Toward personalized music-therapy: a neurocomputational modeling perspective

Music therapy has emerged recently as a successful intervention that improves patient outcomes in a large range of neurological and mood disorders without adverse effects. Brain networks are entrained to music in ways that can be explained both via top-down and bottom-up processes. In particular, the direct interaction of auditory with the motor and the reward system via a predictive framework explains the efficacy of music-based interventions in motor rehabilitation. In this article, we provide a brief overview of current theories of music perception and processing. Subsequently, we summarize the evidence of music-based interventions primarily in motor, emotional, and cardiovascular regulation. We highlight opportunities to improve the quality of life and reduce the stress beyond the clinic environment and in healthy individuals. This relatively unexplored area requires an understanding of how we can personalize and automate music selection processes to fit individual needs and tasks via feedback loops mediated by measurements of neurophysiological responses

Effect of visual distraction and auditory feedback on patient effort during robot-assisted movement training after stroke

<p>Abstract</p> <p>Background</p> <p>Practicing arm and gait movements with robotic assistance after neurologic injury can help patients improve their movement ability, but patients sometimes reduce their effort during training in response to the assistance. Reduced effort has been hypothesized to diminish clinical outcomes of robotic training. To better understand patient slacking, we studied the role of visual distraction and auditory feedback in modulating patient effort during a common robot-assisted tracking task.</p> <p>Methods</p> <p>Fourteen participants with chronic left hemiparesis from stroke, five control participants with chronic right hemiparesis and fourteen non-impaired healthy control participants, tracked a visual target with their arms while receiving adaptive assistance from a robotic arm exoskeleton. We compared four practice conditions: the baseline tracking task alone; tracking while also performing a visual distracter task; tracking with the visual distracter and sound feedback; and tracking with sound feedback. For the distracter task, symbols were randomly displayed in the corners of the computer screen, and the participants were instructed to click a mouse button when a target symbol appeared. The sound feedback consisted of a repeating beep, with the frequency of repetition made to increase with increasing tracking error.</p> <p>Results</p> <p>Participants with stroke halved their effort and doubled their tracking error when performing the visual distracter task with their left hemiparetic arm. With sound feedback, however, these participants increased their effort and decreased their tracking error close to their baseline levels, while also performing the distracter task successfully. These effects were significantly smaller for the participants who used their non-paretic arm and for the participants without stroke.</p> <p>Conclusions</p> <p>Visual distraction decreased participants effort during a standard robot-assisted movement training task. This effect was greater for the hemiparetic arm, suggesting that the increased demands associated with controlling an affected arm make the motor system more prone to slack when distracted. Providing an alternate sensory channel for feedback, i.e., auditory feedback of tracking error, enabled the participants to simultaneously perform the tracking task and distracter task effectively. Thus, incorporating real-time auditory feedback of performance errors might improve clinical outcomes of robotic therapy systems.</p

Swayed by sound: sonic guidance as a neurorehabilitation strategy in the cerebellar ataxias

Cerebellar disease leads to problems in controlling movement. The most common difficulties are dysmetria and instability when standing. Recent understanding of cerebellar function has expanded to include non -motor aspects such as emotional, cognitive and sensory processing. Deficits in the acquisition and processing of sensory information are one explanation for the movement problems observed in cerebellar ataxia. Sensory deficits result in an inability to make predictions about future events; a primary function of the cerebellum. A question therefore, is whether augmenting or replacing sensory information can improve motor performance in cerebellar disease. This question is tested in this thesis by augmenting sensory information through the provision of an auditory movement guide.A variable described in motor control theory (tau) was used to develop auditory guides that were continuous and dynamic. A reaching experiment using healthy individuals showed that the timing of peak velocity, audiomotor coordination accuracy, and velocity of approach, could be altered in line with the movement parameters embedded in the auditory guides. The thesis then investigated the use of these sonic guides in a clinical population with cerebellar disease. Performance on neurorehabilitation exercises for balance control was tested in twenty people with cerebellar atrophy, with and without auditory guides. Results suggested that continuous, predictive, dynamic auditory guidance is an effective way of improving iii movement smoothness in ataxia (as measured by jerk). In addition, generating and swaying with imaginary auditory guides was also found to increase movement smoothness in cerebellar disease.Following the tests of instantaneous effects, the thesis then investigated the longterm consequences on motor behaviour of following a two -month exercise with auditory guide programme. Seven people with cerebellar atrophy were assessed pre - and post -intervention using two measures, weight -shifting and walking. The results of the weight -shifting test indicated that the sonic -guide exercise programme does not initiate long -term changes in motor behaviour. Whilst there were minor, improvements in walking, because of the weight -shifting results, these could not be attributed to the sonic guides. This finding confirms the difficulties of motor rehabilitation in people with cerebellar disease.This thesis contributes original findings to the field of neurorehabilitation by first showing that on -going and predictive stimuli are an appropriate tool for improving motor behaviour. In addition, the thesis is the first of its kind to apply externally presented guides that convey continuous meaningful information within a clinical population. Finally, findings show that sensory augmentation using the auditory domain is an effective way of improving motor coordination in some forms of cerebellar disease

Musical expectancy within movement sonification to overcome low self-efficacy

While engaging in physical activity is important for a healthy lifestyle, low self-efficacy, i.e. one's belief in one's own ability, can prevent engagement. Sound has been used in a variety of ways for physical activity: movement sonification to inform about movement, music to encourage and direct movement, and auditory illusions to adapt people's bodily representation and movement behaviour. However, no approach provides the whole picture when considering low self-efficacy. For example, sonification does not encourage movement past a person's expectation of their ability, music gives no information of one's capabilities, and auditory illusions do not direct changes in movement behaviour in a directed way. This thesis proposes a combined method that leverages the agency felt over sonification, our embodiment of music and movement altering feedback to design \textit{``musical expectancy sonifications''} which incorporate musical expectancy within sonification to alter movement perception and behaviour. This thesis proposes a Movement Sonification Expectation Model (MoSEM), which explores expectation within a movement sonification impact on people's perception of their abilities and the way they move. This MoSEM is then interrogated and developed in four initial control studies that investigate these sonifications for different types of movement as well as how they interact with one's expectation of a given movement. These findings led to an exploration of how the MoSEM can be applied to design sonification to support low-self efficacy in two case study populations: chronic pain rehabilitation, including one control study and one mixed methods study, and general well-being, including one interview study and two control studies. These studies show the impact of musical expectation on people's movement perception and behaviour. The findings from this thesis demonstrate not only how sonifications can be designed to use musical expectancy, but also shows a number of considerations that are needed when designing movement sonifications