Assessing Post-Traumatic Tonic Immobility Responses: The Scale for Tonic Immobility Occurring Post-Trauma

Traumatic events and tonic immobility.

Tonic immobility is a basic defense strategy which has not been studied in depth in humans. Data suggest that it may be a relatively frequent phenomenon in victims of rape and sexual abuse, but its occurrence has not been systematically explored in other types of trauma. We carried out a retrospective study in a sample of 100 university students to establish whether tonic immobility varies depe...

Predictors of tonic immobility during traumatic events

Título: Predictores de la inmovilidad tónica ante eventos traumáticos. Resumen: La inmovilidad tónica (IT) es una posible reacción ante el peligro que es facilitada por el miedo intenso, la restricción física y la incapacidad percibida de escapar. Otras variables que podrían influir, tales como el tipo de eventos traumáticos, características de los mismos y características personales han sido p...

Psychometric properties of the Modified Tonic Immobility Scale

Cholinergic blockade and tonic immobility in chickens

To investigate the effects of cholinergic blockade on duration of tonic immobility (TI) and habituation to handling and the TI testing procedure, two groups of cockerel chicks were tested following injection with scopolamine or saline. One week later half of each group was given a second test for TI following injection with saline or scopolamine. Results indicated that scopolamine significantly...

On the Mechanism of Tonic Immobility in Vertebrates

Tonic immobility (Crozier, 1923), often more popularly known as "playing possum," "animal hypnosis," or even "feigning death," is exhibited by a great variety of animals. Rabaud (1919) discusses at length the condition as seen in arthropods. He points out that most arthropods have regions of the body which seem to be the loci of tactually excitable reflexes causing the animal to pass into a sta...