Biological psychology
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Biological psychology · Feb 2013
Randomized Controlled TrialHormonal contraception use alters stress responses and emotional memory.
Emotionally arousing material is typically better remembered than neutral material. Since norepinephrine and cortisol interact to modulate emotional memory, sex-related influences on stress responses may be related to sex differences in emotional memory. Two groups of healthy women - one naturally cycling (NC women, n=42) and one using hormonal contraceptives (HC women, n=36) - viewed emotionally arousing and neutral images. ⋯ Compared to NC women, HC women exhibited significantly blunted stress hormone responses to the images and CPS. Recall of emotional images differed between HC and NC women depending on noradrenergic and cortisol responses. These findings may have important implications for understanding the neurobiology of emotional memory disorders, especially those that disproportionately affect women.
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Biological psychology · Oct 2012
Randomized Controlled TrialFear extinction in humans: effects of acquisition-extinction delay and masked stimulus presentations.
Fear extinction can be viewed as an inhibitory learning process. This is supported by post-extinction phenomena demonstrating the return of fear, such as reinstatement. Recent work has questioned this account, claiming that extinction initiated immediately after fear acquisition can abolish the return of fear. ⋯ During extinction, we manipulated CS contingency awareness by presenting two of the CSs (one CS+, one CS-) under non-masked conditions and the other two CSs under masked conditions. Compared to delayed extinction, immediate extinction of non-masked CSs promoted less extinction of fear-potentiated startle and shock expectancy ratings and less reinstatement of fear-potentiated startle without affecting shock expectancy ratings. Critically, future research should clarify how the differences between immediate and delayed extinction in within-session extinction modulate the recovery of fear.
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Biological psychology · Dec 2010
Randomized Controlled TrialNeurocognitive effects of HF-rTMS over the dorsolateral prefrontal cortex on the attentional processing of emotional information in healthy women: an event-related fMRI study.
Current evidence concerning the neurocircuitry underlying the interplay between attention and emotion is mainly correlational. We used high-frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) to experimentally manipulate activity within the right or left dorsolateral prefrontal cortex (DLPFC) of healthy women and examined changes in attentional processing of emotional information using an emotional modification of the exogenous cueing task during event-related fMRI. ⋯ Left prefrontal HF-rTMS resulted in diminished attentional engagement by angry faces and was associated with increased activity within the right DLPFC, dACC, right superior parietal gyrus and left orbitofrontal cortex. The present observations are in line with reports of a functionally interactive network of cortical-limbic pathways that play a central role in emotion regulation.
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Biological psychology · May 2010
Randomized Controlled TrialMotivational and situational factors and the relationship between testosterone dynamics and human aggression during competition.
Men engage in aggression at a cost to extrinsic reward, and this behaviour is associated with a rise in testosterone. To characterize the factors underlying aggression, men were assigned to one of the four experimental conditions of a computer game in which they were provoked (points were stolen from them or not) and/or received reward for aggression (received points for aggression or not). ⋯ Moreover, individual differences in aggressive behaviour among these men were positively correlated with the extent to which they enjoyed the task and with testosterone fluctuations. These results indicate that costly aggressive behaviour is intrinsically rewarding, perhaps to regulate future interactions, and that testosterone may be a physiological marker of such reward value.
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Biological psychology · Feb 2008
Randomized Controlled Trial Comparative StudyEffects of naltrexone on electrocutaneous pain in patients with hypertension compared to normotensive individuals.
An opioid mechanism may help explain hypertensive hypoalgesia. A double-blind placebo-controlled design compared the effects of opioid blockade (naltrexone) and placebo on electrocutaneous pain threshold, pain tolerance, and retrospective McGill Pain Questionnaire ratings in 35 unmedicated patients with essential hypertension and 28 normotensive individuals. The hypertensives experienced less pain than normotensives during the assessment of their pain tolerance; however, this manifestation of hypertensive hypoalgesia was not moderated by naltrexone. These findings fail to support the hypothesis that essential hypertension is characterised by relative opioid insensitivity.