Heavy marijuana use but not deprivation is associated with increased stressor reactivity.

Although stressors appear to motivate marijuana use, and marijuana use, in turn, is believed to induce stress system neuroadaptations, relatively little empirical work has explicitly tested for stress neuroadaptations associated with heavy marijuana use. We examined stressor reactivity to threat of unpredictable electric shock via startle potentiation among heavy marijuana users and a control group that reported minimal history of marijuana use. Heavy marijuana users were randomly assigned to 3 days of marijuana deprivation or no deprivation.

Alcohol's effects on emotionally motivated attention, defensive reactivity and subjective anxiety during uncertain threats.

Developing a better understanding of how and under what circumstances alcohol affects the emotions, cognitions and neural functions that precede and contribute to dangerous behaviors during intoxication may help to reduce their occurrence. Alcohol intoxication has recently been shown to reduce defensive reactivity and anxiety more during uncertain vs certain threat. However, alcohol's effects on emotionally motivated attention to these threats are unknown.

Altered subjective reward valuation among female heavy marijuana users.

Maladaptive decision-making is a cardinal feature of drug use, contributing to ongoing use, and reflecting alterations in how drug users assess uncertain reward value. Accumulating evidence indicates the consequences of heavy marijuana use are worse for female versus male animals and humans, but research assessing sex differences in reward-related decision-making among marijuana users remains scarce. We examined sex differences in the subjective valuation of certain and uncertain rewards among heavy marijuana users (52; 26 male and 26 female) and controls (52; 26 male and 26 female).

Altered subjective reward valuation among drug-deprived heavy marijuana users: Aversion to uncertainty.

Marijuana is the most commonly used illicit drug in the United States and its use is rising. Nonetheless, scientific efforts to clarify the risk for addiction and other harm associated with marijuana use have been lacking. Maladaptive decision-making is a cardinal feature of addiction that is likely to emerge in heavy users.

Empirically based comparisons of the reliability and validity of common quantification approaches for eyeblink startle potentiation in humans.

Startle potentiation is a well-validated translational measure of negative affect. Startle potentiation is widely used in clinical and affective science, and there are multiple approaches for its quantification. The three most commonly used approaches quantify startle potentiation as the increase in startle response from a neutral to threat condition based on (1) raw potentiation, (2) standardized potentiation, or (3) percent-change potentiation.

Happiness cools the warm glow of familiarity: psychophysiological evidence that mood modulates the familiarity-affect link.

People often prefer familiar stimuli, presumably because familiarity signals safety. This preference can occur with merely repeated old stimuli, but it is most robust with new but highly familiar prototypes of a known category (beauty-in-averageness effect). However, is familiarity always warm? Tuning accounts of mood hold that positive mood signals a safe environment, whereas negative mood signals an unsafe environment.

Dissociable effects of hippocampus lesions on expression of fear and trace fear conditioning memories in rats.

The role of the hippocampus in memory is commonly investigated by comparing fear conditioning paradigms that differ in their reliance on the hippocampus. For example, the dorsal (septal) portion of the hippocampus is involved in trace, but not delay fear conditioning, two Pavlovian paradigms in which only the relative timing of stimulus presentation is varied. However, a growing literature implicates the ventral (temporal) portion of the hippocampus in the expression of fear, irrespective of prior training.