@article{GrussWieserSchweinbergeretal.2012,
  author    = {Gruss, L. Forest and Wieser, Matthias J. and Schweinberger, Stefan R. and Keil, Andreas},
  title     = {Face-evoked steady-state visual potentials: effects of presentation rate and face inversion},
  series = {Frontiers in Human Neuroscience},
  volume    = {6},
  journal   = {Frontiers in Human Neuroscience},
  number    = {316},
  doi       = {10.3389/fnhum.2012.00316},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134399},
  year      = {2012},
  abstract  = {Face processing can be explored using electrophysiological methods. Research with event-related potentials has demonstrated the so-called face inversion effect, in which the N170 component is enhanced in amplitude and latency to inverted, compared to upright, faces. The present study explored the extent to which repetitive lower-level visual cortical engagement, reflected in flicker steady-state visual evoked potentials (ssVEPs), shows similar amplitude enhancement to face inversion. We also asked if inversion-related ssVEP modulation would be dependent on the stimulation rate at which upright and inverted faces were flickered. To this end, multiple tagging frequencies were used (5, 10, 15, and 20 Hz) across two studies (n=21, n=18). Results showed that amplitude enhancement of the ssVEP for inverted faces was found solely at higher stimulation frequencies (15 and 20 Hz). By contrast, lower frequency ssVEPs did not show this inversion effect. These findings suggest that stimulation frequency affects the sensitivity of ssVEPs to face inversion.},
  language  = {en}
}
@article{StegmannAndreattaPaulietal.2023,
  author    = {Stegmann, Yannik and Andreatta, Marta and Pauli, Paul and Keil, Andreas and Wieser, Matthias J.},
  title     = {Investigating sustained attention in contextual threat using steady-state VEPs evoked by flickering video stimuli},
  series = {Psychophysiology},
  volume    = {60},
  journal   = {Psychophysiology},
  number    = {5},
  doi       = {10.1111/psyp.14229},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312430},
  year      = {2023},
  abstract  = {Anxiety is characterized by anxious anticipation and heightened vigilance to uncertain threat. However, if threat is not reliably indicated by a specific cue, the context in which threat was previously experienced becomes its best predictor, leading to anxiety. A suitable means to induce anxiety experimentally is context conditioning: In one context (CTX+), an unpredictable aversive stimulus (US) is repeatedly presented, in contrast to a second context (CTX-), in which no US is ever presented. In this EEG study, we investigated attentional mechanisms during acquisition and extinction learning in 38 participants, who underwent a context conditioning protocol. Flickering video stimuli (32 s clips depicting virtual offices representing CTX+/-) were used to evoke steady-state visual evoked potentials (ssVEPs) as an index of visuocortical engagement with the contexts. Analyses of the electrocortical responses suggest a successful induction of the ssVEP signal by video presentation in flicker mode. Furthermore, we found clear indices of context conditioning and extinction learning on a subjective level, while cortical processing of the CTX+ was unexpectedly reduced during video presentation. The differences between CTX+ and CTX- diminished during extinction learning. Together, these results indicate that the dynamic sensory input of the video presentation leads to disruptions in the ssVEP signal, which is greater for motivationally significant, threatening contexts.},
  language  = {en}
}