A5053707160- Motor Control and Adaptation
- Visual perception and processing mechanisms
- Vestibular and auditory disorders
- Muscle activation and electromyography studies
- Tactile and Sensory Interactions
- EEG and Brain-Computer Interfaces
- Neural dynamics and brain function
- Transcranial Magnetic Stimulation Studies
- Neural and Behavioral Psychology Studies
- Olfactory and Sensory Function Studies
- Hemispheric Asymmetry in Neuroscience
- Multisensory perception and integration
- Neuroscience and Neural Engineering
- Action Observation and Synchronization
- Gaze Tracking and Assistive Technology
- Neurological disorders and treatments
- Balance, Gait, and Falls Prevention
- Hearing, Cochlea, Tinnitus, Genetics
- Retinal Development and Disorders
- Face Recognition and Perception
- Hand Gesture Recognition Systems
- Ophthalmology and Eye Disorders
- Advanced Memory and Neural Computing
- Spatial Neglect and Hemispheric Dysfunction
- Ear Surgery and Otitis Media
Western University
2016-2025
Robarts Clinical Trials
2016-2025
Western University of Health Sciences
2022
Office of Naval Research
2017-2018
Czech Academy of Sciences, Institute of Physiology
1999-2017
Child Mind Institute
2016
Ontario Brain Institute
2012-2014
Action Network
2011
York University
2011
Canadian Institutes of Health Research
2002-2010
Response inhibition is essential for navigating everyday life. Its derailment considered integral to numerous neurological and psychiatric disorders, more generally, a wide range of behavioral health problems. Response-inhibition efficiency furthermore correlates with treatment outcome in some these conditions. The stop-signal task an tool determine how quickly response implemented. Despite its apparent simplicity, there are many features (ranging from design data analysis) that vary across...
Recent development of neural prosthetics for assisting paralyzed patients has focused on decoding intended hand trajectories from motor cortical neurons and using this signal to control external devices. In study, higher level signals related the goals movements were decoded three monkeys used position cursors a computer screen without animals emitting any behavior. Their performance in task improved over period weeks. Expected value fluid preference, expected magnitude, or probability...
This study addresses the integration of auditory and visual stimuli subserving generation saccades in a complex scene. Previous studies have shown that saccadic reaction times (SRTs) to combined auditory-visual are reduced when compared with SRTs either stimulus alone. However, these results been typically obtained high-intensity distributed over limited number positions horizontal plane. It is less clear how interactions influence under more but arguably natural conditions, low-intensity...
The role of the primate superior colliculus (SC) in orienting head movements was studied by recording electromyographic (EMG) activity from multiple neck muscles following electrical stimulation SC. Combining SC with EMG recordings provides an objective and sensitive measure drive onto muscle motoneurons, particularly relation to evoked gaze shifts. In this paper, we address how responses head-restrained monkeys depend on rostrocaudal, mediolateral, dorsoventral location stimulating...
The appearance of a novel visual stimulus generates rapid stimulus-locked response (SLR) in the motor periphery within 100 ms onset. Here, we recorded SLRs from an upper limb muscle while humans reached toward (pro-reach) or away (anti-reach) stimulus. SLR on anti-reaches encoded location rather than movement goal. Further, magnitude was attenuated when subjects Remarkably, magnitudes also correlated with reaction times both pro-reaches and anti-reaches, but did so opposite ways: larger...
Microsaccades aid vision by helping to strategically sample visual scenes. Despite the importance of these small eye movements, no cortical area has ever been implicated in their generation. Here, we used unilateral and bilateral reversible inactivation frontal fields (FEF) identify a drive for microsaccades. Unexpectedly, FEF altered microsaccade metrics kinematics. Such also impaired deployment following peripheral cue onset, regardless side or configuration. Our results demonstrate that...
We studied the influences of competing visual and auditory stimuli on horizontal gaze shifts in humans. Gaze were made to or targets presence either an irrelevant cue. Within experiment, target cue aligned (enhancer condition) misaligned (distractor space. The times presentation varied so that could have been presented before cue, target. compared subject performance enhancer distractor conditions, measuring reaction latencies frequency incorrect shifts. Performance differed most when was...
We recorded muscle activity from an upper limb while human subjects reached towards peripheral targets. tested the hypothesis that transient visual response sweeps not only through central nervous system, but also system. Like in stimulus-locked responses (< 100 ms) were sensitive to stimulus contrast, and temporally spatially dissociable voluntary orienting activity. Also, arrival of reduced variability by resetting phase ongoing low-frequency oscillations. This latter finding critically...
Pupillometry provides a simple and noninvasive index for variety of cognitive processes, including perception, attention, task consolidation, learning, memory. The neural substrates by which such processes influence pupil diameter remain somewhat unclear, although cortical inputs to the locus coeruleus mediating arousal are likely involved. Changes in also accompany covert orienting; hence oculomotor system may provide an alternative substrate influences on diameter. Here, we show that...
Movement inhibition is an aspect of executive control that can be studied using the countermanding paradigm, wherein subjects try to cancel impending movement following presentation a stop signal. This paradigm permits estimation stop-signal reaction time or needed respond Numerous studies have examined fast, ballistic movements, such as saccades, even though many movements in daily life are not and stopped at any point during their trajectory. A benefit studying nonballistic antagonist...
Response inhibition is essential for navigating everyday life. Its derailment considered integral to numerous neurological and psychiatric disorders, more generally, a wide range of behavioral health problems. Response-inhibition efficiency furthermore correlates with treatment outcome in these conditions. The stop-signal task an tool determine how quickly response implemented. Despite its apparent simplicity, there are many features (ranging from design data analysis) that vary across...
Humans have a remarkable capacity to adjust reaching movements rapidly and accurately when visual targets jump new location. The short latency of such online corrections has led the hypothesis that they constitute distinct class movement arise from an automatic pilot is selectively engaged only during ongoing movements. However, concrete evidence for this scarce. Here, we test idea by measuring muscle recruitment, force, kinematics in jumping target task. In separate blocks trials,...
We report neck muscle activity and head movements evoked by electrical stimulation of the superior colliculus (SC) in head-unrestrained monkeys. Recording electromyography (EMG) circumvents complications arising from head's inertia kinetics force generation allows precise assessment neuromuscular drive to plant. This study served two main purposes. First, we sought test predictions made companion paper a parallel SC onto muscles. Low-current, long-duration both EMG responses either without...
We studied the role of primate frontal eye fields (FEFs) in eye-head gaze shifts by recording EMG activity from multiple dorsal neck muscles after electrical stimulation a broad distribution sites throughout FEF. assess our results light four mechanisms forwarded to account for why and head movements follow FEF stimulation. Two propose that are generated indirectly response either percept or an eccentric orbital position. other evoked directly through issuance command separate commands....
Low-frequency activity within the oculomotor system helps bridge sensation and action. Given ocular stability, low-frequency sustained by some neurons intermediate deep superior colliculus (dSC) is assumed to be separated from motor output. However, dSC an orienting structure influence of at other effectors remains untested. We studied this simultaneously recording saccade-related electromyographic (EMG) neck muscles that turn head. Monkeys performed a gap-saccade paradigm with varying...
Recent studies have described a phenomenon wherein the onset of peripheral visual stimulus elicits short-latency (<100 ms) stimulus-locked recruitment (SLR) neck muscles in nonhuman primates (NHPs), well before any saccadic gaze shift. The SLR is thought to arise from responses within intermediate layers superior colliculus (SCi), hence muscle recordings may reflect presaccadic activity SCi, even humans. We obtained bilateral intramuscular splenius capitis (SPL, an ipsilateral...
In situations requiring immediate action, humans can generate visually-guided responses at remarkably short latencies. Here, to better understand the visual attributes that best evoke such rapid responses, we recorded upper limb muscle activity while participants performed reaches towards Gabor patches composed of differing spatial frequencies (SFs). We studied initiated from a stable posture (experiment 1, static condition), or during on-line reach corrections an abruptly displaced target...