Training raters to assess adult ADHD: reliability of ratings

The standardization of ADHD ratings in adults is important given their differing symptom presentation. The authors investigated the agreement and reliability of rater standardization in a large-scale trial of atomoxetine in adults with ADHD. Training of 91 raters for the investigator-administered ADHD Rating Scale (ADHDRS-IV-Inv) occurred prior to initiation of a large, 31-site atomoxetine trial. Agreement between raters on total scores was established in two ways: (a) by Kappa coefficient (rater agreement for each item with the percentage of raters that had identical item-by-item scores) and (b) intraclass correlation coefficients (reliability). For the ADHDRS-IV-Inv, rater agreement was moderate, and reliability, as measured by Cronbach's alpha, was substantial. The data indicate that clinicians can be trained to reliably evaluate ADHD in adults using the ADHDRS-IV-Inv.     

Mechanisms for ovarian cycle disruption by immune/inflammatory stress

This review summarizes highlights of our experiments investigating mechanisms, mediators and sites by which endotoxin disrupts reproductive neuroendocrine activity and interferes with the estrous cycle of sheep. Endotoxin, or lipopolysaccharide (LPS), is a commonly used model for immune and inflammatory stress. When administered to ovary-intact ewes, endotoxin interrupts the follicular phase of the cycle by interfering with several steps in the preovulatory chain of endocrine events. One such step is the development of high frequency LH pulses, which provide an essential stimulus for the preovulatory increase in estradiol secretion from the ovarian follicle. Follow-up experiments in ovariectomized ewes demonstrate that endotoxin inhibits pulsatile LH secretion at both the hypothalamic and pituitary levels, suppressing pulsatile GnRH secretion and reducing pituitary responsiveness to GnRH. This disruption of GnRH and LH pulsatility is mediated by pathways that include the synthesis of prostaglandins and cortisol, both of which are increased by endotoxin. It is postulated that a prostaglandin-mediated pathway disrupts the cycle during immune and inflammatory stress, whereas a separate cortisol-mediated pathway reinforces this disruption and also participates more generally in suppressing cyclicity during other stressful situations that activate the hypothalamo-pituitary-adrenal axis.     

Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning

Benzodiazepine pharmacology has led to greater insight into the neural mechanisms underlying learning and anxiety. The synthesis of new compounds capable of modulating responses produced by these receptors has been made possible by the development of an isoform model of the GABA(A)/benzodiazepine receptor complex. In the current experiment, rats were pretreated with several concentrations of the novel ligand RY024 (an alpha 5 beta 2 gamma 2 -selective benzodiazepine receptor inverse agonist) in the hippocampus and were trained in a Pavlovian fear conditioning paradigm. RY024 independently produced fear-related behavior prior to training and, at the highest concentration, decreased the strength of conditioning observed 24 h after training. These data provide further evidence for the involvement of hippocampal GABA(A)/benzodiazepine receptors in learning and anxiety.     

Contact with maternal parent and siblings affects hunting behavior,learning, and central nervous system development in spiderlings of <Emphasis Type="Italic">Hogna carolinensis</Emphasis> (Araeneae: Lycosidae)

The purpose of this study was to determine the effects of early experience (rearing conditions) on the central nervous system (CNS) and behavior of spiderlings of Hogna carolinensis (Lycosidae). We were interested in whether or not spiderlings that were allowed to remain in contact with their maternal parent and siblings (enriched condition, EC) would exhibit differences in CNS development or subsequent behavior when compared with those reared in isolation (impoverished condition, IC). Spiderlings emerged from their egg sacs and climbed onto the dorsal surface of their mother's abdomen where they remained until their yolk supply was depleted (5 days). They dispersed on day 6 after emergence. We compared the ability of 16-day-old EC and IC spiderlings to capture prey in a linear runway and to learn a complex maze (spatial learning). We also compared certain aspects of CNS development (brain weight, total number of brain cells, volume of central body and protocerebral neuropil) in EC and IC spiderlings. Results indicated that EC subjects are more efficient at capturing moving prey (crickets) and exhibited improved performance (significantly fewer blind alley errors) in the maze. The volume of the protocerebral neuropil in 6-day-old EC animals increased 30% over a 5-day period after emergence as compared to IC animals of the same age. The volume of the central body of EC animals increased 34.8% over the same time period. On day 6 after emergence, the weight of the protocerebrum was significantly greater in EC versus IC subjects. There were no significant effects of rearing condition (EC vs IC) or age (1- and 6-day-old spiderlings) on the total number of nerve cells in the protocerebrum, suggesting that the difference in protocerebral weight was due primarily to differences in supporting glial tissues and neuropil matrix. In conclusion, the data suggest that early contact with the maternal parent and siblings is of vital importance to CNS development in lycosid spiderlings and can influence the capacity for spatial learning as well as the ability to capture prey. Electronic Publication     

Effects of pointing compared with naming and observing during encoding on item and source memory in young and older adults

Research showed that source memory functioning declines with ageing. Evidence suggests that encoding visual stimuli with manual pointing in addition to visual observation can have a positive effect on spatial memory compared with visual observation only. The present study investigated whether pointing at picture locations during encoding would lead to better spatial source memory than naming (Experiment 1) and visual observation only (Experiment 2) in young and older adults. Experiment 3 investigated whether response modality during the test phase would influence spatial source memory performance. Experiments 1 and 2 supported the hypothesis that pointing during encoding led to better source memory for picture locations than naming or observation only. Young adults outperformed older adults on the source memory but not the item memory task in both Experiments 1 and 2. In Experiments 1 and 2, participants manually responded in the test phase. Experiment 3 showed that if participants had to verbally respond in the test phase, the positive effect of pointing compared with naming during encoding disappeared. The results suggest that pointing at picture locations during encoding can enhance spatial source memory in both young and older adults, but only if the response modality is congruent in the test phase.     

Do Online Exams Facilitate Cheating? An Experiment Designed to Separate Possible Cheating from the Effect of the Online Test Taking Environment

Despite recent growth in distance education, there has been relatively little research on whether online examinations facilitate student cheating. The present paper utilizes an experimental design to assess the difference in student performance between students taking a traditional, proctored exam and those taking an online, unproctored exam. This difference in performance is examined in a manner which considers both the effect of the different physical test environments and the possible effect of a difference in the opportunity for students to cheat. This study, utilizing regression models that also account for relevant control variables, examines 44 undergraduate statistics students, finds evidence that the difference in the testing environment creates a disadvantage to students taking the online exam which somewhat offsets the advantage that the unproctored students gain from greater opportunities to cheat.