Social learning in captive African elephants (Loxodonta africana africana)

Social learning is a more efficient method of information acquisition and application than trial and error learning and is prevalent across a variety of animal taxa. Social learning is assumed to be important for elephants, but evidence in support of that claim is mostly anecdotal. Using a herd of six adult female African bush elephants (Loxodonta africana africana) at the San Diego Zoo’s Safari Park, we evaluated whether viewing a conspecific’s interactions facilitated learning of a novel task. The tasks used feeding apparatus that could be solved in one of two distinct ways. Contrary to our hypothesis, the method the demonstrating animal used did not predict the method used by the observer. However, we did find evidence of social learning: After watching the model, subjects spent a greater percentage of their time interacting with the apparatus than they did in unmodeled trials. These results suggest that the demonstrations of a model may increase the motivation of elephants to explore novel foraging tasks.     

Mood,Anxiety, and Substance‐Use Disorders and Suicide Risk in a Military Population Cohort

There are meager prospective data from nonclinical samples on the link between anxiety disorders and suicide or the extent to which the association varies over time. We examined these issues in a cohort of 309,861 U.S. Air Force service members, with 227 suicides over follow‐up. Mental disorder diagnoses including anxiety, mood, and substance‐use disorders (SUD) were based on treatment encounters. Risk for suicide associated with anxiety disorders were lower compared with mood disorders and similar to SUD. Moreover, the associations between mood and anxiety disorders with suicide were greatest within a year of treatment presentation.     

A Cross‐National Comparison of Suicide Attempts,Drug Use,and Depressed Mood Among Dominican Youth

We compared suicide attempts, depressed mood, and drug use of 1,710 Dominican public high school students in New York City (NYC) and 9,573 in the Dominican Republic (DR) in 2009. Compared to DR Dominicans, NYC Dominicans were more likely to have reported lifetime marijuana use (27.6% vs. 1.5%), lifetime inhalant use (11.0% vs. 7.6%), lifetime other drug use (9.9% vs. 3.0%), depressed mood (31.3% vs. 27.2%), and suicide attempt (13.8% vs. 8.8%). The results of this study supported the hypothesis that substantial increases in illicit drug use, especially cocaine, heroin, ecstasy, and methamphetamines, among NYC Dominican youth account for their increased risk for suicide attempts compared to their DR Dominican counterparts. It also identified suicide attempts as a public health problem among NYC Dominicans, the largest NYC Latino immigrant population.     

Predicting Suicide Attempts among Treatment‐Seeking Male Alcoholics: An Exploratory Study

Documented risk factors for suicide among alcohol‐dependent patients are sensitive but insufficiently specific to effectively identify individuals who are prone to future suicide attempt. As a first step to assess factors not previously considered, this pilot study involved a group of male alcohol‐dependent patients (N = 175) coming to detoxification to examine the potential utility of adverse childhood experiences (ACE) along with other documented events to discriminate individuals with a history of attempted suicide from their detoxifying peers. Family health history questionnaires were used to evaluate their ACEs. Receiver operating characteristic (ROC) analysis was applied to examine the predictive power of ACEs, alone or in combination with documented risk factors, to lifetime history of attempted suicide. Among our participants, 48 (27.4%) had a history of a suicide attempt and 156 (89.1%) reported at least one out of the nine categories of ACEs. Modeling by ROC analysis, we found that a cutoff of four or more ACEs plus a history of personal violence achieved the best predictive power to a history of any suicide attempt, producing a sensitivity of 0.7, specificity of 0.81, and area under curve of 0.75. A prospective study to replicate and extend our findings is necessary.     

A case study investigating the role of the anterior temporal lobes in general semantics and semantics specific to persons,emotions and social conceptual knowledge

The role of the anterior temporal lobes (ATLs) in semantic representation remains still much debated. Long thought to support domain-general semantic processing, recent accounts have alternatively suggested that they may be preferentially involved in the processing of person-related semantic knowledge. Several studies have supported such a distinction, but few have either examined both types of semantic processing together, or considered the role of potentially important confounding variables. Here, we address these issues by investigating both domain-general and person-specific semantic processing in a patient with focal ATL damage. The patient presents with dense anterograde and retrograde amnesia. Performance was impaired on tests of general semantic knowledge, but most striking deficits were for person-related semantics, including recognition and identification, knowledge of emotions and social conceptual knowledge. This unique case provides compelling evidence that, in addition to the role in general semantic knowledge, the ATLs are critical for person-related semantics.     

Psychological vulnerability to completed suicide: a review of empirical studies.

Retrospective research shows that close to 90 percent of suicides have a diagnosable psychiatric disorder; however, only a small proportion of individuals with psychopathology take their own lives. This article reviews the empirical literature on psychological vulnerability to completed suicide. A search of the MEDLINE and PsycINFO databases yielded 46 cohort or case-control studies that used standardized or structured assessments of psychological dimensions. Five constructs have been consistently associated with completed suicide: impulsivity/aggression, depression, anxiety, hopelessness, and self-consciousness/social disengagement. Current knowledge of psychological vulnerability to completed suicide could inform social and neurobiological research, and thereby deepen understanding of suicide while potentially bridging these areas of study.