Suicidal attempt and psychiatric disorders in Iran

This study is part of broader research aimed to determine the lifetime prevalence and pattern of comorbidity on self-reported suicidal attempts in the general population of Iran. Overall, 25,180 subjects were interviewed, face-to-face, at home; the lifetime prevalence was 1.4% (0.9% males and 2% females). The majority of attempters were 26-55 years of age, married, more highly educated, female, retired, and lived in urban areas. Many of the attempters (45.3%) reported at least one psychiatric disorder during their lifetime; major depressive disorder (22%), panic disorder (6.3%), and obsessive compulsive disorder (6%) was the most common. Because less than half of suicidal attempters reported a psychiatric disorder, the existence of other pathways to suicide may be important foci for prevention. Many of the demographic correlates of suicidal behavior in Iran are very similar to those seen in Western cutlures; however, the sociodemographic factors such as few working women and very low levels of divorce is quite different to that of Western populations.     

Perception as abduction: turning sensor data into meaningful representation

This article presents a formal theory of robot perception as a form of abduction. The theory pins down the process whereby low-level sensor data is transformed into a symbolic representation of the external world, drawing together aspects such as incompleteness, top-down information flow, active perception, attention, and sensor fusion in a unifying framework. In addition, a number of themes are identified that are common to both the engineer concerned with developing a rigorous theory of perception, such as the one on offer here, and the philosopher of mind who is exercised by questions relating to mental representation and intentionality.     

Schizophrenia and deliberate self-harm: a systematic review of risk factors

Deliberate self-harm (DSH) is a strong predictor of suicide in schizophrenia. The aim of this review was to identify risk factors for DSH in schizophrenia. This systematic review of the international literature examined cohort and case-control studies of patients with schizophrenia or related diagnoses that reported DSH as an outcome. Studies were identified by searching electronic databases and reference lists, and by consulting international experts. Fourteen studies met the eligibility criteria. Of the 29 variables examined by two or more studies, five (past or recent suicidal ideation, previous DSH, past depressive episode, drug abuse or dependence, and higher mean number of psychiatric admissions) were associated with an increased risk of DSH, and one (unemployment) was associated with a reduced risk. Schizophrenic patients with these risk factors need careful follow-up and monitoring, with treatment of any associated comorbid depression or drug abuse. Large, prospective studies of DSH in schizophrenia are needed to further define risk factors and to build on the findings of this review.     

Changing views about personality disorders: Comment about the prospective studies CIC, CLPS, and MSAD

Three large-scale prospective studies (Children in the Community Study [CIC; Cohen, Crawford, Johnson, & Kasen, this issue], Collaborative Longitudinal Personality Disorders Study [CLPS; Skodol et al., this issue], and the McLean Study of Adult Development [MSAD; Zanarini, Frankenburg, Hennen, Reich, & Silk, this issue]) are discussed with respect to the following issues: shared and complementary features of the study designs, evidence for stable and changing personality disorder features, methodological issues (reliability, stability, and invariance), the relationship between Axis I and II disorders, and dimensional versus categorical representations of personality disorders.     

Sensory sensitivity, attachment experiences, and rejection responses among adults with borderline and avoidant features

Both avoidant and borderline personality disorder (APD and BPD) are theoretically associated with temperamental vulnerabilities, adverse attachment experiences, and negative (pessimistic or catastrophic) reactions to the threat of perceived rejection; however, more work is needed to differentiate how these processes account for the etiology and maintenance of both disorders. In this study, 156 adults completed questionnaires measuring APD and BPD features, temperament (sensory-processing sensitivity), mood, and attachment experiences. A vignette task was devised to examine pessimistic cognitive-affective reactions in situations signaling potential rejection. Both APD and BPD were associated with temperamental sensitivity, but BPD was uniquely linked with a subscale measuring sensitivity to mental and emotive stimuli, whereas APD was uniquely linked with a subscale measuring the control and avoidance of aversive stimulation. Compared to APD, BPD was more strongly linked with negative moods (anxiety, anger, sadness) and insecure attachment to parents, whereas APD was more strongly linked (than BPD) to pessimistic cognitive-affective responses to rejection-related situations.     

A comparative analysis of global and local processing of hierarchical visual stimuli in young children (Homo sapiens) and monkeys (Cebus apella)

Results obtained with preschool children (Homo sapiens) were compared with results previously obtained from capuchin monkeys (Cebus apella) in matching-to-sample tasks featuring hierarchical visual stimuli. In Experiment 1, monkeys, in contrast with children, showed an advantage in matching the stimuli on the basis of their local features. These results were replicated in a 2nd experiment in which control trials enabled the authors to rule out that children used spurious cues to solve the matching task. In a 3rd experiment featuring conditions in which the density of the stimuli was manipulated, monkeys' accuracy in the processing of the global shape of the stimuli was negatively affected by the separation of the local elements, whereas children's performance was robust across testing conditions. Children's response latencies revealed a global precedence in the 2nd and 3rd experiments. These results show differences in the processing of hierarchical stimuli by humans and monkeys that emerge early during childhood.     

Socially meaningful vocal plasticity in adult Campbell's monkeys (Cercopithecus campbelli)

Campbell's monkeys (Cercopithecus campbelli) frequently exchange vocalizations, the combined-harmonic calls, with individuals responding to one another's calls. Previous work has shown that these calls can be grouped into several structural variants. Adult females differ in their variant repertoires, which may change during their adult life, particularly after changes in the group composition. Playback of females' currently produced variants triggered vocal responses from other group members, whereas the same females' former, no longer used variants and those of stranger females never did. In contrast, former variants caused long-term cessation of vocal behavior, whereas stranger variants had no effect. Data showed that monkeys were able to distinguish between the different types of variants, indicating that these calls form part of a long-term social memory.     

Understanding of the concept of numerically "less" by bottlenose dolphins (Tursiops truncatus)

In 2 experiments, bottlenose dolphins (Tursiops truncatus) judged the ordinal relationship between novel numerosities. The dolphins were first trained to choose the exemplar with the fewer number of items when presented with just a few specific comparisons (e.g., 2 vs. 6, 1 vs. 3, and 3 vs. 7). Generalization of this rule was then tested by presenting the dolphins with all possible pairwise comparisons between 1 and 8. The dolphins chose the exemplar with the fewer number of items at levels far above chance, showing that they could recognize and represent numerosities on an ordinal scale. Their pattern of errors was consistent with the idea of an underlying analog magnitude representation.     

Human listeners are able to classify dog (Canis familiaris) barks recorded in different situations

The authors investigated whether human listeners could categorize played-back dog (Canis familiaris) barks recorded in various situations and associate them with emotional ratings. Prerecorded barks of a Hungarian herding dog breed (Mudi) provided the sample. Human listeners were asked to rate emotionality of the vocalization and to categorize the situations on the basis of alternative situations provided on a questionnaire. The authors found almost no effect of previous experience with the given dog breed or of owning a dog. Listeners were able to categorize bark situations high above chance level. Emotionality ratings for particular bark samples correlated with peak and fundamental frequency and interbark intervals. The authors did not find a significant effect of tonality (harmonic-to-noise ratio) on either the emotionality rating or situation categorization of the human listeners. Humans' ability to recognize meaning suggests that barks could serve as an effective means of communication between dog and human.     

Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively.