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Traumatic Brain Injury and Neurocognitive Disorders
Published in Gail S. Anderson, Biological Influences on Criminal Behavior, 2019
In another study, fMRI showed that psychopaths had reduced fear conditioning and reduced amygdala activity in comparison with controls.66 Several studies using fMRI have shown reduced amygdala activity in psychopaths in comparison with normal controls when shown images of amoral behavior and fear, and during aversive stimuli.63 Similarly, youth with conduct disorder (CD) or callous or unemotional traits showed reduced amygdala activity.63 The amygdala is important in fear and emotion conditioning and relearning, in which the brain learns from past mistakes. Fear conditioning occurs when one learns from an aversive experience; for example, touching a pot on the stove hurts, so the brain learns to avoid repeating the action. Psychopaths are known to have very little fear and do not learn from or consider the consequences of their actions. Therefore, a reduction in gray matter volume in the amygdala would explain a lack of fear awareness and ability to learn from past experiences and an inability to relate emotionally to important events.64 It has been suggested that reduced amygdala gray matter volume might be a risk factor for violence, although whether it is causal or treatable is unknown.64 Neuroimaging studies could be useful in assessing treatment options.64
A Biopsychosocial Approach to Anxiety
Published in Stephen M. Stahl, Bret A. Moore, Anxiety Disorders: A Guide for Integrating Psychopharmacology and Psychotherapy, 2013
Allison M. Greene, Christopher R. Bailey, Alexander Neumeister
Fear conditioning is one of the most widely used and successful paradigms in experimental research on anxiety. Its utility is underscored by its versatility. For example, neuroscientists have used fear conditioning in conjunction with positron emission tomography (PET) (Linnman et al. 2012) and functional magnetic resonance imaging (fMRI) (Bonne et al., 2008) to explore the neuro-circuitry of fear. Other lines of research employ fear-conditioning paradigms in symptom provocation studies to investigate physiological responses to fear (Acheson, Forsyth, & Moses, 2012). In its most fundamental use, many researchers use fear conditioning to study the nature of fear acquisition and maintenance. Indeed, much of the knowledge available on fear and anxiety is the result of research that has employed fear conditioning in one form or another (Beckers, Krypotos, Boddez, Effting, & Kindt, in press).
Neuropsychology of Cognitive Aging in Rodents
Published in David R. Riddle, Brain Aging, 2007
Joshua S. Rodefer, Mark G. Baxter
Although the spatial water maze has been frequently used as a common measure of hippocampus-dependent learning, other animal paradigms have attempted to contribute to and expand our understanding of the role of the hippocampus in learning and memory. Fear conditioning is a hippocampally mediated form of associative learning that requires an animal to associate a conditioned stimulus (CS) and a fear-producing unconditioned shock stimulus (US). For delay conditioning, the foot shock immediately follows the tone, whereas in trace conditioning, the tone and shock are often separated by a short interval (15 to 20 seconds) and then the retention of this learning is tested a discrete time late (e.g., 24 hours).
Fear Learning in Genital Pain: Toward a Biopsychosocial, Ecologically Valid Research and Treatment Model
Published in The Journal of Sex Research, 2023
Third, the operationalization of the US, i.e., the pain induction, needs to align with the clinical presentation of genital pain and mimic what women actually experience during sexual penetration to ensure an ecologically valid design. Administering electrical pain stimulation to the wrist, as in the study of Both et al. (2017), does not simulate penetration pain, especially because there is no solid evidence for an increased generalized pain response in women with genital pain (Dewitte et al., 2018; Hellman et al., 2015). Differences in fear learning will manifest more readily when using a disorder-specific US (Meulders, 2020; Pittig et al., 2018). This emphasizes the importance of using relevant CSs and USs and thinking about relevant control conditions and stimuli when developing experimental fear conditioning models. Dynamic sex stimuli such as videos may yield stronger conditioning effects than static sexual pictures (Dawson & Chivers, 2018). In addition, habituation of sexual stimuli occurs rapidly (Koukounas & Over, 1993; O’Donohue & Geer, 1985); therefore, the number of trials should be limited, and a rapid stimulus sequence is recommended.
Systems consolidation and fear memory generalisation as a potential target for trauma-related disorders
Published in The World Journal of Biological Psychiatry, 2022
Lizeth K. Pedraza, Rodrigo O. Sierra, Lucas de Oliveira Alvares
The assumption about the influences of individual factors is not different in animal research. Shumake et al. (2018) developed a data-driven approach in order to define a standard criterion for remission after extinction and identify individual differences in the rate of fear attenuation. The remission was achieved when the animals behaved as if they had never been conditioned (low fear responses). The criterion was based on a logistic regression analysis applied to freezing data from a large sample of rats that either underwent fear conditioning or did not. As evidenced in humans, animals can be clustered according to phenotypic extinction, highlighting the individual responses in rodents to the same training and extinction protocol. This result matches with our recent findings demonstrating that naïve animals are differentially susceptible to discrimination or generalisation after contextual fear conditioning. This heterogeneity affects the subsequent fear extinction outcome (Pedraza et al. 2019). Similar correlative individualities were found by Monfils et al. (2019) showing that CO2 reactivity is able to predict extinction phenotype in rats.
Association between sensory processing and dental fear among female undergraduates in Japan
Published in Acta Odontologica Scandinavica, 2019
Mika Ogawa, Nozomu Harano, Kentaro Ono, Yukiyo Shigeyama-Tada, Tomoko Hamasaki, Seiji Watanabe
Dental treatment-related stimuli provoke dental fear via classical conditioning [18], it may also provoke dental fear through biological and genetic mechanisms. Patients with dental fear can be highly sensitive to dental treatment (e.g. the sight of a needle, sensation of the drill, taste of medications, and bright dental light) even if it is a painless procedure. It is suggested that dental fear is associated with lower distress tolerance to aversive or uncomfortable emotional states [23], and in turn, lower distress tolerance might be associated with higher sensitivity to sensation and/or emotion. We postulate that patients with hypersensitivity to sensation can have more to negative responses to dental procedures. Moreover, fear conditioning might happen more easily for individuals with an extreme sensory processing pattern who have negative experiences, resulting in the subsequent development/maintenance of fear.