Research

My research is constantly evolving. The biggest shift came when I started investigating the use of mindfulness-based therapies to promote resiliency in individuals with impulse control disorders and those around them. Since that shift, we have branched out to work with neurotypical emerging adults, female athletes, and community members. Over time, most of my work has been on longitudinal perspectives on Attention-deficit/Hyperactivity Disorder (ADHD), although my research also includes variables related to temperament/personality, substance abuse/dependence, and factors predicting remission of ADHD symptoms.  My work includes both new data collection and analyses of large extant datasets. 

 

The Mindfulness and Impulse Control Research Group (MIC) is a cooperative effort that includes a dozen students, ranging from advanced doctoral students to second year undergraduates. Group activities include data collection, group manuscripts and presentations using secondary data sources, journal club, and guest speakers. Dr. Miller also conducts research supervision in the context of MIC. At one point, MIC was known at the Impulse Control Disorders Lab (ICDL) and then the Impulse Control and Mindful Awareness (ICMA) Research Group . 


MIC 2019-2020

Group photo ICDL 2013-2014
ICDL 2013-2014

Group photo ICDL 2013-2014
ICDL student members 2010-2011

Mind Wandering and Academic Success: Insight into Student Learning and Engagement

(R. Nurgitz's study)

Objective: Mind-wandering (MW) is common, usually described as shifting from focused to off-task thoughts, and has implications for student engagement and academic success. Research has tried to capture MW via self-report and other measures which may not reflect true MW. Functional imaging has distinguished between activation in the attentional and default mode networks (Harrivel et al., 2013). Specifically, increased dorsolateral prefrontal cortex (dlPFC) activity has been linked to attentional effort (Radel et al., 2017), leading to down-regulation in the default mode network (DMN), which has been linked with mind-wandering. The medial prefrontal cortex (mPFC) is a subcomponent of the DMN that is accessible using fNIRS, thus it was targeted for interrogation.  ​

This study investigated the use of functional near-infrared spectroscopy (fNIRS) to measure MW. We hypothesized: (1) DMN activation would correlate with errors; (2) dlPFC activation would negatively correlate with errors; and (3) higher scores on a sluggish cognitive tempo (SCT) measure would predict greater DMN activation and errors.

Participants and MethodsParticipants (N = 17 undergraduates) completed a computerized sustained attention task (SART; a simple, tedious go/no-go task meant to induce lapses in attention) and watched a 20-minute video lecture while wearing the fNIRS device. Participants then completed a quiz about the video and filled out subjective MW and SCT ratings.

fNIRS Analysis: After raw data was preprocessed to reduce motion artifacts, environmental noise, and physiological noise, it was baseline-corrected and normalized. Out of the 17 people that participated, 14 were included in the fNIRS analysis. Feature extraction was conducted to isolate errors and non-errors (i.e., correct responses) made during both tasks. The SART is thought to best capture mind wandering because participants tend to automate their responses, –—exemplified in commission errors. Thus, only commission errors (i.e., false positives) were considered from the SART task.

Quiz items from the lecture correspond to specific moments in time in the video. Brain activation at those times were then extracted and coded in accordance to participants’ responses (correct or incorrect). The same was done for the SART task. Two features (errors and non-errors) were extracted from brain data for each task (SART and Video) and separated by brain region (mPFC and dlPFC). HbO concentration changes were extracted in 25s epochs around errors and non-errors (from 15s pre-stimulus to 10s post-stimulus) for each task and channel. Concentration changes were averaged across trials, channels, and then participants to attain the mean variation in oxygenation across the temporal window.

Results: Pairwise t-tests indicated a significant difference between mPFC activation for errors and non-errors made on the SART, t(13)=2.39, p= 0.03, d= 0.74. mPFC activation increased before an error compared to a non-error. There was no significant difference in mPFC activation for errors and non-errors made during the video task, t(13)=-0.72, p= 0.94, d=0.02 . Similarly, there was no significant difference between median level dlPFC activation for errors and non-errors on the SART, t(13)=-.125, p= 0.90, d = 0.05, or the real-life analog task, t(13)=0.80, p= 0.44, d= 0.32. Visual inspection of the data indicates the expected trend in mPFC activation for the SART task. mPFC activation is higher prior to error onset compared to activation before a non-error. Bivariate correlations indicate a significant positive correlation between mPFC activation and total errors made on the SART task (Pearson’sr= .51, p= .03, 1-tailed). Although the difference is quite small, the expected trend is also present in dlPFC activation for the SART task. dlPFC activation is higher before a non-error occurs. Unfortunately, this trend is less clear due to overlapping variability between the two conditions. The results are less clear for the real-life analog task. Interestingly, dlPFC activation for the video shows the opposite of what is expected, with activation being higher prior to errors. Once again, there is significant overlap in variability and differences are small.

The General Linear Model (GLM) is a robust method to work around violations of assumptions (Huppert, 2016). A standard boxcar function was convolved with the HRF to create a predicted model of what the data would look like for each condition. Specifically, model 1 predicted that mPFC activation would increase within the 15 seconds before an error occurred, while model 2 predicted a decrease before a non-error. For models 1 and 2, R² coefficients indicated good fit (i.e., that the models explained a good proportion of the variance). Model 1 explained 71% of the variance in mPFC activation during SART errors. Model 2 explained 56% of the variance in mPFC activation during a non-error.

In addition to GLM, a fixed effects model employing a 1st order autoregressive (AR1) covariance matrix was used to investigate the effects of ROI, task, and response on brain activation. Measures of high sluggish cognitive tempo and spontaneous mind wandering were also added to the initial model. Only spontaneous mind wandering,F(1, 34.3) = 7.35, p=.01, and sluggish cognitive tempo, F(1, 34.3) = 5.89, p=.02, had a significant effect on overall brain activation. Participants in the high spontaneous mind wandering group indicated less brain activation regardless of brain region, task, and response, t(34.3) = -2.71, p=.01, 95% CI[-24,  -.03]. Those reporting high ratings of sluggish cognitive tempo demonstrated greater overall activation, t(34.3) = 2.4, p= .02, 95% CI[.02, .23]. Although the difference is not statistically significance, F(1, 14) = 2.35, p=.15, η²= .14, it is notable that participants in the lower spontaneous mind wandering group scored roughly 12% higher than the high spontaneous mind wandering group. Bivariate correlations indicated a significant negative association between spontaneous mind wandering scores and quiz performance (Pearson’sr= -.46, p= .04, 1-tailed). Greater reported perceived stress was found to be positively associated with a greater tendency to make attention-related errors (Pearson’sr= .64, p= .004, 1-tailed) and higher ratings of SCT (Pearson’sr= .69, p= .002, 1-tailed).

Conclusion:Preliminary findings are promising, suggesting that fNIRS can be used to measure mind wandering as functional imaging results line up with analog performance on a sustained attention task. Results further indicate patterns of brain activity can be used to classify mind wandering episodes during the SART task. The expected patterns of neural activation were only apparent in the default mode network, while less clear in the dorsal lateral prefrontal cortex. The dorsal lateral prefrontal cortex is part of several different interconnected neural structures, including the frontoparietal control network (Christoff et al., 2016; Dixon et al., 2018). Thus, activation in this area may reflect a variety of processes other than attention. Further study is necessary to reliably predict correct responses reflective of attention using fNIRS.


Measuring university undergraduate academic engagement with participant-observers

Academic engagement in higher education settings is a difficult construct to quantify based on the limited availability of measures in the public domain. Using the more qualitative First Year Experiences Questionnaire (Krause & Coates, 2008) as a model, we developed a measure to quantify university student engagement with their coursework and their peers: The Undergraduate Engagement Scale (UES).  Our study used two waves of data collection collected over two academic years to demonstrate the psychometrics of this novel measure. Evidence for initial content validity was based on the modification of a previously validated university student engagement scale. Across two waves of independent data collection, the scale was administered to large format introductory psychology classes (N1= 446, N2=481). To assess concurrent validity, the UES was administered with a comparable measure that was adapted from a workplace engagement measure across data collection waves. A statistically significant correlation was found between the two scales. Factor structure was assessed using exploratory factor analysis, with a two-factor solution being selected. The labels applied to the two factors were coursework engagement and peer engagement. We report on further psychometric evidence for the UES, along with future directions for research and validation of the measure.


Pilot project: The role of mindfulness exposure in concussion recovery

This was a pilot project examining the changes in mindfulness that occur over the course of a basketball season when a new coach adds a mindfulness element to her coaching. Because of the small sample size, no tests for statistically significant improvement in self-reported mindfulness were possible. Examination of mean scores suggest slight improvements in mindfulness over the course of the season, but causality could not be tested. Only two players experienced a concussion so analyses of the effect of daily mindfulness practice on concussion recovery could not be tested. 


Cluster Analysis of University Students Who Engage in Non-Suicidal Self-Injury

(J. MacIsaac’s study)

In the current study, university students were placed into three groups based on their last reported episode of non-suicidal self-injury or NSSI (no history of NSSI; NSSI, but not within past year; and, NSSI within the past year). Non-suicidal self-injury was defined as the intentional destruction of one’s own body tissue without suicidal intent (e.g., cutting, burning, hitting, etc.). A discriminant function analysis was used to separate the groups based on responses to variables covering personality, emotionality, emotion regulation, impulsivity, psychopathology, resiliency, mindfulness, and self-compassion. Results revealed that participants who had engaged in NSSI within the past year were best separated from the other two groups by a linear discriminant function conceptualized as compassionate self-care. Participants with lower levels of compassionate self-care had higher scores on the function, which were more indicative of participants in both NSSI groupings. The results from the study demonstrate the importance of compassionate self-care as a protective factor against NSSI.


The effects of an internet-delivered mindfulness-based intervention on perceived stress, psychological symptoms, and emotion regulation.

(M. Cairncross' study)

The study investigated the impacts of an Internet-delivered mindfulness based intervention for university students. The first study assessed participants’ engagement with the intervention by self-reported compliance and a novel proxy measure of compliance (i.e., completed mindfulness exercises). Results demonstrated an excellent degree of reliability between self-reported retrospective and daily measurements of time spent practicing mindfulness and a fair degree of reliability between the retrospective and the proxy compliance measure. The second study examined the impact of personality factors and compliance on the effectiveness of the intervention. Results showed that higher conscientiousness was the only predictor of post intervention mindfulness in the intervention group, suggesting the intervention may be more effective for individuals high on this personality trait. The third study assessed the impact of the intervention on emotion regulation, emotional distress, perceived stress, and mindfulness. Compared to the waitlist group, the intervention group showed significant improvements on emotion regulation, reductions in perceived stress and reductions in negative affect. No changes were seen for emotional distress. Increases in mindfulness, positive affect, and psychological flexibility mediated increases in emotion regulation. The study highlights that a brief Internet-delivered MBI may be effective in higher education settings for improving general well-being in students


Are Normally-Distributed Dark Triad Traits Associated with Trait Mindfulness in University Students?

(A. Scavone's project)

The current study investigated the association between the Dark Triad traits and trait mindfulness, while examining the role of alexithymia and emotional intelligence in this association. Higher scores of psychopathy were not found to be a predictor of mindfulness. However, higher scores of Machiavellianism were associated with lower levels of mindfulness, and higher scores of narcissism were associated with higher levels of mindfulness, with alexithymia influencing these associations. These findings indicate the potential benefit of emotion regulation skills training via mindfulness-based therapy techniques to improve emotion identification and empathy among these individuals.


Attention and Mental Performance Enhancement Study

(B. Brooker's project)

According to a prominent theory of human motivation, self-control constitutes a limited resource that may be depleted through repeated use. Emerging research (Wolff et al., 2013) has experimentally linked self-control depletion to healthy students’ willingness to use substances—including use of caffeine, nicotine, illicit drugs, and non-medical use of prescription medications--with the intent to enhance cognition (also known as “neuroenhancement”). The present study sought to expand upon extant work by examining the impact of state self-control depletion on students’ attitudes toward--and willingness to engage in--neuroenhancement behavior. Participants were assigned to complete either a depleting or non-depleting condition of a well-established self-control paradigm (Baumeister et al., 1998). Following the self-control task, participants in the depletion group reported greater willingness to engage in neuroenhancement compared to the non-depletion group. However, this effect was observed only for ratings of participants’ immediate willingness to engage in neuroenhancement (i.e., “right now”); the two groups did not differ in their willingness to engage in neuroenhancement at longer intervals (e.g. 6 months, 12 months). The groups did not differ on a summary measure of neuroenhancement attitudes; however, exploratory item-level analyses suggested that participants in the depletion condition were more likely to endorse neuroenhancement as a means for students to remain academically competitive. These findings lend support to a potential role of self-control depletion as a risk factor—and possible target for intervention (Baumeister et al., 2006)—for students’ neuroenhancement behavior.


Factors Associated with Use of Substances for Mental Performance Enhancement

(B. Brooker's project)

Prior research has suggested that neuroenhancement (healthy students’ use of substances for mental performance enhancement) is common among university students. This study sought to identify personality/psychological and academic factors associated with university students’ neuroenhancement behaviour, and to explore how such factors may be differentially related to use of discrete categories of substances (e.g., legal substances; illicit substances; non-medical use of prescription stimulants [NMUPS], such as methylphenidate [Ritalin] and amphetamine formulations [Adderall]) for neuroenhancement purposes. University students (N = 210) completed self-report and performance-based measures of personality/psychological traits, such as attention and self-control. Participants also reported on academic history (i.e., GPA) and history of neuroenhancement. Results suggested that history of neuroenhancement involving both use of legal substances and NMUPS was associated with lower self-report ratings of attention and self-control. Participants who endorsed use of legal substances for neuroenhancement also reported more hyperactive/impulsive symptoms of attention-deficit/hyperactivity disorder (ADHD). Performance-based measures of self-control were associated with NMUPS and use of illicit substances for neuroenhancement. Self-reported GPA was lower among students who had engaged in NMUPS, but was not associated with any other modes of neuroenhancement. These findings demonstrate that students’ psychological and academic functioning are related to their risk of neuroenhancement broadly; however, differential patterns of psychological and academic functioning across separate substance-specific classes of neuroenhancement could suggest that unique personality, psychological, and academic profiles exist for specific modes of neuroenhancement behaviour.


Brief Mindfulness intervention in the undergraduate classroom

Mindfulness practices have become a common component of daily life in many settings and may serve to bolster resiliency, particularly among university students. This study expanded on previous work to compare the effects of receiving or not receiving a brief daily mindfulness-based practice in large-scale university courses. Data were collected from 88 participants enrolled in two third-year psychology courses. The scripted “Three-Minute Breathing Space” mindfulness intervention took less than 5 minutes of class time each day in one course while the other course served as a control condition. By the end of the semester, the intervention group reported experiencing greater enhancements in positive emotionality, and fewer episodes of mind-wandering and distractibility than those in the control group. In contrast, there was no effect on mindfulness or negative emotionality between the groups. Those receiving the intervention also reported enjoying the practice and more than half had used the practice outside of the course. Results of this study, and others, suggest that brief mindfulness practices taught in university courses may play a role in promoting mental wellness among students.


Using ecological momentary assessments to evaluate the utility of the existing measures of mind wandering

(D. Ostojic's project)

The results showed that those who reported a greater tendency to mind wander on the questionnaires reported more mind wandering in their day-to-day experience. Importantly, this finding didn’t hold up for deliberate mind wandering, which is an intentional or deliberate shift in attention toward internal thought, but only for mind wandering that occurs spontaneously (without volition). The study highlights the importance of collecting data within the natural environment to validate the utility of measures of mind wandering. Also, it demonstrates the applicability of this technology in psychological research, by showing that with growing use of smart phone technology few additional resources and tools are needed to implement this important methodology in studies.


Mindfulness, academia, and stress: Do mindful coping skills protect students?

(M. Kadziolka’s project)

Mindfulness is the ability to attend to transient thoughts, feelings, and sensations as they arise, without judgment or over-involvement.  Although mindfulness has been a central component of clinical therapies for many years, little is known about how and whether the active ingredients of mindfulness support emotional well-being and coping skills. The aim of this project was to better understand how self-assessments of mindfulness associate with self-ratings of emotion regulation and specific coping skills relevant within the academic environment, such as perceived social support. A total of 250 university undergraduates completed the study. Following elimination of participants with high scores on the Social Adaptation Scale, a validity measure of social desirability bias, 238 participants remained. Self-rated mindfulness was negatively associated with anxiety, rumination, and alexithymia, defined as an inability to perceive or recognize one’s emotional states, and rumination, and positively associated with participants’ perception of the quality of social support they received. Since alexithymia is associated with difficulty forming meaningful connections with other people, these findings suggest that, through mindfulness training, alexithymic individuals might improve their sense of belonging and connectedness with others as well as their overall sense of well-being. In addition, self-rated mindfulness, particularly the mindful tendency to attend to one’s actions and activities in the present moment, was moderately associated with self-ratings of academic self-efficacy, or undergraduate students’ perception of their ability to cope with the academic and interpersonal demands of university. These findings suggest that mindfulness training may raise students’ confidence and engagement with their studies and the university environment. Taken together, these findings validate how dispositional mindfulness, even for a sample of students with little formal training experience in mindfulness techniques, is associated with social, emotional, and occupational benefits.


Three-minute breathing space project

Large class enrollments and internet-connected devices often make the university classroom a place where some students are as likely to be off-task as actively engaged in learning. This project tested the efficacy of a brief mindfulness activity in a large course for enhancing student engagement and reducing course-related stress/distress. The study collected data from 115 participants enrolled in a third year psychology course. The intervention took approximately 5 minutes of the 80 minutes allotted for each instructional day, resulting in no deleterious effects on learning outcomes. Students' self-reports indicated improved mindfulness, with 20% seeking out other opportunities to learn about meditation. Many students (54%) indicated that they had used the practice outside of class, possibly leading to long term positive effects in multiple areas. Future projects should assess the role of brief mindfulness interventions in stress reduction, anxiety reduction, overall coping, and academic engagement in the undergraduate large-class environment.


Mindfulness programming for teachers and parents of children with ADHD

Mindfulness, a central tenet of Buddhist practice, has been adapted for use in a secular context by educators and clinicians in the development of mindfulness-based therapies, including Mindfulness-based Stress Reduction (MBSR). Mindfulness, independent of religious connotations, involves self-regulation of attention that is present-oriented and without judgment of the present experience. Research suggests that these therapies may be effective in reducing distress experienced by parents and teachers, and there may be some benefit to children with ADHD as well. In our ongoing work, we have developed a tailored course in mindfulness to specifically meet the needs of parents and teachers of children with ADHD. Although recruitment focused on participants likely to work/live with a child who has ADHD, programming offered very limited information about ADHD in our first offering of the program. Specifically, the program focused on standard mindfulness practices, such as concentration on the breath, gentle stretching exercises and sitting meditation. Typically, sessions involved group discussion, didactic lectures, activities and practice of mindfulness and exercise. Weekly (9) sessions were 2 hours in duration with a day-long silent retreat at the end of the course. Participants were asked to commit to 20 minutes daily meditation practice. Results from our work suggest that our participants experienced a reduction in their symptoms typically associated with anxiety and depression and in their perceived stress. Those participants who met the 20 minutes per day of daily practice expectation also made significant improvements in their experience of mindfulness, particularly reducing their automatic negative thoughts in response to experiences and in acting with awareness of events. Notably, those participants who reported higher quality of life prior to the intervention (getting enough sleep at night and experiencing work as positive) reported greater time investment in daily meditation practice. Furthermore, those who attended at least 80% of sessions also experienced significant improvement in their knowledge about ADHD. We are hoping to begin recruitment for another wave of participants in the fall and we are working toward downward extensions to children and adolescents with ADHD.


Reward Sensitivity in relation to ADHD Symptoms and Callous-Unemotionality

(B. Brooker's thesis)

Reward sensitivity (RS) has been implicated in a range of suboptimal psychological outcomes, including ADHD, antisocial personality disorder, borderline personality disorder, and callous-unemotional personality traits.  Less known, however, is the relation between these constructs and RS in the non-clinical population.  The current study investigated the utility of these traits in predicting RS in an undergraduate sample (N = 225).  Hierarchical multiple regression analyses suggested that impulsive ADHD symptoms and relational aggression predicted RS, as measured by two distinct questionnaires (R2adj. = .15 for SPSRQ Sensitivity to Reward [Torrubia, Ávila, Moltó, & Caseras, 2001]; R2adj. = .07 for BIS/BAS Scales’ BAS total score [Carver & White, 1994]).  Overall measures of callous-unemotional traits were not significantly related to RS (ps = .54 - .95), although subscale-level associations suggested a small, inverse relation between these constructs.  These findings highlight the role of RS across the spectrum of impulse control abilities.


JK/SK Teacher Survey about ADHD

As a follow-up to a previous study, we surveyed kindergarten teachers (N=53) in a local school board about their experiences working with children who have Attention-deficit Hyperactivity Disorder (ADHD), interventions they have tried, barriers to intervention they have faced, and their knowledge about ADHD. Teachers were highly experienced with a mean number of years teaching = 15.75 years (range 1-34). Of significant concern was slightly over half of participants reported that they cannot identify enough adequate resources for coping with ADHD in the classroom.  All teachers identified some strategies for improving child symptoms in the classroom, including talking to the parent (96.2%), seeking out consultation with a special education consultant (88.7%), seeking out peer support (54.7%), and asking the parent to take their child to the family physician (54.7%). The mean number of different interventions attempted in the last three years was 7.47 (range 0-15) with common strategies including seeking consultation with the special education teacher (96.2%), modifying routines (81.1%), modifying the environment (79.2%), and modifying expectations (79.2%). All of the teachers reported frequent barriers to their intervention efforts, mostly commons lack of parent support (56.6%), large class size (58.5%), and a lack of time (45.3%). Nearly all of the teachers reported symptoms of stress and distress when working with students with ADHD (mean number = 5.11), including bodily pain (86.7%), sleep problems (79.3%), need for more “down time” (69.8%), and headaches (68.0%). A likely significant factor in their distress is their misinformation about ADHD. On a true-false format “quiz” about ADHD based on empirical findings, teachers scored at just over 50% accuracy. Nearly all (96.2%) endorsed medication as effective and 90.6% described the medications as safe yet 58.5% would be reluctant to use medication if their own child had ADHD symptoms and 66.1% reported that media coverage of ADHD medications raises their level of concern. Results of this study strongly support local school boards devoting more available resources to helping teachers better understand this very prevalent disorder.


Are there relationships between mindfulness, self-regulation during stress, coping, and academic achievement?

(M. Kadziolka’s project)

Mindfulness is defined as purposeful, nonjudgmental attention to moment-by-moment experience.  Though it is an integral element of Buddhist meditation practice, it has been identified by Western scientists as an important process in bringing about therapeutic change. Mindfulness has been associated with reduction in depressive and anxious symptomatology as well as improvements in cardiovascular health. However, little is known about the mechanisms of how it leads to change. The aim of this study was to examine the association between mindfulness and physiological self-regulation in response to stress, to shed light on how naturally mindful individuals cope with daily stress. In this study, an emotional recall task designed to elicit an emotional reaction to a personally relevant event was used with 55 university graduates who varied on self-rated mindfulness. Mindfulness was negatively correlated both with the increase in skin conductance response during the emotional recall task and with the drop in skin conductance response immediately following the stressor. Skin conductance response is an index of sympathetic activation, when the organism mobilizes for dealing with threat. Sympathetic reactions, if activated continually, come at a great metabolic cost, leading to physical deterioration. In this study, mindful participants were less prone to dramatic fluctuations in sympathetic reactivity, suggesting more sparing activation of potentially damaging stress-related processes. These findings provide support for mindfulness training as a means of bolstering emotional and physical health. Furthermore, these findings validate how dispositional mindfulness, even for a sample of students with little formal training experience in mindfulness techniques, is associated with physiological indices of effective emotional self-regulation.


Psychometric properties of the Risk-Taking Behavior Questionnaire

Risk-taking, although developmentally normative in some instances, has been associated with increased risk for morbidity and mortality. With more severe cases during adolescence and emerging adulthood, risk-taking has also been linked with antisocial behavior and delinquency.  Yet, there are a limited number of research measures designed to assess a wide range of risk-taking behaviors in a short and efficient questionnaire format. The purpose of the current study was to provide preliminary psychometric data on the Risk-Taking Behavior Questionnaire (RTBQ), which was developed as a research tool for assessing risk-taking in older adolescents and emerging adults in a brief, self-report format. The 22-item RTBQ addresses five behavioral domains: driving, substance experimentation/use, law breaking, breaking family rules, and sexual activity. The RTBQ was completed by 512 undergraduate students (458 females) from a university research pool over three semesters in three independent studies. Reliability was assessed in terms of internal consistency for the full sample and with test-retest reliability in a subset of participants. Internal consistency (Cronbach’s a = 0.71) and test-retest reliability (r = 0.59 – 0.82) were adequate. Validity was assessed in terms of concurrent convergent and discriminant validity with other indicators of risk-taking and related constructs. The RTBQ performed as expected with adequate reliability and validity. Normative scores and alternative scoring are described.  Clinical utility and limitations of using a screener in the assessment of risk-taking are also discussed.


Effects of Puberty Onset on Attention Deficit/Hyperactivity Disorder Symptoms in Female University Students

(D. Ostojic’s thesis)

Despite the growing evidence that circulating sex hormones during puberty may help explain the subtle sex differences that exist in the symptom profile, neuropathology and clinical sequelae of ADHD, there is limited research in this area. The current study investigated how the timing of female pubertal maturation influences the extent of ADHD symptoms in a non-clinical female undergraduate sample (N=253). Participants completed a set of self-report rating scales examining pubertal onset, and ADHD symptoms and related deficits. Using logistic regression models, difficulties in attention, emotion regulation, psychosocial functioning and more risky behaviour were shown to significantly help classify those who reported having an earlier pubertal onset relative to their peers. That is, early puberty was associated with increased symptom endorsement on a variety of ADHD-related variables. Findings highlight the potential role of sex hormones during puberty in explaining the differences in gender prevalence rates of ADHD and symptom profiles.


Callous- unemotional traits: A potential mediator of the impulsivity-antisocial behaviour association

(A. White's thesis)

The study investigated the hypothesis that callous-unemotional traits mediate the relation between impulsivity and antisocial behaviour in an undergraduate, emerging adult sample. Participants (N=181) provided demographic information and completed a computerized battery of questionnaires and tasks addressing personality and behaviour. Total scores on the Inventory of Callous-Unemotional Traits (ICU) and Self-Report Delinquency Scale (SRD) were used as indicators of callous-unemotionality and antisociality, respectively.  Stop-signal reaction time (SSRT) was calculated from a stop-signal task as an indicator of impulsivity.  A stepwise multiple regression showed that the best combination of predictors for antisocial behaviour was having a mother whose highest level of education is a high school diploma and callous-unemotional traits.  Additionally, using the Baron and Kenny (1986) mediation model, it was found that callous-unemotional traits do not mediate the impulsivity-antisocial behaviour relation. Several results were inconsistent with previous studies, indicating the need for more research in this population.


Modeling the Multidimensional Nature of Impulsivity and its Relation to Functional Outcomes

(B. Knezevic's dissertation)

The present study examined the role that impulsivity plays in personality development and emotion dysregulation both concurrently and longitudinally.  The three-study design utilized two extant datasets as well as new data collection with a Canadian undergraduate sample.  First, data from the Block and Block dataset was used to assess the relation between impulsivity and personality development across the life span.  Next, the lifelong relation between impulsivity and emotion dysregulation was examined using the Simmons Longitudinal Study dataset.  Finally, 175 undergraduate students were assessed using multiple measures of impulsivity, to test a model of impulsivity.  The aim was to combine measures from different research paradigms.  The integrated results identified a link between childhood impulsivity and subsequent personality development and emotion dysregulation.  Furthermore, results suggest that impulsivity is multidimensional, including inability to plan/organize, neurotic personality style, engagement in risky behaviours, behavioural disinhibition, and delay discounting.


Teen Pregnancy Study

This study examined the impulse control and reading achievement of pregnant teens compared to demographically-similar peers (i.e., girls who are like the pregnant girls in terms of race, and neighborhood of origin, primary language but have never been pregnant). Results from this study suggest that girls who become pregnant in their teen years do not have significant differences in basic/foundational reading skills, but there are subtle differences in reading fluency (i.e., how fast the person reads) and reading comprehension (i.e., how much the person understands of what was read) with pregnant teens demonstrating lower skill levels compared to peers. Results concerning impulse control were also mixed. Some areas of impulse control, such as risk-taking behaviours, were more problematic in those girls who were pregnant. Other areas of impulse control, such as performance on a task of response inhibition and short-term memory, were not significantly different. These differences may be the result of shared underlying risk for both impulse control problems and teen pregnancy or may reflect an increase in risk for teen pregnancy in those with impulse control problems.  A major limitation of the study was small cell sizes secondary to recruitment difficulties with pregnant teens.


Teacher Survey About ADHD Study

This studied examined the experiences with ADHD, as well as the attitudes toward and knowledge of this disorder in pre-service and in-service teachers who work with children at the point of school entry. The only difference between pre-service and in-service teachers was in the knowledge they have about ADHD with in-service teachers with significantly higher accuracy levels on a knowledge quiz about ADHD. This effect was not related to attitude toward working with children who have ADHD or by increased exposure to printed material about ADHD. All participants reported working with children who have ADHD and most believe that this disorder represents a significant problem in educational settings with young children. Results from this study suggest that teachers do not differ by career stage (either pre-service or in-service) in their attitudes toward working with children with ADHD. Despite the fact that these children represent a significant demand on teacher time, teachers generally report neutral to positive feelings toward working with children who have ADHD. Most of the participants believe that they would benefit from additional training to work more effectively with children who have ADHD. And, most participants do not believe that adequate resources are allocated to support them as they teach children with ADHD. Participants also reported that there are a number of barriers to providing classroom-based interventions for ADHD, most pressing being a lack of time and a lack of training.

** PLEASE NOTE: All results for studies associated with honours theses are posted on the thesis course website that is part of the psychology department website.

(*student authors)

  • Miller, C. J., Elder, K.*, & Scavone, A.* (In press). Bringing brief mindfulness training to the university classroom. Mindfulness.
  • di Pierdomenico, E.*, Kadziolka, M.*, & Miller, C. J. (Accepted). Mindfulness correlates with stress and coping in university students. Canadian Journal of Higher Education.
  • Cairncross, M.* & Miller, C.J. (In press) The efficacy of mindfulness-based therapies for Attention-deficit/Hyperactivity Disorder: A meta-analytic review. Journal of Attention Disorders.
  • Jones, G.*, Ostojic, D.*, Menard, J.*, Picard, E., & Miller, C. J. (2017).  Primary prevention of reading failure: Effect of universal peer-tutoring in the early grades.  Journal of Educational Research, 110, 171-176.
  • Ostojic, D.*, Brooker, B.*, Cairncross, M.*, & Miller, C.J. (2016). Psychosocial status in emerging adult females: Impact of pubertal timing and ADHD symptoms. Psychology and Education, 53, 61-69.
  • Ostojic, D.* & Miller, C. J. (2016). Effects of puberty onset on ADHD symptoms in female university students. Journal of Attention Disorders, 20, 782-791.
  • Kadziolka, M.*, di Pierdomenico, E. A.*, & Miller, C. J. (2016). Trait-like mindfulness promotes healthy self-regulation of stress. Mindfulness, 7, 236-245.
  • Knezevic-Budisin, B.*, Peddens, V., White, A., Miller, C. J., & Hoaken, P. (2015) A multifactorial conceptualization of impulsivity: Implications for research and clinical practice. Journal of Individual Differences, 36, 191-198.
  • Menard, J.*, Knezevic, B.*, Miller, S. R., Edelstein, D., Thompson, K., & Miller, C. J. (2015). Intergenerational transmission of antisocial behavior and age at primiparity. Journal of Child and Family Studies, 24, 798-808.
  • White, A.* & Miller, C. J. (2015). Delinquency in emerging adult females: Importance of callous-unemotionality and impulsivity. Deviant Behavior, 36, 245-258.
  • Bartol, F.*, & Miller, C. J. (2014). Callous-unemotionality in individuals receiving accommodations for disabilities in university.  Journal of Psychopathology and Behavioral Assessment, 36, 510-518.
  • Schentag-Trella, R. N.*, Miller, S. R., Edelstein, D., & Miller, C. J. (2014).  Maternal behavior prior to parenting as a transgenerational predictor of offspring behavior. Journal of Child and Family Studies, 23, 1501-1509.
  • Sanchez-Bloom, J., Garcia-Barrera, M. A., Miller, C. J., Miller, S. R., & Hynd, G. W. (2013).  Planum temporale morphology in children with developmental dyslexia. Neuropsychologia, 51, 1684-1692.
  • Miller, C. J., Miller, S. R., Healey, D. M., Marshall, K.*, & Halperin, J. M. (2013).  Are cognitive control and stimulus-driven processes differentially linked to inattention and hyperactivity in preschoolers? Journal of Clinical Child and Adolescent Psychology, 42, 187-196.