Category: Adult Anxiety
Disinhibition predicts increased physiological arousal to safety cues during fear learning
Kristen E. Frosio*, Jake D. Kraft, Danielle L. Taylor, Evan J. White, & DeMond M. Grant
Fear learning has been found to play a crucial role in the etiology of anxiety disorders, and is one of the most well established models of the acquisition of clinically relevant fear and anxiety. Several studies have demonstrated increased physiological responding to cues that indicate both threat (CS+) and safety (CS-) in clinically anxious individuals compared to healthy controls. This suggests that individuals vulnerable to anxiety experience excessive physiological arousal to neutral stimuli. However, there is little information about factors that lead to this heightened responding to safety cues, although deficits in inhibition may play a role. One useful method for testing this hypothesis is pre-pulse inhibition (PPI), a neurobiological marker of higher order inhibition processes. PPI includes the ability to filter external sensory stimuli in order to appropriately respond to environmental stimuli. Thus, the current study evaluated whether pre-pulse inhibition predicted physiological activation related to safety cues during fear learning.
One hundred and eight participants were recruited from a large Midwestern university with a mean age of 19 (SD = 1.5); 69% of the sample was female (N = 75). Participants completed a fear learning task in which large and small circles (counterbalanced) served as the conditioned threat cue (CS+) and conditioned safety cue (CS-) while galvanic skin response was recorded. The largest and smallest circles paired with an aversive unconditioned stimulus (UCS) were counterbalanced across subjects. The fear learning task consisted of 12 CS+ trials and 12 CS- trials with CS+ reinforced 9 out of 12 trials (75% reinforcement schedule). Weaker pre-pulse stimuli (20ms at 90dB) were delivered on 5 out of 9 reinforced CS+ trials (55% of trials) to measure PPI.
Regression analysis evaluated whether PPI predicted GSR response to CS+ and CS- cues. As hypothesized, PPI significantly predicted GSR magnitude for safety stimuli (β = -0.196, p = .043). More specifically, as PPI decreased, physiological activation to safety cues increased. PPI did not predict GSR magnitude to threat stimuli. These results show that increased ability to inhibit sensory stimuli is associated with decreased anxious responding to neutral stimuli. This suggests that inhibitory processes are important to appropriately responding to fear and safety cues. Future research should evaluate further the relationship between other physiological markers of anxiety and pre-pulse inhibition, exploring how PPI may predict overgeneralization as a result of cue discrimination deficiencies.
Kristen Frosio– Graduate Student Researcher, Oklahoma State University, Stilwater, Oklahoma
Jacob Kraft– Graduate Student, Oklahoma State University
Danielle Taylor– Graduate Research Assistant, Oklahoma State University, Stillwater, Oklahoma
Evan White– Graduate Student, Oklahoma State University, Tulsa, Oklahoma
DeMond Grant– Oklahoma State University
Graduate Student Researcher
Oklahoma State University
Graduate Research Assistant
Oklahoma State University