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  • Several studies provide empirical evidence for the association between impulsivity and time perception. However, little is known about the neural substrates underlying this function. This investigation examined the influence of impulsivity on neural activation patterns during the encoding and reproduction of intervals with durations of 3, 9 and 18s using event-related functional magnetic resonance imaging (fMRI). Twenty-seven subjects participated in this study, including 15 high impulsive subjects that were classified based on their self-rating. FMRI activation during the duration reproduction task was correlated with measures of two self-report questionnaires related to the concept of impulsivity (Barratt Impulsiveness Scale, BIS; Zimbardo Time Perspective Inventory, ZTPI). Behaviorally, those individuals who under-reproduced temporal intervals also showed lower scores on the ZTPI future perspective subscale and higher scores on the BIS. FMRI activation revealed an accumulating pattern of neural activity peaking at the end of the 9- and 18-s intervals within right posterior insula. Activations of brain regions during the reproduction phase of the timing task, such as those related to motor execution as well as to the 'core control network' - encompassing the inferior frontal and medial frontal cortices, the anterior insula as well as the inferior parietal cortex - were significantly correlated with reproduced duration, as well as with BIS and ZTPI subscales. In particular, the greater activation in these regions the shorter were the reproduced intervals, the more impulsive was an individual and the less pronounced the future perspective. Activation in the core control network, thus, may form a biological marker for cognitive time management and for impulsiveness.

  • We examined the effects of symptom induction on neural activation in blood-injection-injury (BII) phobia. Nine phobic and 10 non-phobic subjects participated in an fMRI study in which they were presented with disorder-relevant, generally disgust-inducing, generally fear-evoking and neutral pictures. We observed diminished medial prefrontal cortex (MPFC) activity in patients compared to controls for phobia-relevant and disgust-inducing pictures. The MPFC has been shown to be critically involved in the automatic and effortful cognitive regulation of emotions. Therefore, the results might reflect reduced cognitive control of emotions in BII phobics during the experience of phobic symptoms as well as during states of disgust. The latter response component might be a result of the elevated disgust sensitivity of BII phobics.

  • The aim of this fMRI study was to explore brain structures that are involved in the processing of erotic and disgust-inducing pictures. The stimuli were chosen to trigger approach and withdrawal tendencies, respectively. By adding sadomasochistic (SM) scenes to the design and examining 12 subjects with and 12 subjects without sadomasochistic preferences, we introduced a picture category that induced erotic pleasure in one sample and disgust in the other sample. Since we also presented neutral pictures, all subjects viewed pictures of four different categories: neutral, disgust-inducing, erotic, and SM erotic pictures. The analysis indicated that several brain structures are commonly involved in the processing of disgust-inducing and erotic pictures (occipital cortex, hippocampus, thalamus, and the amygdala). The ventral striatum was specifically activated when subjects saw highly sexually arousing pictures. This indicates the involvement of the human reward system during the processing of visual erotica.

  • Sferics are electromagnetic impulses generated by electrical discharges during thunderstorms (lightning). One category is comprised of very low frequency electromagnetic waves, traveling over distances up to a thousand kilometers. Sferics have been shown to affect biological responses such as pain syndromes, reaction times, and power in the alpha band of the EEG. In the present study, in which 100 subjects took part, sferics have been studied in their relation to performance on a forced-choice extrasensory perception (ESP) task and to several secondary variables. The general finding is a negative correlation between ESP performance and sferics activity around the time of the session, most notably 24-48 hours prior to the session. Secondary variables appear to modulate this correlation, as has been found in previous research on sferics: the correlation tended to be stronger for persons who scored lower on Neuroticism and higher on the Openness scale of a Five-Factor Personality Questionnaire.

Last update from database: 04.06.25, 15:35 (UTC)

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