TY  - JOUR
A1  - Guhn, Anne
A1  - Dresler, Thomas
A1  - Andreatta, Marta
A1  - Müller, Laura D.
A1  - Hahn, Tim
A1  - Tupak, Sara V.
A1  - Polak, Thomas
A1  - Deckert, Jürgen
A1  - Herrmann, Martin J.
T1  - Medial prefrontal  cortex stimulation modulates the processing of conditioned fear
N2  - 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).
KW  - fear conditioning
KW  - memory consolidation and extinction
KW  - learning
KW  - transcranial magnetic stimulation (TMS)
KW  - medial prefrontal cortex (mPFC)
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111309
ER  - 
TY  - JOUR
A1  - Manish, Asthana
A1  - Nueckel, Katharina
A1  - Mühlberger, Andreas
A1  - Neueder, Dorothea
A1  - Polak, Thomas
A1  - Domschke, Katharina
A1  - Deckert, Jürgen
A1  - Herrmann, Martin J.
T1  - Effects of transcranial direct current stimulation on consolidation of fear memory
JF  - Frontiers in Neuropsychiatric Imaging and Stimulation
N2  - It has been shown that applying transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) influences declarative memory processes. This study investigates the efficacy of tDCS on emotional memory consolidation, especially experimental fear conditioning. We applied an auditory fear-conditioning paradigm, in which two differently colored squares (blue and yellow) were presented as conditioned stimuli (CS) and an auditory stimulus as unconditioned stimulus (UCS). Sixty-nine participants were randomly assigned into three groups: anodal, cathodal, and sham stimulation. The participants of the two active groups (i.e., anodal and cathodal) received tDCS over the left DLPFC for 12 min after fear conditioning. The effect of fear conditioning and consolidation (24 h later) was measured by assessing the skin conductance response (SCR) to the CS. The results provide evidence that cathodal stimulation of the left DLPFC leads to an inhibitory effect on fear memory consolidation compared to anodal and sham stimulation, as indicated by decreased SCRs to CS+ presentation during extinction training at day 2. In conclusion, current work suggests that cathodal stimulation interferes with processes of fear memory consolidation.
KW  - transcranial direct current stimulation
KW  - dorsolateral prefrontal cortex
KW  - fear conditioning
KW  - fear memory consolidation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-97294
ER  -