Joseph F X DeSouza

Joseph F X DeSouza
York University · Department of Psychology

PhD Neuroscience

About

89
Publications
18,889
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3,745
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Introduction
Interested in the multisensory motor control in learning complex behaviours (eye movements to dance) and cognitive control see my website for more info... www.joeLAB.com
Additional affiliations
September 2004 - present
York University :: Centre for Vision Research
Position
  • York University
January 1993 - August 2004
The University of Western Ontario
Education
September 2001

Publications

Publications (89)
Article
Full-text available
Background: When we reach out to pick up an object, not only do we direct our moving limb towards the location of the object, but the opening between our fingers and thumb is scaled in flight to the object's size. Evidence obtained from patients with neurological disorders has shown that the visual processing underlying the calibration of grip ape...
Article
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Our knowledge of neural plasticity suggests that neural networks show adaptation to environmental and intrinsic change. In particular, studies investigating the neuroplastic changes associated with learning and practicing motor tasks have shown that practicing such tasks results in an increase in neural activation in several specific brain regions....
Article
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Neurorehabilitation programs are commonly employed with the goal to help restore functionality in patients. However, many of these therapies report only having a small impact. In response to the need for more effective and innovative approaches, rehabilitative methods that take advantage of the neuroplastic properties of the brain have been used to...
Article
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Performing multiple tasks concurrently places a load on limited attentional resources and results in disrupted task performance. Although human neuroimaging studies have investigated the neural correlates of attentional load, how attentional load affects task processing is poorly understood. Here, task-related neural activity was investigated using...
Article
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The brain shifts attention by selectively modulating sensory information about relevant environmental features. It has been shown that eye, head, trunk and limb position can bias spatial attention. This leads to the interesting question: Does the brain only recruit bodily information that is explicitly related to orienting behaviour to direct atten...
Article
Loss of social supports and community programs due to lockdowns and other measures associated with COVID-19 has been linked to concerns over mental health and feelings of isolation. These challenges can be particularly acute for the elderly and people living with chronic or pervasive health conditions. Dance for PD, a program specifically developed...
Article
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Parkinson’s disease (PD) is a neurodegenerative disease that has a fast progression of motor dysfunction within the first 5 years of diagnosis, showing an annual motor rate of decline of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) between 5.2 and 8.9 points. We aimed to determine both motor and non-motor PD sy...
Article
Background Parkinson’s disease (PD) is a progressive neurodegenerative disorder for which there is no cure. Exercise-based programs are customarily suggested to address motor and non-motor impairments. Dance has been used to supplement ongoing therapies for people with PD, usually on a weekly or biweekly basis proving to be a feasible option for ne...
Preprint
Full-text available
Parkinson's disease (PD) is a degenerative neurological disorder with no known cure. While PD is primarily considered in terms of motor dysfunctions, the disease manifests with affective dimensions impacting quality of life and daily function. Music and dance have shown promise in diminishing symptoms and improving quality of life for people living...
Article
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Trance processes are a form of altered states of consciousness (ASC) widely reported across cultures. Entering these states is often linked to auditory stimuli such as singing, chanting, or rhythmic drumming. While scientific research into this phenomenon is relatively nascent, there is emerging interest in investigating the neural correlates of al...
Article
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Background: Previous studies have investigated the effects of dance interventions on Parkinson’s motor and non-motor symptoms in an effort to develop an integrated view of dance as a therapeutic intervention. This within-subject study questions whether dance can be simply considered a form of exercise by comparing a Dance for Parkinson’s class with...
Preprint
Full-text available
Trance processes are a form of altered states of consciousness (ASC) widely reported across cultures. Entering these states is often linked to auditory stimuli such as singing, chanting, or rhythmic drumming. While scientific research into this phenomenon is relatively nascent, there is emerging interest in investigating the neural correlates of al...
Preprint
Full-text available
Background Previous studies have investigated the effects of dance interventions on Parkinson’s motor and non-motor symptoms in an effort to develop an integrated view of dance as a therapeutic intervention. This within-subject study questions whether dance can be simply considered a form of exercise by comparing a Dance for Parkinson’s class with...
Article
Full-text available
By chunking continuous streams of action into ordered, discrete, and meaningful units, event segmentation facilitates motor learning. While expertise in the observed repertoire reduces the frequency of event borders, generalization of this effect to unfamiliar genres of dance and among other sensorimotor experts (musicians, athletes) remains unknow...
Article
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Neuroscience of dance is an emerging field with important applications related to health and well‐being, as dance has shown potential to foster adaptive neuroplasticity and is increasingly popular as a therapeutic activity or adjunct therapy for people living with conditions such as Parkinson’s and Alzheimer’s Diseases. However, the multimodal natu...
Article
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Background: Early stage (preclinical) detection of Parkinson's disease (PD) remains challenged yet is crucial to both differentiate it from other disorders and facilitate timely administration of neuroprotective treatment as it becomes available. Objective: In a cross-validation paradigm, this work focused on two binary predictive probability analy...
Preprint
Full-text available
Background Research has supported the notion that dance alleviates motor symptoms for people with Parkinson’s disease (PD) illustrated by observed improvements in gait, balance, and quality of life. However, what remains unclear is whether engaging in weekly dance classes also positively influences nonmotor symptoms of PD, such as affect regulation...
Article
Movement planning involves transforming the sensory signals into a command in motor coordinates. Surprisingly, the real-time dynamics of sensorimotor transformations at the whole brain level remain unknown, in part due to the spatiotemporal limitations of fMRI and neurophysiological recordings. Here, we used magnetoencephalography (MEG)during pro-/...
Preprint
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Background Dance has been used extensively to help supplement ongoing therapies for people with PD, most commonly on a weekly or biweekly basis. A daily dose, however, may provide additional benefits. This study examines the dose effect of a dance intervention delivered within a clinic for movement disorders in which PwPD are paired with experience...
Preprint
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Mirror Neurons" and the "mirror neuron system" have been invoked in association with cognition, empathy, sociality, language, action understanding, and dysfunction in these areas for almost three decades. The concept of mirror neurons and a mirror neuron system in humans has acquired traction in diverse fields, including that of dance/movement ther...
Preprint
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The use of mindfulness meditation (MM) in the treatment of problem gambling (PG), has been used effectively for over five years. However, the neural mechanisms responsible for the improvements are unknown. The literature describes healthy individuals with an increase in alpha power and a decrease in alpha frequency after eight weeks of mindfulness...
Preprint
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Planning an accurate reach involves the transformation of the neural representation of target location in sensory coordinates into a command for hand motion in motor coordinates. Although imaging techniques such as fMRI reveal the cortical topography of such transformations, and neurophysiological recordings provide local dynamics, we do not yet kn...
Article
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Introduction Change in migraine headache (MH)?preexisting MH change or development of de novo MH?are known potential complications following percutaneous closure of atrial septal defect (ASD), but consensus on a causal trigger remains elusive. Objectives To expose potential MH triggers linked, mainly by timing and occurrence, to the emergence of d...
Article
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Background: EEG studies investigating the neural networks that facilitate action observation (AO) and kinaesthetic motor imagery (KMI) have shown reduced, or desynchronized, power in the alpha (8-12 Hz) and beta (13-30 Hz) frequency bands relative to rest, reflecting efficient activation of task-relevant areas. Functional modulation of these netwo...
Article
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Preliminary research (Westheimer, Heiberger et al., Houston and McGill, Mandelbaum and Lo, Volpe et al., Westheimer et al. [2-7]) suggests dance is beneficial for people with Parkinson's disease (PD) and can serve to compliment traditional medical treatments. There are many types of dance classes (Houston and McGill, Mandelbaum and Lo, Volpe et al....
Article
The ability to recognize others is critical to our everyday social interactions. Although extensive research has explored the role of the face for person recognition, little has explored the role of the body, which may be used for recognition at a distance. Because bodies may be processed similarly to faces (Rhodes, Jeffery, Boeing, & Calder, 2013;...
Article
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The lateral occipitotemporal cortex (LOTC) is comprised of subregions selectively activated by images of human bodies (extrastriate body area, EBA), objects (lateral occipital complex, LO), and motion (MT+). However, their role in motor imagery and movement processing is unclear, as are the influences of learning and expertise on its recruitment. T...
Article
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Eye movements are integral to vision and behavior. The brain's oculomotor system is well characterized because converging studies employing multiple brain mapping tools have uncovered its detailed organization in humans and nonhuman primates. A distributed set of interconnected cortical, subcortical, and brainstem regions are known to function in o...
Poster
This study examines neural integration of the sensory modalities of vision and hearing. The objective is to investigate whether an effect of cross-modal compensation of visual to auditory networks in human participants occurs with the removal of visual input.
Article
Full-text available
Significant developments in health applications for dance have occurred over the past 40 years. While neurological changes associated with physical exercise have been well researched and documented, dance has yet to receive the same attention and represents an area of extreme interest for further study given its many reported benefits. The objectiv...
Article
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The current study used functional magnetic resonance imaging to examine the neural activity of an expert dancer with 35 years of break-dancing experience during the kinesthetic motor imagery (KMI) of dance accompanied by highly familiar and unfamiliar music. The goal of this study was to examine the effect of musical familiarity on neural activity...
Article
Impairments in visuospatial abilities are commonly reported in children and adolescents with multiple sclerosis (MS). Corpus callosum (CC) pathology occurs in patients with MS and may contribute to impairment in visuospatial perception, particularly when interhemispheric information transfer is required. This study used a global-local hierarchical...
Conference Paper
Full-text available
Objective: Our research program examines the neural mechanisms of dance, with a future goal to then examine dance in Parkinson’s disease (Earhart 2009). Although the neural mechanisms of dance have been examined, these mechanisms have not been probed during learning of a novel dance routine in expert, normal and in abnormal brains. Thus, our lon...
Article
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Last year we presented analysis on our project examining the neural networks involved in learning a new ballet to a novel piece of music over 8 months. We scanned dancers up to four times using fMRI along this time period. To date, we have now scanned 11 professional dancers from the National Ballet of Canada and twelve controls. All subjects visua...
Article
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In this paper we propose an agglomerative hierarchical clustering Ward's algorithm in tandem with the Affinity Propagation algorithm to reliably localize active brain regions from magnetoencephalography (MEG) brain signals. Reliable localization of brain areas with MEG has been difficult due to variations in signal strength, and the spatial extent...
Article
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Everyday life requires the ability to flexibly switch between tasks. Often, task switching is accompanied by concurrent cognitive activities that compete for limited attentional resources. This study aimed to characterize the effects of attentional load on task switching. In experiment 1, participants performed an interleaved pro-saccade and anti-s...
Article
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Eye exercises have been prescribed to resolve a multitude of eye-related problems. However, studies on the efficacy of eye exercises are lacking, mainly due to the absence of simple assessment tools in the clinic. Because similar regions of the brain are responsible for eye movements and visual attention, we used a modified rapid serial visual pres...
Article
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Efference copy signals are used to reduce cognitive load by decreasing sensory processing of reafferent information (those incoming sensory signals that are produced by an organism's own motor output). Attenuated sensory processing of self-generated afferents is seen across species and in multiple sensory systems involving many different neural str...
Article
We are examining whether practice during our newly designed emotional stroop paradigm (Ovaysikia, Tahir, Chan and DeSouza, 2011 Frontiers in Human Neuroscience) can change behaviour in two related measures (1) performance as measured with reaction times and error rates and (2) during practice do people change their eye movement patterns to the stim...
Article
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The aim of this methods paper is to describe how to implement a neuroimaging technique to examine complementary brain processes engaged by two similar tasks. Participants' behavior during task performance in an fMRI scanner can then be correlated to the brain activity using the blood-oxygen-level-dependent signal. We measure behavior to be able to...
Article
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We were interested in examining the time course of the evolution when beginning to learn a motor habit and it’s associated neural functional changes in the brain. To accomplish this we employed five professional dancers that were scanned using a within subjects design. Each dancer participated in four fMRI (functional magnetic resonance imaging) sc...
Article
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A sensorimotor neuron's receptive field and its frame of reference are easily conflated within the natural variability of spatial behavior. Here, we capitalized on such natural variations in 3-D eye and head positions during head-unrestrained gaze shifts to visual targets in two monkeys: to determine whether intermediate/deep layer superior collicu...
Conference Paper
While spatial information for perception and action may be processed differently in the brain, some visual illusion studies have demonstrated how actions were not always “immune” to visual illusions. In the Kanizsa compression (KC) illusion, a horizontal line that is occluded by a surface is often perceived to be shorter than it really is. We used...
Conference Paper
Neural integration of different sensory modalities provides a meaningful, unified representation of the world. However, conflict between modalities can cause illusory perceptions when inputs are sufficiently incongruent. As shown previously (Wolfe & Carpinella, 2008, ECVP), monocular blindness induced by an occluder contact lens in the absence of c...
Article
Full-text available
The prefrontal cortex (PFC) has been implicated in higher order cognitive control of behavior. Sometimes such control is executed through suppression of an unwanted response in order to avoid conflict. Conflict occurs when two simultaneously competing processes lead to different behavioral outcomes, as seen in tasks such as the anti-saccade, go/no-...
Conference Paper
Neural mechanisms that integrate inputs from different sensory modalities are in place to provide us with a functionally useful interpretation of our physical surroundings. However, when information from different sensory modalities is conflicting, illusory perceptions may occur. In the case of visual-somatosensory conflict, top-down modulation in...
Article
Full-text available
We sought to discover exactly when does the fMRI signal differ as subjects are planning to execute a pro-saccade or an anti-saccade. Thus as subjects waited prolonged instruction periods (6, 10 or 14-seconds) prior to the onset of a peripheral visual cue to execute either the pro- or anti-saccade, we examined the fMRI signal in various areas along...
Article
Difficulties to suppress prepotent responses is one of the hallmarks of the prefrontal syndrome. This deficit becomes clear in the anti-saccade task in which subjects have to suppress a reflexive saccade towards a peripheral visual stimulus and instead generate a voluntary saccade towards the mirror location. To investigate the role of the prefront...
Article
Planning reaching or pointing movements requires a number of processing steps involving different brain areas. One important step consists of transforming visual information into motor plans that are appropriate for movement control. A key brain region involved in this process is the posterior parietal cortex (PPC). Here we use magnetoencephalograp...
Article
Full-text available
Natural movements towards a target show metric variations between trials. When movements combine contributions from multiple body-parts, such as head-unrestrained gaze shifts involving both eye and head rotation, the individual body-part movements may vary even more than the overall movement. The goal of this investigation was to develop a general...
Article
The anti-saccade task, where participants are instructed to look away from a peripheral stimulus, can be used to probe prefrontal cortex (PFC) function. Increased activity in PFC neurons precedes correct anti-saccades in primates. In addition, two competing processes in these neurons, response selection and response suppression, intersect 400-500ms...
Conference Paper
In the Stroop task, subjects must name the ink colour of a colour word (Stroop, 1935). When the ink colour (ex. red ink) and word (ex. BLUE) are different, a conflict occurs between what must be said and what is automatically read . Our urge to read a word leads to strong ‘stimulus-response’ (SR) associations, therefore inhibiting such strong SR’s...
Article
Natural movements towards a target show metric variations between trials. When movements combine contributions from multiple body-parts, such as head-unrestrained gaze shifts involving both eye and head rotation, the individual body-part movements may vary even more than the overall movement. The goal of this investigation was to develop a general...
Article
Full-text available
Previous studies have shown that prefrontal cortex (PFC) neurons carry task-related activity; however, it is largely unknown how this selectivity is implemented in PFC microcircuitry. Here, we exploited known differences in extracellular action potential waveforms, and antidromic identification, to classify PFC neurons as putative pyramidal or inte...