Socially Evaluated Cold Pressor Test Research Articles

Stress Sensitizes the Brain: Increased Processing of Unpleasant Pictures after Exposure to Acute Stress

A key component of acute stress is a surge in vigilance that enables a prioritized processing of highly salient information to promote the organism's survival. In this study, we investigated the neural effects of acute stress on emotional picture processing. ERPs were measured during a deep encoding task, in which 40 male participants categorized 50 unpleasant and 50 neutral pictures according to arousal and valence. Before picture encoding, participants were subjected either to the Socially Evaluated Cold Pressor Test (SECPT) or to a warm water control procedure. The exposure to the SECPT resulted in increased subjective and autonomic (heart rate and blood pressure) stress responses relative to the control condition. Viewing of unpleasant relative to neutral pictures evoked enhanced late positive potentials (LPPs) over centro-parietal scalp sites around 400 msec after picture onset. Prior exposure to acute stress selectively increased the LPPs for unpleasant pictures. Moreover, the LPP magnitude for unpleasant pictures following the SECPT was positively associated with incidental free recall performance 24 hr later. The present results suggest that acute stress sensitizes the brain for increased processing of cues in the environment, particularly priming the processing of unpleasant cues. This increased processing is related to later long-term memory performance.

Stress effects on declarative memory retrieval are blocked by a β-adrenoceptor antagonist in humans

Previous evidence indicates that stress hormone effects on memory consolidation depend on concurrent emotional arousal-induced noradrenergic activity. Here, we asked whether this is also true for stress effects on memory retrieval and hypothesized that administration of the beta-adrenoceptor antagonist propranolol would block the effects of stress on declarative and procedural retrieval performance. In a double-blind, placebo-controlled, crossover study, 44 healthy young men learned a list of emotional and neutral words (declarative memory task) and completed a serial reaction time task (procedural memory task). On the following day, participants received either a placebo or 40 mg propranolol orally. One hour later, they were exposed to stress (socially evaluated cold pressor test (SECPT)) or a control condition 30 min prior to retention testing. Stress selectively enhanced the retrieval of emotionally arousing words. Pretreatment with propranolol had no effect on memory alone but blocked the stress-induced memory enhancement for emotional words, confirming the importance of noradrenergic activity in stress effects on memory retrieval. Memory for neutral words and the procedural task was neither affected by stress nor by propranolol. The present findings suggest that stress (hormone) effects on emotional memory retrieval require concurrent noradrenergic activation. Procedural memory retrieval and the retrieval of neutral verbal material appear to be less susceptible to stress.

HPA axis activation by a socially evaluated cold-pressor test

The cold-pressor test (CPT) in which subjects immerse their hand in ice water is among the most commonly used laboratory stressors. While the CPT elicits strong sympathetic nervous system activation, cortisol elevations indicative for the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis are moderate to low in response to the CPT. In the present study, we assessed whether cortisol responses to the CPT can be increased by adding social-evaluative elements. Therefore, 70 healthy young men immersed their hand in ice or warm water and were watched by a woman and videotaped during hand immersion or not. While the standard CPT and the socially evaluated cold-pressor test (SECPT) led to comparable increases in blood pressure and subjective stress ratings, saliva cortisol elevations and the proportion of subjects showing a saliva cortisol response (defined as increase >2nmol/l) were significantly higher after the SECPT. Social evaluation during hand immersion in warm water did not affect saliva cortisol levels suggesting that both social evaluation and a challenge are required for HPA axis activation. These findings indicate that the incorporation of social-evaluative elements increases HPA axis responses to the CPT. The SECPT can serve as a tool for future stress research.