International journal of psychophysiology : official journal of the International Organization of Psychophysiology
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Int J Psychophysiol · Jun 2012
Randomized Controlled TrialInvestigating the affective component of pain: no startle modulation by tonic heat pain in startle responsive individuals.
Experimental tonic pain has been assumed to equal clinical pain by triggering sizeable affective responses. A psycho-physiological indicator of defensive affective-motivational responses is the startle reflex. However, earlier studies have not provided unequivocal evidence for a potentiation of the startle reflex during tonic contact heat pain. ⋯ Our findings indicate that tonic heat pain does not trigger defensive affective-motivational responses as measured by the startle reflex when it is applied in a predictable and thus non-threatening fashion. Future research should investigate the effects of manipulations of threat on startle responses to painful stimulation.
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Int J Psychophysiol · May 2012
Randomized Controlled TrialPreexposure to (un)predictable shock modulates discriminative fear learning between cue and context: an investigation of the interaction between fear and anxiety.
It has been suggested that prior experiences with unpredictable/uncontrollable stressors facilitate subsequent fear learning and the development of anxiety disorders. However, animal research documents that preexposure to unpredictable stressors (USs) impede later fear conditioning with that US. These differential predictions were tested in a human experimental model of clinical anxiety. ⋯ Fear responding was assessed through startle modulation and online shock-expectancy ratings. Results showed retarded fear learning in the unpredictable groups compared to the predictable group. We argue that prior experiences of unpredictability may still contribute to the development of clinical anxiety, by impeding adaptive fear learning and perpetuating the perception of unpredictability/uncontrollability.
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Int J Psychophysiol · Apr 2011
Randomized Controlled Trial Comparative StudyHigh pain sensitivity is distinct from high susceptibility to non-painful sensory input at threshold level.
Individuals may differ considerably in their sensitivity towards various painful stimuli supporting the notion of a person as stoical or complaining about pain. Molecular and functional imaging research provides support that this may extend also to other sensory qualities. Whether a person can be characterized as possessing a generally high or low sensory acuity is unknown. ⋯ Moreover, no clustering was obtained for thresholds to both painful and non-painful stimuli together. Thus, individuals could not be characterized as highly sensitive (or insensitive) to all chemical stimuli no matter of evoking pain. This suggests that pain is primarily a singular sensory perception distinct from others such as olfaction or taste.
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Int J Psychophysiol · Apr 2011
Randomized Controlled Trial Comparative StudyAre salivary gonadal steroid concentrations influenced by acute psychosocial stress? A study using the Trier Social Stress Test (TSST).
It is well documented that acute stress activates the sympathetic nervous system (SNS) and the Hypothalamus-Pituitary-Adrenal (HPA) axis. Results regarding the hypothalamus pituitary gonadal (HPG) axis, in contrast, are less consistent. Stress-associated increases as well as decreases have been reported for testosterone and estradiol. ⋯ In contrast, acute stress did not affect testosterone-, progesterone-, and estradiol-concentrations. The results of the present study suggest that an acute psychosocial laboratory stress or has no strong rapid effects on salivary gonadal steroids. In line with several previous studies the findings might suggest that stress-induced changes in gonadal steroids occur in response to physical stressors, to competitive stressors or to more severe stressors only.
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Int J Psychophysiol · Nov 2009
Randomized Controlled TrialDistinct EEG effects related to neurofeedback training in children with ADHD: a randomized controlled trial.
In a randomized controlled trial, neurofeedback (NF) training was found to be superior to a computerised attention skills training concerning the reduction of ADHD symptomatology (Gevensleben et al., 2009). The aims of this investigation were to assess the impact of different NF protocols (theta/beta training and training of slow cortical potentials, SCPs) on the resting EEG and the association between distinct EEG measures and behavioral improvements. In 72 (of initially 102) children with ADHD, aged 8-12, EEG changes after either a NF training (n=46) or the control training (n=26) could be studied. ⋯ Protocol-specific EEG changes (theta/beta training: decrease of posterior-midline theta activity; SCP training: increase of central-midline alpha activity) were associated with improvements in the German ADHD rating scale. Related EEG-based predictors were obtained. Thus, differential EEG patterns for theta/beta and SCP training provide further evidence that distinct neuronal mechanisms may contribute to similar behavioral improvements in children with ADHD.