Caring fathers in the Netherlands

Data from two studies on heterosexual men and their care work at home are discussed. Five groups of fathers are distinguished. They range from the traditional father (hardly any care work within the home) to the very caring father (who does at least as much as his wife). What makes the difference between these five groups of men? Measures at three levels have been studied: present social context, value orientation, and family of origin of the fathers. Measures at the first and second levels seem to be the most important. The role of the female partner is also discussed. Caring men do not report a lesser degree of well-being, including the quality of their relationship.     

Assessment of DSM-IV personality disorders in obsessive-compulsive disorder: comparison of clinical diagnosis, self-report questionnaire, and semi-structured interview

In patients with obsessive-compulsive disorder, personality disorders are not many times assessed according to DSM-IV criteria. The purpose of the present study is to examine the prevalence of personality disorders diagnosed according to the DSM-IV in a severely disordered OCD population (n=65) with three different methods of assessing personality disorders (structured interview, questionnaire, and clinical diagnoses). Furthermore, correspondence between these different methods was investigated and their construct validity was examined by relating the three methods to external variables. Each method resulted in a predominance of Cluster C personality disorders, and obsessive-compulsive personality disorder had the highest prevalence. However, there was generally low correspondence regarding which patient had which personality disorder. Results concerning the relation of external variables were the most promising for the structured clinical interview.     

Interelectrode distance and warning signal interval and the evaluation of clinical electrical shock

Contingent shock is used on a small scale for behaviors that may lead to severe damages to one's body or to others. Research efforts focus on exploring variables that control the evaluation of electrical shocks. This study focuses on two practical questions, that is, whether the distance between the electrodes would influence the evaluation of shock and whether using a variable time interval in the administration would influence the evaluation of shock. Results reveal that both investigated variables control the evaluation of shock. Multiple shocks appear to produce a stronger sensation than single shocks, a phenomenon that was also revealed in previous studies. Copyright © 2009 John Wiley & Sons, Ltd.     

The influence of neurotensin, naloxone, and haloperidol on elements of excessive grooming behavior induced by ACTH

Naloxone, haloperidol, and neurotensin suppress ACTH-induced grooming. The suppressive effects of naloxone and of haloperidol on ACTH-induced grooming are observed following subcutaneous as well as intracerebroventricular administration. The suppression of ACTH-induced grooming by these drugs is not accompanied by a change in the relative distribution of grooming elements. From previous data and from the results of the present study it is suggested that the underlying substrate involved in ACTH-induced excessive grooming may differ from that of bombesin-induced grooming.     

Long-tailed macaques (Macaca fascicularis) understand what conspecifics can see in a competitive situation

Visual perspective taking (VPT), an understanding of what others can see, is a prerequisite for theory of mind (ToM). While VPT in apes is proven, its presence in monkeys is much-debated. Several different paradigms have been developed to test its existence, but all face interpretational problems since results can be explained by simpler cognitive mechanisms than VPT. Therefore, we adjusted one method where two individuals compete for access to food, visible or invisible for the dominant competitor, to preclude cognitively simpler mechanisms. The subordinate long-tailed macaques tested, selected significantly more often the food item invisible than the item visible to the dominant. In most trials, subjects retrieved only one food item and preferred the invisible food item. Surprisingly, they occasionally adopted an alternative strategy to obtain both food items, by first choosing the visible, most at risk food item. Faster animals adopted this strategy proportionally more often than slower ones. Contrary to previous research, our results cannot be explained by simpler cognitive mechanisms, since behavioural reading was prevented by a one-way mirror between the competitor and the food, and accessibility was equal to both food items. This is the first unequivocal evidence of VPT in a monkey species, suggesting that this precursor to ToM is an evolutionarily conserved capacity present in monkeys, apes and humans.     

Spatial learning in pigs: effects of environmental enrichment and individual characteristics on behaviour and performance

This study investigated the effects of both environmental enrichment and individual behavioural characteristics on spatial cognitive capabilities of pigs, using a novel latent spatial learning paradigm based on Tolman’s detour experiments (1948). Pigs were housed either in ‘barren’ pens or in pens enriched with straw bedding from birth. Pigs were restrained in a Backtest at 10 and 17 days postpartum. Based on their escape behaviour in this test, which has been shown to reflect their behavioural style, six ‘high-resisting’(HR) and six ‘low-resisting’ (LR) pigs were selected from each housing environment (n = 24 in total). At 12 weeks of age, pairs of pen mates (LR and HR) were exposed to a maze three times (exploration trials). Pigs were then placed individually in the maze, and social reinstatement proved to be a strong incentive to find the exit leading to the home pen. We subsequently blocked the direct route to the exit, forcing animals to find a detour (memory test 1, MT1). This test was repeated once to investigate the relative improvement, i.e. detour learning (memory test 2, MT2). Housing condition and Backtest response strongly affected exploration patterns. In spite of this, no effects on performance during the subsequent memory tests were found. Performance was substantially improved in MT2, indicating that once a goal is apparent, pigs are able to solve a complex spatial memory task easily. In conclusion, social reinstatement provided a good incentive to complete a spatial task, and the substantial improvement in performance between MT1 and MT2 stresses the need for task complexity when testing spatial memory in pigs. Housing conditions or individual behavioural style did not affect spatial memory during MT1 or MT2. However, housing environment and behavioural style strongly affected explorative behaviour of pigs in an unfamiliar maze during both exploration trials and memory tests. This implicates that apparent effects of environmental enrichment on spatial learning and memory in pigs might reflect differences in explorative patterns rather than in cognitive processes.     

Toward a rodent model of the Iowa gambling task

The Iowa gambling task in humans is, in principle, suited for the study of the long-term efficiency of behavior in a biologically relevant context. Key features of this task are uncertainty of outcomes and a conflict between the immediate and the long-term payoff options. Animal models allow us to study the underlying neurobiology of decision-making processes and the long-term efficiency of behavior in more detail and at a greater depth than is possible in humans. Therefore, we set out to develop a model of this task in rodents, using the task’s key features. In this article, we describe the results of the first series of experiments with rats and mice. The data thus far suggest that mice and rats behave in a way similar to humans; that is, they tend to choose the option with the best long-term payoff more often as the test progresses.     

A Censored Mixture Model for Modeling Risk Taking

Psychometrika - Risk behavior has substantial consequences for health, well-being, and general behavior. The association between real-world risk behavior and risk behavior on experimental tasks is...