Restrictions in means for suicide: an effective tool in preventing suicide: the Danish experience

Restriction of means for suicide is an important part of suicide preventive strategies in different countries. The effect on method-specific suicide rate and overall suicide rate of restrictions on availability of carbon monoxide, barbiturates, and dextropropoxyphene was examined. From 1970 to 2000, overall suicide mortality and method-specific suicide mortality in Denmark were compared with official information about availability of barbiturates and analgesics and carbon monoxide in vehicle exhaust and household gas. Restrictions on availability of household gas with carbon monoxide content and barbiturates was associated with a decline in the number of suicides and suicides by self-poisoning with these compounds after controlling for the effect of calender year. Restricted access occurred concomittantly with a 55 percent decrease in suicide rate.     

Dynamic self-organization and early lexical development in children

In this study we present a self-organizing connectionist model of early lexical development. We call this model DevLex-II, based on the earlier DevLex model. DevLex-II can simulate a variety of empirical patterns in children's acquisition of words. These include a clear vocabulary spurt, effects of word frequency and length on age of acquisition, and individual differences as a function of phonological short-term memory and associative capacity. Further results from lesioned models indicate developmental plasticity in the network's recovery from damage, in a non-monotonic fashion. We attribute the network's abilities in accounting for lexical development to interactive dynamics in the learning process. In particular, variations displayed by the model in the rate and size of early vocabulary development are modulated by (a) input characteristics, such as word frequency and word length, (b) consolidation of lexical-semantic representation, meaning-form association, and phonological short-term memory, and (c) delayed processes due to interactions among timing, severity, and recoverability of lesion. Together, DevLex and DevLex-II provide an accurate computational account of early lexical development.     

A developmental approach to violence, hostile attributions, and paranoid thinking in adolescence

Research within the area of paranoid thinking has focused primarily on adults and has only recently looked at the effects during the critical life stage of adolescence, with even less research in the context of the juvenile justice system. This article aims to explore the relationship between antisocial behaviour in adolescence and the development of paranoid thinking, set within wider contexts that surround the juvenile justice system. The information presented is drawn from both the current research and the clinical experiences of those working in adolescent forensic psychiatry services. The relationships with other disorders such as conduct disorder, ADHD, PTSD, and depression are also explored.     

The ultimate challenge: prove B. F. Skinner wrong

For much of his career, B. F. Skinner displayed the optimism that is often attributed to behaviorists. With time, however, he became less and less sanguine about the power of behavior science to solve the major problems facing humanity. Near the end of his life he concluded that a fair consideration of principles revealed by the scientific analysis of behavior leads to pessimism about our species. In this article I discuss the case for Skinner's pessimism and suggest that the ultimate challenge for behavior analysts today is to prove Skinner wrong.     

Some comments on the distinction between intention and intentionality

The topic of intention has recently received attention from behavior analysts (Hineline, 2003; Neuman, 2004). From a behavior-analytic perspective, it is important to identify the circumstances in which people utter such terms, and to identify the potential circumstances that maintain such utterances. It follows that from a behavior-analytic perspective, the focus is primarily on those who observe behavior and attribute intentions to that behavior. However, there has not been a distinction between intention and intentionality. The current analysis stresses the distinction between the two terms, both from a traditional point of view (psychologist and layperson) and from a behavior-analytic point of view. From a behavior analyst's perspective, the distinction is important because observers may be responding to distinct functional relations when they attribute intention or intentionality to behavior.     

The curse of knowledge in reasoning about false beliefs

Assessing what other people know and believe is critical for accurately understanding human action. Young children find it difficult to reason about false beliefs (i.e., beliefs that conflict with reality). The source of this difficulty is a matter of considerable debate. Here we show that if sensitive-enough measures are used, adults show deficits in a false-belief task similar to one used with young children. In particular, we show a curse-of-knowledge bias in false-belief reasoning. That is, adults' own knowledge of an event's outcome can compromise their ability to reason about another person's beliefs about that event. We also found that adults' perception of the plausibility of an event mediates the extent of this bias. These findings shed light on the factors involved in false-belief reasoning and are discussed in light of their implications for both adults' and children's social cognition.     

The origins of cognitive dissonance: evidence from children and monkeys

In a study exploring the origins of cognitive dissonance, preschoolers and capuchins were given a choice between two equally preferred alternatives (two different stickers and two differently colored M&M's, respectively). On the basis of previous research with adults, this choice was thought to cause dissonance because it conflicted with subjects' belief that the two options were equally valuable. We therefore expected subjects to change their attitude toward the unchosen alternative, deeming it less valuable. We then presented subjects with a choice between the unchosen option and an option that was originally as attractive as both options in the first choice. Both groups preferred the novel over the unchosen option in this experimental condition, but not in a control condition in which they did not take part in the first decision. These results provide the first evidence of decision rationalization in children and nonhuman primates. They suggest that the mechanisms underlying cognitive-dissonance reduction in human adults may have originated both developmentally and evolutionarily earlier than previously thought.     

Anton's syndrome following callosal disconnection

Anosognosia for cortical blindness, also called Anton's syndrome, is a rare neurological disorder usually following bilateral lesions to occipital cortices. Neuropsychological, morphological and functional neuroimaging (SPECT and fMRI) findings are reported in a patient who incurred Anton's syndrome after an ischaemic lesion confined to the left occipital lobe involving the corpus callosum. The present case study suggests that Anton's syndrome may also follow from lesions disconnecting the occipital cortices.     

Characteristics and reversibility of dementia in Normal Pressure Hydrocephalus

Studies of the cognitive outcome after shunt insertion for treatment of Normal Pressure Hydrocephalus have reported widely mixed results. We prospectively studied performance of 60 patients with Normal Pressure Hydrocephalus on a comprehensive battery of neuropsychological tests before and after shunt surgery to determine which cognitive functions improve with shunt insertion. We also administered a subset of cognitive tests before and after temporary controlled drainage of cerebrospinal fluid to determine if change on this brief subset of tests after drainage could predict which patients would show cognitive improvement three to six months after shunt insertion. There was a significant improvement in learning, retention, and delayed recall of verbal memory three to six months after surgery (using paired t-tests). The majority (74%) of patients showed significant improvement (by at least one standard deviation) on at least one of the memory tests. Absence of improvement on verbal memory after temporary drainage of cerebrospinal fluid had a high negative predictive value for improvement on memory tests at 3-6 months after surgery (96%; p=0.0005). Also, the magnitude of improvement from Baseline to Post-Drainage on few specific tests of learning and recall significantly predicted the magnitude of improvement after shunt surgery on the same tests (r2=0.32-0.58; p=0.04-0.001). Results indicate that testing before and after temporary drainage may be useful in predicting which patients are less likely to improve in memory with shunting.