[Seminar] Age-related changes in brain function and connectivity in relation to motor behavior by Dr. Stephan Swinnen

Abstract

Even though bimanual coordination skills are prominent in daily life, movement neuroscience has invested limited effort in studying the principles underlying bimanual control. Nevertheless, bimanual skills are a useful vehicle to unravel and understand motor control under normal and pathological conditions.

Aging results in alterations in functional brain activation as well as in structural and functional brain connectivity that have consequences for motor behavior. I will address the effects of aging on motor functioning in view of the ‘compensation’ versus ‘dedifferentiation’ hypothesis.

In Part 1, I will discuss age-related processes of brain over- and underactivation in cortical and subcortical areas, respectively. I will address whether the increased brain activity is indicative of compensatory mechanisms. I will also discuss associations between grey matter integrity of subcortical structures and motor learning capability in young and older adults.

In Part 2, I will present a global and local perspective on age-related functional connectivity alterations. On one hand, functional brain connectivity during resting-state conditions in the motor network in interaction with other brain networks will be addressed. This reveals age-related alterations in inter-network connectivity that may be a signature of the dedifferentiation hypothesis of aging. One the other hand, using noninvasive dual-site Transcranial Magnetic Stimulation (TMS) approaches, I will elaborate on functional connectivity mediated by pairwise interhemispheric interactions between motor cortex (M1), dorsal premotor cortex (PMd) and dorsolateral prefrontal cortex (DLPFC) during planning of bimanual movements with different degrees of complexity. I will discuss evidence consistent with the hypothesis that bilateral DLPFC entertains a general facilitatory interaction with contralateral M1 during preparation of bimanual actions. Conversely, left PMd shows inter-hand task-allocation-specific modulations in its interaction with the contralateral M1, a function not observed in right PMd. These results support a model of bimanual movement planning in which left PMd is responsible for division of labor between both hands, a unique feature of bimanual skill. Our multimodal imaging approach reveals age-related interactions between brain structural/functional connectivity and motor behavior.

Biography

Stephan Swinnen currently directs the Movement Control & Neuroplasticity Research Center at Group Biomedical Sciences KU Leuven (Belgium), consisting of a multidisciplinary team of > 35 scientists. He teaches motor control and learning and behavioural neuroscience at the Departments of Movement Sciences, Revalidation Sciences, and Psychology at KU Leuven.

He has (co)authored more than 300 publications in refereed scientific journals. He was appointed as Francqui Research Professor from 2013-2016.

His current research is focused on mechanisms underlying movement control and neuroplasticity using a multidisciplinary and multimodal imaging approach, spanning the behavioural sciences and the (cognitive) neurosciences. This includes the study of brain function, structure, connectivity and neurochemicals, using medical imaging and movement registration technologies. Normal as well as pathological conditions are investigated. During the past decades, his team has devoted increasing attention to the study of lifespan changes in brain function and structure and how these can account for age-related deficits in motor performance with emphasis on interlimb/bimanual coordination. His team has also developed an extensive research program on movement and cognitive control deficits in patients with traumatic brain injury.