Outliers and Influential Observations in Exponential Random Graph Models

We discuss measuring and detecting influential observations and outliers in the context of exponential family random graph (ERG) models for social networks. We focus on the level of the nodes of the network and consider those nodes whose removal would result in changes to the model as extreme or “central” with respect to the structural features that “matter”. We construe removal in terms of two case-deletion strategies: the tie-variables of an actor are assumed to be unobserved, or the node is removed resulting in the induced subgraph. We define the difference in inferred model resulting from case deletion from the perspective of information theory and difference in estimates, in both the natural and mean-value parameterisation, representing varying degrees of approximation. We arrive at several measures of influence and propose the use of two that do not require refitting of the model and lend themselves to routine application in the ERGM fitting procedure. MCMC p values are obtained for testing how extreme each node is with respect to the network structure. The influence measures are applied to two well-known data sets to illustrate the information they provide. From a network perspective, the proposed statistics offer an indication of which actors are most distinctive in the network structure, in terms of not abiding by the structural norms present across other actors.     

How Do You Say Nature?: Opening the Design Space with a Knowledge Environment

In this paper, we describe a design study on how families in Los Angeles experience nature, with a particular focus on how using alternative formats for research analysis and presentation can enrich a design research inquiry. Conducted in Pasadena, CA as a part of Super Studio, the year-long design research class emphasized knowledge building and sharing through design methods of analysis, exhibition, and concept prototypes. After conducting interviews and engaging participants with probes, the class built the results into an open-ended knowledge environment. The main observation from the exhibition – that Angelenos have a limited vocabulary for describing nature and their interaction with it – helped to define the opportunity for design intervention that created connection points between Angelenos and nature. There are few attempts to describe how probe returns evolve into design concepts. Showcased is a process that depends on the unique affordances of design as the vehicle for discovery and invention.     

Multiple Depression

The subject of this paper is the problematisation of depression in today's mental health care. It is based on a study of the professional discussion on depression in Finland from the mid-1980s to the 1990s. The ways in which Finnish mental health experts define the object of depression treatment bring out an ambivalence that stems from the discrepancy between two parallel but incongruent notions of what depression is: the psychopharmacological and the psychotherapeutic. The analysis of the discussion demonstrates how clinical and practical rationales of today's mental health care are formed in the space between the two poles. Two tendencies of these rationales are also pointed out: first, the DSM paradigm of depressive illness inclines to become problematic and to dissolve in the actual practices. Second, they insinuate emphasis on antidepressant medication and overall neuropsychiatric approach in the treatment of depressive disorders, although in an ambivalent way.     

The Effect of Language Immersion Education on the Preattentive Perception of Native and Non-native Vowel Contrasts

Proficiency in a second language (L2) may depend upon the age of exposure and the continued use of the mother tongue (L1) during L2 acquisition. The effect of early L2 exposure on the preattentive perception of native and non-native vowel contrasts was studied by measuring the mismatch negativity (MMN) response from 14-year-old children. The test group consisted of six Finnish children who had participated in English immersion education. The control group consisted of eight monolingual Finns. The subjects were presented with Finnish and English synthetic vowel contrasts. The aim was to see whether early exposure had resulted in the development of a new language-specific memory trace for the contrast phonemically irrelevant in L1. The results indicated that only the contrast with the largest acoustic distance elicited an MMN response in the Bilingual group, while the Monolingual group showed a response also to the native contrast. This may suggest that native-like memory traces for prototypical vowels were not formed in early language immersion.     

Adolescent athletes with learning disability display atypical maturational trajectories on concussion baseline testing: Implications based on a Finnish sample

Previous research has reported lower cognitive test scores on baseline testing in athletes reporting multiple previous concussions or a history of learning disability (LD). Age also has an important influence on cognitive performance. While these factors have been considered individually in previous studies, the present study is the first to explore the interaction of age, self-reported LD, and history of concussion on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) in a nationwide study of adolescent athletes. ImPACT® was administered to 1823 Finnish male ice hockey players (aged 12–21 years old) prior to the 2015–2016 or 2016–2017 playing seasons. Linear regressions and simple slopes analyses were used for clarifying the impact of LD and previous concussion history on maturational trajectories. In comparison to typically developing athletes, athletes with LD had lower neurocognitive scores in all composites and differing maturational trajectory in verbal memory and visual motor speed. The number of previous concussions did not impair neurocognitive performance at baseline assessment. Application of standard age-based norms to adolescent athletes with a history of LD has the potential to negatively skew clinical decision-making. Separate reference values for LD athletes are warranted due to their unique developmental cognitive trajectories. The reference values for the Finnish participants in this study are presented.