Working memory deficits in retinoid X receptor gamma-deficient mice

Retinoid signaling has been recently shown to be required for mnemonic functions in rodents. To dissect the behavioral and molecular mechanisms involved in this requirement, we have analyzed the spatial and recognition working memory in mice carrying null mutations of retinoid receptors RARbeta and RXRgamma. Double mutants appeared deficient in spatial working memory as tested in spontaneous alternation in the Y-maze and delayed nonmatch to place (DNMTP) test in the T-maze. These mutant mice did acquire, however, spatial place reference or right/left discrimination tasks in the T-maze set-up, indicating that basic sensorimotor functions, spatial orientation, and motivational factors are unlikely to account for deficits in working memory-sensitive tasks. Double-mutant mice were also deficient in novel object recognition at intermediate, but not short delays. RXRgamma appeared to be the functionally predominant receptor in modulation of the working memory, as RXRgamma, but not RARbeta single null mutant mice exhibited deficits similar to those observed in the double mutants. The mechanism of this modulation is potentially related to functions of RXRgamma in frontal and perirhinal cortex, structures in which we detected RXRgamma expression and which are functionally implicated in working memory processes.     

Modern prejudice toward gay men and lesbian women: assessing the viability of a measure of modern homonegative attitudes within an Irish context

The authors examined the psychometric properties of the gay and lesbian versions of the Modern Homonegativity Scale (MHS-G and MHS-L) in samples of heterosexual Irish university students (Ns=179 and 353). Confirmatory factor analyses revealed that the MHS-G and MHS-L were unidimensional and factorially distinct from a well-established measure of old-fashioned homonegativity (Attitudes Toward Lesbians and Gay Men Scale [ATLG]). Alpha coefficients for both versions of the MHS were good (range = .81 to .86), with 95% confidence intervals suggesting that unsatisfactory levels of scale score reliability (i.e., alpha values < .70) were relatively implausible. As hypothesized, participants' level of modern homonegativity correlated positively with their levels of old-fashioned and modem racism, patriotism, nationalism, religious fundamentalism, social dominance, and perceived political conservatism. The authors also observed a substantial inverse correlation between modern prejudice toward sexual minorities and support for their human rights. Finally, a series of multiple regression analyses indicated that, despite their interrelatedness, modern and old-fashioned homonegativity, particularly as they pertain to gay men, possess differential predictors. Limitations of the current series of studies and the need to conduct further research on attitudes toward sexual minorities within an Irish context are also discussed.     

The effectiveness of expatriate coping strategies: the moderating role of cultural distance, position level, and time on the international assignment

On the basis of the stress and coping literature, the authors examined the diverse coping strategies used by expatriate managers in response to the problems encountered while on international assignments. It was hypothesized that although problem-focused coping strategies may be more effective than are emotion-focused coping strategies in affecting cross-cultural adjustment and intention to remain on the international assignment, the relationship is moderated by contextual factors such as hierarchical level in the organization, time on the assignment, and cultural distance. Coded semistructured interview responses from 116 German expatriates on assignment in either Japan or the United States were analyzed with moderated regression analyses. The results suggest that the effectiveness of problem-focused coping strategies in predicting cross-cultural adjustment is moderated by cultural distance and position level but not by time on the assignment. The use of problem-focused coping strategies was not related to expatriates' intention to remain on the assignment.     

Strategies Used in the Treatment of Borderline Personality Disorder: A Survey of Practicing Psychologists

One hundred and twenty three practicing psychologists completed surveys regarding the therapeutic techniques they employ for patients with Borderline Personality Disorder (BPD). Participants identified their predominant orientation and rated the frequency with which they used a range of 27 specific strategies. Logistic regression analyses identified an expected relationship between specific techniques and the theoretical orientations to which they are most closely linked. These findings suggest a high level of concordance between self-described theoretical orientation and the specific treatment techniques utilized, but also that some theoretical orientations are comprised of smaller independent clusters of strategies. The implications of these findings are discussed.     

Role of appearance and nonverbal behaviors in the perception of sexual orientation among lesbians and gay men

According to the zero-acquaintance paradigm gay men and lesbians possess the ability to identify other homosexuals accurately after only very brief interpersonal contact. Given the vulnerability gay men and lesbians face in terms of antigay violence and prejudice, perceptual accuracy provides self-protection. In an exploratory study, 123 respondents were classified as low, moderate, and high perceivers on the basis of their responses to a recognition index designed by the authors. Next, respondents rated on a series of 5-point Likert scales the helpfulness of several characteristics for identifying gay men and lesbians. Analysis supported the importance of eye contact for lesbians and gay men in identifying one another. For both lesbian and gay male participants, several other variables emerged as significantly helpful in identifying gay men: clothing style and fit, jewelry, facial expressions, posture, body type, walk or gait, and both the types and frequencies of gestures.     

What Do We Mean by “The Biology of Menopause”?

Most commonly, the biology of menopause is equated with the biomedical model of menopause. The biomedical model emphasizes the central importance of estrogen and has an overriding focus on disease. A broader-biological model is presented, which emphasizes the role of hormones in healthy functioning. Hormones are team players in complex, multidetermined systems that have a purpose. Hormones act in concert with other physiological systems and with sensory and social inputs. Human biology is both similar to and different from that of other animals. The implications of these assumptions for understanding menopause are discussed, especially the kinds of questions that are asked and the kinds of evidence needed before conclusions are drawn with regard to clinically significant areas. A broader-biological model of menopause provides a framework within which health-related issues can be considered from a perspective that is, on the one hand, more holistic, and on the other hand, more attentive to individual differences.     

The effects of beta-noradrenergic receptor blockade on acquisition of eyeblink conditioning in 3-month-old F344 rats

There is evidence that blocking beta-noradrenergic receptors will cause deficits in some forms of learning. We investigated the effects of systemic injections of 1, 5, and 10 mg/kg doses of propranolol on acquisition of delay eyeblink conditioning in 3-month-old Fischer 344 rats. We presented a 3-kHz, 90-dB tone as a conditioning stimulus and a 6 psi airpuff as our unconditioned stimulus to freely moving rats. We monitored eyelid activity using EMG signals. The treatment subjects were injected with either propranolol or saline 0.5 h prior to daily training sessions. Two groups of control subjects, one receiving injections of saline and one receiving injections of 5 mg/kg propranolol, received daily training sessions with unpaired and randomized presentation of the tone and airpuff. Each daily training session for the treatment groups consisted of 27 paired training trials and 3 conditioned stimulus-alone training trials. Rats injected with saline vehicle or with 1 mg/kg propranolol achieved a 60% or better learned response rate within two training sessions. Rats injected with 5 or 10 mg/kg propranolol never achieved a response rate significantly different from animals that received unpaired, random presentations of the tone and airpuff stimuli. These results agree with prior studies from our lab that have shown a dose-dependent effect of beta-noradrenergic receptor blockade on learning in rabbit eyeblink conditioning as well as in a runway, motor learning paradigm. We believe that the beta-noradrenergic system plays an important role in learning and memory in more than one cerebellar-dependent learning paradigm.     

Adapting production to comprehension: The explicit mention of instruments

This study investigated whether production is adapted to comprehension. Experiment 1 examined whether or not instruments are explicitly mentioned in accordance with their likelihood of being inferred. Subjects read and retold 20 short stories. An analysis of the transcribed stories revealed that atypical instruments (e.g., an ice pick in a stabbing) were specified significantly more often than typical instruments (e.g., a knife in a stabbing), and instruments that were important in the story were specified slightly more often than unimportant instruments. Experiment 2 examined the mechanism accounting for this phenomenon and revealed that the speaker's beliefs about the listener's knowledge of the instrument had little impact on whether and how the instrument was mentioned. A quantitative model for mentioning instruments was proposed. Instrument concepts can be selected at three points in the production process: (1) during creation of a macroproposition encoding the main idea of a discourse episode, (2) during the elaboration of the macroproposition, and (3) during the monitoring and repair process.     

Risk and the recognition of driving situations

This paper reports a series of experiments that explore the relationship between subjective risk when viewing driving situations and subsequent recognition memory for such films. In the first experiment no simple relationship was found between risk and recognition performance. Instead the experience of subjective risk was associated with good recognition of generally dangerous situations but poor recognition of generally safe ones. The remaining experiments replicated this result and explored possible reasons for it. An account of the results in terms of schema theory was tested and rejected. The effect is instead interpreted in terms of the types of information that are present and attended to in different kinds of dangerous situation. Overall recognition memory for films of driving situations was surprisingly poor, but the pattern of results was consistent with drivers showing good memory for central details from dangerous situations. Copyright © 2004 John Wiley & Sons, Ltd.