Glucocorticoids are required for extinction of predator stress-induced hyperarousal

Background

The role of glucocorticoids in extinction of traumatic memories has not been fully characterized despite its potential as a therapeutic target for acquired posttraumatic stress disorder (PTSD). The predator stress paradigm allows us to determine whether glucocorticoids mediate the extinction of both context-dependent and context-independent fear memories.

Methods

Male C57BL/6J mice were exposed to a predator (cat) then repeatedly exposed to the predator stress context in the absence of the cat. Context-dependent (associative) fear memory was assessed as suppression of activity during re-exposure to the predator stress context without the cat (extinction trials). Context-independent fear (non-associative) was assessed seven days after extinction trials using measures of hyperarousal and anxiety-like behaviours in environments unlike the predator stress context. To assess the role of glucocorticoids, mice were injected with metyrapone (50 mg/kg) 90 min prior to extinction trials in predator stressed mice and context-dependent and context-independent fear memories were assessed. Finally, metyrapone-treated predator stressed mice were injected with corticosterone (5 or 10 mg/kg) immediately following extinction trials and context-dependent and context-independent fear memories were assessed.

Results

Repeated re-exposure to the predator stress context without the cat present extinguished context-dependent fear memory, and also reduced hyperarousal, a generalized, chronic PTSD-like symptom. We show that extinction of context-independent predator stress-induced hyperarousal is dependent on endogenous glucocorticoids during the extinction trials. Furthermore, the inhibition of extinction by metyrapone on startle amplitude was reduced by exogenous administration of corticosterone following extinction trials. Overall, these data implicate glucocorticoids in the extinction of hyperarousal, a core symptom of PTSD.     

Sound to meaning correspondences facilitate word learning

A fundamental assumption regarding spoken language is that the relationship between sound and meaning is essentially arbitrary. The present investigation questioned this arbitrariness assumption by examining the influence of potential non-arbitrary mappings between sound and meaning on word learning in adults. Native English-speaking monolinguals learned meanings for Japanese words in a vocabulary-learning task. Spoken Japanese words were paired with English meanings that: (1) matched the actual meaning of the Japanese word (e.g., “hayai” paired with fast); (2) were antonyms for the actual meaning (e.g., “hayai” paired with slow); or (3) were randomly selected from the set of antonyms (e.g., “hayai” paired with blunt). The results showed that participants learned the actual English equivalents and antonyms for Japanese words more accurately and responded faster than when learning randomly paired meanings. These findings suggest that natural languages contain non-arbitrary links between sound structure and meaning and further, that learners are sensitive to these non-arbitrary relationships within spoken language.     

Memory for noun pairs in the same or different underlying strings

A number of studies have shown that children learn noun pairs faster when they have been presented in a noun-verb-noun context than when they are presented in a noun-conjunction-noun context. Suzuki and Rohwer (1969) hypothesized that the underlying strings of sentences correspond to memory units, making it easier to recall two nouns from the same underlying string than from two different underlying strings. They reported that data from fifth graders supported this hypothesis but that data from college students did not. The experiments reported here were done to determine whether the hypothesis would be supported (a) if the test rate were faster than that used by Suzuki and Rohwer or (b) if sentences longer and more complex than those used by them were employed. The recall data accorded with some predictions derived from the hypothesis. However, data from Ss’ posttraining reports on how they learned the pairs suggest that Ss, particularly adults, often made up their own strings rather than using those provided, and raise the question of the adequacy of Suzuki and Rohwer’s procedure for testing this hypothesis, particularly in adults.     

Personal disturbance scale: factor structure confirmed in a large nonclinical sample

The two-component structure of anxiety and depression items of the short form Personal Disturbance Scale, reported in an earlier clinical study of 480 adult psychiatric patients, was substantially replicated in a large nonclinical sample of 758 adults.     

Champagne,beer, or coffee? A corpus of gender-related and neutral words

A list of gender-related and gender-neutral words for use in testing gender stereotyping and memory was created and evaluated. Words were rated by samples of undergraduates at universities located in the northeast, southeast, and south-central United States. A substantial list of masculine, feminine, and gender-neutral words was identified. These lists allow researchers to construct large lists of gender-associated words while being able to control for extraneous variables, such as word frequency and word length. In addition, the high reliability across the samples suggests that gender ratings are a fairly stable phenomenon. Applications for this list are discussed. The word lists presented in Tables 1–3 and the raw data analyzed in this article may be downloaded fromwww.psychonomic.org/archive/.     

When mutations meet motivations: Attitude biases in counterfactual thought

The present research examines whether existing attitudes can spontaneously bias the content and direction of generated counterfactual thoughts, and whether these thoughts influence subsequent attitude-relevant judgments. Two experimental studies demonstrate that attitudes can bias the content of counterfactual thoughts, and that these biased thoughts in turn predict polarized attitudes. These effects were obtained regardless of whether explicit instructions for counterfactual generation were given. Furthermore, both studies demonstrate that these effects are mediated by judgments of future likelihood. Implications of these results for theories of counterfactual thinking and persuasion are discussed.     

Political Intolerance,Right and Left

Research recently published in Political Psychology suggested that political intolerance is more strongly predicted by political conservatism than liberalism. Our findings challenge that conclusion. Participants provided intolerance judgments of several targets and the political objective of these targets (left‐wing vs. right‐wing) was varied between subjects. Across seven judgments, conservatism predicted intolerance of left‐wing targets, while liberalism predicted intolerance of right‐wing targets. These relationships were fully mediated by perceived threat from targets. Moreover, participants were biased against directly opposing political targets: conservatives were more intolerant of a left‐wing target than the opposing right‐wing target (e.g., pro‐gay vs. anti‐gay rights activists), while liberals were more intolerant of a right‐wing target than the opposing left‐wing target. These findings are discussed within the context of the existing political intolerance and motivated reasoning literatures.     

Transient positive and negative experiences accompanying stage hypnosis.

Frequency of positive and negative experiences accompanying stage hypnosis was assessed in follow-up interviews with 22 participants of university-sponsored performances. Most subjects described their experience positively (relaxing, interesting, exciting, satisfying, illuminating, and pleasurable), but some described it negatively (confusing, silly, annoying, and frightening). Five subjects (22.7%) reported partial or complete amnesia; all were highly responsive to the stage hypnosis suggestions. One subject was completely unable to breach amnesia and felt annoyed and frightened. Five subjects (22.7%) believed the hypnotist had control over their behavior. Participants (n = 15) tested subsequently on the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & Hilgard, 1962) were mostly moderately to highly hypnotizable (M = 7.07), and the scores correlated significantly (r = .68) with the percentage of passed stage hypnosis suggestions.     

Construct validity and case validity in assessment

Clinical assessment relies on both construct validity, which focuses on the accuracy of conclusions about a psychological phenomenon drawn from responses to a measure, and case validity, which focuses on the synthesis of the full range of psychological phenomena pertaining to the concern or question at hand. Whereas construct validity is grounded in understanding causal influences of a distinct phenomenon on responses to various measures and life contexts, case validity encompasses the joint influences of multiple phenomena on individuals' responses. Two sets of distinctions essential to understanding psychological phenomena, hence to understanding construct validity, are (a) implicit and explicit versions of personality constructs and (b) ability and personality as versions of constructs measured by performance tests presenting maximal and typical conditions, respectively. Since both implicit and explicit versions of constructs interface with maximal or typical performance conditions, case validity requires systematic inclusion of these distinctions in assessment protocols.