The Epidemiology of Homicide followed by Suicide: A Systematic and Quantitative Review

This systematic review of population based studies of homicide followed by suicide was conducted to examine the associations between rates of homicide‐suicide, rates of other homicides and rates of suicide. The review analysed 64 samples, including the case of an outlier (Greenland) that were reported in 49 studies. There was a significant association between the rates of homicide‐suicide and those of other homicides in studies from the U.S.A. Outside the U.S.A. there was no clear association between homicide‐suicide and other homicide but there was modest but significant association between rates of suicide and homicide‐suicide. Homicide‐suicide appears to be closer in epidemiological terms to homicide than suicide in regions with high rates of homicide and measures to reduce homicide in these regions may also reduce homicide‐suicide.     

Tests of the ratio rule in categorization.

Many theories of learning and memory (e.g., connectionist, associative, rational, exemplar based) produce psychological magnitude terms as output (i.e., numbers representing the momentary level of some subjective property). Many theories assume that these numbers may be translated into choice probabilities via the ratio rule, also known as the choice axiom (Luce, 1959) or the constant-ratio rule (Clarke, 1957). We present two categorization experiments employing artificial, visual, prototype-structured stimuli constructed from 12 symbols positioned on a grid. The ratio rule is shown to be incorrect for these experiments, given the assumption that the magnitude terms for each category are univariate functions of the number of category-appropriate symbols contained in the presented stimulus. A connectionist winner-take-all model of categorical decision (Wills & McLaren, 1997) is shown to account for our data given the same assumption. The central feature underlying the success of this model is the assumption that categorical decisions are based on a Thurstonian choice process (Thurstone, 1927, Case V) whose noise distribution is not double exponential in form.     

Blocking of human causal learning involves learned changes in stimulus processing

Several theories of associative learning propose that blocking reflects changes in the processing devoted to learning about cues. The results of the only direct test of this suggestion in human learning (Kruschke & Blair, 2000) could equally well be explained in terms of, among others, interference in learning or memory. The present study tested this suggestion in a situation in which processing-change and interference accounts predict opposing results. Results support the idea that blocking in human learning can reflect a change in processing of the cues involved.     

Evaluating the performance of departments of psychotherapy

Conceptual and practical issues which surround attempts at assessing the efficiency of psychotherapy departments are surveyed and the advantages and disadvantages associated with performance indicators reviewed. The issues of assessing efficiency in general and the selection of appropriate indicators at both national and local levels are discussed. It is concluded that it is possible to find indicators which reflect the value of a psychotherapeutic service to the community within which it is based, and that the identification of a generally agreed set of such parameters is a matter of priority.     

Brief communication: The role of category structure in determining the effects of stimulus preexposure on categorization accuracy

What are the effects of preexposure of stimuli on participants' subsequent ability to categorize them accurately? An experiment employing artificial, abstract, visual stimuli confirms that, for adult humans, the effect of preexposure is dependent upon category structure. Whether preexposure has beneficial or detrimental effects is shown to be dependent on the way category examples are generated from the category base patterns. The results are predicted by salience reduction accounts of perceptual learning but may be problematic for stimulus differentiation accounts.     

An Institution for Change: Developing a Family Day Unit

This paper describes the theory and structure of a day unit designed to intervene in the systems of families who present with severe or multiple problems to agencies attempting to help them, but who are difficult to engage in a therapeutic pact and unresponsive to attempts at outpatient therapy. An analysis of these families is offered in terms of the relations between internal and external boundaries and difficulties in making transitions in the daily contexts of life. The principles of the unit are described in terms of the creation of an artificial extended family, the intensification of sequence and patterns of interaction, and the making and traversing of boundaries. Particular attention is paid to the function of agency interventions in family patterns and to redefining the relationship between family and agencies.     

Representation and discrimination on an artificial dimension

How we represent stimuli that are drawn from either natural (e.g., hue) or artificial (e.g., morphed face) dimensions is an issue of great significance for human learning. In this paper we outline a model of human dimensional representation in conjunction with some supporting empirical evidence for transfer along a continuum in humans (following Lawrence, 1952) and the first recorded case of transfer after outcome reversal with human subjects (following Mackintosh & Little, 1970). Our results support an elemental representation for dimensional stimuli in conjunction with algorithms that modulate both the salience and the associability of those representations.