How Fear Differs From Anxiety
Animal models conceptualize anxiety as a response to potential danger while fear is a response to present danger. The way humans experience anxiety involves our capacity for higher thinking while the human experience of fear appears to be much the same as the animal model. This article examines these differences at both a phenomenological and neurological level and highlights implications for the treatment of conditioned fear in PTSD. The stimuli for human fear are sensory-perceptual, while the stimuli for most forms of anxiety are conceptual-linguistic. Individuals in a state of fear/terror undergo a radical shift from top-down to bottom-up processing in which access to conceptual-linguistic thought processes is severely restricted and the frontal regions of the cortex are no longer able to override impulses from brain stem and midbrain regions. Conditioned fear involves actual neurological changes in the limbic system. To overcome a traumatic memory, the individual must (1) gain some level of access to the bottom-up state in order to habituate or extinguish the conditioned fear response, and (2) also achieve access to the top-down state in order to process the fear experience and establish explicit memory. Effective treatments for trauma vary in regard to the degree to which they require the client to enter the bottom-up state, but all activate the fear state and eventually facilitate top-down processing.