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sleep terror disorder

a sleep disorder characterized by repeated episodes of abrupt awakening from NREM sleep accompanied by signs of disorientation, extreme panic, and intense anxiety. More intense than nightmares and occurring during the first few hours of sleep, these episodes typically last between 1 and 10 minutes and involve screaming and symptoms of autonomic arousal, such as profuse perspiration, dilated pupils, rapid breathing, and a rapidly beating heart. The individual is difficult to wake or comfort and does not have detailed recall of the dream upon waking; complete loss of memory for the episode is common. The disorder occurs most often in children and generally resolves itself during adolescence. In adults, it is often associated with psychopathology and a more chronic course. Also called night terror. See also parasomnia.

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Psychology term of the day

November 16th 2024

dendrogram

dendrogram

n. a type of treelike diagram used in hierarchical clustering. It lists all of the participants at one end and then directs branches out from those participants who are similar and connects them with a node that represents a cluster. A dendrogram could be used, for example, to cluster individuals into various categories of HIV risk, depending on their number of sexual partners, their frequency of unprotected sex, and the perceived risk of their partners. Individuals who had few sexual partners with little or no unprotected sex and who perceived little or no partner risk of HIV infection would be branched into a cluster that could be labeled low risk, whereas individuals with high values on these three variables would branch into a high-risk cluster, with other individuals presumably clustering into a medium-risk group.