Storage of verbal associations is sufficient to activate the left medial temporal lobe

Neuroimaging studies have shown that memory encoding activates the medial temporal lobe (MTL). Many believe that these activations are related to novelty but it remains unproven which is critical - novelty detection or the rich associative encoding it triggers. We examined MTL activation during verbal associative encoding using functional magnetic resonance imaging. First, associative encoding activated left posterior MTL more than single word encoding even though novelty detection was matched, indicating not only that associative encoding activates the MTL particularly strongly, but also that activation does not require novelty detection. Moreover, it remains to be convincingly shown that novelty detection alone does produce such activation. Second, repetitive associative encoding produced less MTL activation than initial associative encoding, indicating that priming of associative information reduces MTL activation. Third, re-encoding familiar associations in a well-established way had a minimal effect on both memory and MTL activation, indicating that MTL activation reflects storage of associations, not merely their initial representation.     

Assessing the specificity of autobiographical memory in individuals at a trait-based vulnerability to bipolar disorder using a sentence completion task

Overgeneral autobiographical memory recall has been associated with the diagnosis of bipolar disorder, but the role of overgenerality in the vulnerability to bipolar disorder remains under-researched. While a previous study suggested that high-risk individuals for bipolar disorder recall emotionally negative memories in specific detail, this is in contrast to memory recall patterns noted in bipolar samples. The Autobiographical Memory Test (AMT) used in previous non-clinical studies has also been criticised for not being sensitive to overgenerality due to its repetition of specificity instructions and practice trials. The traditional AMT format may allow some individuals to override their trait-based tendencies to be overgeneral. The current study used a sentence completion task to assess memory specificity in groups of students at a low and high trait-based vulnerability for bipolar disorder. In contrast to previous research, high-risk individuals recalled fewer specific positive memories and greater numbers of overgeneral negative memories than low-risk individuals. These results support the notion that the vulnerability for bipolar disorder might be associated with similar recall biases as demonstrated in bipolar samples, and that the AMT might not be sufficiently sensitive to detect overgenerality in non-clinical groups. The implications of these findings and directions for future research are discussed.     

Resilience to suicidal ideation in psychosis: Positive self-appraisals buffer the impact of hopelessness

Recent years have seen growing interest into concepts of resilience, but minimal research has explored resilience to suicide and none has investigated resilience to suicide amongst clinical groups. The current study aimed to examine whether a proposed resilience factor, positive self-appraisals of the ability to cope with emotions, difficult situations and the ability to gain social support, could buffer against the negative impact of hopelessness amongst individuals with psychosis-spectrum disorders when measured cross-sectionally. Seventy-seven participants with schizophrenia-spectrum disorders completed self-report measures of suicidal ideation, hopelessness and positive self-appraisals. Positive self-appraisals were found to moderate the association between hopelessness and suicidal ideation. For those reporting high levels of positive self-appraisals, increased levels of hopelessness were significantly less likely to lead to suicidality. These results provide cross-sectional evidence suggest that positive self-appraisals may buffer individuals with psychosis against the pernicious impact of a well known clinical risk factor, hopelessness. Accounting for positive self-appraisals may improve identification of individuals at high risk of suicidality, and may be an important area to target for suicide interventions.     

Development of Phonological Constancy: Toddlers' Perception of Native- and Jamaican-Accented Words

ABSTRACT— Efficient word recognition depends on detecting critical phonetic differences among similar-sounding words, or sensitivity to phonological distinctiveness , an ability evident at 19 months of age but unreliable at 14 to 15 months of age. However, little is known about phonological constancy , the equally crucial ability to recognize a word's identity across natural phonetic variations, such as those in cross-dialect pronunciation differences. We show that 15- and 19-month-old children recognize familiar words spoken in their native dialect, but that only the older children recognize familiar words in a dissimilar nonnative dialect, providing evidence for emergence of phonological constancy by 19 months. These results are compatible with a perceptual-attunement account of developmental change in early word recognition, but not with statistical-learning or phonological accounts. Thus, the complementary skills of phonological constancy and distinctiveness both appear at around 19 months of age, together providing the child with a fundamental insight that permits rapid vocabulary growth and later reading acquisition.     

Effectiveness of antidepressants: an evidence myth constructed from a thousand randomized trials?

Antidepressants, in particular newer agents, are among the most widely prescribed medications worldwide with annual sales of billions of dollars. The introduction of these agents in the market has passed through seemingly strict regulatory control. Over a thousand randomized trials have been conducted with antidepressants. Statistically significant benefits have been repeatedly demonstrated and the medical literature is flooded with several hundreds of "positive" trials (both pre-approval and post-approval). However, two recent meta-analyses question this picture. The first meta-analysis used data that were submitted to FDA for the approval of 12 antidepressant drugs. While only half of these trials had formally significant effectiveness, published reports almost ubiquitously claimed significant results. "Negative" trials were either left unpublished or were distorted to present "positive" results. The average benefit of these drugs based on the FDA data was of small magnitude, while the published literature suggested larger benefits. A second meta-analysis using also FDA-submitted data examined the relationship between treatment effect and baseline severity of depression. Drug-placebo differences increased with increasing baseline severity and the difference became large enough to be clinically important only in the very small minority of patient populations with severe major depression. In severe major depression, antidepressants did not become more effective, simply placebo lost effectiveness. These data suggest that antidepressants may be less effective than their wide marketing suggests. Short-term benefits are small and long-term balance of benefits and harms is understudied. I discuss how the use of many small randomized trials with clinically non-relevant outcomes, improper interpretation of statistical significance, manipulated study design, biased selection of study populations, short follow-up, and selective and distorted reporting of results has built and nourished a seemingly evidence-based myth on antidepressant effectiveness and how higher evidence standards, with very large long-term trials and careful prospective meta-analyses of individual-level data may reach closer to the truth and clinically useful evidence.     

Prospective predictors of suicidality: defeat and entrapment lead to changes in suicidal ideation over time

Theoretical perspectives into suicidality have suggested that heightened perceptions of defeat and entrapment lead to suicidality. However, all previous empirical work has been cross-sectional. We provide the first longitudinal test of the theoretical predictions, in a sample of 79 students who reported suicidality. Participants completed self-report measures of suicidal ideation, depression, defeat, and entrapment at two time points, approximately 12 months apart. People higher in defeat became more suicidal over time (β= .45), with baseline levels of suicidality and depressive symptoms controlled. The current results support the posited role of perceived defeat in driving suicidal ideation.     

Suicide schema in schizophrenia: the effect of emotional reactivity, negative symptoms and schema elaboration

Suicide risk is thought to increase with a greater potential for activation of suicide-related schemas. Suicide schemas are less likely to be activated with reductions of emotional range associated with certain negative symptoms of schizophrenia. The study tested whether suicide risk would increase in patients with recent onset schizophrenia with increased potential for suicide schema activation as indicated by lower levels of specific negative symptoms that reflected emotional reactivity, namely emotional withdrawal and blunted affect. A logistic regression analysis of baseline data of 278 recent onset schizophrenic patients with a measure of suicide behaviour as the dependent variable and negative symptoms, delusions, hallucinations, depression, gender, episode, ethnicity, education, age, duration of untreated psychosis and substance use as independent variables was carried out. Emotional withdrawal, but not blunted affect was significant and negatively associated, and depression positively associated with suicide behaviour. There was evidence to indicate that restricted emotions are associated with reduced suicide risk as predicted.     

Four Brief Studies of Relations Between Postformal Thought and Non-Cognitive Factors: Personality, Concepts of God, Political Opinions, and Social Attitudes

This is a report of four studies extending research on Complex Postformal Thought using the Postformal Thought Scale (PTS) (Sinnott 1998a, b). In Study I PTS was studied in relation to personality as conceptualized in the NEO Five Factor Model. Data from 82 participants indicated that PTS is significantly related to the Openness to Experience and the Conscientiousness factors of the NEO. In Study II PTS was examined in relation to the Concept of God Scale to answer the question whether postformal and non-postformal respondents were likely to hold different god concepts. Data from 50 participants indicated no relationship between the two measures. In Study III PTS was examined in relation to political opinions using the newly created Political Opinion Survey. Data from 50 participants demonstrated no relation between the two tests. In Study IV PTS was studied in relation to the Attitudes Toward Lesbians and Gay Men Scale. Data from 112 participants indicated that PTS was related to positive attitudes toward lesbians and gay men. Current conceptualizations of PTS development are used to interpret these findings.     

Scientific Discovery as Creative Exploration: Faraday's Experiments

In this article, I address the distance between historical and psychological approaches to creativity (particularly cognitive approaches). I argue that neither can get very far without the other, and I offer examples from the creative work of Michael Faraday, the eminent 19th-century physicist. These examples display similarities between fine detail of Faraday's creative work and the broad sweep of his development and illustrate the tension between historians' attention to particular features of creativity and cognitive scientists' desire for general, preferably computable features. I conclude with a discussion of the difficult issue of finding a common language based on agreement about appropriate levels of abstraction.