Motivational deficits in schizophrenia relate to abnormalities in cortical learning rate signals

Individuals from across the psychosis spectrum display impairments in reinforcement learning. In some individuals, these deficits may result from aberrations in reward prediction error (RPE) signaling, conveyed by dopaminergic projections to the ventral striatum (VS). However, there is mounting evidence that VS RPE signals are relatively intact in medicated people with schizophrenia (PSZ). We hypothesized that, in PSZ, reinforcement learning deficits often are not related to RPE signaling per se but rather their impact on learning and behavior (i.e., learning rate modulation), due to dysfunction in anterior cingulate and dorsomedial prefrontal cortex (dmPFC). Twenty-six PSZ and 23 healthy volunteers completed a probabilistic reinforcement learning paradigm with occasional, sudden, shifts in contingencies. Using computational modeling, we found evidence of an impairment in trial-wise learning rate modulation (α) in PSZ before and after a reinforcement contingency shift, expressed most in PSZ with more severe motivational deficits. In a subsample of 22 PSZ and 22 healthy volunteers, we found little evidence for between-group differences in VS RPE and dmPFC learning rate signals, as measured with fMRI. However, a follow-up psychophysiological interaction analysis revealed decreased dmPFC-VS connectivity concurrent with learning rate modulation, most prominently in individuals with the most severe motivational deficits. These findings point to an impairment in learning rate modulation in PSZ, leading to a reduced ability to adjust task behavior in response to unexpected outcomes. At the level of the brain, learning rate modulation deficits may be associated with decreased involvement of the dmPFC within a greater RL network.     

Acculturative stress in Latin-American immigrants: an assessment proposal

The aim of this paper was to develop an instrument to assess levels of stress experienced by Latin-American immigrants in their acculturative process in Spain. A sample of 692 immigrants from Latin America, aged 20 to 63 years, took part on this study (54.9% males and 45.1% females). A 24-item questionnaire with high reliability (.92) was elaborated. Six factors related to acculturative stress were found: 1) discrimination and rejection; 2) differences with the out-group (native Spaniards); 3) citizenship problems and legality; 4) problems concerning social relationships with other immigrants; 5) nostalgia and longing; and 6) family break-up. Our findings show that participants have a high level of stress related to nostalgia and longing, family break-up, and the perception of discrimination and rejection by natives. The usefulness of the instrument and its applications and restrictions are discussed.     

Sex differences in perceptions of romantic acts in Portuguese adolescents

The study was done to examine sex differences in the importance attributed to romantic acts by adolescents. On a 15-item Romantic Acts questionnaire of Neto participants rated the importance of each act. Four factors of Offerings, Physical Intimacy, Altruistic Behavior, and Sexual Behavior were found. The 108 girls judged physical intimacy as more important than the 79 boys.     

Conditioned and unconditioned fear organized in the periaqueductal gray are differentially sensitive to injections of muscimol into amygdaloid nuclei

The lateral and basolateral nuclei of the amygdala (LaA and BLA, respectively) serve as a filter for unconditioned and conditioned aversive information that ascends to higher structures from the brainstem, whereas the central nucleus of the amygdala (CeA) is considered to be the main output for the defense reaction. It has been shown that the dorsal periaqueductal gray (dPAG) is activated by threatening stimuli and has important functional links with the amygdala through two-way anatomical connections. In this work, we examined the influence of chemical inactivation of these nuclei of amygdala on the freezing and escape responses induced by electrical stimulation through electrodes implanted in the dPAG of Wistar rats. Each rat also bore a cannula implanted in the LaA, BLA or CeA for injections of muscimol (0.5 microg/0.5 microL) or its vehicle. The duration of freezing behavior that outlasts electrical stimulation of the dPAG was also measured. On the following day, these animals were submitted to a contextual fear-conditioning using foot shocks as unconditioned stimulus. Conditioned freezing to contextual cues previously associated with foot shocks was also inhibited by injections of muscimol into these amygdaloid nuclei. The contextual conditioned freezing behavior is generated in the neural circuits of conditioned fear in the amygdala. The data obtained also show that injections of muscimol into the three amygdaloid nuclei did not change the aversive threshold of freezing, but disrupted the dPAG post-stimulation freezing. Previous findings that the latter freezing results directly from dPAG stimulation and that it is not sensitive to a context shift suggest that it is unconditioned in nature. Thus, the amygdala can affect some, but not all, aspects of unconditioned freezing. Post-stimulation freezing may reflect the process of transferring aversive information from dPAG to higher brain structures.     

Hostility, anger, aggressiveness, and coronary heart disease: an interpersonal perspective on personality, emotion, and health

The related traits of hostility, anger, and aggressiveness have long been suggested as risk factors for coronary heart disease (CHD). Our prior review of this literature (Smith, 1992) found both considerable evidence in support of this hypothesis and important limitations that precluded firm conclusions. In the present review, we discuss recent research on the assessment of these traits, their association with CHD and longevity, and mechanisms possibly underlying the association. In doing so, we illustrate the value of the interpersonal tradition in personality psychology (Sullivan, 1953; Leary, 1957; Carson, 1969; Kiesler, 1996) for not only research on the health consequences of hostility, anger, and aggressiveness, but also for the general study of the effects of emotion, personality and other psychosocial characteristics on physical health.     

Relevance of multicultural training to students' applications to clinical psychology programs

Interest in the efficacy of multicultural training for practitioners and scientists working with multicultural populations has led to questions about the characteristics of students who seek this training. Students of ethnic minority background, as compared with White students, may be more likely to seek programs that offer this training, and their ethnic or racial identity may be related to this preference. This study explores the relevance of multicultural training to White and ethnic minority graduate students in accredited clinical psychology programs. Students rated the relevance of multicultural and general training components to their decisions about where to apply to graduate school. The ethnic minority students' mean ratings of the relevance of multicultural components were higher than those of White students, and the degree of ethnic minority students' ethnic identification was positively correlated to these relevance ratings.     

The myth of macho dominance in decision making within Mexican and Chicano families

The myth concerning Hispanic family life which prevails in the social science literature can best be summarized by abbreviated quotations attributed to Alvirez and Bean. The Mexican or Chicano husband is a macho autocrat who rules as "absolute head of the family with full authority over the wife and children" where "all major decisions are his responsibility." Domination by husbands in marriage is logically consistent with their wives' submissivesness accompanied by passive acceptance of the future, strong religious beliefs, and a tendency to reside in the temporal present. The myth is also deeply imbedded in the social pathology model: differences between Hispanics and Anglos are assumed to reflect negatively on Hispanics. The myth, it should be noted, is seldom subjected to the scrutiny of empirical inquiry. The review of 4 studies on both Mexican and Chicano samples fails to support the notion of male dominance in marital desision making. Refutation of the hypothesis of masculine dominance in marital decision making calls other components of the myth into question. Research among Hispanics on alledged female submissiveness, fatalism, eligiosity, and temporal perspective are called for. More sophisicated designs involving experimental manipulations are needed. Experimental studies on the process of decision making, actual behaviors involved in economic or budgetary negotiations, and parental interaction around childrearing would also be of interest. While the data reviewed may suggest that Hispanic males may behave differently from nonHispanic males in their family and marital lives, the behavior is not in the inappropriate fashion suggested by the myth with its strong connotations of social deviance. Additional research is recommended among Hispanics on sex role behavior among both men and women, with special emphasis on how it influences family life and marriage.     

Does who you marry matter for your health? Influence of patients' and spouses' personality on their partners' psychological well-being following coronary artery bypass surgery

Research suggests that presurgical personality attributes influence postsurgical well-being in both patients and their spouses in the context of coronary artery bypass grafting (CABG) surgery. The authors hypothesized that a spouse's characteristics would influence a partner's psychological well-being, regardless of whether he or she was the patient or the caregiver. In this study, 111 male patients and their caregiver spouses completed measures of neuroticism, optimism, perceived marital satisfaction, and depression prior to elective CABG. Follow-up was conducted at 18 months. As expected, higher caregiver presurgical neuroticism predicted higher patient depressive symptoms at follow-up, with caregiver's concurrent 18-month affect controlled for. Likewise, higher patient presurgical neuroticism predicted higher caregiver depressive symptoms at follow-up. Additionally, higher patient presurgical depressive symptoms and lower presurgical optimism contributed to greater caregiving burden. Relationship satisfaction moderated these effects. These results suggest that partners' personality traits are important determinants of both patients' and their caregiving spouses' well-being.     

Distinguishing narcissism and hostility: similarities and differences in interpersonal circumplex and five-factor correlates

Narcissism and hostility are both characterized by dysfunctional social interactions, including tendencies to perceive slights, experience anger, and behave aggressively. The aim of this study was to examine the similarities and differences of narcissism and hostility, using 2 conceptual tools-the interpersonal circumplex and the Five-factor model. In a sample of 292 undergraduate men and women, composite measures of hostility (i.e., Buss-Perry Aggression Questionnaire [Buss & Perry, 1992] and Cook-Medley Hostility [Cook & Medley, 1954] total scores) were inversely correlated with affiliation and unrelated to dominance. In contrast, composite narcissism scores (i.e., Narcissistic Personality Inventory) were positively correlated with dominance and inversely correlated with affiliation. Examination of components of these traits revealed additional similarities and differences, as did associations with other dimensions of the Five-factor model. These findings suggest that the traits of narcissism and hostility are distinguishable by their interpersonal referents, as are their components.     

A comparison of implicit memory tests in schizophrenic patients and normal controls

The objective of the current study was to compare the performance of schizophrenic patients and normal controls on implicit memory tests. Two neuropsychological tasks were administered to 29 patients and normal participant samples. The implicit tests were: Word fragment completion and Word production from semantic categories. The priming score was the variable of interest. Priming effects are obtained in normal subjects and schizophrenia patients, regardless of the implicit test used. However, a dissociation in priming between normal and patient groups was observed, depending on the test used. For word fragment test, priming was identical between the two groups. However, for word production, priming obtained in schizophrenics was lower than priming in normal controls. Results confirm a dissociation effect in implicit memory tests. These results could be explained in the context of the Roediger and Blaxton (1987) distinction between data-driven and conceptually-driven processing. This evidence suggests that a complete neuropsychological assessment of memory in schizophrenia should include different kinds of implicit memory tests (procedural, perceptual, and conceptual tasks).