Digital spiral analysis for objective assessment of fine motor timing variability in Parkinson's disease

OBJECTIVES: To develop a method for objective assessment of fine motor timing variability in Parkinson’s disease (PD) patients, using digital spiral data gathered by a touch screen device. BACKGROUND: A retrospective analysis was conducted on data from 105 subjects including65 patients with advanced PD (group A), 15 intermediate patients experiencing motor fluctuations (group I), 15 early stage patients (group S), and 10 healthy elderly subjects (HE) were examined. The subjects were asked to perform repeated upper limb motor tasks by tracing a pre-drawn Archimedes spiral as shown on the screen of the device. The spiral tracing test was performed using an ergonomic pen stylus, using dominant hand. The test was repeated three times per test occasion and the subjects were instructed to complete it within 10 seconds. Digital spiral data including stylus position (x-ycoordinates) and timestamps (milliseconds) were collected and used in subsequent analysis. The total number of observations with the test battery were as follows: Swedish group (n=10079), Italian I group (n=822), Italian S group (n = 811), and HE (n=299). METHODS: The raw spiral data were processed with three data processing methods. To quantify motor timing variability during spiral drawing tasks Approximate Entropy (APEN) method was applied on digitized spiral data. APEN is designed to capture the amount of irregularity or complexity in time series. APEN requires determination of two parameters, namely, the window size and similarity measure. In our work and after experimentation, window size was set to 4 and similarity measure to 0.2 (20% of the standard deviation of the time series). The final score obtained by APEN was normalized by total drawing completion time and used in subsequent analysis. The score generated by this method is hence on denoted APEN. In addition, two more methods were applied on digital spiral data and their scores were used in subsequent analysis. The first method was based on Digital Wavelet Transform and Principal Component Analysis and generated a score representing spiral drawing impairment. The score generated by this method is hence on denoted WAV. The second method was based on standard deviation of frequency filtered drawing velocity. The score generated by this method is hence on denoted SDDV. Linear mixed-effects (LME) models were used to evaluate mean differences of the spiral scores of the three methods across the four subject groups. Test-retest reliability of the three scores was assessed after taking mean of the three possible correlations (Spearman’s rank coefficients) between the three test trials. Internal consistency of the methods was assessed by calculating correlations between their scores. RESULTS: When comparing mean spiral scores between the four subject groups, the APEN scores were different between HE subjects and three patient groups (P=0.626 for S group with 9.9% mean value difference, P=0.089 for I group with 30.2%, and P=0.0019 for A group with 44.1%). However, there were no significant differences in mean scores of the other two methods, except for the WAV between the HE and A groups (P<0.001). WAV and SDDV were highly and significantly correlated to each other with a coefficient of 0.69. However, APEN was not correlated to neither WAV nor SDDV with coefficients of 0.11 and 0.12, respectively. Test-retest reliability coefficients of the three scores were as follows: APEN (0.9), WAV(0.83) and SD-DV (0.55). CONCLUSIONS: The results show that the digital spiral analysis-based objective APEN measure is able to significantly differentiate the healthy subjects from patients at advanced level. In contrast to the other two methods (WAV and SDDV) that are designed to quantify dyskinesias (over-medications), this method can be useful for characterizing Off symptoms in PD. The APEN was not correlated to none of the other two methods indicating that it measures a different construct of upper limb motor function in PD patients than WAV and SDDV. The APEN also had a better test-retest reliability indicating that it is more stable and consistent over time than WAV and SDDV.

Audiovisual Storytelling and Ideological Horizons : Audiences, Cultural Contexts and Extra-textual Meaning Making

Abstract: Audiovisual Storytelling and Ideological Horizons: Audiences, Cultural Contexts and Extra-textual Meaning Making In a society characterized by mediatization people are to an increasing degree dependent on mediated narratives as a primary means by which we make sense of our experience through time and our place in society (Hoover 2006, Lynch 2007, Hjarvard 2008, Hjarvard & Lövheim 2012). American media scholar Stewart Hoover points to symbols and scripts available in the media environment, what he call the “symbolic inventory” out of which individuals make religious or spiritual meaning (Hoover 2006: 55). Vernacular meaning-making embedded in everyday life among viewers’ dealing with fiction narratives in films and tv-series highlight a need for a more nuanced understanding of complex audiovisual storytelling. Moving images provide individuals with stories by which reality is maintained and by which humans construct ordered micro-universes for themselves using film as a resource for moral assessment and ideological judgments about life (Plantinga 2009, Johnston 2010, Axelson 2015). Important in this theoretical context are perspectives on viewers’ moral frameworks (Zillman 2005, Andersson & Andersson 2005, Frampton 2006, Avila 2007).This paper presentation will focus on ideological contested meaning making where audiences of different cultural background engage emotionally with filmic narratives, possibly eliciting ideological and spiritual meaning-making related to viewers’ personal world views. Through the example of the Homeland tv-series I want to discuss how spectators’ cultural, religious, political and ideological identities could be understood playing a role in the interpretative process of decoding content. Is it possible to trace patterns of different receptions of the multilayered and ambiguous story depicted in Homeland by religiously engaged Christians and Moslems as well as non-believers, in America, Europe and Middle East? How is the fiction narrative dealt with by spectators in the audience in different cultural contexts and how is it interpreted through the process of extra-text evaluation and real world2understanding in a global era preoccupied with war on terror? The presentation will also discuss methodological considerations about how to reach out to audiences anchored in different cultural context.