Medicine and Health Sciences Commons^™

An Examination Of Psychological Variables Influencing Perceptions Of The Self Among A Sample Of Female Exercise Initiates, Lisa Cooke

Electronic Thesis and Dissertation Repository

The general purpose of this dissertation was to explore the relationship among and within cognitive variables associated with exercise initiation and maintenance in a sample of female exercise initiates.

Manuscript 1 was structured to explore the changes to exercise identity among a population of female exercise initiates (N = 78) grouped into an imagery or control condition. Previous research has found that a strong exercise identity is associated with more frequent exercise (Strachan et al., 2009) and increases over time as a person continues to exercise (Cardinal & Cardinal, 1997). Participants were assessed multiple times (weeks 0, 5, 9, …

Developmental Differences In The Influence Of Phonological Similarity On Spoken Word Processing In Mandarin Chinese., Jeffrey G Malins, Danqi Gao, Ran Tao, James R Booth, Hua Shu, Marc F Joanisse, Li Liu, Amy S Desroches

Brain and Mind Institute Researchers' Publications

The developmental trajectory of spoken word recognition has been well established in Indo-European languages, but to date remains poorly characterized in Mandarin Chinese. In this study, typically developing children (N=17; mean age 10; 5) and adults (N=17; mean age 24) performed a picture-word matching task in Mandarin while we recorded ERPs. Mismatches diverged from expectations in different components of the Mandarin syllable; namely, word-initial phonemes, word-final phonemes, and tone. By comparing responses to different mismatch types, we uncovered evidence suggesting that both children and adults process words incrementally. However, we also observed key developmental differences in how subjects treated onset …

Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

Cognitive deficits are recognized in Parkinson's disease. Understanding cognitive functions mediated by the striatum can clarify some of these impairments and inform treatment strategies. The dorsal striatum, a region impaired in Parkinson's disease, has been implicated in stimulus-response learning. However, most investigations combine acquisition of associations between stimuli, responses, or outcomes (i.e., learning) and expression of learning through response selection and decision enactment, confounding these separate processes. Using neuroimaging, we provide evidence that dorsal striatum does not mediate stimulus-response learning from feedback but rather underlies decision making once associations between stimuli and responses are learned. In the experiment, 11 males …

Transcranial Magnetic Stimulation Of The Prefrontal Cortex In Awake Nonhuman Primates Evokes A Polysynaptic Neck Muscle Response That Reflects Oculomotor Activity At The Time Of Stimulation., Chao Gu, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Transcranial magnetic stimulation (TMS) has emerged as an important technique in cognitive neuroscience, permitting causal inferences about the contribution of a given brain area to behavior. Despite widespread use, exactly how TMS influences neural activity throughout an interconnected network, and how such influences ultimately change behavior, remain unclear. The oculomotor system of nonhuman primates (NHPs) offers a potential animal model to bridge this gap. Here, based on results suggesting that neck muscle activity provides a sensitive indicator of oculomotor activation, we show that single pulses of TMS over the frontal eye fields (FEFs) in awake NHPs evoked rapid (within ∼25 …

Burning Pain Secondary To Clozapine Use: A Case Report., Bradley Linton, Rachel Fu, Penny A Macdonald, Hooman Ganjavi

Brain and Mind Institute Researchers' Publications

BACKGROUND: The first of the atypical antipsychotics introduced in the 1970s, clozapine remains the most efficacious neuroleptic to this day. However, serious and potentially fatal side effects have necessitated careful regular monitoring among prescribing clinicians. Some adverse effects (e.g. ischaemic bowel) remain under recognized, while newly identified adverse effects continue to be described in the literature.

CASE PRESENTATION: In this report, we describe a healthy 43-year old Caucasian male who experienced onset of a full body deep burning pain several months after the onset of treatment with clozapine. The pain worsened over time, ceased with cessation of treatment, and returned …

The Cost Of Moving Optimally: Kinematic Path Selection., Dinant A Kistemaker, Jeremy D Wong, Paul L Gribble

Brain and Mind Institute Researchers' Publications

It is currently unclear whether the brain plans movement kinematics explicitly or whether movement paths arise implicitly through optimization of a cost function that takes into account control and/or dynamic variables. Several cost functions are proposed in the literature that are very different in nature (e.g., control effort, torque change, and jerk), yet each can predict common movement characteristics. We set out to disentangle predictions of the different variables using a combination of modeling and empirical studies. Subjects performed goal-directed arm movements in a force field (FF) in combination with visual perturbations of seen hand position. This FF was designed …

Exploring Communication Apprehension And Its Relationship To Communication Attitude And Socio-Communicative Functioning In Children With Velopharyngeal Insufficiency, Agnieszka Dzioba

Electronic Thesis and Dissertation Repository

Myriad findings on children with velopharyngeal insufficiency (VPI) indicate the potential for this population of children to experience feelings of apprehension specific to communication and the potential for other psychological and social difficulties. The purpose of the present investigation was to explore the construct of communication apprehension (CA) and its potential relationship to social and communicative functioning in a diverse group of children with VPI. Potential linkages between CA and multiple socio-communicative constructs including attitude, speech satisfaction, speech and language skill, social competence, and speech severity were explored in a cohort of children with and without VPI, followed by an …

Mirror Reversal And Visual Rotation Are Learned And Consolidated Via Separate Mechanisms: Recalibrating Or Learning De Novo?, Sebastian Telgen, Darius Parvin, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Motor learning tasks are often classified into adaptation tasks, which involve the recalibration of an existing control policy (the mapping that determines both feedforward and feedback commands), and skill-learning tasks, requiring the acquisition of new control policies. We show here that this distinction also applies to two different visuomotor transformations during reaching in humans: Mirror-reversal (left-right reversal over a mid-sagittal axis) of visual feedback versus rotation of visual feedback around the movement origin. During mirror-reversal learning, correct movement initiation (feedforward commands) and online corrections (feedback responses) were only generated at longer latencies. The earliest responses were directed into a nonmirrored …

Dopaminergic Therapy Affects Learning And Impulsivity In Parkinson's Disease., Nole M Hiebert, Ken N Seergobin, Andrew Vo, Hooman Ganjavi, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

OBJECTIVE: The aim was to examine the effect of dopaminergic medication on stimulus-response learning versus performing decisions based on learning.

METHOD: To see the effect of dopaminergic therapy on stimulus-response learning and response selection, participants with Parkinson's disease (PD) were either tested on and/or off their prescribed dose of dopaminergic therapy during different testing days. Forty participants with PD and 34 healthy controls completed the experiment on consecutive days. On Day 1, participants learned to associate abstract images with spoken, "right" or "left" responses via feedback (Session 1). On Day 2, participants recalled these responses (Session 2) and indicated the …

Developmental Stress, Condition, And Birdsong: A Case Study In Song Sparrows., Kim L Schmidt, Elizabeth A Macdougall-Shackleton, Shawn P Kubli, Scott A Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

Sexual-selection theory posits that ornaments and displays can reflect a signaler's condition, which in turn is affected both by recent and developmental conditions. Moreover, developmental conditions can induce correlations between sexually selected and other traits if both types of traits exhibit developmental phenotypic plasticity in response to stressors. Thus, sexually selected traits may reflect recent and/or developmental characteristics of signalers. Here, we review data on the relationships between birdsong, a sexually selected trait, and developmental and current condition of birds from a long-term study of a population of song sparrows (Melospiza melodia). Field studies of free-living birds indicate that the …

The Epidemic Of Mental And Neurological Health, Mohsyn I. Malik

Psychology Publications

This paper composes an image of modern mental and neurological health issues and looks to draw links to the current epidemic based on research and studies found online the internet and off-line. The goal is to examine what may be the underlying problem for a lot of these increases in mental health issues and neurodegenerative diseases and what are some promising clinical and sociocultural advances that may help. It explores problems such as the negative impact of the pharmaceutical giants, the increase in apathy in the work place and the general stigma towards mental disease. Through current research, the use …

Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo

Brain and Mind Institute Researchers' Publications

Sustained activity encoding visual working memory representations has been observed in several cortical areas of primates. Where along the visual pathways this activity emerges remains unknown. Here we show in macaques that sustained spiking activity encoding memorized visual motion directions is absent in direction-selective neurons in early visual area middle temporal (MT). However, it is robustly present immediately downstream, in multimodal association area medial superior temporal (MST), as well as and in the lateral prefrontal cortex (LPFC). This sharp emergence of sustained activity along the dorsal visual pathway suggests a functional boundary between early visual areas, which encode sensory inputs, …

The Antisaccade Task: Visual Distractors Elicit A Location-Independent Planning 'Cost', Jesse C. Desimone

Electronic Thesis and Dissertation Repository

Prosaccades are rapid eye movements with direct stimulus and response relations and are designed to bring the fovea onto a target or area of interest. In contrast, antisaccades require the inhibition of a prosaccade and the evocation of a saccade to a target’s mirror-symmetrical location. Previous work has shown that a remote (i.e., midline, contralateral) – but not proximal (i.e., ipsilateral) – task-irrelevant distractor relative to a visual target delays prosaccade reaction times (RT) (i.e., remote distractor effect: RDE). To my knowledge, however, no work has examined whether antisaccade RTs are similarly influenced by a RDE. Accordingly, I sought to …

Task-Switching In Oculomotor Control: Systematic Investigations Of The Unidirectional Prosaccade Switch-Cost, Jeffrey Weiler

Electronic Thesis and Dissertation Repository

An antisaccade requires suppressing a stimulus-driven prosaccade (i.e., response suppression) and remapping a target’s spatial location to its mirror-symmetrical position (i.e., vector inversion). Notably, my previous work demonstrated that the successful execution of an antisaccade selectively lengthens the reaction time (RT) of a subsequently completed prosaccade (i.e., the unidirectional prosaccade switch-cost; Weiler & Heath, 2012a; Weiler & Heath, 2012b). Thus, the objective of this dissertation was further investigate, and ultimately provide a mechanistic explanation for the unidirectional prosaccade switch-cost.

In Chapter Two, I demonstrate that the magnitude of the unidirectional prosaccade switch-cost is not dependent of the number of …

Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Skilled performance is characterized by precise and flexible control of movement sequences in space and time. Recent theories suggest that integrated spatio-temporal trajectories are generated by intrinsic dynamics of motor and premotor networks. This contrasts with behavioural advantages that emerge when a trained spatial or temporal feature of sequences is transferred to a new spatio-temporal combination arguing for independent neural representations of these sequence features. We used a new fMRI pattern classification approach to identify brain regions with independent vs integrated representations. A distinct regional dissociation within motor areas was revealed: whereas only the contralateral primary motor cortex exhibited unique …

Self-Injurious Behaviours Are Associated With Alterations In The Somatosensory System In Children With Autism Spectrum Disorder., Emma G Duerden, Dallas Card, S Wendy Roberts, Kathleen M Mak-Fan, M Mallar Chakravarty, Jason P Lerch, Margot J Taylor

Brain and Mind Institute Researchers' Publications

Children with autism spectrum disorder (ASD) frequently engage in self-injurious behaviours, often in the absence of reporting pain. Previous research suggests that altered pain sensitivity and repeated exposure to noxious stimuli are associated with morphological changes in somatosensory and limbic cortices. Further evidence from postmortem studies with self-injurious adults has indicated alterations in the structure and organization of the temporal lobes; however, the effect of self-injurious behaviour on cortical development in children with ASD has not yet been determined. Thirty children and adolescents (mean age = 10.6 ± 2.5 years; range 7-15 years; 29 males) with a clinical diagnosis of …

Continuous Executive Function Disruption Interferes With Application Of An Information Integration Categorization Strategy., Sarah J Miles, Kazunaga Matsuki, John Paul Minda

Brain and Mind Institute Researchers' Publications

Category learning is often characterized as being supported by two separate learning systems. A verbal system learns rule-defined (RD) categories that can be described using a verbal rule and relies on executive functions (EFs) to learn via hypothesis testing. A nonverbal system learns non-rule-defined (NRD) categories that cannot be described by a verbal rule and uses automatic, procedural learning. The verbal system is dominant in that adults tend to use it during initial learning but may switch to the nonverbal system when the verbal system is unsuccessful. The nonverbal system has traditionally been thought to operate independently of EFs, but …

Seeing With Sound: Investigating The Behavioural Applications And Neural Correlates Of Human Echolocation, Jennifer L. Milne

Electronic Thesis and Dissertation Repository

Some blind humans use the reflected echoes from self-produced signals to perceive their silent surroundings. Although the use of echolocation is well documented in animals such as bats and dolphins, comparatively little is known about human echolocation. The overarching goal of the work presented in this thesis was to shed light on some of the basic functions of human echolocation, including the perception of the shape, size, and material. I addressed these aspects of echolocation using behavioural psychophysics and neuroimaging.

In Chapter 2 I show that blind echolocators were able to accurately identify the shape of 2D objects, but that …

Overt Responses During Covert Orienting., Brian D Corneil, Douglas P Munoz

Brain and Mind Institute Researchers' Publications

A distributed network of cortical and subcortical brain areas controls our oculomotor behavior. This network includes the superior colliculus (SC), which coordinates an ancient visual grasp reflex via outputs that ramify widely within the brainstem and spinal cord, accessing saccadic and other premotor and autonomic circuits. In this Review, we discuss recent results correlating subliminal SC activity in the absence of saccades with diverse components of the visual grasp reflex, including neck and limb muscle recruitment, pupil dilation, and microsaccade propensity. Such subtle manifestations of covert orienting are accessible in the motor periphery and may provide the next generation of …

Examining Dorsal Striatum In Cognitive Effort Using Parkinson's Disease And Fmri., Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Adrian M Owen, Jean-Sebastien Provost, Oury Monchi, Hooman Ganjavi, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

OBJECTIVE: Understanding cognition mediated by the striatum can clarify cognitive deficits in Parkinson's disease (PD). Previously, we claimed that dorsal striatum (DS) mediates cognitive flexibility. To refute the possibility that variation in cognitive effort confounded our observations, we reexamined our data to dissociate cognitive flexibility from effort. PD provides a model for exploring DS-mediated functions. In PD, dopamine-producing cells supplying DS are significantly degenerated. DS-mediated functions are impaired off and improved on dopamine replacement medication. Functional magnetic resonance imaging (fMRI) can confirm striatum-mediated functions.

METHODS: Twenty-two PD patients, off-on dopaminergic medication, and 22 healthy age-matched controls performed a number selection …

Mixed Methods Pilot Study Of Peri-Diagnostic Exercise Behaviour Change Among Women With Suspected Breast Cancer, Amy L. Deckert

Electronic Thesis and Dissertation Repository

Approximately 1 in 9 Canadian women will develop breast cancer in their lifetime (CCS, 2013). Over the past 30 years, population-based screening programs have contributed to decreased mortality rates (CCS, 2013), however the psychosocial sequelae associated with screening for breast cancer cannot be ignored (Holland et al., 2010). Although the majority of women screened will receive a benign diagnosis, the threat of malignancy can induce elevated levels of distress (Andrykowski et al., 2002).

We conducted a mixed methods pilot study to assess the feasibility and acceptability of a 6-week self-managed exercise behaviour change intervention to attenuate distress in women with …

From Their Perspective: How Adolescents And Young Adults Experience And Conceptualize Life And Occupation Surrounding Parental Divorce Or Separation, Laura R. Hartman

Electronic Thesis and Dissertation Repository

Parental divorce affects adolescents’ emotions, routines, habits, occupations and relationships. The current body of research indicates that parental divorce leads to many unfavourable social, behavioural, and mental health outcomes for adolescents. This dissertation explores the daily lives and occupations of adolescents and young adults surrounding the transition of a parental divorce or marital separation.

This thesis contains four manuscripts in addition to the introductory and final reflection chapters. The first manuscript explores the current North American literature relating to adolescent life surrounding a parental divorce or marital separation, ranging form 1998 to 2014. The second manuscript provides an overview of …

Interesting Shapes Of Vegetables: Is It A Strategy To Promote Consumption Among Preschool Children?, Salma H. Alhabshi

Electronic Thesis and Dissertation Repository

This study highlighted the low intake of vegetables by preschool children and determined whether changing the shape of vegetables increased their level of consumption. A new strategy of repeated exposure to interesting-shaped vegetables was a step aimed at increasing vegetable consumption by increasing the fun element in having vegetables as snacks. Vegetables are the less desirable food in comparison to more attractive unhealthy choices available to children, and discovering a strategy to promote vegetables is considered an important step in nutrition. The primary aim was to explore the effect of repeated exposure (eight times) of shaped vegetables on consumption by …

Secondary Traumatic Stress And Alexithymia In High-Risk Professionals, Matthew R. J. Vandermeer

Electronic Thesis and Dissertation Repository

This study investigated the role that cognitive deficits in emotional processing (i.e., alexithymia) play in the development of traumatic responses, such as secondary traumatic stress (STS), following work with clients who have experienced trauma. Using a prospective cohort of novice counselling psychology and pre-service education students, participants were measured for traits of alexithymia and STS before and after their first practicum placements. Elevated rates of STS consistent with a diagnosis of post-traumatic stress disorder were identified in participants following initial practicum placement. Correlation analyses demonstrated that alexithymia and alexithymia symptom clusters were significantly, and robustly, associated with STS and STS …

Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences …

Obtaining A Diagnosis Of Fetal Alcohol Spectrum Disorder: Experiences Of Caregivers And Professionals, Erica R. Lundberg

Electronic Thesis and Dissertation Repository

The current study describes the lived experiences of stakeholders in a community-based fetal alcohol spectrum disorders assessment clinic. A qualitative methodology was used. Five participants, one caregiver and four professionals, were interviewed about their experiences. Six themes emerged from this process including: clinic organization: systemic strengths and challenges; attitudes and approach: laying the foundation; beyond yes or no: assessment and diagnosis; the moment of truth: delivering the diagnosis; outcomes: what happens after the diagnosis?; what does the future hold? next steps and needs. These themes formed a sequential story-telling of participant experience. Study results are critiqued and practical implications are …

A Dedicated Binding Mechanism For The Visual Control Of Movement., Alexandra Reichenbach, David W Franklin, Peter Zatka-Haas, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

The human motor system is remarkably proficient in the online control of visually guided movements, adjusting to changes in the visual scene within 100 ms [1-3]. This is achieved through a set of highly automatic processes [4] translating visual information into representations suitable for motor control [5, 6]. For this to be accomplished, visual information pertaining to target and hand need to be identified and linked to the appropriate internal representations during the movement. Meanwhile, other visual information must be filtered out, which is especially demanding in visually cluttered natural environments. If selection of relevant sensory information for online control …

Gene Co-Citation Networks Associated With Worker Sterility In Honey Bees., Emma Kate Mullen, Mark Daley, Alanna Gabrielle Backx, Graham James Thompson

Brain and Mind Institute Researchers' Publications

BACKGROUND: The evolution of reproductive self-sacrifice is well understood from kin theory, yet our understanding of how actual genes influence the expression of reproductive altruism is only beginning to take shape. As a model in the molecular study of social behaviour, the honey bee Apis mellifera has yielded hundreds of genes associated in their expression with differences in reproductive status of females, including genes directly associated with sterility, yet there has not been an attempt to link these candidates into functional networks that explain how workers regulate sterility in the presence of queen pheromone. In this study we use available …

The Nature Of Conflict In Sport: Development And Validation Of The Group Conflict Questionnaire, Kyle F. Paradis

Electronic Thesis and Dissertation Repository

The purpose of the present dissertation was to develop a questionnaire to assess intra-group conflict in sport teams. To this end, the current dissertation consisted of three phases which followed a logical progression that is typical in the questionnaire development process. A total of (N = 752) participants took part in the three phases (Phase 1: N = 10; Phase 2: N = 437; Phase 3: N = 305).

Phase 1 was a qualitative investigation of athletes’ (N = 10) perceptions of the nature of conflict in sport. This phase was undertaken to gain a better understanding of the conflict …

Investigating The Relation Between Striatal Volume And Iq., Penny A Macdonald, Hooman Ganjavi, D Louis Collins, Alan C Evans, Sherif Karama

Brain and Mind Institute Researchers' Publications

The volume of the input region of the basal ganglia, the striatum, is reduced with aging and in a number of conditions associated with cognitive impairment. The aim of the current study was to investigate the relation between the volume of striatum and general cognitive ability in a sample of 303 healthy children that were sampled to be representative of the population of the United States. Correlations between the WASI-IQ and the left striatum, composed of the caudate nucleus and putamen, were significant. When these data were analyzed separately for male and female children, positive correlations were significant for the …