Dynamic Epistemic Logics of Diffusion and Prediction in Social Networks

Studia Logica - We take a logical approach to threshold models, used to study the diffusion of opinions, new technologies, infections, or behaviors in social networks. Threshold models consist of a...     

Substance Use Research with Indigenous Communities: Exploring and Extending Foundational Principles of Community Psychology

Many Indigenous communities are concerned with substance use (SU) problems and eager to advance effective solutions for their prevention and treatment. Yet these communities also are concerned about the perpetuation of colonizing, disorder‐focused, stigmatizing approaches to mental health, and social narratives related to SU problems. Foundational principles of community psychology—ecological perspectives, empowerment, sociocultural competence, community inclusion and partnership, and reflective practice—provide useful frameworks for informing ethical community‐based research pertaining to SU problems conducted with and by Indigenous communities. These principles are explored and extended for Indigenous community contexts through themes generated from seven collaborative studies focused on understanding, preventing, and treating SU problems. These studies are generated from research teams working with Indigenous communities across the United States and Canada—inclusive of urban, rural, and reservation/reserve populations as well as adult and youth participants. Shared themes indicate that Indigenous SU research reflects community psychology principles, as an outgrowth of research agendas and processes that are increasingly guided by Indigenous communities. At the same time, this research challenges these principles in important ways pertaining to Indigenous–settler relations and Indigenous‐specific considerations. We discuss these challenges and recommend greater synergy between community psychology and Indigenous research.     

Knowledge-based inferencing after childhood head injury

Inferencing was studied with a story comprehension task that required inferences to be made from a controlled knowledge base. Despite similar rates of knowledge base acquisition, knowledge base retention, and speeded access to the knowledge base across groups, the 18 children with severe head injury had lower rates of inferencing than the 15 children with mild head injury or the 18 age-matched controls. Results suggest that cognitive functions such as working memory and metacognitive skill that are disrupted by severe head injury may also play a role in some of the text- and discourse-level deficits commonly reported in these children, notably those involving inferencing.     

Are there pre-existing neural, cognitive, or motoric markers for musical ability?

Adult musician's brains show structural enlargements, but it is not known whether these are inborn or a consequence of long-term training. In addition, music training in childhood has been shown to have positive effects on visual-spatial and verbal outcomes. However, it is not known whether pre-existing advantages in these skills are found in children who choose to study a musical instrument nor is it known whether there are pre-existing associations between music and any of these outcome measures that could help explain the training effects. To answer these questions, we compared 5- to 7-year-olds beginning piano or string lessons (n=39) with 5- to 7-year-olds not beginning instrumental training (n=31). All children received a series of tests (visual-spatial, non-verbal reasoning, verbal, motor, and musical) and underwent magnetic resonance imaging. We found no pre-existing neural, cognitive, motor, or musical differences between groups and no correlations (after correction for multiple analyses) between music perceptual skills and any brain or visual-spatial measures. However, correlations were found between music perceptual skills and both non-verbal reasoning and phonemic awareness. Such pre-existing correlations suggest similarities in auditory and visual pattern recognition as well a sharing of the neural substrates for language and music processing, most likely due to innate abilities or implicit learning during early development. This baseline study lays the groundwork for an ongoing longitudinal study addressing the effects of intensive musical training on brain and cognitive development, and making it possible to look retroactively at the brain and cognitive development of those children who emerge showing exceptional musical talent.     

A memory-based theory of verbal cognition

The syntagmatic paradigmatic model is a distributed, memory-based account of verbal processing. Built on a Bayesian interpretation of string edit theory, it characterizes the control of verbal cognition as the retrieval of sets of syntagmatic and paradigmatic constraints from sequential and relational long-term memory and the resolution of these constraints in working memory. Lexical information is extracted directly from text using a version of the expectation maximization algorithm. In this article, the model is described and then illustrated on a number of phenomena, including sentence processing, semantic categorization and rating, short-term serial recall, and analogical and logical inference. Subsequently, the model is used to answer questions about a corpus of tennis news articles taken from the Internet. The model's success demonstrates that it is possible to extract propositional information from naturally occurring text without employing a grammar, defining a set of heuristics, or specifying a priori a set of semantic roles.     

Retroactive interference as a function of degree of interpolated study without overt retrieval practice

In two experiments, retroactive interference (RI) was examined under conditions designed to minimize retrieval-induced inhibition and output interference. In Experiment 1, the participants first learned a list of 10 person-location pairs, after which they viewed an interpolated list with the same person terms and different locations for one, four, or eight cycles. Learning was via a study-only method, so that the experimental participants did not perform instructed retrieval of the second list before a cued recall test that asked for List 1 locations only. The experimental participants in Experiment 2 received incidental learning instructions and then viewed a list of 20 unrelated words followed by another list presented either one or four times; the first two letters of each List 1 word were provided on the critical recall test. In both experiments, RI occurred and increased with degree of interpolation. The results suggest that RI does not require retrieval-induced inhibition.     

Correlations among within-channel and between-channel auditory gap-detection thresholds in normal listeners

We obtained data on within-channel and between-channel auditory temporal gap-detection acuity in the normal population. Ninety-five normal listeners were tested for gap-detection thresholds, for conditions in which the gap was bounded by spectrally identical, and by spectrally different, acoustic markers. Separate thresholds were obtained with the use of an adaptive tracking method, for gaps delimited by narrowband noise bursts centred on 1.0 kHz, noise bursts centred on 4.0 kHz, and for gaps bounded by a leading marker of 4.0 kHz noise and a trailing marker of 1.0 kHz noise. Gap thresholds were lowest for silent periods bounded by identical markers--'within-channel' stimuli. Gap thresholds were significantly longer for the between-channel stimulus--silent periods bounded by unidentical markers (p < 0.0001). Thresholds for the two within-channel tasks were highly correlated (R = 0.76). Thresholds for the between-channel stimulus were weakly correlated with thresholds for the within-channel stimuli (1.0 kHz, R = 0.39; and 4.0 kHz, R = 0.46). The relatively poor predictability of between-channel thresholds from the within-channel thresholds is new evidence on the separability of the mechanisms that mediate performance of the two tasks. The data confirm that the acuity difference for the tasks, which has previously been demonstrated in only small numbers of highly trained listeners, extends to a population of untrained listeners. The acuity of the between-channel mechanism may be relevant to the formation of voice-onset time-category boundaries in speech perception.     

Increasing pretend toy play of toddlers with disabilities in an inclusive setting

We evaluated a program for increasing pretend toy play of 2-year-old children with disabilities in an inclusive classroom. Classroom personnel implemented the program, which involved choices of classroom centers containing toys that tend to occasion pretend play in toddlers without disabilities, along with prompting and praise. Increases occurred in independent pretend-play rates among all 5 participating toddlers. Results are discussed regarding the importance of promoting toy play of very young children with disabilities that is similar to the type of play of their nondisabled peers, and the need to identify critical program components that are applicable in inclusive settings. DESCRIPTORS: pretend play, young children with disabilities     

New Factor Structure of the Interpretation of Intrusions Inventory with University Students

The Obsessive Compulsive Cognitions Working Group (OCCWG) created the Interpretation of Intrusions Inventory (III) to measure appraisals (interpretations) of mental intrusions. Validation attempts by the OCCWG suggest that the three appraisal mechanisms hypothesized to comprise the III are better described as a single construct. The underlying factor structure of the III was investigated with university students (n = 307). Confirmatory factor analyses were conducted on the theoretically-derived three-factor model and on the empirically-derived one-factor model of the III. Both models failed to adequately fit the data. Thus, an exploratory factor analysis was conducted, which produced a two-factor model consisting of appraisals of Responsibility and Importance/Control of Thoughts. The new factors exhibited good predictive validity, as they predicted the severity of obsessive-compulsive symptoms and subtypes of obsessive-compulsive disorder (OCD).