Pupillary response explained

Pupillary response is a physiological response that varies the size of the pupil, via the optic and oculomotor cranial nerve.

A constriction response (miosis),[1] is the narrowing of the pupil, which may be caused by scleral buckles or drugs such as opiates/opioids or anti-hypertension medications. Constriction of the pupil occurs when the circular muscle, controlled by the parasympathetic nervous system (PSNS), contracts, and also to an extent when the radial muscle relaxes.A dilation response (mydriasis), is the widening of the pupil and may be caused by adrenaline; anticholinergic agents; stimulant drugs such as MDMA, cocaine, and amphetamines; and some hallucinogenics (e.g. LSD). Dilation of the pupil occurs when the smooth cells of the radial muscle, controlled by the sympathetic nervous system (SNS), contract, and also when the cells of the iris sphincter muscle relax.The responses can have a variety of causes, from an involuntary reflex reaction to exposure or inexposure to light—in low light conditions a dilated pupil lets more light into the eye—or it may indicate interest in the subject of attention or arousal, sexual stimulation,[2] uncertainty,[3] decision conflict,[4] errors,[5] physical activity[6] or increasing cognitive load[7] or demand. The responses correlate strongly with activity in the locus coeruleus neurotransmitter system.[8] [9] [10] The pupils contract immediately before REM sleep begins.[11] A pupillary response can be intentionally conditioned as a Pavlovian response to some stimuli.[12]

Some humans have the ability to exert direct and voluntary control over their iris sphincter muscles and dilator muscles, granting them the ability to dilate and constrict their pupils on command, regardless of lighting condition and/or eye accommodation state.[13] However, this ability is very rare, and its potential use or advantages are unclear.

The latency of pupillary response (the time in which it takes to occur) increases with age.[14]

In ophthalmology, intensive studies of pupillary response are conducted via videopupillometry.[15]

Anisocoria is the condition of one pupil being more dilated than the other.

! Constriction (Parasympathetic) !! Dilation (Sympathetic)
Muscular mechanismActivation of iris dilator muscle, relaxation of iris sphincter muscle
Cause in pupillary light reflexIncreased light Decreased light
Other physiological causesFight-or-flight response, sexual arousal
Corresponding non-physiological stateMydriasis

See also

Notes and References

  1. Ellis CJ . The pupillary light reflex in normal subjects . The British Journal of Ophthalmology . 65 . 11 . 754–9 . November 1981 . 7326222 . 1039657 . 10.1136/bjo.65.11.754 .
  2. Hess EH, Polt JM . Pupil size as related to interest value of visual stimuli . Science . 132 . 3423 . 349–50 . August 1960 . 14401489 . 10.1126/science.132.3423.349 . James Polt --> . 1960Sci...132..349H . 12857616 . Eckhard Hess .
  3. Nassar MR, Rumsey KM, Wilson RC, Parikh K, Heasly B, Gold JI . Rational regulation of learning dynamics by pupil-linked arousal systems . Nature Neuroscience . 15 . 7 . 1040–6 . June 2012 . 22660479 . 10.1038/nn.3130 . 3386464 .
  4. Lin H, Saunders B, Hutcherson CA, Inzlicht M . Midfrontal theta and pupil dilation parametrically track subjective conflict (but also surprise) during intertemporal choice . NeuroImage . 172 . 838–852 . May 2018 . 29107773 . 10.1016/j.neuroimage.2017.10.055 . 4960140 .
  5. Decker. Alexandra. Finn. Amy. Duncan. Katherine. 2020-11-01. Errors lead to transient impairments in memory formation. Cognition. en. 204. 104338. 10.1016/j.cognition.2020.104338. 32593745. 220044505. 0010-0277.
  6. Kuwamizu . Ryuta . Yamazaki . Yudai . Aoike . Naoki . Ochi . Genta . Suwabe . Kazuya . Soya . Hideaki . 2022-09-24 . Pupil-linked arousal with very light exercise: pattern of pupil dilation during graded exercise . The Journal of Physiological Sciences . 72 . 1 . 23 . 10.1186/s12576-022-00849-x . 36153491 . 1880-6562. free . 10717467 .
  7. Kahneman D, Beatty J . Pupil diameter and load on memory . Science . 154 . 3756 . 1583–5 . December 1966 . 5924930 . 10.1126/science.154.3756.1583 . 1966Sci...154.1583K . 22762466 .
  8. Aston-Jones G, Cohen JD . An integrative theory of locus coeruleus-norepinephrine function: adaptive gain and optimal performance . Annual Review of Neuroscience . 28 . 1 . 403–50 . 2005-07-21 . 16022602 . 10.1146/annurev.neuro.28.061604.135709 . 535645 .
  9. Joshi S, Li Y, Kalwani RM, Gold JI . Relationships between Pupil Diameter and Neuronal Activity in the Locus Coeruleus, Colliculi, and Cingulate Cortex . Neuron . 89 . 1 . 221–34 . January 2016 . 26711118 . 4707070 . 10.1016/j.neuron.2015.11.028 .
  10. Murphy PR, O'Connell RG, O'Sullivan M, Robertson IH, Balsters JH . Pupil diameter covaries with BOLD activity in human locus coeruleus . Human Brain Mapping . 35 . 8 . 4140–54 . August 2014 . 24510607 . 6869043 . 10.1002/hbm.22466 .
  11. Lowenstein O, Feinberg R, Loewenfeld IE . Otto Lowenstein . Pupillary Movements During Acute and Chronic Fatigue: A New Test for the Objective Evaluation of Tiredness . Investigative Ophthalmology . C.V. Mosby Company . St. Louis . 2 . 2 . 138–157 . April 1963 . dead . https://web.archive.org/web/20120319233224/http://www.faa.gov/library/reports/medical/oamtechreports/1960s/media/AM65-09.pdf . 2012-03-19.
  12. Baker . Lynn Erland . vanc . Lynn Baker . The Pupillary Response Conditioned to Subliminal Auditory Stimuli . Ohio State University . 1938 . 6894644 .
  13. Eberhardt . Lisa V. . Grön . Georg . Ulrich . Martin . Huckauf . Anke . Strauch . Christoph . 2021-10-01 . Direct voluntary control of pupil constriction and dilation: Exploratory evidence from pupillometry, optometry, skin conductance, perception, and functional MRI . International Journal of Psychophysiology . 168 . 33–42 . 10.1016/j.ijpsycho.2021.08.001 . 0167-8760. free .
  14. Book: Feinberg R, Podolak E . Latency of pupillary reflex to light stimulation and its relationship to aging . Federal Aviation Agency, Office of Aviation Medicine, Georgetown Clinical Research Institute . 12 . September 1965 . 84657376 . dead . https://web.archive.org/web/20120320010318/http://www.faa.gov/library/reports/medical/oamtechreports/1960s/media/AM65-25.pdf . 2012-03-20.
  15. Ishikawa S, Naito M, Inaba K . A new videopupillography . Ophthalmologica . 160 . 4 . 248–59 . 1970 . 5439164 . 10.1159/000305996 .

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