Sonification of arm movements in stroke rehabilitation: a novel approach in neurologic music therapy

I can't wrap my head around this so would need to see a demonstration. But really impressive for a dissertation. You can even read it in German if you want to.

Sonification of arm movements in stroke rehabilitation: a novel approach in neurologic music therapy

Stroke is one of the leading causes of disabilities worldwide, and the number of affected
patients per year and country is increasing due to the societies growing older. Rehabilitation
of stroke patients remains a challenge, although currently several new training programs are
being investigated, all aiming at an improved efficiency and sustainability of rehabilitation
effects. Some traditional rehabilitation programs lack general acceptance by patients, due to
high demands on the patients' cooperation, which sometimes may be perceived by patients as
frustrating. Yet, even the well established standard physiotherapeutical approaches do not
unambiguously provide evidence of efficacy when it comes to improvement of skilled motor
behavior. Therefore there is an urgent need for innovative, patient motivating, goal directed
and efficient training programs in stroke rehabilitation.
Sonification stands for the usage of non-speech audio conveying otherwise not audible
information. The first sonification device was the Geiger-Müller counter 
which detects electromagnetic radiation and communicates a decay by a click sound.
 In this thesis, stroke patients arm movements in a predefined three dimensional space were sonified. Sonification was then applied to develop and to incorporate musical retraining for the arm affected by the stroke.
The first  experimental study was  conducted  in order to  examine and validate the
effectiveness of a certain type of sonification for a later application in stroke rehabilitation.
To   date,   no  established   sonification-supported   rehabilitation   protocol   strategy   exists.
Therefore a computer program was developed, the “SonicPointer”, to sonify participants'
computer mouse movements in real-time with complex tones. Tone characteristics were
derived from a parameter mapping, invisible and unbeknown to the participants, which was
overlaid on the computer screen. In each trial, a target tone was presented and subjects were
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instructed to indicate its “origin” with respect to the overlaid parameter mappings on the
screen as quickly and accurately as possible with a mouse click. Due to the participants'
ignorance of the parameter map on the screen, only implicit learning over a series of trials
led to an increase in accuracy in this task. One of the aims of the study was to find out how
sonification parameters should be mapped in space optimally. Twenty-six elderly healthy
participants were tested with this device. Generally, subjects' localizing performance was
better on the tone pitch axis as compared to the tone brightness axis. Furthermore, the
learning curves were steepest and participants were fastest when pitch was mapped onto the
vertical and brightness onto the horizontal axis, suggesting that this is the optimal
constellation for this two-dimensional sonification.
In the second experimental study presented herein we applied the previously acquired
optimal sonification mapping in a newly developed musical sonification therapy designed to
retrain gross-motor functions. Four stroke patients were included in this clinical pre-post
feasibility study and were trained with the musical sonification therapy. Patients' upper
extremity functions and their psychological states were assessed pre and post training with
numerous   standardized   motor   function   tests,   assessments   and   neuropsychological
questionnaires. The four patients were subdivided into two groups. Both groups received
nine days of musical sonification therapy (MG) or a sham sonification movement training
(CG). The only difference between the training protocols was that in the CG no sound was
played back at the patients. During the training, patients started by exploring the acoustic
effects when moving their affected arm in a predefined three-dimensional space. The training
proceeded with increasingly complex tone sequences leading to the patients playing simple
melodies only by moving their impaired arms in the 3D space. The two MG patients
improved in nearly all motor-function tests after the training. Also they reported to be less
impaired by the stroke. The two CG patients did not benefit noticeably from the movement
training.
Since the second feasibility study yielded promising results, - although with limited
statistical power,- a third clinical musical sonification therapy study was run. The setup was
basically the same as in experiment two but this time 25 stroke patients were trained and
tested. An advanced 3D analysis of the arm movement smoothness was developed and
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included into the pre post-test battery. The 15 MG patients showed significantly reduced
joint pain in the Fugl Meyer Assessment as compared to the control-group after the musical
sonification training. They also reported a trend to have an improved hand function on the
Stroke Impact Scale.
Summarizing the results of the experiments presented in this thesis it can be concluded that
the mapping of sounds in space is crucial for the outcome and a musical sonification can be
applied   as   a   promising   stroke   rehabilitation   tool.   Of   course   the   number   of   patients
investigated   is   limited   and   further   evaluation   and   research   is   necessary.  Furthermore,
different motor tests should be included in future research in order to prevent floor and
ceiling effects.