@article{GuhnDreslerAndreattaetal.2014,
  author    = {Guhn, Anne and Dresler, Thomas and Andreatta, Marta and M{\"u}ller, Laura D. and Hahn, Tim and Tupak, Sara V. and Polak, Thomas and Deckert, J{\"u}rgen and Herrmann, Martin J.},
  title     = {Medial prefrontal cortex stimulation modulates the processing of conditioned fear},
  doi       = {10.3389/fnbeh.2014.00044},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111309},
  year      = {2014},
  abstract  = {The extinction of conditioned fear depends on an efficient interplay between the amygdala and the medial prefrontal cortex (mPFC). In rats, high-frequency electrical mPFC stimulation has been shown to improve extinction by means of a reduction of amygdala activity. However, so far it is unclear whether stimulation of homologues regions in humans might have similar beneficial effects. Healthy volunteers received one session of either active or sham repetitive transcranial magnetic stimulation (rTMS) covering the mPFC while undergoing a 2-day fear conditioning and extinction paradigm. Repetitive TMS was applied offline after fear acquisition in which one of two faces (CS+ but not CS-) was associated with an aversive scream (UCS). Immediate extinction learning (day 1) and extinction recall (day 2) were conducted without UCS delivery. Conditioned responses (CR) were assessed in a multimodal approach using fear-potentiated startle (FPS), skin conductance responses (SCR), functional near-infrared spectroscopy (fNIRS), and self-report scales. Consistent with the hypothesis of a modulated processing of conditioned fear after high-frequency rTMS, the active group showed a reduced CS+/CS- discrimination during extinction learning as evident in FPS as well as in SCR and arousal ratings. FPS responses to CS+ further showed a linear decrement throughout both extinction sessions. This study describes the first experimental approach of influencing conditioned fear by using rTMS and can thus be a basis for future studies investigating a complementation of mPFC stimulation to cognitive behavioral therapy (CBT).},
  language  = {en}
}
@article{HahnDreslerPykaetal.2013,
  author    = {Hahn, Tim and Dresler, Thomas and Pyka, Martin and Notebaert, Karolien and Fallgatter, Andreas J.},
  title     = {Local Synchronization of Resting-State Dynamics Encodes Gray's Trait Anxiety},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0058336},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131057},
  pages     = {e58336},
  year      = {2013},
  abstract  = {The Behavioral Inhibition System (BIS) as defined within the Reinforcement Sensitivity Theory (RST) modulates reactions to stimuli indicating aversive events. Gray's trait Anxiety determines the extent to which stimuli activate the BIS. While studies have identified the amygdala-septo-hippocampal circuit as the key-neural substrate of this system in recent years and measures of resting-state dynamics such as randomness and local synchronization of spontaneous BOLD fluctuations have recently been linked to personality traits, the relation between resting-state dynamics and the BIS remains unexplored. In the present study, we thus examined the local synchronization of spontaneous fMRI BOLD fluctuations as measured by Regional Homogeneity (ReHo) in the hippocampus and the amygdala in twenty-seven healthy subjects. Correlation analyses showed that Gray's trait Anxiety was significantly associated with mean ReHo in both the amygdala and the hippocampus. Specifically, Gray's trait Anxiety explained 23\% and 17\% of resting-state ReHo variance in the left amygdala and the left hippocampus, respectively. In summary, we found individual differences in Gray's trait Anxiety to be associated with ReHo in areas previously associated with BIS functioning. Specifically, higher ReHo in resting-state neural dynamics corresponded to lower sensitivity to punishment scores both in the amygdala and the hippocampus. These findings corroborate and extend recent findings relating resting-state dynamics and personality while providing first evidence linking properties of resting-state fluctuations to Gray's BIS.},
  language  = {en}
}
@article{HahnKarolienDresleretal.2014,
  author    = {Hahn, Tim and Karolien, Hilde and Dresler, Thomas and Kowarsch, Linda and Reif, Andreas and Fallgatter, Andreas J.},
  title     = {Linking online gaming and addictive behavior: converging evidence for a general reward deficiency in frequent online garners},
  series = {Frontiers in Behavioral Neuroscience},
  volume    = {14},
  journal   = {Frontiers in Behavioral Neuroscience},
  number    = {8},
  issn      = {1662-5153},
  doi       = {10.3389/fnbeh.2014.00385},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114737},
  year      = {2014},
  abstract  = {Millions of people regularly play so-called massively multiplayer online role playing games (MMORPGs). Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal, and craving have been described. Based on behavioral, resting state, and task-related neuroimaging data, we test whether frequent players of the MMORPG "World of VVarcraft" (WoW) similar to drug addicts and individuals with an increased risk for addictions show a generally deficient reward system. In frequent players of the MMORPG "World of VVarcraft" (WoW-players) and in a control group of non-gamers we assessed (1) trait sensitivity to reward (SR), (2) BOLD responses during monetary reward processing in the ventral striatum, and (3) ventral-striatal resting-state dynamics. We found a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state). On the behavioral level, we found differences in trait SR, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers.},
  language  = {en}
}