Error-related brain activity dissociates hoarding disorder from obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is associated with an abnormally large error-related negativity (ERN), an electrophysiological measure of error monitoring in response to performance errors, but it is unclear if hoarding disorder (HD) also shows this abnormality. This study aimed to determine whether the neurophysiological mechanisms underlying error monitoring are similarly compromised in HD and OCD. METHOD: We used a visual flanker task to assess ERN in response to performance errors in 14 individuals with HD, 27 with OCD, 10 with HD+OCD, and 45 healthy controls (HC). Age-corrected performance and ERN amplitudes were examined using analyses of variance and planned pairwise group comparisons. RESULTS: A main effect of hoarding on ERN (p = 0.031) was observed, indicating ERN amplitudes were attenuated in HD relative to non-HD subjects. A group × age interaction effect on ERN was also evident. In HD-positive subjects, ERN amplitude deficits were significantly greater in younger individuals (r = -0.479, p = 0.018), whereas there were no significant ERN changes with increasing age in OCD and HC participants. CONCLUSIONS: The reduced ERN in HD relative to OCD and HC provides evidence that HD is neurobiologically distinct from OCD, and suggests that deficient error monitoring may be a core pathophysiological feature of HD. This effect was particularly prominent in younger HD participants, further suggesting that deficient error monitoring manifests most strongly early in the illness course and/or in individuals with a relatively early illness onset.

Visual information processing dysfunction across the developmental course of early psychosis.

BACKGROUND: Patients with schizophrenia consistently demonstrate information processing abnormalities assessed with visual masking (VM) tasks, and these deficits have been linked to clinical and functional severity. It has been suggested that VM impairments may be a vulnerability marker in individuals at risk for developing psychosis. METHOD: Forward and backward VM performance was assessed in 72 first-episode (FE) psychosis patients, 98 subjects at risk (AR) for psychosis and 98 healthy controls (HC) using two identification tasks (with either a high- or low-energy mask) and a location task. VM was examined for stability in a subgroup (FE, n=15; AR, n=35; HC, n=21) and assessed relative to clinical and functional measures. RESULTS: In the identification tasks, backward VM deficits were observed in both FE and AR relative to HC whereas forward VM deficits were only present in FE patients compared to HC. In the location task, AR subjects demonstrated superior performance in forward VM relative to HC. VM performance was stable over time, and VM deficits were associated with baseline functional measures and predicted future negative symptom severity in AR subjects. CONCLUSIONS: Visual information processing deficits, as indexed by backward VM, are present before and after the onset of frank psychosis, and probably represent a stable vulnerability marker that is associated with negative symptoms and functional decline. Additionally, the paradoxically better performance of AR subjects in select forward tasks suggests that early compensatory changes may characterize an emerging psychotic state.

Nitrogênio e fósforo no desenvolvimento inicial da guavira [Campomanesia adamantium (Cambess. ) O. Berg] cultivada em vasos / Effect of nitrogen and phosphorus supply on initial development of guavira [Campomanesia adamantium (Cambess. ) O. Berg] cultivated in pots

O objetivo deste trabalho foi avaliar o desenvolvimento inicial da guavira (Campomanesia adamantium) cultivada sob diferentes doses de fósforo e nitrogênio. O experimento foi realizado em casa de vegetação, da Universidade Federal da Grande Dourados, em Dourados-MS. Foram estudadas cinco doses de fósforo (20, 120, 200, 280 e 380 kg ha-1), na forma de superfosfato simples e cinco doses de nitrogênio (6, 36, 60, 84 e 114 kg ha-1), na forma de sulfato de amônio. Os tratamentos foram definidos utilizando-se a matriz experimental Plan Puebla III, dando origem a nove combinações, respectivamente, de doses de fósforo e de nitrogênio (kg ha-1): 280 e 84; 280 e 36; 120 e 6; 120 e 36; 120 e 84; 200 e 60; 380 e 84, 20 e 36 e 280 e 114. O delineamento experimental utilizado foi blocos casualizados, com quatro repetições. A unidade experimental foi composta por cinco vasos, com uma planta por vaso. A colheita das plantas foi feita aos 270 dias após o transplante (DAT). Sob as maiores doses de P e N utilizadas observaram-se as maiores alturas de plantas (38,12 cm), aos 261 DAT; o maior número de folhas por planta (54), aos 186 DAT; a maior massa seca de folhas (5,68 g planta-1), a maior área foliar (610 cm² planta-1), a maior massa seca de raiz (6,2 g planta-1) e o maior número de ramos (3 planta-1) aos 270 DAT. O teor de clorofila foi em média de 36 ICF. Recomenda-se o uso de 380 kg ha-1 de fósforo e de 114 kg ha-1 de nitrogênio para o melhor desenvolvimento inicial da guavira.

The aim of this trial was to evaluate the initial development of Campomanesia adamantium grown under different phosphorus and nitrogen rates. The experiment was conducted in a greenhouse at the Universidade Federal da Grande Dourados, Dourados-MS. It was studied five phosphorus rates (20, 120, 200, 280 and 380 kg ha-1) in the form of superphosphate and five nitrogen rates (6, 36, 60, 84 and 114 kg ha-1) in the form of ammonium sulfate. Treatments were defined using the Plan Puebla experimental matrix, resulting in nine combinations, respectively, of phosphorus and nitrogen (kg ha-1): 280 and 84, 280 and 36, 120 and 6, 120 and 36, 120 and 84, 200 and 60, 380 and 84, 20 and 36 and 280 and 114. The experimental design was randomized block with four replications. Experimental unit consisted of five vessels, with one plant per pot. The trial harvest was carried out 270 days after transplanting (DAT). Highest rates of N and P resulted on the greatest plant height (38.12 cm) reached after 261 DAT, maximum number of leaves per plant (54) at 186 DAT, highest dry weight of leaves (13.99 and 5.68 g plant-1) and root (15.9 and 6.2 g plant-1), greatest leaf area (610 cm² plant-1) and number of branches (3 planta-1), all at 270 DAT. The average of Chlorophyll levels was 36 ICF. Thus, it's recommend the supply of high doses of phosphorus (380 kg ha-1) and nitrogen (114 kg ha-1) for guavira cultivation.