Mapping differential responses to cognitive training using machine learning

We used two simple unsupervised machine learning techniques to identify differential trajectories of change in children who undergo intensive working memory (WM) training. We used self‐organizing maps (SOMs)—a type of simple artificial neural network—to represent multivariate cognitive training data, and then tested whether the way tasks are represented changed as a result of training. The patterns of change we observed in the SOM weight matrices implied that the processes drawn upon to perform WM tasks changed following training. This was then combined with K‐means clustering to identify distinct groups of children who respond to the training in different ways. Firstly, the K‐means clustering was applied to an independent large sample (N = 616, M_age = 9.16 years, range = 5.16–17.91 years) to identify subgroups. We then allocated children who had been through cognitive training (N = 179, M_age = 9.00 years, range = 7.08–11.50 years) to these same four subgroups, both before and after their training. In doing so, we were able to map their improvement trajectories. Scores on a separate measure of fluid intelligence were predictive of a child's improvement trajectory. This paper provides an alternative approach to analysing cognitive training data that go beyond considering changes in individual tasks. This proof‐of‐principle demonstrates a potentially powerful way of distinguishing task‐specific from domain‐general changes following training and of establishing different profiles of response to training.     

Barriers and facilitators affecting the sustainability of dialectical behaviour therapy programmes: A qualitative study of clinician perspectives

Dialectical behaviour therapy (DBT) is a psychological treatment developed for individuals experiencing chronic suicidality and high‐risk behaviours. Despite the substantial evidence supporting the effectiveness of DBT, many programmes have problems with its sustainability. The goals of the current qualitative study were to identify factors that impact the sustainability of DBT programmes within a publicly funded mental health system and identify factors that are particularly relevant for youth DBT programmes. Interviews with trained adult and youth DBT clinicians (N = 31) were conducted to explore their experiences providing DBT. Three major themes that emerged as barriers to the sustainability of DBT programmes included the following: systemic challenges, conflicts within the consultation teams and clinician burnout. Factors influencing the success of DBT programmes included the following: systemic support, clinician commitment and “buy in”, and team cohesion. Factors specific to providing DBT with youth (i.e. level of commitment, simplifying the language, and parental investment) and recommendations for sustainability for adults and youth programmes were also identified. Findings of this study provide valuable information on factors impacting DBT programmes within the unique context of a Canadian mental health service system, where community‐based services are publicly funded. These findings have clear clinical utility and can be used to generate solutions to clinicians' perceived barriers and to foster perceived facilitators within similar contexts.     

Are attentional dwell times inconsistent with serial visual search?

Duncan, Ward, and Shapiro (1994) estimated that attention must remain focused on an object for several hundred milliseconds before being shifted to another object, and they referred to this period as theattentional dwell time. An important implication of these long estimates of the dwell time for models of visual search is that the search process must not involve an item-by-item serial scanning mechanism. If it did, then searching through an array of items would require enormous amounts of time, which—based on data from visual search experiments—it does not. The present report, however, provides evidence that the long estimates of attentional dwell time were caused, at least in part, by the use of masked targets. Implications of these variable estimates of the attentional dwell time for models of visual search are discussed.     

Perceived Risks and Benefits in a Text Message Study of Substance Abuse and Sexual Behavior

To inform ethical procedures for human subjects research using mobile health (mHealth), we examined perceived risks and benefits of study participation among emerging adults (N = 54) with drug use who completed text message assessments of substance use and sexual behaviors. Most participants reported comfort with participation and some reported perceived benefits, such as improved relationships. Perceived risks were infrequently reported, including negative emotions and legal or financial concerns. In conclusion, participants from a vulnerable population reported few perceived harms of participation in longitudinal mHealth assessments of sensitive behaviors. Researchers should continue characterizing participants’ perspectives on ethical aspects of mHealth research.     

Fostering At-Risk Kindergarten Children's Number Sense

A 9-month training experiment evaluated whether computer-assisted discovery learning of arithmetic regularities can facilitate kindergartners’ fluency with the easiest sums. After a pretest, kindergartners with at least one risk factor (n = 28) were randomly assigned to either a structured add-0/1 training condition, which focused on recognizing the n + 0/0 + n = n and the n + 1/1 + n = the number-after-n rules, or an active control group. Using pretest fluency as the covariate, ANCOVAs revealed that the structured add-0/1 group significantly outperformed the control group on both practiced and unpracticed (transfer) n + 0/0 + n and n + 1/1 + n items at the delayed posttest and had significantly larger gains in mathematics achievement. Key instructional implications include: Early intervention that targets discovering rules for adding with 0 and 1 and family-specific developmental prerequisites is feasible and more effective than typical classroom instruction in promoting fluency with such basic sums. Such rules may be a critically important bridge between informal and formal mathematics.     

Examination of the Relationship Between PTSD and Distress Tolerance in a Sample of Male Veterans With Comorbid Substance Use Disorders

Distress tolerance (DT), the perceived or actual ability to tolerate negative emotional or physical states, is inversely related to posttraumatic stress disorder (PTSD) symptoms in civilian, community samples. No studies to date have examined the relationship between DT and PTSD in clinical samples of veterans with a comorbid diagnosis of PTSD and a substance use disorder (SUD). Thus, the present study examined the relationship between DT and PTSD in a sample of predominately African American, male veterans (n = 75) diagnosed with comorbid PTSD and SUD (according to a structured clinical interview). Results of hierarchical linear regression models indicated that DT was inversely related to total PTSD symptom severity score, above and beyond depressive symptoms and SUD severity. Of the 4 symptom clusters, DT was inversely associated with intrusions and hyperarousal. These findings are discussed in light of previous work with civilian samples. Determining whether treatment incorporating DT skills would be useful for veterans undergoing PTSD treatment should be evaluated.     

The flexible use of inductive and geometric spatial categories

The present study examined the flexibility with which people can adopt different category schemes in the spatial domain. In a location memory task, participants viewed and estimated the locations of four kinds of objects that were spatially grouped by object identity. This identity-based arrangement was either congruent or incongruent with the perceptually based, geometric categories that have been reported in previous research. Four experiments examined the conditions under which these different category schemes are used to inform estimates of locations. The results showed that use of identity information depended on the number of objects to be remembered during a trial: When one or two objects were remembered at a time, only geometric categories affected estimates, but when four objects were to be remembered, both geometric categories and identity groupings affected estimates. As memory load increases, participants rely on additional sources to inform their estimates of location.     

Interpersonal competence across domains: relevance to personality pathology

Interpersonal problems are significant markers of personality disorders (PDs). There is little research examining the specific interpersonal problems which lead to social impairment in PD. This study used canonical correlation analyses to examine the relationship between interpersonal competence and PDs, first as categorized by DSM-IV diagnoses, then as categorized by empirically-derived factors, in a sample at risk for recurrence of major depression. The most significant sources of shared variance were social inhibition and self-disclosure competence. The empirically-derived PD categories accounted for more variance in interpersonal competence than the DSM-IV diagnostic categories. Social skills training in initiation and self-disclosure may be useful for treating individuals with PD who experience interpersonal problems. Empirically-derived categories of PD symptoms may capture interpersonal problems experienced by individuals with PD which DSM-IV categories do not.     

Perceptual biases in processing facial identity and emotion

Normal observers demonstrate a bias to process the left sides of faces during perceptual judgments about identity or emotion. This effect suggests a right cerebral hemisphere processing bias. To test the role of the right hemisphere and the involvement of configural processing underlying this effect, young and older control observers and patients with right hemisphere damage completed two chimeric faces tasks (emotion judgment and face identity matching) with both upright and inverted faces. For control observers, the emotion judgment task elicited a strong left-sided perceptual bias that was reduced in young controls and eliminated in older controls by face inversion. Right hemisphere damage reversed the bias, suggesting the right hemisphere was dominant for this task, but that the left hemisphere could be flexibly recruited when right hemisphere mechanisms are not available or dominant. In contrast, face identity judgments were associated most clearly with a vertical bias favouring the uppermost stimuli that was eliminated by face inversion and right hemisphere lesions. The results suggest these tasks involve different neurocognitive mechanisms. The role of the right hemisphere and ventral cortical stream involvement with configural processes in face processing is discussed.