When Fear Is Near: Threat Imminence Elicits Prefrontal-Periaqueductal Gray Shifts in Humans

• DOI: 10.1126/science.1144298
• Publication Date: 2007-08-23T20:53:54Z
• Authors: Dean Mobbs; Predrag Petrovic; Jennifer L. Marchant; Demis Hassabis; Nikolaus Weiskopf; Ben Seymour; Raymond J. Dolan; Christopher D. Frith
• Keywords: Periaqueductal gray; Ventromedial prefrontal cortex; Gray (unit); Anticipation (artificial intelligence)

Humans, like other animals, alter their behavior depending on whether a threat is close or distant. We investigated spatial imminence of by developing an active avoidance paradigm in which volunteers were pursued through maze virtual predator endowed with ability to chase, capture, and inflict pain. Using functional magnetic resonance imaging, we found that as the grew closer, brain activity shifted from ventromedial prefrontal cortex periaqueductal gray. This shift showed maximal expression when high degree pain was anticipated. Moreover, imminence-driven gray correlated increased subjective dread decreased confidence escape. Our findings cast light neural dynamics anticipation have implications for neurobiology human anxiety-related disorders.