For over two decades, research has shown that providing instructions and feedback to promote an external focus (i.e., mentally focusing on movement effects or outcome) leads to enhanced motor performance and learning, compared to an internal focus (i.e., mentally focusing on the muscles and joints, or movement kinematics). Notably, while a majority of the research has been on healthy young adults, the external focus benefit has also been found to extend to individuals recovering from musculoskeletal dysfunction. Despite the potential benefit of an external focus for rehabilitation, observational studies have revealed that physiotherapists provide their clients with more internal, than external, focus statements and have little awareness of the focus of attention literature. Consequently, the end goal of this doctoral research was to translate the focus of attention research findings into Canadian physiotherapy practice through the design, delivery and assessment of an educational workshop for practicing physiotherapists. With this in mind, the first step became to determine whether such a workshop was warranted by assessing the self-reported focus of attention provision by Canadian physiotherapists. Thus, in Study 1 a study-specific questionnaire, titled the "Therapists' Perceptions of Motor Learning Principles Questionnaire" (TPMLPQ), was designed and completed by 121 Canadian physiotherapists. Results showed an overall low relative frequency of self-reported external focus promotion (M = 31.3%, SD = 14.9), across six hypothetical rehabilitation scenarios. Markedly, descriptions of a functional reaching (M = 55.5 %, SD = 37.0) and pelvic floor task (M = 65.6%, SD = 32.9) resulted in a greater self-reported promotion of external, than internal, focus of attention. These results suggested that Canadian physiotherapists could benefit from an educational workshop on focus of attention, and that there was a potential task dependency for their focus of attention promotion. Study 2 employed virtual one-on-one interviews with eight Southern Ontario-based physiotherapists, all whom completed the TPMLPQ just prior to the interview. The first few questions gathered participants' perceptions on factors that influence physiotherapists' focus of attention use, as well as barriers to promoting an external focus and potential solutions to them. Coding of the interview data generated four themes related to factors that influenced focus of attention use: (1) physiotherapist experiences and characteristics, (2) client experiences and characteristics, (3) task characteristics and (4) focus of attention statement provision strategies. Moreover, the barriers to external focus promotion were organized into three themes: (1) educational experiences, (2) reinforcement of internal focus encouragement once in practice and (3) research aspects. All interviewed physiotherapists proposed continuing education on focus of attention as a solution to these barriers. Questions in the second half of the interview garnered input on how to get physiotherapists to attend a focus of attention workshop, and what activities to include before, during or after the workshop to promote physiotherapists to use more externally focusing statements in their practice. This information was used to inform the workshop design and delivery. In addition to the physiotherapists' input, I also considered previous research that has emphasized the importance of evidence-based training programs to be based on theoretical frameworks. In this regard, Bandura's social cognitive theory was selected as a theoretical foundation. Further, knowing that the target population for the workshop consisted of adults with higher education, Knowles' adult learning theory was also selected as a complimentary theoretical foundation. Additionally, the Kirkpatrick model for training evaluation was selected to guide the assessment of the workshop, due to its strong overlap with constructs from both theoretical frameworks adopted. A final contribution to the workshop design process was holding a virtual group session with four focus of attention researchers in order to gain input on workshop content. The final workshop product consisted of two parts: seven self-directed asynchronous website modules and a synchronous virtual group session. Ultimately, in Study 3, the workshop was delivered to fifteen Canadian physiotherapists. In addition to completing the two workshop components (asynchronous and synchronous), participants completed assessment packages at three time points: (1) one-week pre-synchronous workshop, (2) immediately post-synchronous workshop, and (3) one-week post-synchronous workshop. Analysis of the data revealed a chain of evidence supporting the merits of the workshop. Explicitly, physiotherapists reported high satisfaction (Mdn = 4.60), perceived relevance (Mdn = 4.83), and engagement in the workshop (Mdn = 4.83). Comparing one-week pre- to immediately post-workshop, analyses revealed significant improvements to physiotherapists' (1) scores on the knowledge assessment (pre M = 51.30%, SD = 22.30; post M = 84.30%, SD = 11.50; p < .001, d = 2.06) with an accompanying decrease in the uncertainty in their responses (pre M = 23.19%, SD = 18.05; post M = 1.16%, SD = 1.99; p < .001, d = 1.28), (2) relative frequency of externally focusing to total focus of attention statements created on the skill assessment (pre M = 18.23%, SD = 13.17; post M = 67.95%, SD = 25.13; p < .001, d = 2.11), (3) self-reported attitudes towards learning and practice of external focus promotion (pre M = 88.25, SD = 11.00; post M = 92.83, SD = 6.59; p = .024, d = 0.56) and self-efficacy (pre M = 59.50, SD = 22.36; post M = 85.72, SD = 7.95, p < .001, r = 0.86). Using descriptive statistics, physiotherapists reported that participating in the workshop allowed them to increase their encouragement of external focus adoption (M = 79.00, SD = 15.14). Thirteen of the physiotherapists reported that they believed that their use of externally focusing statements led to improvements in their clients' rehabilitation outcomes (n = 13; M = 68.08, SD = 22.13), while the other two physiotherapists noticed no difference. Finally, those 13 physiotherapists also reported a high intention to continue to provide external focus statements in their practice (M = 87.31, SD = 15.09). In the context of social cognitive theory, these findings suggest that the workshop was successful in strengthening the physiotherapists' behavioral capabilities, self-efficacy, and outcome expectations, suggesting that the behavior change self-reported by the physiotherapists (i.e., more external focus promotion) could extend beyond the short-term assessment period used here. The whole of this doctoral research acts as a powerful step on the pathway to translate focus of attention research into Canadian physiotherapy, and also provides a useful framework for future studies aiming to translate motor learning research into the field - in Canada or globally.

No description available.

<p>Our ability to control unstable objects highlights the sophistication of voluntary motor behaviour. In this thesis, we used an inverted pendulum (i.e., stick) balancing paradigm to investigate the task, learning and context-dependent attributes of unstable object control. We hypothesized that learning would mediate the functional integration of posture and upper limb dynamics and expected changes in the task demand and context to be reflected in the control of posture and the upper limb. We found that training increased the average length of balancing trials and applied this result to further investigate the circumstantial properties of unstable object control.</p> <p>We investigated the temporal structure of posture and upper limb dynamics using statistical and nonlinear time series analysis. We demonstrated that subjects used an intermittent strategy to control the inverted pendulum (Chapters 3 and 5) and found that motor learning modulated the statistical and spatiotemporal attributes of posture (Chapter 5) and upper limb displacements (Chapters 2, 3 and 5). We confirmed the balance control strategy was intermittent by showing that posture and upper limb time series are composed of two independent timescale components: a fast component linked to small stochastic displacements and a slow component related to feedback control (Chapters 3, 4 and 5). The interplay between timescale components was affected by the balancing context (Chapter 3) and task demand (Chapter 4).</p> <p>Chapter 5 investigated the acquisition of individual and coupled posture-upper limb control mechanisms. We found that motor learning involved two independent adaptation processes. The first process modified the timescale composition of posture and upper limb displacements and was followed by incremental changes in the occurrence and duration of correlated posture-upper limb trajectories. In Chapter 6, we investigated learning-mediated changes in multijoint coordination and control. Motor learning led to the flexible, error-compensating recruitment of individual joints and we showed that the preferential constraint of destabilizing joint angle variance was the putative mechanism underlying performance.</p> <p>This thesis performed a detailed examination of unstable object control mechanisms. The undertaken studies have provided knowledge about the acquisition and adaptation of control mechanisms at multiple levels of the motor system. Our data provide convergent evidence that the control mechanisms governing complex human balancing tasks are intermittent and modulated by the task and context.</p> / Doctor of Philosophy (PhD)

Introduction: Being able to ignore distracting thoughts is often linked with better sports performance (Kane &amp; Engle, 2003). Depending on how the performer directs their attentional focus it can either enhance or impair performance (Wulf &amp; Su, 2016). However, the combined effects of distracting thoughts and attentional focus on motor performance need to be further explored. Objective: To examine the effects of distracting thoughts on golf shot performance during internal and external focus of attention. Methods: Twenty Swedish senior golf players, with ages varying between 21-52, were instructed to hit a golf ball as straight and as far as possible, both with (dual-task conditions) and without (single-task conditions) distracting thoughts, either with internal or external focus of attention. After each of these four conditions, participants evaluated their cognitive effort using a Rating Scale Mental Effort (RSME; Zijlstra, 1993). Results: In the single-task conditions, directing attentional focus externally was linked with an improved performance compared to an internal focus of attention which impaired performance. Findings also showed an impaired performance in the dual-task conditions, compared to single-task conditions. No substantial performance effects were found when comparing external with internal focus of attention under dual-task conditions. Results from the RSME showed that it requires more cognitive effort when performing a golf shot while influenced by distracting thoughts. Also, more cognitive effort was required during internal focus of attention compared to external focus of attention, which was true both with and without distracting thoughts. Conclusions: The current study’s findings indicate that there is a negative relationship between distracting thoughts and golf shot performance, also, focus of attention does not influence golf shot performance during dual-task. The findings also contribute to an increased knowledge concerning the association between dual-task, focus of attention and performance. This knowledge could be implemented into golf practice, both theoretical and practical, to enhance golf performance. / Introduktion: Att kunna ignorera distraherande tankar är ofta sammankopplat med bättre idrottsprestationer (Kane &amp; Engle, 2003). Beroende på hur utövaren riktar sin uppmärksamhetsfokus kan det antingen bidra till en förbättrad eller försämrad prestation (Wulf &amp; Su, 2016). Däremot finns det behov av att vidare utforska den kombinerade effekten som distraherande tankar och uppmärksamhetsfokus har på motorisk prestation. Syfte: Att undersöka effekterna av distraherande tankar på golfslagsprestation under intern och extern uppmärksamhetsfokus. Metod: Tjugo svenska senior golfspelare, i åldrarna 21–52, hade som uppgift att slå golfslag så långt och rakt som möjligt, både med (dual-task conditions) och utan (single-task conditions) distraherande tankar, med antingen intern eller extern uppmärksamhetsfokus. Deltagarna värderade även sin upplevda kognitiva ansträngning efter varje förhållande med hjälp av Rating Scale Mental Effort (RSME; Zijlstra, 1993). Resultat: Vid single-task förhållandet var externt riktat uppmärksamhetsfokus kopplat till en bättre prestation jämfört med internt riktat fokus som i stället försämrade prestationsförmågan. Resultatet visade också en försämrad prestation i förhållandet med dual-task, jämfört med single-task förhållandet. Inga betydande prestationseffekter hittades vid jämförelse mellan extern och intern uppmärksamhetsfokus under dual-task förhållandet. Slutsats: Den aktuella studiens resultat indikerar att det finns ett negativt samband mellan distraherande tankar och golfprestation, samt att uppmärksamhetsfokus inte påverkar golfprestation under dual-task. Resultaten bidrar till en ökad kunskap om relationen mellan dual-task, uppmärksamhetsfokus och prestation. Denna kunskap kan implementeras i golfträning, både teoretisk och praktisk, för att förbättra golfprestation.

This thesis, within the subfield of computer science known as computer vision, deals with the use of scale-space analysis in early low-level processing of visual information. The main contributions comprise the following five subjects: The formulation of a scale-space theory for discrete signals. Previously, the scale-space concept has been expressed for continuous signals only. We propose that the canonical way to construct a scale-space for discrete signals is by convolution with a kernel called the discrete analogue of the Gaussian kernel, or equivalently by solving a semi-discretized version of the diffusion equation. Both the one-dimensional and two-dimensional cases are covered. An extensive analysis of discrete smoothing kernels is carried out for one-dimensional signals and the discrete scale-space properties of the most common discretizations to the continuous theory are analysed. A representation, called the scale-space primal sketch, which gives a formal description of the hierarchical relations between structures at different levels of scale. It is aimed at making information in the scale-space representation explicit. We give a theory for its construction and an algorithm for computing it. A theory for extracting significant image structures and determining the scales of these structures from this representation in a solely bottom-up data-driven way. Examples demonstrating how such qualitative information extracted from the scale-space primal sketch can be used for guiding and simplifying other early visual processes. Applications are given to edge detection, histogram analysis and classification based on local features. Among other possible applications one can mention perceptual grouping, texture analysis, stereo matching, model matching and motion. A detailed theoretical analysis of the evolution properties of critical points and blobs in scale-space, comprising drift velocity estimates under scale-space smoothing, a classification of the possible types of generic events at bifurcation situations and estimates of how the number of local extrema in a signal can be expected to decrease as function of the scale parameter. For two-dimensional signals the generic bifurcation events are annihilations and creations of extremum-saddle point pairs. Interpreted in terms of blobs, these transitions correspond to annihilations, merges, splits and creations. Experiments on different types of real imagery demonstrate that the proposed theory gives perceptually intuitive results. / <p>QC 20120119</p>