Mental Disorders, the Positivity Effect, and Questions of Identity and Responsibility

In order to judge how behavior caused by the positivity effect should be considered, comparisons were made between the positivity effect and two mental disorders. These disorders, Tourette’s syndrome and psychopathy, were selected due to their extreme differences in what Strawsonian attitudes they inspire and how they are perceived relative to disordered patients’ will. Disorder-affected behavior of Tourette’s patients inspires the objective attitude and is seen as a condition affecting an individual’s will, while disorder-affected behavior of psychopaths inspires the interpersonal attitude and is seen as a character trait. Relevant distinctions between psychopathy and Tourette’s syndrome were found to include their neurological causes, the obviousness of the suffering they caused, and how easily their disorder-affected behavior could be mapped onto goal-seeking behavior. These considerations suggest the positivity effect should be viewed similarly to psychopathy in terms of responsibility, although this is complicated by its time of development and other factors

The development and application of structural priors for diffuse optical imaging in infants from newborn to two years of age

This thesis describes the development and application of age-appropriate structural priors to improve the localisation accuracy of diffuse optical tomography (DOT) approaches in infants aged from birth to two years of age. Knowledge of the target cranial anatomy, known as a structural prior, is required to produce three-dimensional images localising concentration changes to the cortex. A structural prior would ideally be subject-specific, i.e. derived from structural magnetic resonance imaging (MRI) data from each specific subject. Requiring a structural scan from every infant participant, however, is not feasible and undermines many of the benefits of DOT. A review was conducted to catalogue available infant structural MRI data, and selected data was then used to produce structural priors for infants aged 1- to 24-months. Conventional analyses using functional near-infrared spectroscopy (fNIRS) implicitly assume that head size and array position are constant across infants. Using DOT, the validity of assuming these parameters constant in a longitudinal infant cohort was investigated. The results show that this assumption is reasonable at the group-level in infants aged 5- to 12-months but becomes less valid for smaller group sizes. A DOT approach was determined to illicit more subtle effects of activation, particularly for smaller group sizes and expected responses. Using state-of-the-art MRI data from the Developing Human Connectome Project, a database of structural priors of the neonatal head was produced for infants aged pre-term to term-equivalent age. A leave-one-out approach was used to determine how best to find a match between a given infant and a model from the database, and how best to spatially register the model to minimise the anatomical and localisation errors relative to subject-specific anatomy. Model selection based on the 10/20 scalp positions was determined to be the best method (of those based on external features of the head) to minimise these errors

Single Case Experimental Design Examining Cognitive Behavioural Therapy for Post-Stroke Depression

Background. Post-stroke depression (PSD) is common in older-age adults and is typically treated with cognitive-behavioural therapy (CBT). However, research has ascertained mixed findings regarding the efficacy of CBT for PSD in older-age adults, with limited evidence in people from global majority backgrounds. Materials and Methods. This case study used single case experimental design methodology to examine the effectiveness of CBT for PSD in a black, older-age man. The effects of health conditions, cohort beliefs, transitions in role investments, socio-cultural context and early experiences on the client’s thoughts, emotions, physical sensations and behaviours were formulated, before behavioural activation was used to increase engagement in meaningful and pleasurable activities. Results. Throughout therapy, the client’s mood, motivation and optimism for the future improved, and their depression and anxiety symptoms reduced. Conclusions. This case study offers tentative evidence that CBT for PSD may be effective in black older-age adults

Ultra-narrow (sub-MHz) linewidth emission from discrete mode laser diodes

A class of laser which exhibits ultra-narrow sub MHz linewidth emission necessary for numerous applications in optical communications and sensors is described. The spectral performance of commercial discrete mode (DM) and distributed feedback (DFB) lasers is compared. The devices used in this work are asymmetrically coated ridge waveguide Fabry Perot lasers which incorporated etched slot features and emitting around lambda = 1.55 mum. The active region of the devices consisted of a strained compensated InAlGaAs MQW structure

Four errors students make with inverse-square law vectors

In this paper, we discuss four errors introductory physics students make when attempting to add two inverse-square law vectors. We observe multiple instances in which students 1) add vectors as if they were scalars, 2) project the $r$ (or $r^2$) in the denominator, instead of the entire vector, when attempting to find the vector's components, 3) incorrectly apply the Pythagorean theorem when attempting to calculate the magnitude of the resultant vector, and 4) incorrectly relate the signs of the components of an electric field (or force) to the signs of the electric charges. While these are not the only errors students make, they are the most frequently occurring based on our analysis of 678 exams taken by students in either introductory mechanics or electricity and magnetism (E&M). We then show how these errors can be encoded into a new type of activity or assessment question which we call a ``student error task." Introductory physics instructors can use the student error task in this paper as a way to engage or assess their students' understandings of how to add two inverse-square law vectors.Comment: 22 pages, 7 figures, submitted to the European Journal of Physic

(Mis-)understanding COVID-19 and digit ratio: Methodological and statistical issues in Manning and Fink (2020)

Manning and Fink (2020) report that country level mean 2D:4D is associated with COVID-19 case fatality ratio and percentage of male deaths. We discuss here a range of methodological and statistical issues with Manning and Fink's work that offer a different interpretation of their claims

Mass spectrometry in medicine: a technology for the future?

Mass spectrometry in medicine: a technology for the future

Smokers and ex-smokers have shared differences in the neural substrates for potential monetary gains and losses

Despite an increased understanding of nicotine addiction, there is a scarcity of research comparing the neural correlates of non-drug reward between smokers and ex-smokers. Long-term changes in reward-related brain functioning for non-drug incentives may elucidate patterns of functioning that potentially contribute to ongoing smoking behaviour in current smokers. Similarly, examining the effects of previous chronic nicotine exposure during a period of extended abstinence may reveal whether there are neural correlates responsible for non-drug reward processing that are different from current smokers