Grant: Master's Award: Canada Graduate Scholarships

Each of us has an internal map of the body in the brain that helps us to process information and be aware of the world around us. This internal representation is formed from previous sensory experiences and it affects how incoming sensory information is processed. This internal map guides movement, for instance, so that our hands can reach easily for a light switch in the darkness. Even small changes to this internal model can impact motor skill and performance, for instance, impacting driving skill when navigating through a parking lot or impacting timing and precision of high-level performance sports like golfing. The neck is biomechanically and neurologically connected to the upper limb. When sensory information from the neck is altered, this may change the internal map of the body as well as the motor response of the upper limb. The cerebellum is a main integrator of sensory information, including input from muscle spindles and joint receptors that are located within the neck. The role of the cerebellum is to integrate this sensory information to allow for learning and adaption and ultimately for internal maps to be formed. My master’s project plans to explore the effect of altered sensory input in the form of ongoing neck stiffness (muscle tightness and lack of mobility of the neck) to see what alterations occur to sensory integration by the cerebellum using ongoing neck stiffness as a model of chronic alterations to sensory input. My previous work has been to develop a method to measure changes to cerebellar function following motor learning in healthy participants and this work just recently has been published. My first aim is to use this method to show whether there are differences in cerebellar processing when sensory input to the neck is altered. Participants will also complete a throwing task which is known to rely heavily on cerebellar integration. During the throw, a special 3D motion capture system will be used to track neck and upper limb positions and movement patterns, and accuracy and speed will also be measured. My second aim will investigate how people with neck stiffness perform on a task which requires them to integrate input from more than one sense. My underlying hypothesis is that altered afferent input from the neck changes the way that multisensory information is processed. To assess this, participants will be asked to report the number of stimuli occurring in sequence from three senses (hearing, vision, and touch). The stimuli will be delivered initially in unison with a monitor displaying a series of visual events, headphones emitting beeps and a small motor vibrating on the upper arm. Participants will then be told to focus on one of the three sensory modalities while the other two sensory modalities present contradictory information. We will record whether variance is similar between participants with neck stiffness compared to controls to show the extent that altered sensory input affects the ability to process tactile, auditory and/or visual stimuli. We will also consider how tactile information influences accuracy when participants respond to vision and audition, as well as the influence of visual and auditory stimuli on the other two senses. Altered sensory input in the form of neck stiffness may alter the body’s internal map, compromising output to the upper limb. Office work and technology use often lead to neck stiffness, which may interfere with how the brain perceives the body’s position and activates upper limb muscles to perform given tasks. Understanding how altered sensory input arising from the neck may influence performance has the potential to lead to improved technology and workplace design which will improve the health, well-being, and productivity of Canadian workers.