This study seeks to measure the time course of circulating proinflammatory markers (interleukin-1 beta [IL-1β], interleukin-6 [IL-6], tumor necrosis factor alpha [TNF-α], and C-reactive protein [CRP]) and salivary alpha amylase (sAA) following laboratory fear arousal. Further, this study seeks to implement neurocognitive, physiological, and self-report measures to explore the role of threat sensitivity as a predictor of this response. The broad research question seeks to better understand the relationship between neurocognitive fear and subsequent stress responding elicited by both the immune system (i.e., proinflammatory markers) and autonomic nervous system (i.e., sAA). In light of these aims, the primary outcomes of the current study are the proinflammatory markers (IL-1β, IL-6, TNF-α, CRP), while secondary outcomes consist of sAA, neurocognitive measures (i.e., dot-probe task), physiological correlates (i.e., heart rate, galvanic skin response), and self-report measures.

Inclusion Criteria:

• 18 - 40 years old
• Phobic or nonphobic fear of spiders.
• Willing to proceed through 5-stimulus fear hierarchy or maintain 7 or higher subjective units of distress through fear task (see Procedures section).

Exclusion Criteria:

• Lifetime history of serious mental illness
• Lifetime history of intellectual or developmental delays
• Lifetime history of chronic physical or medical illness including blood clotting disorders
• Lifetime history of allergies to latex
• Lifetime history of hormonal replacement therapy
• Lifetime history of blindness
• Lifetime history of blood/injection phobia or aversion to needles/injection (based on IPS-Anx and MQ)
• Substance abuse in the past 2 years
• Cigarette/tobacco use in the past 2 years
• Major depression within the past 12 months
• Traumatic stress within the past 12 months
• Pregnancy within the past 12 months
• Anesthesia within the past 3 months
• Night shift work within the past month
• Use of medication within the past month (except for oral contraception)
• Acute illness or infection within the past month
• Average sleep outside of 6 - 10 hours per night within the past month
• Average intake of 4 or more alcoholic beverages per week
• Average intake of 6 or more cups caffeine per day
• Use of marijuana within the week before the laboratory session
• Use of alcohol within the week before the laboratory session
• Body mass index outside of 18.5 - 24.9 range

Healthy participants exhibit high or low fear towards spiders.