Investigating sustained attention in contextual threat using steady-state VEPs evoked by flickering video stimuli

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 (32s 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. The current results contribute to our understanding of the visuocortical processing of more ecologically valid context stimuli and its modulation during situations of potential threat. Besides clear indices of aversive learning, we provide evidence for a disruption of the visuocortical signal by the dynamic sensory input which is enhanced for motivationally significant stimuli.

Automated summary

Anxiety is characterized by anxious anticipation and heightened vigilance to uncertain threat. Context conditioning can experimentally induce anxiety, and dynamic sensory input from video presentation disrupts the visuocortical signal, particularly for motivationally significant and threatening contexts.