Edinger–Westphal nucleus

a collection of small nerve cells in the midbrain. It is part of the parasympathetic nervous system pathway to the ciliary muscle and the pupillary sphincter of the eye, which play a role in visual accommodation. [Ludwig Edinger (1855–1918), German neuroanatomist; Karl Friedrich Otto Westphal (1833–1890), German neurologist]

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Psychology term of the day

July 27th 2024

primary insomnia

in DSM–IV–TR, a sleep disorder characterized by difficulty in initiating or maintaining a restorative sleep to a degree in which the severity and persistence of the sleep disturbance causes clinically significant distress, impairment in a significant area of functioning, or both. The disorder is not caused by a general medical condition or the effects of a substance and is not exclusively an aspect of another sleep disorder or mental disorder. It is termed insomnia disorder in DSM–5. See dyssomnia. Compare primary hypersomnia.