People in the Lab
Dr. Dywan is a clinical neuropsychologist who studies age-related changes in cognitive function as they occur in healthy older adults. She focuses particularly on the relationship between a decline in attentional control and the ability to monitor the source of remembered events. By examining electrical event-related brain activation while participants engage in various cognitive tasks, she monitors neural activity occurring prior to a behavioural response. In this context, Dr. Dywan has also been examining the relation between heart-rate variability (vagal tone), an index of general physiological response, and control attention and response tendencies. She is also investigating how the general physiological reactivity associated with the perception of emotional information interacts with other cognitive functions. The inability to accurately perceive and physiologically respond to emotional expression may lead to an inappropriate response. In this regard, she has studied individuals with traumatic brain injury and violent offenders who vary in their degree of psychopathy.
Sleep, Sleepiness, Sleep Deprivation, Performance while Sleepy, Event Related Potentials (ERPs), Risk Assessment during Sleepiness
I am interested in how the brain functions and how well people perform while sleepy. My recent research has looked at :
- 1) the effect of 20 hours of sleep deprivation on several EEG and ERP (P300, CNV, ERN, Pe) indices of brain functioning, attention and performance monitoring and how they relate to behavioural performance
- 2) the effect of habituation on an event-related potential component (P300) thought to be reflective of attention
- 3) unintentional sleep onset (falling asleep while intending to remain awake).
Future research may involve combining sleep deprivation and mild intoxication as
Our Cognitive and Affective Neuroscience Laboratory includes several high-density EEG recording systems, including ones that are portable for data acquisition with special populations, and the latest software in modeling source generators. We also examine other psychophysiological responses, especially heart rate variability, as a reflection of parasympathetic control. My current research projects, for which I am seeking interested graduate students, include the following:
(a) Personality individual differences: A person's personality relates to his or her ERP responses to incorrect or correct performance or to receiving feedback of a failed versus successful response. Of particular interest to me are personality characteristics of risk-taking and sensation-seeking personality styles, responses to rewards and punishments (including harm-avoidance), and the degree of empathy and obsessive-compulsiveness or perfectionism.(b) Developmental differences: The prefrontal cortex of the adolescent brain is still rapidly maturing, and so does its production of the ERN. I am examining the relation between brain maturation and the production of various ERPs, especially the ERN, and what cognitive or personality characteristics account for the individual differences in this growth. Of special interest is the relation between these brain responses and the adolescent's propensity to engage in gamblling and other high-risk behaviours.(c) Child and adolescent mental health: The growth and function of the medial prefrontal cortex and its relation to subjective well-being and mental health is central to another study, focusing on adolescents. In this study, we will be examining internalizing the externalizing personallity characteristics as they relate to life history, physical health, functions of the medial prefrontal cortex, and the role of variation in catecholamine and HPA axis related genes, as they interact with life experiences in the growth of ERP responses from the prefrontal cortex.
My research program is directed toward understanding basic neural mechanisms underlying emotional processes in normal and atypical development. I use measures of regional brain electrical activity (EEG), event-related potentials (ERPs) and autonomic activity (heart rate and cardiac vagal tone) to understand emotion regulatory processes in human development. Certain temperament profiles (e.g., shyness) and the pattern of resting frontal brain asymmetry have been also associated with increased stress reactivity, particularly in response to social and emotional stimuli in healthy adults and children. My Ph.D. work was focused on the consideration that temperament profiles may be identifiable, stable and influence social functioning and affective processing in individuals with schizophrenia. The results of my dissertation suggested that in patients with schizophrenia, shyness remains stable and is related to resting frontal EEG activity. I also found that in patients with schizophrenia, shyness was related to attention allocation, to emotional faces and to aspects of emotion face processing.
Currently, I am working in our collaboration with Penn State University on the “Neuroscience of Prevention of Violence” project, which has been designed to assess the effectiveness of an early intervention program aimed at reducing aggression in high-risk children
Lab Technician, BA Visual Arts, BA Psychology, MA Psychology (Behavioural Neuroscience)
My research interests center on the relative contribution of top-down and bottom-up processes in perception. More specifically, what is the earliest junction of a perceptual path that can be altered by mental context manipulations? For example, when presented with multiple instances of an identical stimulus, how do brain responses vary from presentation to presentation, and how far down the sensation-to-perception-to-representation continuum can these variations take place? Further, what factors (such as arousal, attention, task demands, expertise, etc.) contribute to changes in the relative influence of top-down and bottom-up processes in perception?
In addition, as a technician I am developing analysis tools for exploring and testing complex patterns in EEG signals, including Matlab tools compatible with EEGLab and High Power Computing facilities (e.g SHARCNet) for automated artifact detection, pattern detection in continuous or segmented data, batch processing and robust bootstrap testing.
As the lab coordinator, I train and assist students with their data acquisition and processing, from study design to applications for ethical clearance. We work with both the EGI system and BioSemi. We use a wide array of programs for analyzing data, from Brain Vision Analyzer, BESA, LORETA, GeoSource, and NetStation. I have organized the booking and collected data for studies involving community participants, ranging from teenagers, to senior adults.
Risk-taking behaviour is generally considered maladaptive and can be observed in variety of populations. However, some populations and individuals are thought to be more vulnerable to such behaviours. My MA research focuses on testing a model of reward-related behaviour through the development of two gambling paradigms that will allow us to identify and investigate differences in event-related potentials (ERPs) at various stages of the proposed model. Additionally, I will be looking at variability of these ERPs as a function of individual differences in order to examine the role of personality factors in risk-taking behaviour. In the future, we plan to use the developed paradigms to investigate developmental factors that are associated with vulnerability to risk-taking behaviour.
I am interested in issues related to aging and cognition. While the majority of research in this area has focused primarily on the relations between cognitive performance and various brain measures, I am interested in exploring the role that other physiological factors may have in modulating age-related change. My particular focus is on how medial regions of the prefrontal cortex through vagus nerve connections are involved in parasympathetic modulation of the heart, slowing heart rate and increasing the variability between successive heart beats. This increased variability is considered relevant to behavioural flexibility and adaptability. Because heart rate variability declines with age, I am trying to determine whether this, in part, explains the increased attentional control problems that accompany the aging process.
Over the course of my PhD I have been, and continue to, investigate the neurophysiological and genetic correlates of adolescent self-regulation abilities. To achieve these goals I employ EEG/ERP techniques to collect data on the neural markers of attentional control (one aspect of self-regulation). I am interested in early (bottom-up) control of attention (e.g., the P50 ERP component) as well as later (top-down) control of attention. I also collect data on adolescent’s self-regulatory skills as they play out in the real world. Lastly, I collect genetic material for investigating allelic variations that might be associated with the above. I have a particular interest in genes that are related to the dopamine and serotonin systems. I am currently supervised by Dr. Sid Segalowitz in the Behavioural Neuroscience stream.
Stefon Van Noordt
My research examines the functional role of the ACC (and medial prefrontal cortex in general) in performance monitoring using EEG/ERP technology. Currently, we are focusing on the role of the ACC in task-switching, specifically in terms of whether the ACC is sensitive to stimulus cues that signal changes in response contingencies. The ultimate goal is to better understand the functional significance of ACC responses within a coordinated network of brain regions that support behavioural control. Methodologically, my research incorporates a variety of signal processing tools and analytical approaches including time-frequency decomposition, independent components analysis, as well as bootstrapping and robust estimation techniques for testing effects in single subjects and single trials. In addition, I frequently utilize Shared Hierarchical Academic Research Computing Network (SHARCNet) to implement these tools of signal processing and hypothesis testing.
Other research interests I am pursuing include the neuropsychological and psychophysiological correlates of (i) sociopolitical attitudes, (ii) mild head injury in university students, (iii) reward processing across development, and (iv) affect/arousal in performance monitoring.
For my master’s thesis I examined early ERP correlates of emotional face processing (i.e., P1, N170/VPP) as they related to psychopathic personality traits in a subclinical, undergraduate sample. More generally, I am interested in studying the neural mechanisms that underlie the affective abnormalities commonly observed in individuals high in psychopathy. Moreover, the field has increasingly begun to conceptualize psychopathy as a developmental disorder, with evidence of callous-unemotional traits in children as young as five. As such I am also interested in how these abnormalities develop throughout childhood and adolescents. For the purpose of my doctoral dissertation I plan to focus on early ERP components (e.g., P1 to N250) as potential markers of abnormal attention allocation during affective information processing in aggressive adolescents high in callous-unemotional traits. Moreover, I intend to further examine the role that executive functioning ability plays in both neural and behavioural measures of affect processing, as it has been proposed that high executive control may contribute to the legal “success” of psychopathic individuals (e.g., avoiding conviction).
Xin (Reno) Zheng
I am currently doing my Ph.D. in psychology at Brock University, with a major concentration on behavioral neuroscience. My research is focused on cortical neural activations during visual recognition of complex stimuli, including words, faces and objects. To address this issue, I am following two approaches. With a “bottom-up” approach, we center on the properties of visual stimuli themselves and study the effects of such factors as word frequency and facial features on visual recognition. In contrast, with a “top-down” approach, we focus on how a person’s mental state (e.g., attention or appraisal of social/cognitive context) may affect visual recognition. At any particular moment, since an individual’s visual experience of the surrounding environment is constantly influenced by these “bottom-up” and “top-down” factors, it is essential to take both into account in order to have a more comprehensive unde
I am a 3rd year Psychology and Child and Youth Studies major working with Dr Tim Murphy. We are currently working on a project testing the use of the Immediate Feedback Assessment Technique (IFAT), a relatively new method of administering multiple choice tests. We are examining its effect on student's test performance and its relationship to personality (specifically measures of perfectionism and compulsivity) and student acceptance of this method of testing.
Undergraduate Thesis Student
First, I am dedicated to learning the current computer software systems (e.g., MATLAB, EEGLAB, DMAT, sLORETA, ERPScore, E-Prime, BESA) with the intention of helping others in the lab explore their data to the fullest. This is done under the supervision of Dr. Sid Segalowitz. Second, I will be spending the upcoming years studying the time-course and constituents of top-down modulation on expert level, bottom-up processing (faces). Specifically, I will be exploring the N170 and D220 (P200) in the context of sleep deprivation (SD) to see how and if they are differentially affected. These components index automatic (N170) and manual (D220) processing in the brain (see Philiastides et al., 2006). Thus, they offer a dichotomous and specific approach to the exploration of SD on cognition. Further, I am interested in the individual differences in noise sensitivity that have been observed in relation to these components (Rousselet, 2011), and how SD alters (perhaps amplifies) these differences. This is done under the supervision of Dr. Tim Murphy.
CURRENT POSITION: Lawson Post-Doctoral Fellow in Healthy Child Development, Department of Psychiatry and Behavioural Neurosciences, Hamilton Health Sciences Centre and the Child Emotion Laboratory, PC-130, McMaster University, Hamilton, Ontario
In graduate research I investigated relations between cardiac autonomic regulation and the performance of executive function tasks in older and younger adults. With age, parasympathetic cardiac control declines, whereas sympathetic control is unchanged or increased. Thus, normal aging results in a form of autonomic dysregulation. However, when parasympathetic control (as measured by heart rate variability) is relatively preserved, executive processing appears to be more efficient. The anterior cingulate cortex (ACC) in the mid-brain prefrontal region has been identified as a neural interface linking cognitive and biobehavioural systems, including autonomic functioning. We have shown that older adults with higher heart rate variability or lower sympathetic predominance produce fewer errors in complex source memory and spatial learning tasks, better error signalling in ACC, and reduced reactivity to non-target information. My goal in future research is to learn more about the interplay betwee
CURRENT POSITION: Assistant Professor in Psychology, School of Psychology (Faculty of Science and Technology), Plymouth University.
I am interested in social political psychology. In general, I study antecedents and consequences of tolerance and intolerance, including socio-political attitudes and beliefs (e.g., prejudicial attitudes, political attitudes and ideologies), and prejudice and discrimination. My link to the lab is through collaborations begun during my undergraduate and graduate work at Brock University (PhD, 2008) and following postdoc at Wilfrid Laurier University. Recent collaborations involve how political orientation relates to medial frontal cortex activity during performance monitoring tasks.
My research questions focus on the natural changes to information-processing systems seen in older adults (60+ years). Specifically, are there unique differences in executive functions and working memory that contribute to changes in behavioural performance of older adults on cognitive tasks? Also, are differential brain responses, seen from brain imaging techniques, associated with these changes in behavioural performance? I use electroencephalography (EEG/ERP) to relate changes in cognitive abilities to specific aspects of brain activity in the hopes of identifying the specific mechanisms of information processing that change with age. The perspective I take in my research stresses the importance of individual difference factors in cognitive ageing
Undergraduate Thesis Student
Before joining the lab I completed an honours thesis in Psychology at Brock, and I have decided to continue my studies in Neuroscience. My research interests are generally focused on isolating neural mechanisms of personality traits and mood.
For the 2011 / 2012 year I am working with Dr. Sid Segalowitz on my honours thesis in Neuroscience. For my current project, I will attempt to isolate amygdala activity in response to fearful faces by relating enhanced P1 amplitude to low spatial frequency information. Previous FMRI studies show that the amygdala responds to low spatial frequency information through a rapid processing, sub-cortical pathway. Furthermore, differences in P1 amplitude between shy and social individuals may indicate varying amygdala sensitivities in response to threatening stimuli.
Undergraduate Thesis Student
I am a fourth year Honours Neuroscience student at Brock, and I am interested in cognition and aging. Together with Jane Dywan and Lesley Capuana, I am currently involved in research that examines brain measures and other physiological factors that may modulate age-related cognitive changes.
Gillian Elizabeth Munro
I completed my PhD in 2009, under the supervision of Jane Dywan. I am currently an MD candidate (class of 2014) at the Michael G. DeGroote School of Medicine, McMaster University, in Hamilton, Ontario.
High School Mentoring Student
I am a high school senior student, of A. N. Myer Secondary School, mentoring under Professor Segalowitz for a duration of five months. I have been familiarizing myself with the technology and methods used in recording and analyzing EEG data. Specifically, I have been studying the ERP components associated with emotional face recognition. With help from the other lab members, I have been assigned to a set of EEG data which I am in the process of analyzing into presentable statistics. My first three months have been a thoroughly enriching experience and I feel so privileged to be learning the things that I am, and to be working with such incredible people! My thanks goes out to the entire BUCANL team.
Undergraduate Thesis Student
I am a fourth year Honours Psychology student completing my undergraduate thesis with Dr. Tim Murphy. We are currently investigating the electrophysiological effects of sleep deprivation on the expectancy and reaction to wins and losses. Specifically, we are looking at contingent negative variation (CNV) and feedback-related negativity (FRN) collected during a gambling paradigm. This research is important in order to further understand cognitive differences between an alert and a sleep deprived state.
Undergraduate Thesis Student
I'm currently completing my fourth year of my honours psychology degree here at Brock. My interests span many fields of psychology as well as many other disciplines of academia; however, I find the junction where psychology and neuroscience meet to be particularly intriguing. For my undergraduate thesis I’m examining differences in the psychology and neuroscience of the politically liberal and conservative with Dr. Segalowitz. Specifically, we’re looking at how liberals and conservatives differ in the activation of their rostral and dorsal anterior cingulate cortices when confronted with conflicting information.
Undergraduate Thesis Student
I am in my 4th year, majoring in psychology and speech and language sciences. I am working on my ndergraduate thesis with Dr. Segalowitz. The project we are currently working on involves second language fluency and specifically, what it is during brain processing that reflects someone?s fluency level. We are interested in discovering if there are early components in the ERP that are able to predict whether someone is fluent or less fluent.