Fear and Anxiety 6: Neurobiological Underpinnings of
Anxiety
A different neurological system guides the expression of anxiety and supports the notion that these
emotions are dis tinct because of different functional origins. LeDoux (1996) distinguishes fear
from anxiety when he states sources of anxiety are not directly linked to an external source.
Blanchard and Blanchard (1989) contrast fear and anxiety. They describe anxiety as more a state of
general arousal to potential threat and include apprehensive expectation, vigi lance and scanning,
and risk assessment, which is consis tent with Gray's (1982, 1995) comparator model of anxiety.
In Gray's model, the subiculum of the hippocampus is viewed as a comparator or a system, which,
moment to moment, "predicts the next likely event and compares this prediction to the actual event"
(Gray, 1995, p. 662). Gray's definition of anxiety includes a state evoked by response to threat
and punishment or threat and nonre ward or novelty where the reaction is to "stop, look, lis ten,
and get ready for action" (p. 661). Once a mismatch is identified between what the next likely
event should have been in light of the actual event, communication with the motor programming
system occurs. This com munication involves the prefrontal cortex, the nucleus accumbens, and
caudate motor system. Upon activation of the motor program, the memory system is updated.