Developmental sequences in the age of onset of disruptive child behaviors

Retrospective and prospective reports of the onset of disruptive child behaviors were analyzed in a sample of clinic-referred boys. The younger boys (ages 7–9 years), compared with the older boys (ages 10–12 years), showed the highest level of disruptive behavior and, judging from mothers' reports, had the fastest progression of onsets from less serious to more serious problem behaviors. Despite some overlap, developmental sequences in problem behavior within the domains of hyperactivity/inattention, oppositional behavior, and conduct problems were similar across the two age groups. This was also the case for developmental sequences of overt or confrontive problem behaviors and covert or concealing conduct problems. Sequences of the onset of oppositional behavior and conduct problems were validated through prospective data, based on the information from mothers, teachers, and boys themselves. The implications of the findings are discussed for the formulation of developmental pathways of behavior and the analysis of causal factors.     

Testing visual short-term memory: Simultaneous versus sequential presentations

Two experiments testing immediate ordered recall are presented; in these experiments, subjects engaged in repetitive speech (“articulatory suppression”) during a visual presentation in order to prevent auditory recoding of the stimuli. In both experiments, a simultaneous presentation produced results that suggested the use of visual short-term memory, whereas a sequential presentation did not. In Experiment 1, visual confusion errors occurred more often than would be expected by chance for a simultaneous presentation but not for a sequential presentation. In Experiment 2, recall from visual short-term memory was expected to suffer more when subjects wrote a prefix than when they spoke a prefix; this effect occurred for a simultaneous presentation but not for a sequential presentation. These results suggest that existence of a visual short term store that retains a simultaneous presentation but not a sequential presentation.     

A new quantitative approach to the assessment of stages of vigilance as defined by spatiotemporal EEG patterning

Electroencephalographically oriented research on vigilance needs valid measures for assessing the level of vigilance between wakefulness and sleep. When studying different psychologically, psychopathologically, and pharmacologically induced states, special attention has to be paid to minor alterations of the level of vigilance which are reflected, essentially, in topographical changes of alpha-activity (Stage A). Since vigilance is a dynamic process, brief fluctuations in the range of a few seconds must also be recorded. In our opinion existing methods of quantification do not fully meet these demands. We have, therefore, developed a relatively simple procedure which can be characterized as an attempt quantitatively to reconstruct visually, i.e., spatiotemporally defined patterns of vigilance. The usefulness of this method, which also has certain limitations, has been demonstrated in psychopharmacological studies.     

Accepting the null hypothesis

This article concerns acceptance of the null hypothesis that one variable has no effect on another. Despite frequent opinions to the contrary, this null hypothesis can be correct in some situations. Appropriate criteria for accepting the null hypothesis are (1) that the null hypothesis is possible; (2) that the results are consistent with the null hypothesis; and (3) that the experiment was a good effort to find an effect. These criteria are consistent with the meta-rules for psychology. The good-effort criterion is subjective, which is somewhat undesirable, but the alternative—never accepting the null hypothesis—is neither desirable nor practical.     

The problems of internal validation without a theoretical context: the different conceptual underpinnings of psychopathy and the disruptive behavior disorder criteria

G. L. Burns (2000) has concluded that the Psychopathy Screening Device's content is limited because it contains items that overlap with criteria for several disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM). The problem with G. L. Burns's analysis is that it was conducted without an adequate understanding or specification of the conceptual underpinnings of either the construct of psychopathy or the constructs assessed by the DSM criteria. This reply attempts to clarify these conceptual frameworks to illustrate that to judge the adequacy of the content of a measure of psychopathy by comparing it with DSM criteria is inconsistent with the differing theoretical frameworks underlying these classification systems. Forcing measures of psychopathy to be designed around DSM criteria leads to inadequate measures of psychopathy and can limit advances both in our understanding of developmental precursors to psychopathy and in the classification of DSM disorders.     

Psychopathy in Children and Adolescents: The Need for a Developmental Perspective

The current paper introduces the special issue on research attempting to extend the construct of psychopathy to child and adolescent samples. Past special sections and reviews have typically focused on the implications of this research for forensic research and practice. The current special issue focuses on topics relevant for integrating this research within the broader literature on childhood psychopathology. Papers included in this special issue focus on the structure of psychopathic traits in youth, the relation of these traits to other important psychopathological and personality constructs in children and adolescents, and the utility of these traits for identifying a distinct subgroup of antisocial youth who differ on important cognitive processes and on the severity and stability of their problem behavior. These empirical works are followed by commentary provided by two prominent scholars who outline the potential importance of the construct for advancing our understanding of childhood psychopathology. In addition, these scholars provide a discussion of important directions for future research.     

Effects of environmental enrichment on spatial memory and neurochemistry in middle-aged mice

The present study compared the effects of environmental enrichment on spatial memory, glutamic acid decarboxylase (GAD) activity, and synaptophysin levels in middle-aged male and female mice. Prior to testing, a subset of 18-month-old male and female C57BL/6 mice was housed with two to three toys and a running wheel in the home cage for up to 29 d. Adult mice (7 mo) of both sexes and the remaining middle-aged mice were group (social) housed, but not exposed to enriching objects. After the enrichment period, all mice were tested in a 1-day version of the Morris water maze, in which both spatial and nonspatial memory were assessed. Immediately after testing, the hippocampus and frontoparietal cortex were dissected, and GAD activity and synaptophysin levels were measured. Environmental enrichment reduced the age-related impairment in spatial acquisition and retention; relative to adult social controls, middle-aged enriched mice were unimpaired, whereas middle-aged social controls were impaired. This reduction was similar in middle-aged males and females. Enrichment did not affect cued memory in either sex. Although hippocampal GAD activity was increased by enrichment in males, all other neurochemical measurements were unaffected by enrichment or aging in either sex. These data suggest that environmental enrichment initiated at middle age can reduce age-related impairments in spatial memory in males and females, although the underlying neurobiological mechanisms of this effect remain unknown.     

Callous-Unemotional Traits and Subtypes of Conduct Disorder

There has been growing consensus that children with conduct disorder (CD) constitute a very heterogeneous group containing children who vary substantially on the development, course, and causes of the disorder. While many have recognized the importance of this heterogeneity for developing better causal theories and for developing more effective treatments, there has been little consensus as to the best way to subtype children with CD. In this paper, we review a number of approaches to subtyping, each with some evidence for its validity for certain purposes. We focus on two recent approaches that have great potential for integrating past subtyping approaches and for advancing causal theory. The first approach is the division of children with CD into those with a childhood onset to their severe antisocial behavior and those with an adolescent onset to their behavior. The second approach is to designate children within the childhood-onset group who show callous and unemotional traits, which is analogous to adult conceptualizations of psychopathy. Both approaches help designate children who many show different causal processes underlying their severe aggressive and antisocial behavior, and who may warrant different approaches to treatment.