Bradford Scholars is the University of Bradford online research archive. Access is free to anyone interested in research being conducted at Bradford. In the repository you will find a range of materials from journal articles and conference papers to research reports and theses.

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  • Age and task difficulty differences in dual tasking using circle tracing and serial subtraction tasks

    Vaportzis, Ria; Georgiou-Karistianis, N.; Stout, J.C. (2014-04)
    The aim of this study was to investigate age-related differences in dual task performance by using an upper limb proprioceptive task. Twenty-eight younger (18–30 years) and 28 older (>60 years) healthy adults performed circle tracing and serial subtraction tasks separately and concurrently. The tasks had two levels of difficulty: easy and hard. The circle tracing task included direct (easy) and indirect (hard) visual feedback conditions, and it was paired with serial subtraction by twos (easy) or threes (hard). We found that older adults were significantly slower than younger adults across all conditions and had significantly greater dual task costs when they performed circle tracing with easy serial subtraction. Higher levels of task difficulty were associated with slower speed in both groups. We found no age differences in accuracy. Participants either traded speed for accuracy or accuracy for speed regardless of age group. Overall, the findings suggest that speed and accuracy may be affected differently during dual tasking. In addition, older adults may rely more extensively on proprioceptive feedback to guide upper limb movement compared with younger adults.
  • Effects of task difficulty during dual-task circle tracing in Huntington's disease

    Vaportzis, Ria; Georgiou-Karistianis, N.; Churchyard, A.; Stout, J.C. (2015-02)
    Huntington’s disease (HD) is associated with impairments in dual-task performance. Despite that, only a few studies have investigated dual-tasking in HD. We examined dual-task performance in 15 participants in the early stages of HD and 15 healthy controls. Participants performed direct circle tracing (able to view arm) and indirect circle tracing (arm obscured) either on their own (single tasks) or paired with serial subtraction by twos or threes (dual tasks). Overall, our results suggested that HD participants were significantly slower and less accurate than controls. Both groups were slower and less accurate when performing indirect circle tracing compared with direct circle tracing. HD participants experienced greater dual-task interference in terms of accuracy when performing direct circle tracing compared with indirect circle tracing. Despite that, controls were more inclined to speed–accuracy trade-offs compared with HD participants. Importantly, unlike controls, HD participants were not disproportionately faster when performing direct circle tracing as a single task compared with the dual-task conditions. Our results suggest that simple tasks place greater attentional demands on HD participants compared with controls. These findings support that impaired automaticity may be responsible for some of the attentional deficits manifested in HD.
  • A tablet for healthy ageing: the effect of a tablet computer training intervention on cognitive abilities in older adults

    Vaportzis, Ria; Martin, M.; Gow, A.J. (2017-08)
    Objective: To test the efficacy of a tablet computer training intervention to improve cognitive abilities of older adults. Design: Prospective randomized controlled trial. Setting: Community-based aging intervention study, Edinburgh, UK. Participants: Forty-eight healthy older adults aged 65 to 76 years were recruited at baseline with no or minimal tablet experience;43 completed follow-up testing. Intervention: Twentytwo participants attended a weekly 2-hour class for 10 weeks during which they learned how to use a tablet and various applications on it. Measurements: A battery of cognitive tests from theWAIS-IV measuring the domains ofVerbal Comprehension, Perceptual Processing,Working Memory, and Processing Speed, as well as health, psychological, and well-being measures. Results: A 2× 2 mixed model ANOVA suggested that the tablet intervention group (N = 22) showed greater improvements in Processing Speed (η2 = 0.10) compared with controls (N = 21), but did not differ in Verbal Comprehension, Perceptual Processing, or Working Memory (η2 ranged from −0.03 to 0.04). Conclusions: Engagement in a new mentally challenging activity (tablet training) was associated with improved processing speed.Acquiring skills in later life, including those related to adopting new technologies, may therefore have the potential to reduce or delay cognitive changes associated with ageing.It is important to understand how the development of these skills might further facilitate everyday activities, and also improve older adults’ quality of life.
  • Dual task performance may be a better measure of cognitive processing in Huntington's disease than traditional attention tests

    Vaportzis, Ria; Georgiou-Karistianis, N.; Churchyard, A.; Stout, J.C. (2015)
    Background: Past research has found cancellation tasks to be reliable markers of cognitive decline in Huntington’s disease (HD). Objective: The aim of this study was to extend previous findings by adopting the use of a dual task paradigm that paired cancellation and auditory tasks. Methods: We compared performance in 14 early stage HD participants and 14 healthy controls. HD participants were further divided into groups with and without cognitive impairment. Results: Results suggested that HD participants were not slower or less accurate compared with controls; however, HD participants showed greater dual task interference in terms of speed. In addition, HD participants with cognitive impairment were slower and less accurate than HD participants with no cognitive impairment, and showed greater dual task interference in terms of speed and accuracy. Conclusions: Our findings suggest that dual task measures may be a better measure of cognitive processing in HD compared with more traditional measures.
  • Dual task performance in Huntington's disease: a comparison of choice reaction time tasks

    Vaportzis, Ria; Georgiou-Karistianis, N.; Churchyard, A.; Stout, J.C. (2015-09)
    Objective: This study investigated whether dual tasks make disproportionately high demands in Huntington’s disease (HD) compared with controls, and also tested the Multiple Resources Theory. Method: Thirteen HD participants and 13 controls completed 2 dual task sets that varied in difficulty and complexity: Set 1 paired simple choice reaction time (RT) with digit forward, and Set 2 paired complex choice RT with digit backward. Results: We found that HD participants were overall slower; however, although they maintained similar levels of accuracy in the simple choice RT tasks with controls, their accuracy decreased in the complex choice RT tasks. In addition, we found that HD participants were more susceptible to speed-accuracy trade-offs. Despite that, they did not show greater dual task costs than controls. Conclusions: Overall, our findings do not support the Multiple Resources Theory, but they do provide some support for the Unitary Resource Theory and the attentional impairment hypothesis.

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