The photic sneeze reflex in the human newborn: A preliminary report
Rebecca B. Anderson 1 2 *, Judy F. Rosenblith 1 2
1Institute for Health Sciences, Brown University, Providence, Rhode Island
2Wheaton College, Norton, Massachusetts
*Correspondence to Rebecca B. Anderson, Box 1910, Institute for Health Sciences, Brown University, Providence, Rhode Island 02912, U.S.A.
Keywords
Photic sneeze in neonates • Sneezing to light • Visual function in newborns • Visual stimulation
Abstract
In an ongoing, comprehensive study of newborn infants, visual following was tested by moving a shiny bicycle bell across the horizontal and vertical planes in front of the infant's eyes. During the course of this test, it was noted that many of the babies sneezed at the time the test object was presented. The race-sex distribution of this sneeze response in the infant population stuided was recorded and the phenomenon discussed as an early indicator of visual sensitivity.
Received: 26 December 1967
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AFAICT there would be no functional advantage for a newborn infant backfloating hydrostatically in sunlit seawater lagoon to have a photic sneeze unless it joined a parent during a dive, holding the scalp hair and/or riding on the parents' shoulders, then both photic exhaling at emergence. Frowning at direct sunlight is typical for human infants, less so for chimp infants and rarely for orangutan infants, sun sneezing is unique to humans and only occurs after dark adaptation (the infant may have kept the eyes closed at depth).
Functionally, the photic sneeze (or post-dark-adaptation respiration) would be (hypothetically) advantageous for apneic dive-foragers who rest at the surface with minimal energy expenditure after a couple swift emergent sun-triggered (small?) exhales and immobile relaxed sunwarmed posture would presumably enable cyclical diving to cold depths repeatedly.
Why some people sneeze when the sun comes out - health - 15 April 2009 - New Scientist
"The answer to that, Bhutta suggests, might lie in another one of Everett's hypotheses: that the confusion arises in the way the medulla regulates our reflex actions. Everett originally proposed this idea to explain just photic sneezing, but Bhutta thinks it could explain all the strange sneezing conditions, since all of the triggers involve stimulation of a parasympathetic nerve response controlled by the medulla. When bright sunlight hits our eyes, our pupils contract involuntarily - a parasympathetic response. When our stomachs are full, the parasympathetic system kicks in to start our gastric juices flowing. When we think of sex, parasympathetic action stimulates blood flow to our genitals.
All these nerve responses flow to and from regions of the medulla close to where the sneeze centre is located. This suggests that far from being a neat system of discrete responses to individual stimuli, our reflex systems at their base in the medulla are often a tangled web of cross-talking nerve wires. Sometimes when bright sunlight hits our eyes, the parasympathetic system responds appropriately and our pupils constrict. But for certain people whose medullas are wired differently, sunlight triggers a different reflex response, such as a sneeze."
"About 20% of people sneeze because of reflex action when exposed to sudden, bright light. The Guthrie Journal, 64(3):104-105 (1995)
A 1987 study in the Cleveland Clinic Journal of Medicine, for example, estimated its prevalence at 17 to 35 percent of the population.
A 1983 study in Human Heredity found a 24 percent prevalence among 460 blood donors.
-
Between 20-30% of Europeans have sun sneeze tendencies. That is much higher than left-handedness, and must have had strong natural selection in the past. Since the gene is found on Chromosome 2 (a fusion of 2 ape chromosomes into one human chromosome), parsimony rules that it was functionally advantageous within the last 5 million years since the genetic split. What was that function?
Why would a savanna runner sneeze at the sun? No others do.
Why would a forest ground forager sneeze at the sun? No others do.
Why would a seashore forager sneeze at the sun? Ask a dolphin.
[But since dolphins also hunt at night, they are far more dependent on touch sensors around the blowhole and sonar reflection. Also, they breathe only through their blowhole nostril, not the mouth (because they eat fast-moving prey which might enter an oral breathing tube, while humans eat non-moving food), human sneezes are triggered by the nose/eyes but exhaled through the mouth, possibly indicating that during a dive sequence the paranasal sinuses and middle ears were saline-flooded but the mouth was not.]
Perhaps there is no easy answer, but thus far, all known physiological & genetic data which I have found plausibly fit the pattern of Aquaphotic Respiratory Cycle dive-foraging in human ancestors, remaining in various human populations as vestiges (after technological, geographic and climactic changes reduced dependence on dive-foraging for sustenance), just as wisdom teeth affect some populations more than others, or amylase duplication increases in populations which consume more starches.
Photic Sneeze Reflex The View From My Fishbowl
Many (not all) photic sneezers also sneeze when tasting dark chocolate (origin America) and peppermint (eg. altoid).
Origin of peppermint: It is a native of the Mediterranean...It is a perennial herb that grows up to 1 meter (3 feet) high...It has underground runners by which it easily propagates. This herb has many species, and peppermint piperita is a hybrid of water-mint (M. aquatica) and spearmint (M. spicata). (wikianswers)
Spice Pages: Peppermint (Mentha piperita, spicata, arvensis, nane, mint)
Whenever high*ly concentrated menthol is used, one must consider that menthol is toxic to infants(?) and can (allegedly) induce apnoea. Charac*teristically pure and refreshing odour, pungent and burning taste (insecticide?). The typical "mint scent" is most pure in peppermint...
-
Interesting, possibly there was early selection for (food/medicinal?) herb consumption which was flavorful (minty) that repelled insects (like lemongrass/citronella/citrus) in the Mediterranean during the MSC (when the Medit. mostly dried out 6-5ma and humans separated from chimps). Having a habit of snacking on waterside water-mint, spearmint and hybrid peppermint leaves, other aquatic herbs and seafood might have improved apnea diving, and the sneeze reaction to strong mint thus correlated to sunlight offshore foraging. (Consider that airborne allergies and asthma may have been alternative reactions which developed inland.)
Water Mint (Mentha Aquatica, L.)
Water Mint (and similarly spearmint/peppermint) is a hygrophyte, luxuriating in the moisture of riversides, wet places by ditches, pools, and (beaver) ponds, around the margins.. a spring issues from a hill-side, one will also find it. It is a regular component of marsh and bog floras. [I suspect the water-mint herb may signify a pure water source (not overly acidic, stagnant or briny), a double-blessing for a thirsty hungry hominin in Europe, central Asia etc.]
-
Apparently dark chocolate co-incidentally contains similar phytochemicals to peppermint, probably as anti-herbivore armour.
-
That does make interesting the possible complementary use of isotonic saline sino-nasal rinses and mint/menthol vapors for nasal clearing, in association with cyclic dive foraging.
Rebecca B. Anderson 1 2 *, Judy F. Rosenblith 1 2
1Institute for Health Sciences, Brown University, Providence, Rhode Island
2Wheaton College, Norton, Massachusetts
*Correspondence to Rebecca B. Anderson, Box 1910, Institute for Health Sciences, Brown University, Providence, Rhode Island 02912, U.S.A.
Keywords
Photic sneeze in neonates • Sneezing to light • Visual function in newborns • Visual stimulation
Abstract
In an ongoing, comprehensive study of newborn infants, visual following was tested by moving a shiny bicycle bell across the horizontal and vertical planes in front of the infant's eyes. During the course of this test, it was noted that many of the babies sneezed at the time the test object was presented. The race-sex distribution of this sneeze response in the infant population stuided was recorded and the phenomenon discussed as an early indicator of visual sensitivity.
Received: 26 December 1967
-
AFAICT there would be no functional advantage for a newborn infant backfloating hydrostatically in sunlit seawater lagoon to have a photic sneeze unless it joined a parent during a dive, holding the scalp hair and/or riding on the parents' shoulders, then both photic exhaling at emergence. Frowning at direct sunlight is typical for human infants, less so for chimp infants and rarely for orangutan infants, sun sneezing is unique to humans and only occurs after dark adaptation (the infant may have kept the eyes closed at depth).
Functionally, the photic sneeze (or post-dark-adaptation respiration) would be (hypothetically) advantageous for apneic dive-foragers who rest at the surface with minimal energy expenditure after a couple swift emergent sun-triggered (small?) exhales and immobile relaxed sunwarmed posture would presumably enable cyclical diving to cold depths repeatedly.
Why some people sneeze when the sun comes out - health - 15 April 2009 - New Scientist
"The answer to that, Bhutta suggests, might lie in another one of Everett's hypotheses: that the confusion arises in the way the medulla regulates our reflex actions. Everett originally proposed this idea to explain just photic sneezing, but Bhutta thinks it could explain all the strange sneezing conditions, since all of the triggers involve stimulation of a parasympathetic nerve response controlled by the medulla. When bright sunlight hits our eyes, our pupils contract involuntarily - a parasympathetic response. When our stomachs are full, the parasympathetic system kicks in to start our gastric juices flowing. When we think of sex, parasympathetic action stimulates blood flow to our genitals.
All these nerve responses flow to and from regions of the medulla close to where the sneeze centre is located. This suggests that far from being a neat system of discrete responses to individual stimuli, our reflex systems at their base in the medulla are often a tangled web of cross-talking nerve wires. Sometimes when bright sunlight hits our eyes, the parasympathetic system responds appropriately and our pupils constrict. But for certain people whose medullas are wired differently, sunlight triggers a different reflex response, such as a sneeze."
"About 20% of people sneeze because of reflex action when exposed to sudden, bright light. The Guthrie Journal, 64(3):104-105 (1995)
A 1987 study in the Cleveland Clinic Journal of Medicine, for example, estimated its prevalence at 17 to 35 percent of the population.
A 1983 study in Human Heredity found a 24 percent prevalence among 460 blood donors.
-
Between 20-30% of Europeans have sun sneeze tendencies. That is much higher than left-handedness, and must have had strong natural selection in the past. Since the gene is found on Chromosome 2 (a fusion of 2 ape chromosomes into one human chromosome), parsimony rules that it was functionally advantageous within the last 5 million years since the genetic split. What was that function?
Why would a savanna runner sneeze at the sun? No others do.
Why would a forest ground forager sneeze at the sun? No others do.
Why would a seashore forager sneeze at the sun? Ask a dolphin.
[But since dolphins also hunt at night, they are far more dependent on touch sensors around the blowhole and sonar reflection. Also, they breathe only through their blowhole nostril, not the mouth (because they eat fast-moving prey which might enter an oral breathing tube, while humans eat non-moving food), human sneezes are triggered by the nose/eyes but exhaled through the mouth, possibly indicating that during a dive sequence the paranasal sinuses and middle ears were saline-flooded but the mouth was not.]
Perhaps there is no easy answer, but thus far, all known physiological & genetic data which I have found plausibly fit the pattern of Aquaphotic Respiratory Cycle dive-foraging in human ancestors, remaining in various human populations as vestiges (after technological, geographic and climactic changes reduced dependence on dive-foraging for sustenance), just as wisdom teeth affect some populations more than others, or amylase duplication increases in populations which consume more starches.
Photic Sneeze Reflex The View From My Fishbowl
Many (not all) photic sneezers also sneeze when tasting dark chocolate (origin America) and peppermint (eg. altoid).
Origin of peppermint: It is a native of the Mediterranean...It is a perennial herb that grows up to 1 meter (3 feet) high...It has underground runners by which it easily propagates. This herb has many species, and peppermint piperita is a hybrid of water-mint (M. aquatica) and spearmint (M. spicata). (wikianswers)
Spice Pages: Peppermint (Mentha piperita, spicata, arvensis, nane, mint)
Whenever high*ly concentrated menthol is used, one must consider that menthol is toxic to infants(?) and can (allegedly) induce apnoea. Charac*teristically pure and refreshing odour, pungent and burning taste (insecticide?). The typical "mint scent" is most pure in peppermint...
-
Interesting, possibly there was early selection for (food/medicinal?) herb consumption which was flavorful (minty) that repelled insects (like lemongrass/citronella/citrus) in the Mediterranean during the MSC (when the Medit. mostly dried out 6-5ma and humans separated from chimps). Having a habit of snacking on waterside water-mint, spearmint and hybrid peppermint leaves, other aquatic herbs and seafood might have improved apnea diving, and the sneeze reaction to strong mint thus correlated to sunlight offshore foraging. (Consider that airborne allergies and asthma may have been alternative reactions which developed inland.)
Water Mint (Mentha Aquatica, L.)
Water Mint (and similarly spearmint/peppermint) is a hygrophyte, luxuriating in the moisture of riversides, wet places by ditches, pools, and (beaver) ponds, around the margins.. a spring issues from a hill-side, one will also find it. It is a regular component of marsh and bog floras. [I suspect the water-mint herb may signify a pure water source (not overly acidic, stagnant or briny), a double-blessing for a thirsty hungry hominin in Europe, central Asia etc.]
-
Apparently dark chocolate co-incidentally contains similar phytochemicals to peppermint, probably as anti-herbivore armour.
-
That does make interesting the possible complementary use of isotonic saline sino-nasal rinses and mint/menthol vapors for nasal clearing, in association with cyclic dive foraging.
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