Effects of delayed visual feedback on handwriting in Parkinson's disease

Interrelations between cognitive dysfunction and motor symptoms of Parkinson's disease: behavioral and neural studies

Parkinson's disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (tremor, bradykinesia/akinesia, and rigidity), PD patients also show other motor deficits, including gait disturbance, speech deficits, and impaired handwriting. However, along with these key motor symptoms, PD patients also experience cognitive deficits in attention, executive function, working memory, and learning. Recent evidence suggests that these motor and cognitive deficits of PD are not completely dissociable, as aspects of cognitive dysfunction can impact motor performance in PD. In this article, we provide a review of behavioral and neural studies on the associations between motor symptoms and cognitive deficits in PD, specifically akinesia/bradykinesia, tremor, gait, handwriting, precision grip, and speech production. This review paves the way for providing a framework for understanding how treatment of cognitive dysfunction, for example cognitive rehabilitation programs, may in turn influence the motor symptoms of PD.

Game-Based Augmented Visual Feedback for Enlarging Speech Movements in Parkinson's Disease

PURPOSE

The purpose of this pilot study was to demonstrate the effect of augmented visual feedback on acquisition and short-term retention of a relatively simple instruction to increase movement amplitude during speaking tasks in patients with dysarthria due to Parkinson's disease (PD).

METHOD

Nine patients diagnosed with PD, hypokinetic dysarthria, and impaired speech intelligibility participated in a training program aimed at increasing the size of their articulatory (tongue) movements during sentences. Two sessions were conducted: a baseline and training session, followed by a retention session 48 hr later. At baseline, sentences were produced at normal, loud, and clear speaking conditions. Game-based visual feedback regarding the size of the articulatory working space (AWS) was presented during training.

RESULTS

Eight of nine participants benefited from training, increasing their sentence AWS to a greater degree following feedback as compared with the baseline loud and clear conditions. The majority of participants were able to demonstrate the learned skill at the retention session.

CONCLUSIONS

This study demonstrated the feasibility of augmented visual feedback via articulatory kinematics for training movement enlargement in patients with hypokinesia due to PD.

SUPPLEMENTAL MATERIALS

https://doi.org/10.23641/asha.5116840.

Basic and supplementary sensory feedback in handwriting

The mastering of handwriting is so essential in our society that it is important to try to find new methods for facilitating its learning and rehabilitation. The ability to control the graphic movements clearly impacts on the quality of the writing. This control allows both the programming of letter formation before movement execution and the online adjustments during execution, thanks to diverse sensory feedback (FB). New technologies improve existing techniques or enable new methods to supply the writer with real-time computer-assisted FB. The possibilities are numerous and various. Therefore, two main questions arise: (1) What aspect of the movement is concerned and (2) How can we best inform the writer to help them correct their handwriting? In a first step, we report studies on FB naturally used by the writer. The purpose is to determine which information is carried by each sensory modality, how it is used in handwriting control and how this control changes with practice and learning. In a second step, we report studies on supplementary FB provided to the writer to help them to better control and learn how to write. We suggest that, depending on their contents, certain sensory modalities will be more appropriate than others to assist handwriting motor control. We emphasize particularly the relevance of auditory modality as online supplementary FB on handwriting movements. Using real-time supplementary FB to assist in the handwriting process is probably destined for a brilliant future with the growing availability and rapid development of tablets.

Emotional and nonemotional facial expressions in people with Parkinson's disease

We investigated facial expressivity in 19 people with Parkinson's disease (PD; 14 men and 5 women) and 26 healthy controls (13 men and 13 women). Participants engaged in experimental situations that were designed to evoke emotional facial expressions, including watching video clips and holding conversations, and were asked to pose emotions and imitate nonemotional facial movements. Expressivity was measured with subjective rating scales, objective facial measurements (Facial Action Coding System), and self-report questionnaires. As expected, PD participants showed reduced spontaneous facial expressivity across experimental situations. PD participants also had more difficulty than controls posing emotional expressions and imitating nonemotional facial movements. Despite these difficulties, however, PD participants' overall level of expressivity was still tied to emotional experience and social context.

Distorted visual feedback effects on drawing in Parkinson's disease

We investigated the effects of distorted visual feedback on the drawing performance of a group with Parkinson's disease (PD) and a control group. Twenty older healthy adults and 20 PD patients copied figures onto a digitizer tablet with a pen under normal and distorted visual feedback conditions. PD patients were less able than controls to adjust the size of their drawing to compensate for distortions in visual feedback. The effect was particularly pronounced when patients were required to draw smaller than normal. Nevertheless, with practice. PD patients showed a similar degree of improvement in size as controls, although they did not match the control group's level of performance. Overall, these findings support the notion that PD may have specific difficulty adjusting to a change in gain (or discrepancy) between visual and kinesthetic feedback when they must alter the size of their drawing. These findings point to the putative role of the basal ganglia in adjusting for the intermodal discrepancy between sensory feedback, and re-scaling the size of movements.