Towards a Heuristic Neuropsychological Model of Adjudicative Competency.

This study sought to delineate the neuropsychological processes that undergird the psycho-legal concept of competency to stand trial (CST). Accordingly, we retrospectively examined the relationship between clinical judgments of competence or incompetence of defendants committed to a maximum-security psychiatric facility and neuropsychological measures of cognitive and social intelligence and declarative memory. Results indicated that both groups (competent and incompetent) showed similar levels of depressed cognitive intelligence with Wechsler full-scale IQ levels falling in the upper end of the borderline range. Compared with defendants clinically judged as incompetent, defendants recommended as competent scored significantly higher on measures of social intelligence and episodic memory, with the most pronounced advantage occurring on tests of verbal memory that place heavy demands on encoding, consolidation, and retrieval of aurally presented narrative material. Cognitive capacities in areas of social intelligence and episodic memory may play critical roles in developing a heuristic neuropsychological model of CST. The evaluation of these domains offers implications for the assessment, restoration, and understanding of CST.

Stable isotopes (δ13C, δ15N) and biomarkers as indicators of the hydrological regime of fens in a European east-west transect.

Peatland degradation is tightly connected to hydrological changes and microbial metabolism. To better understand these metabolism processes, more information is needed on how microbial communities and substrate cycling are affected by changing hydrological regimes. These activities should be imprinted in stable isotope bulk values (δ 15N, δ 13C) due to specific isotopic fractionation by different microbial communities, their metabolic pathways and nutrient sources. We hypothesize that stable isotope values and microbial abundance are correlated and act as indicators of different hydrological regimes. We sampled an East-West transect across European fens in 14 areas and conducted a stable isotope (δ 13C, δ 15N) and membrane fatty acid (mFA) analysis. Within each area an undrained, drained and rewetted site was selected. Rewetted sites were separated based on when rewetting occurred. We found differences in the upper layers of all sites in microbial-derived mFAs and stable isotope values corresponding to hydrological regimes. The highest and lowest quantities of microbial-derived mFAs were measured in undrained and drained sites, respectively. Fungal-derived mFAs were especially lower in drained sites. Simultaneously, δ15N stable isotope values were highest in drained sites. In addition, stable isotope values and microbial-derived mFAs showed distinct depth trends. In undrained sites stable isotopes values slightly increased with depth. In drained sites, δ15N values decreased downwards, whereas δ13C values increased. Overall microbial-derived mFAs decreased with depth. These patterns presumably result from anoxic conditions and high peat recalcitrance in the deeper layers. In sites with short time of rewetting, the microbial-derived mFAs and stable isotope values were similar to values of drained sites, while with increasing rewetting time values shifted to those of undrained sites. We conclude that biomarkers indicate that stable isotope values reflect specific microbial metabolic processes, which differ with hydrological regimes, and thus could indicate both drainage and rewetting in fens.

Publisher Correction: Soil organic matter stoichiometry as indicator for peatland degradation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Soil organic matter stoichiometry as indicator for peatland degradation.

Peatlands accumulate organic matter (OM) under anaerobic conditions. After drainage for forestry or agriculture, microbial respiration and peat oxidation induce OM losses and change the stoichiometry of the remaining organic material. Here, we (i) evaluate whether land use (cropland CL, grassland GL, forest FL, natural peatland NL) is associated with different peat stoichiometry, (ii) study how peat stoichiometry changes with OM content and (iii) infer the fate of nitrogen upon soil degradation. Organic C and soil N were measured for 1310 samples from 48 sites in Switzerland, and H and O for 1165. The soil OM content and C/N ratio were most sensitive to land use and are hence best suited as indicators for peatland degradation. OM contents (CL < GL < FL < NL), H/C, O/C, C/N ratios, and OM oxidation states were significantly different between land use types in top- and subsoils. With decreasing bulk OM content, C was relatively depleted while H and particularly N were higher. The data suggest very high N mobilization rates from strongly decomposed peat in agricultural topsoil. A comparison to peat C and N from mostly intact peatlands of the Northern hemisphere reveals that agriculture and, to a lesser extent, forestry induce a progressed state of soil degradation.

Gaze cueing of attention in schizophrenia: individual differences in neuropsychological functioning and symptoms.

Inhibition of return (IOR) represents a well-known mechanism of human perception that biases attentional orienting to novel locations in the environment. Behaviorally, IOR reflects slower reaction time (RT) to stimuli presented in previously cued locations. In this study, we examined within patients with schizophrenia this inhibitory aftereffect using two different cue types--eye gaze and standard peripheral cues. Results indicated that patients showed evidence of IOR, as reflected in a 3.2% slowing in RT to previously peripherally cued locations. However, for eye gaze, patients failed to show evidence of IOR and instead had 1.7% faster RT to targets presented following delay in locations that had been previously cued. This inhibitory failure correlated strongly with reduced neuropsychological performance and global symptoms ratings of attention and bizarre behavior. Reduced inhibitory aftereffect in RT for eye-gaze cues may reflect disease-related abnormalities in social attention.

Linkage analysis of attention deficit hyperactivity disorder.

Results of behavioral genetic and molecular genetic studies have converged to suggest that both genes contribute to the development of ADHD. Although prior linkage studies have produced intriguing results, their results have been inconsistent, with no clear pattern of results emerging across studies. We genotyped 5,980 SNPs across the genome in 1,187 individuals from families with children diagnosed with ADHD. We then performed two nonparametric linkage analyses on ADHD families: (1) an affected sibling pair linkage analysis on 217 families with 601 siblings diagnosed with ADHD and (2) a variance components linkage analysis using the number of ADHD symptoms as the phenotype on 260 families with 1,100 phenotyped siblings. The affection status linkage analysis had a maximum LOD score of 1.85 on chromosome 8 at 54.2 cM. The maximum LOD score in the variance components linkage analysis was 0.8 on chromosome 8 at 93.4 cM. The absence of regions of significant or suggestive linkage in these data suggest that there are no genes of large effect contributing to the ADHD phenotype.

Psychopathology in females with attention-deficit/hyperactivity disorder: a controlled, five-year prospective study.

BACKGROUND: Despite the importance of understanding the long-term outcome of children with attention-deficit/hyperactivity disorder (ADHD), the available literature is predominantly based on male samples. This study estimated the lifetime burden of comorbid psychopathology in a large sample of girls with and without ADHD followed up over five years. METHODS: We conducted a blind, five-year prospective longitudinal study of girls with (n=140) and without (n=122) ADHD, aged 6-18 years at baseline, consecutively ascertained from either community pediatricians or psychiatrists at an academic medical center. At the five-year follow-up, 123 (88%) and 112 (92%) of the ADHD and control children, respectively, were re-assessed at a mean age of 16.7 years. Psychiatric disorders were assessed using blinded structured diagnostic interviews. RESULTS: At follow-up, females with ADHD were at significantly higher risk than controls to manifest disruptive behavior, mood and anxiety disorders, and substance dependence. The magnitude of increased risk was greatest for major depression and oppositional-defiant disorder, followed by substance dependence and anxiety disorders. CONCLUSIONS: These prospective follow-up findings documenting high morbidity associated with ADHD extend to females previously reported findings in male samples and underscore the importance of early recognition and intervention efforts for youth with ADHD of both genders.