Paul van Donkelaar

Paul van Donkelaar
University of British Columbia - Okanagan | UBC Okanagan · School of Health and Exercise Sciences

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147
Publications
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Publications

Publications (147)
Article
Full-text available
Reactive balance control following hand perturbations is important for everyday living as humans constantly encounter perturbations to the upper limb while performing functional tasks while standing. When multiple tasks are performed simultaneously, cognitive processing is increased, and performance on at least one of the tasks is often disrupted,...
Article
Full-text available
Objectives There is growing concern repetitive head contacts sustained by soccer players may lead to long-term health ramifications. Therefore, this preliminary investigation examined the impact an acute soccer heading bout has on dynamic cerebral autoregulation (dCA) metrics. Methods In this preliminary investigation, 40 successful soccer headers...
Article
Background: Women who experience intimate partner violence (IPV) are at a high risk for traumatic brain injuries (TBIs). Women's shelters may be an ideal location for TBI screening. Behavior change theory can help understand factors that influence screening at women's shelters and develop interventions to promote screening. Objective: To use behavi...
Article
Full-text available
Intimate partner violence (IPV) affects at least 1 in 3 women worldwide and up to 92% report symptoms consistent with brain injury (BI). Although a handful of studies have examined different aspects of brain structure and function in this population, none has characterized potential deficits in cognitive-motor function. This knowledge gap was addre...
Article
Full-text available
Intimate partner violence includes psychological aggression, physical violence, sexual violence, and stalking from a current or former intimate partner. Past research suggests that exposure to intimate partner violence can impact cognitive and psychological functioning, as well as neurological outcomes. These seem to be compounded in those who suff...
Preprint
Full-text available
Intimate partner violence (IPV) affects at least 1 in 3 women worldwide and up to 92% report symptoms consistent with brain injury (BI). Although a handful of studies have examined different aspects of brain structure and function in this population, none has characterized potential deficits in cognitive-motor function. This knowledge gap was addre...
Article
Full-text available
Objective: The current investigation examined how a bout of soccer heading may impact brain function. Design: Semi-randomized crossover cohort. Setting: Controlled soccer heading. Participants: Seven male soccer players (24.1 ± 1.5 years). Intervention: 40 successful soccer headers were performed in 20 min (25 m, launch velocity ~80 km/h). X2 xPatc...
Article
Full-text available
During destabilizing, voluntary arm movements, the vestibular system provides sensory cues related to head motion that are necessary to preserve upright balance. Although sensorimotor processing increases in accordance with task complexity during the preparation phase of reaching, it is unclear whether vestibular signals are also enhanced when main...
Article
Objective: This study examined the extent symptoms associated with potential traumatic brain injury (TBI) in intimate partner violence (IPV) survivors overlap with sport-related concussions (SRC). IPV survivor responses on the Brain Injury Severity Assessment (BISA) tool, an IPV-specific questionnaire developed to assess TBI symptoms; and the widel...
Article
In the present study we investigated how attention contributes to the interaction between reach planning and execution, and postural control. Reaching movements were generated while standing and were performed either in isolation or in conjunction with a secondary reaction time (RT) task. In addition, to better understand how online movement contro...
Article
Full-text available
For a simple RT task, movement complexity increases RT and also corticospinal excitability, as measured by the motor evoked potential (MEP) elicited by TMS of the motor cortex. However, it is unknown if complexity-related increases in corticospinal excitability during the preparation of movement are mediated at the cortical or spinal level. The pur...
Article
Full-text available
Movement complexity is known to increase reaction time (RT). More recently, transcranial magnetic stimulation (TMS) of the motor cortex has revealed that movement complexity can alter corticospinal excitability. However, the impact of a sequential addition of movement components on corticospinal excitability during the preparatory phase of a simple...
Conference Paper
For a simple reaction time (RT) task, movement complexity increases RT and motoneuron excitability during movement preparation. Previous studies have demonstrated that increases in motoneuron excitability can occur independent of increases in motor cortical excitability; however, it is unknown if the motoneurons receive information related to movem...
Article
Attention involves three distinct networks for alerting, orienting, and executive control. Interventions targeting the specific attentional networks remain lacking. Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability, which potentially serves as an interventional tool to treat individuals with attention i...
Article
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Background An integrated curriculum is designed to be repetitive yet progressive and the concept has rapidly established itself within medical education. National organizations have recommended a shift to a spiral curriculum design, which uses both vertical and horizontal integration. This study examined differences between the recently implemented...
Article
Full-text available
Sport-related concussion (SRC), a mild form of traumatic brain injury (TBI), is a common injury in contact sports. Health care professionals rely on subjective criteria (e.g., symptoms), as there is no objective marker for identification of athletes with SRC. Blood-based biomarkers have shown promise as diagnostic and prognostic tools following TBI...
Article
Full-text available
Repetitive subconcussive head impacts across a season of contact sports participation are associated with a number of deficits in brain function. To date, no research has investigated the effect of such head impact exposure on dynamic cerebral autoregulation (dCA). To address this issue, 179 elite, junior-level (age 19.6 ± 1.5 years) contact sport...
Article
The central nervous system preplans postural responses to successfully perform complex multi-joint movements. These responses have been termed anticipatory postural adjustments (APAs), and they constitute a general type of response to stabilize posture prior to movement initiation. APA sequences are elicited with shorter latency when a startling ac...
Article
Full-text available
Objectives To determine the effect of heading a soccer ball on serum neurofilament light (NF-L) protein, plasma tau protein and symptom metrics including total number of symptoms reported and symptom severity scores on the Standardized Concussion Assessment Tool— 3rd edition (SCAT3). Methods Eleven male collegiate soccer players were recruited to...
Article
Ocular near point of convergence (NPC) has been shown to be sensitive to the effects of concussion and subconcussive impacts. To determine if NPC is also sensitive to a previous history of concussion, male contact-sport athletes either with (n=26) or without (n=16) a history of at least one previous concussion had their NPC assessed. The results sh...
Article
Full-text available
Sport-related concussion is known to affect a variety of brain functions. However, the impact of this brain injury on cerebral autoregulation (CA) is poorly understood. Thus, the goal of the current study was to determine the acute and cumulative effects of sport-related concussion on indices of dynamic CA. Toward this end, 179 elite, junior-level...
Article
Objective: To determine the effects of repetitive subconcussive head trauma on neurovascular coupling (NVC) responses. Design: Prospective cohort study collected between September 2013 and December 2016. Setting: University laboratory. Participants: One hundred seventy-nine elite, junior-level (age, 19.6 ± 1.5 years) contact sport (ice hocke...
Chapter
Objective: Cerebral pressure-flow dynamics are typically reported between mean arterial pressure and mean cerebral blood velocity. However, by reporting only mean responses, potential differential regulatory properties associated with systole and diastole may have been overlooked. Materials and methods: Twenty young adults (16 male, age: 26.7 ±...
Chapter
Objective: To determine whether acute sports-related concussion (SRC) exerts differential effects on cerebral autoregulatory properties during systole versus diastole. Materials and methods: One hundred and thirty-six contact-sport athletes tested preseason; 14 sustained a concussion and completed follow-up testing at 72 hours, 2 weeks, and 1 mo...
Article
Sport-related concussion has been shown to alter cerebral blood flow (CBF) both acutely and chronically, and may exert cumulative effects across multiple injuries. Such dysfunction may be mediated by trauma-induced deficits to CBF control mechanisms, though our understanding of these effects is limited, including dynamics of neurovascular coupling...
Article
Objective To examine the effect of repetitive contact sport-related head trauma on indices ofheart rate variability (HRV). Design Prospective Cohort. Setting Laboratory. Participants Forty-ninemale contact-sport (hockey or football) and four non-contact control athletes (age range: 17–22). Intervention Prior to (T1) and upon completion of (T2)...
Article
Objective Examine differences between the recently implemented integrated spiral (year 1) and conventional block (years 2-4) MD curriculum at University of British Columbia (UBC) with respect to knowledge of concussion diagnosis and management. Design Cross-sectional survey Setting UBC undergraduate MD program Participants An online survey was d...
Article
Objective Examine how the frequency-dependent relationship between blood pressure (BP) and cerebral blood velocity (CBV) is affected by acute sport-related concussion. Design Prospective Cohort. Setting Laboratory. Participants 136 male contact-sport athletes (19.1±1.4 years) recruited, subset of 14 sustained concussions (19±1.4 years). Interve...
Article
Objective To determine how a history of 3+ concussions alters elevations in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks. Design Retrospective Cohort. Setting Laboratory. Participants 136 male contact-sport athletes (19.1±1.4 years, 66 football, 70 hockey) were recruited; 39 presented with 0 previous c...
Article
Objective To examine the effect of acute sport-related concussion on heart rate variability (HRV) in contact-sport athletes over 1 month post-injury. Design Prospective Cohort. Setting Laboratory. Participants 136 male contact-sport athletes (19.1±1.4 years) were recruited and a subset of 14 athletes sustained concussions (19±1.4 years) and were...
Article
Objective To determinethe extentto which an acute sport-related concussion disrupts elevations in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks. Design Prospective Cohort. Setting Laboratory. Participants 136 male contact-sport athletes (19.1±1.4 years) recruited, subset of 14 participants (19±1.4 years...
Article
Objective To examine how sub-concussive head trauma throughout a contact-sport season affects quiet stance centre of pressure (COP) sway Design Prospective cohort Setting Laboratory Participants : Twenty-four elite male football players (age range 18–22) were recruited for the study Intervention Quiet stance data was collected at the start and...
Article
Objective To examine how head-impact exposures affect the elevation in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks. Design Prospective Cohort. Setting Laboratory. Participants To date: 40 male contact-sport athletes (19.4±1.2 years) and 3 cross-country athletes (20.0±1.0 years) have completed testing...
Article
Objective To determine the influence of a history of 3+ previous concussions on quiet stance. Design Retrospective cohort. Setting Laboratory. Participants Eighty-seven male (age range 17–22) contact-sport athletes (football and hockey) entered the study. Participants were recruited from the same sport teams and tested during the pre-season. Exc...
Article
Objective To examine how acute sport-related concussion influences centre of pressure (COP) sway during quiet stance Design Prospective cohort Setting Laboratory Participants Eighty-seven male contact-sport (football and hockey) athletes entered the study. Seven subjects (age range 17–22) were concussed and completed follow-up testing 72-hours,...
Article
Objective To examine the relationship between cerebral autoregulation changes and impact exposuresthroughout a season of contact sports (hockey or football). Design Prospective Cohort. Setting Laboratory. Participants 40 male contact sport athletes (19.4±1.2 years); to date, 3 cross-country athletes (20.0±1.0 years) have completed testing (non-c...
Article
Objective To examine the effect of multiple previous concussions on heart rate variability (HRV) in contact-sport athletes. Design Retrospective Cohort. Setting Laboratory. Participants 136 male elite contact-sport (hockey and football) athletes were recruited for this study. Forty-one had no previous concussion history (Hx-), while nineteen had...
Article
Objective To examine the effects of concussion history on an index of cerebral autoregulation in a healthy athlete population. Design Retrospective Cohort. Setting Laboratory. Participants 136 male contact sport athletes (19.1±1.4 years, 66 football, 70 hockey) were recruited; 39 presented with 0 previous concussions, 16 with 3+ previous concuss...
Article
Mild traumatic brain injury (mTBI) is a common health problem. There is tremendous variability and heterogeneity in human mTBI, including mechanisms of injury, biomechanical forces, injury severity, spatial and temporal pathophysiology, genetic factors, pre-injury vulnerability and resilience factors, and clinical outcomes. Animal models greatly re...
Conference Paper
The purpose of this study was to examine cerebral autoregulation (CA) in young athletes experiencing concussion. The subjects were monitored and repeatedly tested 72 hours, 2 weeks and 1 month post-injury. Mean arterial blood pressure (MABP), end-tidal partial pressure of carbon dioxide (PETCO2) and cerebral blood flow velocity (CBFV) in the middle...
Article
Full-text available
The authors characterized how motor planning influences temporal order judgment (TOJ) tasks. They examined this by applying vibrotactile stimulation during the planning stages of a bimanual arm movement that would bring the arms into a crossed configuration. The authors have previously shown that planning to cross the arms induces a subjective reve...
Article
Background: The concept of neurovascular coupling has been postulated since the late 1800s and has been demonstrated most commonly in humans using visual stimuli (e.g. reading, checkerboards). These traditional paradigms evoke only a moderate cerebral blood flow response due to the relative simplicity of the visual stimuli. New method: Forty sub...
Article
Full-text available
Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is...
Data
Raw myelin water fraction values across concussed athletes for each scan. Each column represents raw myelin water fraction data from a given subject (S##) at baseline (BL), 72 hours (72H), 2-weeks (2W), or 2 months (2M) post-injury. (ZIP)
Conference Paper
Full-text available
Concussion often causes executive function deficits, which can be measured using a simple task-switching paradigm. However, little is known about subconcussive impacts and their influence on executive function. This particular study examined executive function in college-aged soccer players immediately prior to and following an acute bout of soccer...
Article
Full-text available
Obstacle crossing during walking requires visuospatial attention to identify the obstacle, so that individuals can integrate visual and somatosensory information for raising the foot with appropriate height and timing without being tripped. However, the interaction between control of foot trajectory and orientation of visuospatial attention during...
Chapter
Sport-related concussion has been referred to as a functional rather than a structural injury with neurometabolic and microstructural alterations reported in several studies. Accordingly, conventional neuroimaging techniques, such as computed tomography (CT) and structural magnetic resonance imaging (MRI), have limited value beyond ruling out struc...
Article
Full-text available
Traumatic brain injury influences regulation of cerebral blood flow in animal models and in human studies. We reviewed the use of transcranial Doppler ultrasound (US) to monitor cerebrovascular reactivity following sport-related concussion. A narrative and systematic review of articles published in the English language, from December 1982 to Octobe...
Article
Full-text available
The ability to decide which of the two stimuli is presented first can be probed using a temporal order judgment (TOJ) task. When the stimuli are delivered to the fingers, TOJ decisions can be confounded by the fact that the hands can be moved to different locations in space. How and where this confounded information is processed in the brain is poo...
Article
Full-text available
Concussion frequently results in executive function deficits that can be specifically probed using task-switching tasks. The current study examined in detail the influence of concussion on task switching performance using both spatial and numerical stimuli. Individuals with concussion (n = 16) were tested within 48 hours of injury and 7, 14, and 28...
Article
Full-text available
Abstract A multitude of events bombard our sensory systems at every moment of our lives. Thus, it is important for the sensory cortex to gate unimportant events. Tactile suppression is a well-known phenomenon defined as a reduced ability to detect tactile events on the skin before and during movement. Previous experiments found detection rates decr...
Article
When the target of a goal-directed reach changes location, people normally respond rapidly and automatically to the target shift. Here, we investigate whether explicit knowledge about a moving target (knowing whether a location change is likely/unlikely) improves responsiveness, with the goal of understanding top-down effects on real-time reaching....
Article
Background: Head trauma in adolescents has been linked with deficits in attention and executive function that can compromise the performance of everyday tasks. Although previous research has examined this issue using computerized neuropsychological testing, little work has been done using laboratory-based measurements of attention and executive fu...
Article
Full-text available
The question of how infants attain upright sitting is at the core of understanding the development of most functional abilities. Our simple, practical method of securing the hips and different trunk segments while evaluating the infant's ability to vertically align and stabilize the trunk in space contributes a useful method and new insights into t...
Article
This study was undertaken to determine if target predictability could modulate saccadic planning and timing at the level of the frontal eye fields (FEF). To this end, healthy participants performed two gap saccade tasks in which the targets were displaced left or right of the midline in either a predictable or a random fashion. Additionally, half o...
Article
The purpose of this study was to investigate the typical development of postural control in younger (5-6 yrs) and older (7-16 yrs) children (YTD and OTD) during two gait tasks, including level walking and obstacle-crossing, using a dual-task paradigm, and to compare the results of the children's performance with that of healthy young adults (HYA)....
Article
Accurate motor execution is achieved by estimating future sensory states via a forward model of limb dynamics. In the current experiment, we probed the time course over which state estimation evolves during movement planning by combining a bimanual arm crossing movement with a temporal order judgment (TOJ) task. Human participants judged which of t...
Article
Full-text available
The supplementary motor area (SMA) is involved in planning limb movements. An important component of such planning is the prediction of the sensory consequences of action. The authors used transcranial magnetic stimulation (TMS) to probe the contribution of SMA to motor planning during a predictive load-bearing task. Single TMS pulses were delivere...
Article
Full-text available
Fractals have been very successful in quantifying the visual complexity exhibited by many natural patterns, and have captured the imagination of scientists and artists alike. Our research has shown that the poured patterns of the American abstract painter Jackson Pollock are also fractal. This discovery raises an intriguing possibility - are the vi...
Article
Full-text available
The purpose of this study was to examine how individuals modulate attention in a gait/cognition dual task during a 4-week period following a concussion. Ten individuals suffering from a grade 2 concussion and 10 matched controls performed a single task of level walking, a seated auditory Stroop task and a simultaneous auditory Stroop and walking ta...
Article
Full-text available
Saccadic eye movements are used to rapidly align the fovea with the image of objects of interest in peripheral vision. We have recently shown that in children there is a high preponderance of quick latency but poorly planned saccades that consistently fall short of the target goal. The characteristics of these multiple saccades are consistent with...
Article
Full-text available
Deficits in postural control are one of the hallmarks of disability in children with cerebral palsy (CP). Yet, much remains unknown regarding the etiology of postural deficits in these children. Here we evaluated postural control at a simplified task level by measuring head stability during quiet sitting while systematically manipulating the level...
Article
Full-text available
Re-injury to the brain during recovery from an initial concussion leads to increased probability of permanent brain damage or death. Recovery from concussion has been proposed to be ongoing even up to a month post-injury. The goal of the current study was to investigate the relationship between the visuospatial orientation of attention and obstacle...
Article
To compare the effect of 3 different approaches to balance training on dual-task balance performance in older adults with balance impairment. A double-blind, randomized controlled trial. University research laboratory. Older adults (N=23) with balance impairment (mean age, 74.8y). They scored 52 or less on the Berg Balance Scale (BBS) and/or walked...