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Abstract

Reviews data from a series of studies designed to test the hypothesis that tonic immobility (TI) represents an innate fear-potentiated response. In experiments using mostly 3–4 wk old Production Red chickens, fear was operationally defined by behavioral changes associated with long immobility reactions (i.e., defecation) and by certain manipulations, including (a) tranquilization, (b) intense auditory stimulation, (c) punishment, and (d) predatory confrontation with live and simulated stimuli, artificial eyes, and a visual cliff. Findings suggest that fear, while not the cause of TI, is an important antecedent condition for manipulating response duration and susceptibility. (61 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
... Tonic immobility is an innate behavioral response to predators in birds [88][89][90] , which has been counter-selected during the divergence process in these two lines. A quail was placed and maintained on its back by the experimenter's hand for 10 s (induction) in a plastic U-shaped cradle (20 [length] x 10 [width] x 10 [height] cm) covered with a cloth. ...
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Many species, including humans exhibit a wide range of social behaviors that are crucial for the adaptation and survival of most species. Brain organization and function are shaped by genetic and environmental factors, although their precise contributions have been relatively understudied in the context of artificial selection. We used divergent lines of quail selected on their high versus low level of motivation to approach a group of conspecifics (S + and S-, respectively) to investigate the influence of genetic selection and early social environment on sociability. We observed distinct sex- and brain-region-specific expression patterns of three neuronal markers: mesotocin, and vasotocin, the avian homologues of mammalian oxytocin and vasopressin, as well as aromatase, the enzyme that converts androgens into estrogens. These markers displayed pronounced and neuroanatomically specific differences between S + and S- quail. Additionally, in a second experiment, we assessed the influence of early social environment on social skills in juvenile birds. Mixing S + and S- resulted in more S- males approaching the group without affecting the sociability of S + or other behaviors, suggesting that the early social environment may influence the results of genetic selection. In conclusion, the divergent quail lines offer a valuable model for unraveling the neuronal and behavioral mechanisms underlying social behaviors.
... Many predators do not consume dead prey and thus this behaviour is supposed to be an antipredator behaviour, increasing survival (Sazima, 1974;Teles et al., 2017). Tonic immobility often occurs after prey and predator are in physical contact and thus it is believed to be the last attempt of the prey to survive (Gallup, 1977;Humphreys & Ruxton, 2018, but see Damas-Moreira, 2021, for an example of spontaneous tonic immobility). Interestingly, in the Central American cichlid (Parachromis friedrichsthalii), tonic immobility has also been described as a predatory behaviour, which individuals display to mimic a rotten fish to attract prey that scavenge on dead bodies (Tobler, 2005). ...
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Tonic immobility is an antipredator defence in which the prey animal remains motionless after physical contact with the predator, pretending to be dead. This behaviour has been observed among a variety of taxa but has received only little attention in amphibian larvae. During our field studies with fire salamander larvae, we observed that larvae from different habitats display tonic immobility after handling. In our study site, we find larvae in pond and stream habitats, that differ in several aspects such as their stress response and their risk-taking behaviour, likely caused by the very different habitat conditions. We measured the time that the tonic immobility behaviour was displayed but found no difference between larvae from the two habitat types. Likewise, we also found no correlation between the size of the larvae and the duration of displaying the behaviour. In conclusion, we found that fire salamander larvae show tonic immobility, but found no evidence that the different habitat conditions influence the tonic immobility behaviour.
... TI is a product of the defence cascade that involves stress, fear, the threat to life, and is one of four outcomes that manifest when the body system is highly stressed: fight, flight, freeze, and TI [16]. The onset of TI manifests itself as a reversible catatonic-like state with muscle hyperor hypo-tonicity; tremors, trembling or shaking; the inability to vocalise or control the muscles and movement, feeling of numbness, cold, detachment from self and the immediate environment; and relative unresponsiveness to external stimuli in a context of the inescapable threat [4,14,17]. Other signs of TI include intense fright expressed at a later recant with phrases such as "I was scared stiff" and "I was frozen with fear" [18]. ...
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Tonic immobility (TI) is a common uncontrollable autonomic mammalian response to an extremely fearful situation. It is one of the most immediate devastating consequences of rape and remains poorly understood. While controversies over its definition persist among researchers, this also reflects on the care for and support to victims. The study aimed to explore and describe the onset of TI and the meaning attached to the experience among women raped victims in Nigeria. The study design was the qualitative narrative inquiry approach. Criterion and purposive sampling were conducted across four post-rape care facilities in Lagos, Nigeria, to recruit 13 participants. In-depth face-to-face interviews were conducted using a semi-structured interview guide to generate data that were thematically analysed. The findings of the study revealed five themes relating to the onset of TI as follows: the first two focused on the experience of TI: (1) the onset of TI prior to rape due to perceived imminent danger, (2) the onset of TI as a self-protection mechanism from further harm) while the last three relate to the meaning-making of the experience of TI (3) self-loathing as a meaning attached to TI, (4) suicidal ideations as a meaning attached to TI, and (5) divine intervention as a meaning attached to TI. Conclusion: The findings underscore the experiences and meanings that participants attach to TI following rape. There is a strong likelihood that tonic-immobility is not an uncommon experience amongst rape victims, but that in the absence of research, specialized care on the condition, and its associated consequences will haunt many women, affecting their psychological well-being and their entire quality of life. Describing the phenomenon as it is experienced by the participants is critical because understanding the condition is the first step toward effective appropriate management.
... It has long been recognized that defecation is a valid measure of conditioned fear and is closely related to freezing (Hunt & Otis, 1953). This close relationship (see also Figure 2 in Fanselow, 1986) is noteworthy given recent writings about the functional significance of a variety of behaviors motivated or organized by fear (e.g., Fanselow, 1984;Gallup, 1977). Prominent among these behaviors are freezing, fleeing, fear-potentiated startle, conditioned analgesia, and tonic immobility. ...
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In a sample of 208 Holtzman-descended albino rats, we found evidence with 4 measures of conditioning (freezing, defecation, side crossing, and nose crossing) that a single 2-s, 1.0-mA immediate shock could condition fear to a context (Experiments 1, 2, and 4). When we reduced the shock intensity to 0.5 mA, we obtained a complete immediate-shock conditioning deficit according to all measures in Experiment 3 and to all but the defecation measure in Experiment 4. Results suggest two conclusions: (a) Differences in shock potency between laboratories may help explain discrepant findings about whether immediate shock supports contextual conditioning; (b) theories of contextual conditioning need a mechanism that permits that conditioning to result from immediate shock.
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Vertebrates, including humans exhibit a wide range of social behaviors that are crucial for the adaptation and survival of most species. The brain organization and function are shaped by genetic and environmental factors, although their precise contributions have been poorly explored in the context of artificial selection. We used divergent lines of quail selected on their high versus low level of motivation to approach a group of conspecifics (S+ and S-, respectively) to investigate the influence of genetic selection and early social environment on sociability. We observed distinct sex- and brain-region-specific expression patterns of three neuronal markers: mesotocin, and vasotocin, the avian homologues of mammalian oxytocin and vasopressin, as well as aromatase, the enzyme that converts androgens into estrogens. These markers displayed pronounced and neuroanatomically specific differences between S+ and S- quail. Additionally, we assessed the influence of early social environment on social skills in adolescent birds. Mixing S+ and S- resulted in more S- males approaching the group without affecting the sociability of S+ or other behaviors, suggesting that the early social environment may influence the results of genetic selection. In conclusion, the divergent quail lines offer a valuable model for unraveling the neuronal and behavioral mechanisms underlying social behaviors.
Chapter
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Notes that, because of its sensitivity to various manipulations associated with either increases or decreases in aversive stimulation, tonic immobility seems to qualify as a fear reaction. The present experiments provided an independent assessment of the aversive properties of immobility induction. In Exp I, using 32 Production Red day-old chickens, a cue previously paired with onset of immobility suppressed activity in a stabilimeter. Similarly, in Exp II, with 24 Production Red day-old chickens, response-contingent immobilization produced punishmentlike effects in an instrumental conditioning paradigm. Taken together, results support the notion that the physical restraint involved in immobility induction is an aversive event.
Chapter
The researchers who, three centuries ago, applied the term “hypnosis” to catalepsy in animals most probably did so because of the similar appearance of these two conditions. From the results of subsequent investigations, it is justifiable to regard the term “animal hypnosis” as highly appropriate. Motor inhibition in animals and the state of hypnotic trance in man appear to be genetically interrelated, have a similar adaptive significance and, in all probability, possess certain common neurophysiological mechanisms.
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Two experiments were performed to investigate the effects of age and prior testing on immobility reactions of chickens from two through 66 days of age. In each experiment, one group was tested repeatedly while different subgroups were tested only once at the ages of the repeated test group and then discarded. Tests were conducted by turning each of the 305 birds on its side and holding it down for 15 seconds after which the immobility reactions were observed and timed. The immobility reaction was found to be virtually absent until seven to ten days of age, after which the response reached and maintained the arbitrary maximum duration of twelve minutes until birds were 59 days of age. Prior testing and the handling associated with it significantly reduced duration and incidence of immobility at all ages after nine days. The results are interpreted in terms of immobility as part of a fear reaction.