Evidence for the integrity of central processing during tonic immobility

Blood pressure and heart rate during tonic immobility in the black tipped reef shark,Carcharhinus melanoptera

“…Thus, while the brain stem reticular formation in response to TI induction stimuli (inversion, air exposure) inhibits spinal motoneurons (Klemm 1976) the vagal centres (see Short et al 1977) are able to receive information from the ventilatory system and alter heart rate. The integrity of brain(stem) function during TI has been noted in birds (Gallup et al 1980) and is a key feature in the behavioral significance of the response. While the biological significance of the response is not clear the two most likely situations in which TI would be useful include "playing possum" in response to a predator at a distance (Gallup et al 1980) and immobility associated with reproductive activities (Whitmann et al 1986).…”

“…The integrity of brain(stem) function during TI has been noted in birds (Gallup et al 1980) and is a key feature in the behavioral significance of the response. While the biological significance of the response is not clear the two most likely situations in which TI would be useful include "playing possum" in response to a predator at a distance (Gallup et al 1980) and immobility associated with reproductive activities (Whitmann et al 1986). In both of these situations it seems that awareness of and ability to respond to external stimuli during TI would be of great advantage.…”

Factor structure of the Tonic Immobility Scale in female sexual assault survivors: An exploratory and Confirmatory Factor Analysis

“…The TIS includes two items designed to assess depersonalization and derealization, namely, ''felt detached from yourself'' and ''felt detached from what was going on around you,'' respectively. Based on findings demonstrating that animals remain conscious and actively scan their environment for opportunities to escape during TI (Gallup, Boren, Suarez, Wallnau, & Gagliardi, 1980), we predicted that the depersonalization item, but not the item reflecting derealization, would load on the same factor as physical immobility. In fact, we anticipated that depersonalization would be the clearest psychological parallel to the shutting down processes seen in TI.…”

Induction and duration of tonic immobility in the lemon shark, Negaprion brevirostris

“…While in the tonic immobility state some animals are capable of both retrieval and extinction of previously learned associations (Gallup et al 1980). Tonic immobility can be induced by various procedures which place the subject in an 'unnatural' posture or situation, which has the effect of altering the usual course of its sensorimotor and emotional interchanges with its environment (Chertok 1968).…”