A note on computing Louis’ observed information matrix identity for IRT and cognitive diagnostic models

Using Louis’ formula, it is possible to obtain the observed information matrix and the corresponding large-sample standard error estimates after the expectation–maximization (EM) algorithm has converged. However, Louis’ formula is commonly de-emphasized due to its relatively complex integration representation, particularly when studying latent variable models. This paper provides a holistic overview that demonstrates how Louis’ formula can be applied efficiently to item response theory (IRT) models and other popular latent variable models, such as cognitive diagnostic models (CDMs). After presenting the algebraic components required for Louis’ formula, two real data analyses, with accompanying numerical illustrations, are presented. Next, a Monte Carlo simulation is presented to compare the computational efficiency of Louis’ formula with previously existing methods. Results from these presentations suggest that Louis’ formula should be adopted as a standard method when computing the observed information matrix for IRT models and CDMs fitted with the EM algorithm due to its computational efficiency and flexibility.     

Reducing drug and alcohol use and improving well-being for Indigenous and non-Indigenous Australians using the Community Reinforcement Approach: A feasibility and acceptability study

There is a lack of evidence of effective and appropriate drug and alcohol treatment for Aboriginal and Torres Strait Islander peoples. This paper contributes to addressing the evidence gap by examining the feasibility and acceptability and conducting a pre/post-evaluation of the Aboriginal-adapted Community Reinforcement Approach (CRA) delivered in New South Wales, Australia. Aboriginal and non-Aboriginal clients (n = 55) received tailored CRA delivery between March and November 2013. Compared to the original US version, tailored CRA had reduced technical language, reduced number of treatment sessions, and the addition of group delivery option. An Australian training manual with local case studies was developed. Alcohol, Smoking and Substance Involvement Test (ASSIST), Kessler-5 (K-5) and the Growth Empowerment Measure were used. 58% of participants were followed-up at 3 months. Tailored CRA was feasible to deliver in a rural, community-based health setting, and rated by clients as highly effective and acceptable. CRA was associated with statistically significant reductions in the use of alcohol, tobacco, cannabis, amphetamine and over the counter medication, and levels of psychological distress, and an increase in levels of empowerment for Aboriginal and non-Aboriginal clients. This study provides evidence for the feasibility and acceptability of an Aboriginal-adapted psychological intervention addressing drug, alcohol and mental health outcomes.     

The neural pathways mediating quiet-biting attack behavior from the hypothalamus in the cat: A functional autoradiographic study

Electrical stimulation of the region of the lateral hypothalamus produced a consistent form of quiet-biting attack behavior in cats. In one series of experiments, cats, implanted with electrodes from which attack had been elicited, were anesthetized and then were injected with a bolus of ¹⁴C-2-deoxyglucose at the same time as electrical stimulation was delivered through the attack electrodes. Brains prepared for X-ray autoradiography revealed that lateral hypothalamic stimulation activated the classical medial forebrain bundle pathway supplying the septal region, diagonal band, lateral preoptic area, and ventral tegmental region. Stimulation of quiet-attack sites in perifornical hypothalamus resulted in the activation of a much more extensive projection system which included the central and lateral tegmental fields of the midbrain and pons, and central gray region, as well as the structures described above. In a second series of experiments, ³H-leucine was placed into the region of the electrode tip from which attack was elicited in order to identify more precisely the pathways arising from that site. In general, tritiated amino acid radioautography replicated the ¹⁴C-2-deoxyglucose findings. In addition, the amino acid radioautographic data revealed the presence of extensive projections from perifornical hypothalamus to such pontine structures as the nucleus locus coeruleus, motor nucleus of NV , and the lateral pontine tegmental field. The functional connections between the lateral hypothalamic “attack region” and lateral preoptic zone were also confirmed by electrophysiological methods.     

The arrogant physician--a Judaic perspective

Arrogance among physicians is all too common. This is in sharp contrast with medicine's sacred religious origins. The author presents a concise historical review of the Judaic perspective on the role of the physician, his position in the community, and the attitudes/values that should characterize his healing pursuit.     

Emotion and cognition: feeling and character identification in dreaming

This study investigated the relationship between dream emotion and dream character identification. Thirty-five subjects provided 320 dream reports and answers to questions on characters that appeared in their dreams. We found that emotions are almost always evoked by our dream characters and that they are often used as a basis for identifying them. We found that affection and joy were commonly associated with known characters and were used to identify them even when these emotional attributes were inconsistent with those of the waking state. These findings are consistent with the finding that the dorsolateral prefrontal cortex, associated with short-term memory, is less active in the dreaming compared to the wake brain, while the paleocortical and subcortical limbic areas are more active. The findings are also consistent with the suggestion that these limbic areas have minimal input from the dorsolateral prefrontal cortex in the dreaming brain.     

Measuring self-efficacy among drug-involved probationers

Self-efficacy has been shown to be related to outcomes from interventions for alcohol and tobacco abuse but relatively little attention has been focused on it in evaluations of treatment for illicit drug abuse. Almost no research has examined offenders involved with drugs. The current study, therefore, adapted the Alcohol Abstinence Self-efficacy Scale of DiClemente, Carbonari, Montgomery, and Hughes and administered it to 250 probationers mandated to 6 months of residential treatment. With some modifications, confirmatory factory models replicated four previously reported dimensions, e.g., Negative Affect, Social/Positive, Physical and Other Concerns, Cravings and Urges. Findings also indicated high construct validity for the Alcohol Abstinence Self-efficacy Scale as adapted here. Studies are needed to examine the use of self-efficacy as a prospective measure of treatment progress and to explore its association with outcomes from corrections-based treatment.     

Dual processes in recognition: Does a focus on measurement operations provide a sufficient foundation?

Current theoretical thinking about dual processes in recognition relies heavily on the measurement operations embodied within the process dissociation procedure. We critically evaluate the ability of this procedure to support this theoretical enterprise. We show that there are alternative processes that would produce a rough invariance in familiarity (a key prediction of the dual-processing approach) and that the process dissociation procedure does not have the power to differentiate between these alternative possibilities. We also show that attempts to relate parameters estimated by the process dissociation procedure to subjective reports (remember-know judgments) cannot differentiate between alternative dual-processing models and that there are problems with some of the historical evidence and with obtaining converging evidence. Our conclusion is that more specific theories incorporating ideas about representation and process are required.     

Age and emotional response to the Northridge earthquake: a longitudinal analysis

Cross-sectional studies have found older adults to have lower levels of emotional distress after natural disasters. The maturation hypothesis suggests that older adults are less reactive to stress events, whereas the inoculation hypothesis argues that prior experience with disaster is protective. One hundred and sixty-six adults aged 30 to 102 were interviewed regarding the 1994 Northridge earthquake. Longitudinal data were available on depressed mood before and after the earthquake. The maturation hypothesis was generally not supported. The young-old were least depressed; however, this age difference was present prior to the earthquake. The old-old showed lowest levels of earthquake-specific rumination, but age did not buffer the relationship between damage exposure and rumination. The inoculation hypothesis was supported for depressed mood. Prior earthquake experience was related to lower postearthquake depression scores.