moving ring. In other words, despite the reality that the two retinal images were actually spatially aligned, the flashed object was usually observed to trail a continuously moving object in space — a phenomenon referred to as the ''flash-lag effect''.
The first proposed explanation, called the "motion extrapolation" hypothesis, is that the visual system
extrapolates the position of moving objects but not flashing objects when accounting for neural delays (i.e., the lag time between the retinal image and the observer's perception of the flashing object). The second proposed explanation by David Eagleman and Sejnowski, called the "latency difference" hypothesis, is that the visual system processes moving objects at a faster rate than flashed objects. In the attempt to disprove the first hypothesis, David Eagleman conducted an experiment in which the moving ring suddenly reverses direction to spin in the other way as the flashed object briefly appears. If the first hypothesis were correct, we would expect that, immediately following reversal, the moving object would be observed as lagging behind the flashed object. However, the experiment revealed the opposite — immediately following reversal, the flashed object was observed as lagging behind the moving object. This experimental result supports the "latency difference" hypothesis. A recent study tries to reconcile these different approaches by treating perception as an inference mechanism aiming at describing what is happening at the present time.
Oddball effect
Humans typically overestimate the perceived duration of the initial and final event in a stream of identical events.
This ''oddball effect'' may serve an evolutionarily adapted "alerting" function and is consistent with reports of time slowing down in threatening situations. The effect seems to be strongest for images that are expanding in size on the retina, , that are "looming" or approaching the viewer,
and the effect can be eradicated for oddballs that are contracting or perceived to be receding from the viewer.
The effect is also reduced
or reversed
with a static oddball presented among a stream of expanding stimuli.
Initial studies suggested that this oddball-induced "subjective time dilation" expanded the perceived duration of oddball stimuli by 30–50%
but subsequent research has reported more modest expansion of around 10%
or less.
The direction of the effect, whether the viewer perceives an increase or a decrease in duration, also seems to be dependent upon the stimulus used.
Reversal of temporal order judgment
Numerous experimental findings suggest that temporal order judgments of actions preceding effects can be reversed under special circumstances. Experiments have shown that sensory simultaneity judgments can be manipulated by repeated exposure to non-simultaneous stimuli. In an experiment conducted by
David Eagleman
David Eagleman (born April 25, 1971) is an American neuroscientist, author, and science communicator. He teaches neuroscience at Stanford University and was CEO and co-founder of Neosensory, a now-defunct company that developed devices for senso ...
, a temporal order judgment reversal was induced in subjects by exposing them to delayed motor consequences. In the experiment, subjects played various forms of video games. Unknown to the subjects, the experimenters introduced a fixed delay between the mouse movements and the subsequent sensory feedback. For example, a subject may not see a movement register on the screen until 150 milliseconds after they had moved the mouse. Participants playing the game quickly adapted to the delay and felt as though there was less delay between their mouse movement and the sensory feedback. Shortly after the experimenters removed the delay, the subjects commonly felt as though the effect on the screen happened just before they commanded it. This work addresses how the perceived timing of effects is modulated by expectations, and the extent to which such predictions are quickly modifiable.
In an experiment conducted by Haggard and colleagues in 2002, participants pressed a button that triggered a flash of light at a distance, after a slight delay of 100 milliseconds. By repeatedly engaging in this act, participants had adapted to the delay (i.e., they experienced a gradual shortening in the perceived time interval between pressing the button and seeing the flash of light). The experimenters then showed the flash of light instantly after the button was pressed. In response, subjects often thought that the flash (the effect) had occurred before the button was pressed (the cause). Additionally, when the experimenters slightly reduced the delay, and shortened the spatial distance between the button and the flash of light, participants had often claimed again to have experienced the effect before the cause.
Several experiments also suggest that temporal order judgment of a pair of
tactile stimuli delivered in rapid succession, one to each hand, is noticeably impaired (i.e., misreported) by crossing the hands over the midline. However, congenitally blind subjects showed no trace of temporal order judgment reversal after crossing the arms. These results suggest that tactile signals taken in by the congenitally blind are ordered in time without being referred to a visuospatial representation. Unlike the congenitally blind subjects, the temporal order judgments of the late-onset blind subjects were impaired when crossing the arms to a similar extent as non-blind subjects. These results suggest that the associations between tactile signals and visuospatial representation is maintained once it is accomplished during infancy. Some research studies have also found that the subjects showed reduced deficit in tactile temporal order judgments when the arms were crossed behind their back than when they were crossed in front.
Physiological associations
Tachypsychia
Tachypsychia is a neurological condition that alters the perception of time, usually induced by
physical exertion,
drug use, or a
traumatic event. For someone affected by tachypsychia, time perceived by the individual either lengthens, making events appear to slow down, or possibly the reverse, with objects appearing as moving in a speeding blur.
Effects of emotional states
Awe
Research has suggested the feeling of
awe has the ability to expand one's perceptions of time availability. Awe can be characterized as an experience of immense perceptual vastness that coincides with an increase in focus. Consequently, it is conceivable that one's temporal perception would slow down when experiencing awe. The perception of time can differ as people choose between savoring moments and deferring gratification.
Fear
Possibly related to the
oddball effect, research suggests that time seems to slow down for a person during dangerous events (such as a car accident, a robbery, or when a person perceives a potential predator or
mate), or when a person
skydives or bungee jumps, where they are capable of complex thoughts in what would normally be the blink of an eye (See
Fight-or-flight response
The fight-or-flight or the fight-flight-freeze-or-fawn (also called hyperarousal or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first describ ...
).
This reported slowing in temporal perception may have been evolutionarily advantageous because it may have enhanced one's ability to intelligibly make quick
decisions in moments that were of critical importance to our survival. However, even though observers commonly report that time seems to have moved in slow motion during these events, it is unclear whether this is a function of increased time resolution during the event, or instead an illusion created by the remembering of an emotionally salient event.
A strong time dilation effect has been reported for perception of objects that were looming, but not of those retreating, from the viewer, suggesting that the expanding discs — which mimic an approaching object — elicit
self-referential
Self-reference is a concept that involves referring to oneself or one's own attributes, characteristics, or actions. It can occur in language, logic, mathematics, philosophy, and other fields.
In natural language, natural or formal languages, ...
processes which act to signal the presence of a possible danger.
Anxious people, or those in great
fear
Fear is an unpleasant emotion that arises in response to perception, perceived dangers or threats. Fear causes physiological and psychological changes. It may produce behavioral reactions such as mounting an aggressive response or fleeing the ...
, experience greater "time dilation" in response to the same threat stimuli due to higher levels of
epinephrine
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands a ...
, which increases brain activity (an adrenaline rush). In such circumstances, an illusion of time dilation could assist an effective escape. When exposed to a threat, three-year-old children were observed to exhibit a similar tendency to overestimate elapsed time.
Research suggests that the effect appears only at the point of retrospective assessment, rather than occurring simultaneously with events as they happened.
Perceptual abilities were tested during a frightening experience — a
free fall
In classical mechanics, free fall is any motion of a physical object, body where gravity is the only force acting upon it.
A freely falling object may not necessarily be falling down in the vertical direction. If the common definition of the word ...
— by measuring people's sensitivity to flickering stimuli. The results showed that the subjects' temporal resolution was not improved as the frightening event was occurring. Events appear to have taken longer only in retrospect, possibly because memories were being more densely packed during the frightening situation.
Other researchers suggest that additional variables could lead to a different state of consciousness in which altered time perception does occur during an event. Research does demonstrate that visual sensory processing increases in scenarios involving action preparation. Participants demonstrated a higher detection rate of rapidly presented symbols when preparing to move, as compared to a control without movement.
People shown extracts from films known to induce
fear
Fear is an unpleasant emotion that arises in response to perception, perceived dangers or threats. Fear causes physiological and psychological changes. It may produce behavioral reactions such as mounting an aggressive response or fleeing the ...
often overestimated the elapsed time of a subsequently presented visual stimulus, whereas people shown emotionally neutral clips (weather forecasts and stock market updates) or those known to evoke feelings of sadness showed no difference. It is argued that fear prompts a state of arousal in the
amygdala
The amygdala (; : amygdalae or amygdalas; also '; Latin from Greek language, Greek, , ', 'almond', 'tonsil') is a paired nucleus (neuroanatomy), nuclear complex present in the Cerebral hemisphere, cerebral hemispheres of vertebrates. It is c ...
, which increases the rate of a hypothesized "internal clock". This could be the result of an evolved defensive mechanism triggered by a threatening situation. Individuals experiencing sudden or surprising events, real or imagined (e.g., witnessing a crime, or believing one is seeing a ghost), may overestimate the duration of the event.
Changes with age
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
Aging of the Human brain, brain is a process of transformation of the brain in old age, older age, including changes all individuals experience and those of illness (including unrecognised illness). Usually this refers to humans.
Since life extens ...
, such as the lowering in dopaminergic levels with older age; however, the details are still being debated.
Very young children will first experience the passing of time when they 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
In mammalian brain anatomy, the prefrontal cortex (PFC) covers the front part of the frontal lobe of the cerebral cortex. It is the association cortex in the frontal lobe. The PFC contains the Brodmann areas BA8, BA9, BA10, BA11, BA12, ...
and
hippocampus
The hippocampus (: hippocampi; via Latin from Ancient Greek, Greek , 'seahorse'), also hippocampus proper, is a major component of the brain of humans and many other vertebrates. In the human brain the hippocampus, the dentate gyrus, and the ...
.
The common explanation is that most external and internal experiences are new for young children but repetitive for adults. Children have to be extremely engaged (i.e. dedicate many neural resources or significant brain power) in the present moment because they must constantly reconfigure their mental models of the world to assimilate it and manage behaviour properly.
Adults, however, may rarely need to step outside mental habits and external routines. When an adult frequently experiences the same stimuli, such stimuli may seem "invisible" as a result of having already been sufficiently mapped by the brain. This phenomenon is known as
neural adaptation
Neural adaptation or sensory adaptation is a gradual decrease over time in the responsiveness of the sensory system to a constant stimulus. It is usually experienced as a change in the stimulus. For example, if a hand is rested on a table, the t ...
. According to this picture, the rate of new stimuli and new experiences may decrease with age as does the number of new memories created to record them. If one then assumes that the perceived duration of a given interval of time is linked to how many new memories are formed during it, the aging adult may underestimate long stretches of time because, in their recollection, these now contain fewer memory-creating events. Consequently, the subjective perception is often that time passes by at a faster rate with age.
Proportional to the real time
Let be subjective time, be real time, and define both to be zero at birth.
One model proposes that the passage of subjective time relative to actual time is inversely proportional to real time:
:
When solved,
.
One day would be approximately 1/4,000 of the life of an 11-year-old, but approximately 1/20,000 of the life of a 55-year-old. This helps to explain why a random, ordinary day may therefore appear longer for a young child than an adult. So a year would be experienced by a 55-year-old as passing approximately five times more quickly than a year experienced by an 11-year-old. If long-term time perception is based solely on the
proportionality of a person's age, then the following four periods in life would appear to be quantitatively equal: ages 5–10 (1x), ages 10–20 (2x), ages 20–40 (4x), age 40–80 (8x), as the end age is twice the start age. However, this does not work for ages 0–10, which corresponds to ages 10–∞.
Proportional to the subjective time
Lemlich posits that the passage of subjective time relative to actual time is inversely proportional to total subjective time, rather than the total real time:
:
When mathematically solved,
:
It avoids the issue of infinite subjective time passing from real age 0 to 1 year, as the
asymptote
In analytic geometry, an asymptote () of a curve is a line such that the distance between the curve and the line approaches zero as one or both of the ''x'' or ''y'' coordinates tends to infinity. In projective geometry and related contexts, ...
can be integrated in an
improper integral
In mathematical analysis, an improper integral is an extension of the notion of a definite integral to cases that violate the usual assumptions for that kind of integral. In the context of Riemann integrals (or, equivalently, Darboux integral ...
. Using the
boundary condition
In the study of differential equations, a boundary-value problem is a differential equation subjected to constraints called boundary conditions. A solution to a boundary value problem is a solution to the differential equation which also satis ...
s S = 0 when R = 0 and K > 0,
:
:
This means that time appears to pass in proportion to the square root of the perceiver's real age, rather than directly proportional. Under this model, a 55-year-old would subjectively experience time passing times more quickly than an 11-year-old, rather than five times under the previous. This means the following periods in life would appear to be quantitatively equal: ages 0–1, 1–4, 4–9, 9–16, 16–25, 25–36, 36–49, 49–64, 64–81, 81–100, 100–121.
In a study, participants consistently provided answers that fit this model when asked about time perception at 1/4 of their age, but were less consistent for 1/2 of their age. Their answers suggest that this model is more accurate than the previous one.
A consequence of this model is that the fraction of subjective life remaining is always less than the fraction of real life remaining, but it is always more than one half of real life remaining.
This can be seen for
and
:
:
Effects of drugs on time perception
Stimulants
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognitio ...
such as thyroxine, caffeine, and amphetamines lead to overestimation of time intervals by both humans and rats, while
depressants
Depressants, also known as central nervous system depressants, or colloquially known as "downers", are drugs that lower neurotransmission levels, decrease the electrical activity of brain cells, or reduce arousal or stimulation in various ar ...
and
anesthetics
An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia — in other words, to result in a temporary loss of sensation or awareness. They may be divided into tw ...
such as barbiturates and nitrous oxide can have the opposite effect and lead to underestimation of time intervals. The level of activity in the brain of
neurotransmitters
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
Neurotransmitters are rele ...
such as
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
and
norepinephrine
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic compound, organic chemical in the catecholamine family that functions in the brain and human body, body as a hormone, neurotransmitter and neuromodulator. The ...
may be the reason for this. A research on stimulant-dependent individuals (SDI) showed several abnormal time processing characteristics including larger time differences for effective duration discrimination, and overestimating the duration of a relatively long time interval. Altered time processing and perception in SDI could explain the difficulty SDI have with delaying gratification. Another research studied the dose-dependent effect in methamphetamine dependents with short term abstinence and its effects on time perception. Results shows that motor timing but not perceptual timing, was altered in meth dependents, which persisted for at least three months of abstinence. Dose-dependent effects on time perception were only observed when short-term abstinent meth abusers processed long time intervals. The study concluded that time perception alteration in meth dependents is task specific and dose dependent.
The
effect of cannabis on time perception has been studied with inconclusive results mainly due to methodological variations and the paucity of research. Even though 70% of time estimation studies report over-estimation, the findings of time production and time reproduction studies remain inconclusive. Studies show consistently throughout the literature that most cannabis users self-report the experience of a slowed perception of time. In the laboratory, researchers have confirmed the effect of cannabis on the perception of time in both humans and animals. Using PET scans it was observed that participants who showed a decrease in cerebellar blood flow (CBF) also had a significant alteration in time sense. The relationship between decreased CBF and impaired time sense is of interest as the cerebellum is linked to an internal timing system.
Effects of body temperature
The chemical clock hypothesis implies a causal link between body temperature and the perception of time.
Past work shows that increasing body temperature tends to make individuals experience a dilated perception of time and they perceive durations as shorter than they actually were, ultimately leading them to underestimate time durations. While decreasing body temperature has the opposite effect – causing participants to experience a condensed perception of time leading them to over-estimate time duration – observations of the latter type were rare. Research establishes a parametric effect of body temperature on time perception with higher temperatures generally producing faster subjective time and vice versa. This is especially seen to be true under changes in arousal levels and stressful events.
Social networks
Time perception can be used as a tool in
social network
A social network is a social structure consisting of a set of social actors (such as individuals or organizations), networks of Dyad (sociology), dyadic ties, and other Social relation, social interactions between actors. The social network per ...
s to define the
subjective experiences of each node within a system. This method can be used to study characters'
psychology
Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ...
in dramas, both
film
A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, sinc ...
and
literature
Literature is any collection of Writing, written work, but it is also used more narrowly for writings specifically considered to be an art form, especially novels, Play (theatre), plays, and poetry, poems. It includes both print and Electroni ...
, analyzed by social networks. Each character's subjective time may be calculated, with methods as simple as word counting, and compared to the real time of the story to shed light on their internal states.
See also
*
Arrow of time
An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers ca ...
*
Benjamin Libet
*
Time dilation
Time dilation is the difference in elapsed time as measured by two clocks, either because of a relative velocity between them (special relativity), or a difference in gravitational potential between their locations (general relativity). When unsp ...
*
Déjà vu
''Déjà vu'' ( , ; "already seen") is the phenomenon of feeling like one has
lived through the present situation in the past.Schnider, Armin. (2008). ''The Confabulating Mind: How the Brain Creates Reality''. Oxford University Press. pp. 167–1 ...
*
Dyschronometria
*
Temporal resolution
Temporal resolution (TR) refers to the discrete resolution of a measurement with respect to time. It is defined as the amount of time needed to revisit and acquire data for exactly the same location. When applied to remote sensing, this amount of ...
*
Time perspective (Wikiversity)
References
Further reading
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External links
Time perception research at the University of Manchester"A Cognitive Model of Retrospective Duration Estimations", Hee-Kyung Ahn, et al., March 7, 2006."Time, Force, Motion, and the Semantics of Natural Languages", Wolfgang Wildgen, ''Antwerp Papers in Linguistics'', 2003/2004.Can Time Slow Down?Registration required.
*
ttp://sourceforge.net/projects/picturespacetime/ Picture Space Time helps to add Time Perception to Photographs using sound
{{DEFAULTSORT:Time Perception
Cognition
Concepts in the philosophy of mind
Metaphysics of mind
Perception
Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous syste ...
Philosophy of science
Philosophy of time
Concepts in metaphysics
Thought
Perception
Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous syste ...
Time management
Unsolved problems in neuroscience
Unsolved problems in physics