How orienting and defense drives oscillatory responses in human visual and motor cortical circuits during viewing of threat pictures: Evidence from ssVEPs and beta band desynchronization.

When encountering a potential threat, humans and animals engage in different strategic behaviors, such as orienting and defense, depending on the perceived threat imminence. Orienting has been associated with attentional immobility and heightened 'stimulus intake,' while defense is linked to action preparation and 'sensory rejection'. First, we replicated previous findings showing that humans exhibit either heart rate (HR) acceleration or deceleration in response to the same threat-related picture content. Second, we provide direct evidence that orienting, as indexed by increased HR deceleration, leads to enhanced visuocortical processing of threat-related images, as measured by steady-state visual evoked potentials (ssVEPs). Excitation of motor-relevant cortical circuits, assessed by beta-band desynchronization, was reduced in relation to HR deceleration. Conversely, HR acceleration was associated with a reversed pattern: reduced visual processing and increased excitation of cortical motor circuits, as reflected in ssVEP and beta-band modulations. While self-reported measures of state and trait anxiety, along with valence, arousal, and dominance ratings, did not account for variations in HR response patterns, faster avoidance motor responses were linked to defensive HR changes, and longer avoidance latencies were associated with orienting-like HR changes.