瞳孔大小的认知指示

Pupil size and cognition
Non-cognitive influences on pupil size: 2) The lid-closure reflex • The lid-closure reflex manifests as a systematic miosis (of around 8% surface area), occurring after blinks, which is followed by redilation (DeLaunay, 1949; Hupé, Lamirel, & Lorenceau, 2009; Loewenfeld, 1999) • Some researchers have observed only a dilation after eye-blinks (Fukuda, Stern, Brown, & Russo, 2005).
Tonic activation in both systems balance each other to produce an average waking pupil-size in ambient illumination of 2-6mm, with an average of 5mm and a range of 1-9mm (Beatty, & Lucero-Wagoner, 2000; Reeves, & Swenson, 2004).
"Pain, shame, ire, impatience, disgust, detestation, seemed momentarily to hold a quivering conflict in the large pupil dilating under his ebon eyebrow"
Early comments on the relationship between pupil size and emotion:
William Harvey, Physician (1578-1657)
“In anger, the eyes are fiery, and the pupils are dilated”
2) Early Research into pupil size and cognition
3) Recording pupil size changes
Pupil size and cognition
“No other part of the body supplies greater indications of the mind – this is so with all animals alike, but specially with man” (Philosopher Pliny – AD23-79 – talking about eyes...)
Pupil size and cognition
It is not just the eye’s “shape” that gives us information about cognitive / emotional state – the pupil is very revealing…
The word “pupil” comes from the Latin Pupilla – meaning little girls – because you can see reflections of little people in the pupil.
Pupil size and cognition
Non-cognitive influences on pupil size: 1) The pupiliary light reflex • The pupil is usually between 2-6mm in ambient illumination, dilating in dim light, and constricting in bright light (Beatty, & Lucero-Wagoner, 2000) • This constriction is known as the Pupillary Light Reflex (PLR), and serves to regulate the total intensity of light entering the eye, optimising image quality. • In response to large increases in luminance the pupil can decrease in diameter by more than 50% in just 200ms (Miller, & Newman, 2005), peaking between 500-1000ms (Beatty, & Lucero-Wagoner, 2000).
Pupil size and cognition
Woman with a Mirror – a Venetian “Bella donna”
Titian, c1515
I can’t see whether her pupils are dilated…
Pupil size and cognition
ቤተ መጻሕፍቲ ባይዱ
radial dilator pupillae
Pupil size and cognition
The sphincter and dilator muscles are innervated by the Autonomic Nervous System (ANS) parasympathetic and sympathetic pupillomotor fibres of the third cranial nerve respectively (Foster, 1891; Reeves, & Swenson, 2004).
Pharmacology of parasympathetic pathway:
• Acetyle Choline (Ach) acts on the sphincter via muscarinic receptors, leading to constriction of the pupil • ACh agonists, such as pilocarpine, and ACh-breakdown inhibitors, such as physostigmine cause constriction • ACh antagonists, such as atropine, relax the sphincter, enhancing the efforts of the dilator muscle (Miller, & Newman, 2005). • Miosis (constriction) can also be induced centrally by the effects of chloroform, sedation, and through direct stimulation of the Edinger-Westphal nucleus by morphine and other opioids (Foster, 1891; Knaggs, Crighton, Cobby, Fletcher, & Hobbs, 2004; Miller, & Newman, 2005).
circular sphincter pupillae
Two muscle groups regulate the size of the pupil: circular sphincter pupillae contract to make the pupil smaller, radial dilator pupillae contract to make the pupil larger.
An increase in efferent activity to either muscle group leads to increasing central inhibition of the motor-nucleus of the other group (Miller, & Newman, 2005).
Charlotte Bronte writing in Jane Eyre, 1847.
The relationship between pupil size and cognitive / emotional state has also been known for a long time.
Pupil size and cognition
Pupil size and cognition
Pharmacology of sympathetic pathway:
• Norepinephrine (NE) acts on the dilator via α-adrenergic receptors, leading to dilation of the pupil (Fountoulakis, 1999). • NE agonists, such as ephedrine, and NE-reuptake inhibitors such as cocaine, cause dilation of the pupil • NE antagonists, such as thymoxamine, relax the dilator muscle and reduce its opposition of the sphincter. • Mydriasis (dilation) can be induced centrally via Selective Serotonin-Reuptake Inhibitor (SSRI) antidepressants and Lysergic Acid Diethylamide (LSD), as well as N-Methyl-DAspartate (NMDA) glutamate antagonists, such as ketamine, in addition to opioid withdrawal and alcohol poisoning (Doughty, 2001; Foster, 1891).
The eyes are considered the most expressive part of the face – we look at the eyes more often and longer. “…the eye is not only a passive organ and one of the gateways of knowledge, but is also a portal through which the working of the brain becomes manifest.” Samuel Wilks, 1883, p. 5-6.
Guangzhou Workshop
Eye tracking technology application in pupilometry
Pupil size and Cognition
Talk Outline 1) Background - History - Physiology / Pharmacology - Factors effecting pupil size (non-cognitive)
Pupil size and cognition
Pharmacology of pupil size: • Belladonna (from the Deadly Nightshade plant) contains atropine, which blocks the parasympathetic input to the sphincter muscle. • This fact was exploited by 17th Century Venetian women to make themselves appear more attractive (Belladonna means beautiful woman in Italian). • Another example of the ancient understanding of the power of pupil size!