Functional changes in brain activity after hypnosis in patients with dental phobia.
Visiting the dentist is often accompanied by apprehension or anxiety. People, who suffer from specific dental phobia (a disproportional fear of dental) procedures show psychological and physiological symptoms which make dental treatments difficult or impossible. For such purposes, hypnosis is often used in dental practice as an alternative for a number of treatments adjuvant or instead of sedation or general anesthetics, as the medication is often associated with risks and side effects. This is the first study to address the effects of a brief dental hypnosis on the fear-processing structures of the brain in dental phobics using functional magnetic resonance imaging (fMRI). 12 dental phobics (DP; mean 34.9years) and 12 healthy controls (CO; mean 33.2years) were scanned with a 3T MRI whole body-scanner observing brain activity changes after a brief hypnotic intervention. A fMRI event-related design symptom provocation task applying animated audio-visual pseudorandomized strong phobic stimuli was presented in order to maximize the fearful reactions during scanning. Control videos showed the use of familiar electronic household equipment. In the DP group, main effects of fear condition were found in the left amygdala and bilaterally in the anterior cingulate cortex (ACC), insula and hippocampus (R<L). During hypnosis, DP showed a significantly reduced activation in all of these areas. Reduced neural activity patterns were also found in the control group. No amygdala activation was detected in healthy subjects in the two experimental conditions. Compared to DP, CO showed less bilateral activation in the insula and ACC in the awake condition. Findings show that anxiety-provoking stimuli such as undergoing dental surgery, endodontic treatments or insufficient anesthetics, can be effectively reduced under hypnosis. The present study gives scientific evidence that hypnosis is a powerful and successful method for inhibiting the reaction of the fear circuitry structures.
Cognition: The Ultimate Brain
Robbins, T. W. (2011). Cognition: the ultimate brain function. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology, 36(1), 1.
This fourth issue of Neuropsychopharmacology Reviews focuses on cognition, the ultimate function of the brain. Arguably, most, if not all, of the major neuropsychiatric disorders such as schizophrenia, depression, and anxiety are cognitive in nature. Increasingly, it is realized that symptoms such as delusions and hallucinations, as well as other motivational and emotional signs, may have important cognitive elements. These arise, for example, from aberrant learning and associative factors, impaired attributional systems, and deficient control processes that are recruited to regulate emotional outputs and inappropriate behavioral responses. In general, cognition refers to those, sometimes mysterious, covert processes that have to be inferred from behavior. Cognitive processes include seemingly miraculous products of modular processing to produce, for example, representational knowledge such as language, and mechanisms that intervene between stimulus and response, often in a ‘top-down’ or ‘executive’ manner to mediate and resolve competition between what are often autonomous neurocognitive systems. Deficits in such cognitive processes as working memory are now acknowledged to be important factors in their own right that determine the likelihood of rehabilitation in disorders such as schizophrenia, and this has led to recent initiatives of the National Institute of Health such as the MATRICS project on the measurement and remediation of cognitive functions for the purpose of clinical trials (Green, 2007). Moreover, the state of psychiatric genetics is helping us to realize that the accurate definition of phenotype, and the corollary identification of cognitive endophenotypes, is a vital aim in any program that seeks to understand the genetic basis of psychopathology.