catatonia

n. a state of muscular rigidity or other disturbance of motor behavior, such as catalepsy, extreme overactivity, or adoption of bizarre postures. It is most frequently observed in catatonic schizophrenia, but it can also occur with other disorders, such as bipolar disorder, major depressive disorder, and neurological conditions such as encephalitis, among others. Also called catatonic state. —catatonic adj.

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Psychology term of the day

November 18th 2024

center–surround antagonism

a characteristic of the receptive fields of many visual and somatosensory neurons in which stimulation in the center of the receptive field evokes opposite responses to stimulation in the periphery. Thus, some neurons depolarize with center stimulation and hyperpolarize when the same stimulus appears in the surrounding region of the receptive field, whereas other neurons have the opposite pattern of responses. Center–surround antagonism greatly increases the sensitivity of the nervous system to contrast. See also off response; on response; simple cell.