Dual-Task Training Effects on the Cognitive-Motor Interference in Individuals with Intellectual Disability

REFERENCES

• Abasıyanık, Z., & Kahraman, T. (2022). Effect of dual-task training on cognitive functions in persons with multiple sclerosis: A systematic review and meta-analysis. Multiple Sclerosis and Related Disorders, 62, 103801. https://doi.org/10.1016/j.msard.2022.103801
   PubMed Web of Science ®Google Scholar
• Abuín-Porras, V., Jiménez Antona, C., Blanco-Morales, M., Palacios, A., Romero-Morales, C., López-López, D., Villafañe, J. H., & Rodríguez-Costa, I. (2020). Could a multitask balance training program complement the balance training in healthy preschool children: A quasi-experimental study. Applied Sciences, 10(12), 4100. https://doi.org/10.3390/app10124100
   Google Scholar
• American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (4th ed.; DSM-IV). American Psychiatric Association.
   Google Scholar
• An, H. J., Kim, J. I., Kim, Y. R., Lee, K. B., Kim, D. J., Yoo, K. T., & Choi, J. H. (2014). The effect of various dual task training methods with gait on the balance and gait of patients with chronic stroke. Journal of Physical Therapy Science, 26(8), 1287–1291. https://doi.org/10.1589/jpts.26.1287
   PubMedGoogle Scholar
• Asghar, M., Aabroo, S., Salik, S., Manzoor, S., Rani, S., Maqbool, S., & Address, M. (2022). Comparative effects of motor and cognitive dual-task gait training on balance and mobility in persons with intellectual disabilities. Pakistan Journal of Medical and Health Sciences, 16(8), 125–127. https://doi.org/10.53350/pjmhs22168125
   Google Scholar
• Atak, E., & Algun, Z. C. (2022). Dual-task balance training for motor skill development among children with intelligence quotient discrepancy. Rehabilitation Research and Practice, 2022, 1–7. https://doi.org/10.1155/2022/2822171
   Web of Science ®Google Scholar
• Atak, E., Hajebrahimi, F., & Algun, Z. C. (2022). The effect of dual-task balance exercises on cognitive functions among children with mild and borderline mental retardation: A randomized controlled trial. European Journal of Physiotherapy, 24, 1–9. https://doi.org/10.1080/21679169.2022.2113138
   Web of Science ®Google Scholar
• Aydoğdu, Y. T., Aydoğdu, O., & İnal, H. S. (2018). The effects of dual-task training on patient outcomes of institutionalized elderly having chronic stroke. Dementia and Geriatric Cognitive Disorders Extra, 8(3), 328–332. https://doi.org/10.1159/000492964
   PubMed Web of Science ®Google Scholar
• Azimizadeh, M. J., Hoseini, S. H., & Norasteh, A. A. (2021). Effect of a combined strengthening and proprioceptive training program on balance and gait of female children with intellectual disability. Journal of Sport Biomechanics, 7(2), 136–147. https://doi.org/10.32598/biomechanics.7.2.5
   Google Scholar
• Beck, T. W. (2013). The importance of a priori sample size estimation in strength and conditioning research. Journal of Strength and Conditioning Research, 27(8), 2323–2337. https://doi.org/10.1519/JSC.0b013e318278eea0
   PubMed Web of Science ®Google Scholar
• Blomqvist, S., Olsson, J., Wallin, L., Wester, A., & Rehn, B. (2013). Adolescents with intellectual disability have reduced postural balance and muscle performance in trunk and lower limbs compared to peers without intellectual disability. Research in Developmental Disabilities, 34(1), 198–206. https://doi.org/10.1016/j.ridd.2012.07.008
   PubMed Web of Science ®Google Scholar
• Carmeli, E., Bar-Yossef, T., Ariav, C., Paz, R., Sabbag, H., & Levy, R. (2008). Sensorimotor impairments and strategies in adults with intellectual disabilities. Motor Control, 12(4), 348–361. https://doi.org/10.1123/mcj.12.4.348
   PubMed Web of Science ®Google Scholar
• Choi, J. H., Kim, B. R., Han, E. Y., & Kim, S. M. (2015). The effect of dual-task training on balance and cognition in patients with subacute post-stroke. Annals of Rehabilitation Medicine, 39(1), 81–90. https://doi.org/10.5535/arm.2015.39.1.81
   PubMedGoogle Scholar
• Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Erlbaum.
   Google Scholar
• Danielsson, H., Henry, L., Messer, D., & Rönnberg, J. (2012). Strengths and weaknesses in executive functioning in children with intellectual disability. Research in Developmental Disabilities, 33(2), 600–607. https://doi.org/10.1016/j.ridd.2011.11.004
   PubMed Web of Science ®Google Scholar
• Della Sala, S., Baddeley, A., Papagno, C., & Spinnler, H. (1995). Dual-task paradigm: A means to examine the central executive. In K. J. Grafman & F. Boller (Eds.), Structure and functions of the human prefrontal cortex (pp. 161–190). Annals of the New York Academy of Sciences. https://doi.org/10.1111/j.1749-6632.1995.tb38137.x
   Google Scholar
• Diz, S., Gomes, F., & Santos, S. (2021). Does physical activity improve adaptive behaviour, fitness, and quality of life of adults with intellectual disability? Revista Brasileira de Ciências Do Esporte, 43, e001621. https://doi.org/10.1590/rbce.43.e001621
   Google Scholar
• Egan, M. F., Kojima, M., Callicott, J. H., Goldberg, T. E., Kolachana, B. S., Bertolino, A., Zaitsev, E., Gold, B., Goldman, D., Dean, M., Lu, B., & Weinberger, D. R. (2003). The BDNF val66met polymorphism affects activity-dependent secretion of BDNF and human memory and hippocampal function. Cell, 112(2), 257–269. https://doi.org/10.1016/s0092-8674(03)00035-7
   PubMed Web of Science ®Google Scholar
• Elhinidi, E. I. M., Ismaeel, M. M. I., & El-Saeed, T. M. (2016). Effect of dual-task training on postural stability in children with infantile hemiparesis. Journal of Physical Therapy Science, 28(3), 875–880. https://doi.org/10.1589/jpts.28.875
   PubMedGoogle Scholar
• Enkelaar, L., Smulders, E., van Schrojenstein Lantman-de Valk, H., Geurts, A. C., & Weerdesteyn, V. (2012). A review of balance and gait capacities in relation to falls in persons with intellectual disability. Research in Developmental Disabilities, 33(1), 291–306. https://doi.org/10.1016/j.ridd.2011.08.028
   PubMed Web of Science ®Google Scholar
• Erickson, K. I., Colcombe, S. J., Wadhwa, R., Bherer, L., Peterson, M. S., Scalf, P. E., Kim, J. S., Alvarado, M., & Kramer, A. F. (2007). Training-induced functional activation changes in dual-task processing: An FMRI study. Cerebral Cortex (New York, N.Y.: 1991), 17(1), 192–204. https://doi.org/10.1093/cercor/bhj137
   PubMed Web of Science ®Google Scholar
• Esnafoglu, E., & Adıgüzel, Ö. (2021). Association of BDNF levels with IQ: Comparison of S100B and BDNF levels in typically developing children and subjects with neurologically normal nonsyndromic intellectual disability. Journal of Intellectual Disability Research: JIDR, 65(12), 1073–1084. https://doi.org/10.1111/jir.12896
   PubMed Web of Science ®Google Scholar
• Faul, F., Erdfelder, E., Lang, A. G., & Buchner, A. (2007). G* Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behavior Research Methods, 39(2), 175–191. https://doi.org/10.3758/bf03193146
   PubMed Web of Science ®Google Scholar
• Fernandes, Â., Rocha, N., Santos, R., & Tavares, J. M. R. (2015). Effects of dual-task training on balance and executive functions in Parkinson’s disease: A pilot study. Somatosensory & Motor Research, 32(2), 122–127. https://doi.org/10.3109/08990220.2014.1002605
   PubMed Web of Science ®Google Scholar
• Ghai, S., Ghai, I., & Effenberg, A. O. (2017). Effects of dual tasks and dual-task training on postural stability: A systematic review and meta-analysis. Clinical Interventions in Aging, 12, 557–577. https://doi.org/10.2147/CIA.S125201
   PubMed Web of Science ®Google Scholar
• Gheysen, F., Poppe, L., DeSmet, A., Swinnen, S., Cardon, G., De Bourdeaudhuij, I., Chastin, S., & Fias, W. (2018). Physical activity to improve cognition in older adults: Can physical activity programs enriched with cognitive challenges enhance the effects? A systematic review and meta-analysis. International Journal of Behavioral Nutrition and Physical Activity, 15(1), 1–13. https://doi.org/10.1186/s12966-018-0697-x
   PubMed Web of Science ®Google Scholar
• Gligorović, M., & Buha, N. (2014). Verbal fluency in children with intellectual disability: Influence of basic executive components. Specijalna edukacija i rehabilitacija, 13(3), 275–292. https://doi.org/10.5937/specedreh13-6829
   Google Scholar
• Glumbikj, N., & Bozhinovikj, A. (2005). Semantic verbal fluency of the bilingual children with mild intellectual disability. Journal of Special Education and Rehabilitation, 6(1-2), 99–108.
   Google Scholar
• Halligan, P. W., & Wade, D. T. (2005). Effectiveness of rehabilitation for cognitive deficits. Oxford University Press.
   Google Scholar
• Hartman, E., Houwen, S., Scherder, E., & Visscher, C. (2010). On the relationship between motor performance and executive functioning in children with intellectual disabilities. Journal of Intellectual Disability Research: JIDR, 54(5), 468–477. https://doi.org/10.1111/j.1365-2788.2010.01284.x
   PubMed Web of Science ®Google Scholar
• Hiyamizu, M., Morioka, S., Shomoto, K., & Shimada, T. (2012). Effects of dual task balance training on dual task performance in elderly people: A randomized controlled trial. Clinical Rehabilitation, 26(1), 58–67. https://doi.org/10.1177/0269215510394222
   PubMed Web of Science ®Google Scholar
• Horvat, M., Croce, R., & Zagrodnik, J. (2010). Utilization of sensory information in intellectual disabilities. Journal of Developmental and Physical Disabilities, 22(5), 463–473. https://doi.org/10.1007/s10882-009-9182-4
   Web of Science ®Google Scholar
• Jankowicz-Szymanska, A., Mikolajczyk, E., & Wojtanowski, W. (2012). The effect of physical training on static balance in young people with intellectual disability. Research in Developmental Disabilities, 33(2), 675–681. https://doi.org/10.1016/j.ridd.2011.11.015
   PubMed Web of Science ®Google Scholar
• Kachouri, H., Borji, R., Baccouch, R., Laatar, R., Rebai, H., & Sahli, S. (2016). The effect of a combined strength and proprioceptive training on muscle strength and postural balance in boys with intellectual disability: An exploratory study. Research in Developmental Disabilities, 53-54, 367–376. https://doi.org/10.1016/j.ridd.2016.03.003
   PubMed Web of Science ®Google Scholar
• Kachouri, H., Jouira, G., Laatar, R., Borji, R., Rebai, H., & Sahli, S. (2022). Different types of combined training programs to improve postural balance in single and dual tasks in children with intellectual disability. Journal of Intellectual Disabilities, 26, 174462952211485. https://doi.org/10.1177/17446295221148585
   Web of Science ®Google Scholar
• Kachouri, H., Laatar, R., Borji, R., Rebai, H., & Sahli, S. (2020). Using a dual‐task paradigm to investigate motor and cognitive performance in children with intellectual disability. Journal of Applied Research in Intellectual Disabilities: JARID, 33(2), 172–179. https://doi.org/10.1111/jar.12655
   PubMed Web of Science ®Google Scholar
• Karbach, J., & Kray, J. (2021). Executive function training. In T. Strobach & J. Karbach (Eds.), Cognitive training: An overview of features and applications (pp. 199–212). Springer.
   Google Scholar
• Kelly, V. E., Janke, A. A., & Shumway-Cook, A. (2010). Effects of instructed focus and task difficulty on concurrent walking and cognitive task performance in healthy young adults. Experimental Brain Research, 207(1-2), 65–73. https://doi.org/10.1007/s00221-010-2429-6
   PubMed Web of Science ®Google Scholar
• Lee, I. H., Seo, E. J., & Lim, I. S. (2014). Effects of aquatic exercise and CES treatment on the changes of cognitive function, BDNF, IGF-1, and VEGF of persons with intellectual disabilities. Journal of Exercise Nutrition & Biochemistry, 18(1), 19–24. https://doi.org/10.5717/jenb.2014.18.1.19
   PubMedGoogle Scholar
• Lennie, P. (2003). The cost of cortical computation. Current Biology: CB, 13(6), 493–497. https://doi.org/10.1016/s0960-9822(03)00135-0
   PubMed Web of Science ®Google Scholar
• Leyssens, L., Van Hecke, R., Moons, K., Luypaert, S., Danneels, M., Patru, J., Willems, M., & Maes, L. (2022). Postural balance problems in people with intellectual disabilities: Do not forget the sensory input systems. Journal of Applied Research in Intellectual Disabilities: JARID, 35(1), 280–294. https://doi.org/10.1111/jar.12948
   PubMed Web of Science ®Google Scholar
• Li, Z., Wang, T., Liu, H., Jiang, Y., Wang, Z., & Zhuang, J. (2020). Dual-task training on gait, motor symptoms, and balance in patients with Parkinson’s disease: A systematic review and meta-analysis. Clinical Rehabilitation, 34(11), 1355–1367. https://doi.org/10.1177/0269215520941142
   PubMed Web of Science ®Google Scholar
• Ma, Y., Wang, L., Li, M., & Wang, T. (2020). Meta-analysis of the effects of exercise programs in improving the balance ability of children with intellectual disabilities. Journal of Intellectual & Developmental Disability, 45(2), 144–154. https://doi.org/10.3109/13668250.2019.1632040
   Web of Science ®Google Scholar
• Maiano, C., Hue, O., Morin, A. J., Lepage, G., Tracey, D., & Moullec, G. (2019). Exercise interventions to improve balance for young people with intellectual disabilities: A systematic review and meta‐analysis. Developmental Medicine and Child Neurology, 61(4), 406–418. https://doi.org/10.1111/dmcn.14023
   PubMed Web of Science ®Google Scholar
• Martino Cinnera, A., Bisirri, A., Leone, E., Morone, G., & Gaeta, A. (2021). Effect of dual-task training on balance in patients with multiple sclerosis: A systematic review and meta-analysis. Clinical Rehabilitation, 35(10), 1399–1412. https://doi.org/10.1177/02692155211010372
   PubMed Web of Science ®Google Scholar
• Massion, J. (1994). Postural control system. Current Opinion in Neurobiology, 4(6), 877–887. https://doi.org/10.1016/0959-4388(94)90137-6
   PubMedGoogle Scholar
• Mikołajczyk, E., & Jankowicz-Szymańska, A. (2014). The effect of unstable-surface functional exercises on static balance in adolescents with intellectual disability–A preliminary report. Medical Studies, 1(1), 1–5. https://doi.org/10.5114/ms.2014.41984
   Google Scholar
• Mikolajczyk, E., & Jankowicz-Szymanska, A. (2015). The effect of dual-task functional exercises on postural balance in adolescents with intellectual disability–A preliminary report. Disability and Rehabilitation, 37(16), 1484–1489. https://doi.org/10.3109/09638288.2014.967414
   PubMed Web of Science ®Google Scholar
• Mikołajczyk, E., & Jankowicz-Szymańska, A. (2020). The effect of Kinesio Taping on balance and foot arching in children with intellectual disability. Journal of Intellectual & Developmental Disability, 45(1), 46–53. https://doi.org/10.3109/13668250.2018.1478805
   Web of Science ®Google Scholar
• Miyamoto, T., Hashimoto, S., Yanamoto, H., Ikawa, M., Nakano, Y., Sekiyama, T., Kou, K., Kashiwamura, S.-I., Takeda, C., & Fujioka, H. (2018). Response of brain-derived neurotrophic factor to combining cognitive and physical exercise. European Journal of Sport Science, 18(8), 1119–1127. https://doi.org/10.1080/17461391.2018.1470676
   PubMed Web of Science ®Google Scholar
• Neumann, O. (1987). Beyond capacity: A functional view of attention. In H. Heuer & A. F. Sanders (Eds.), Perspectives on perception and action (Vol. 14, pp. 361–394). Erlbaum.
   Google Scholar
• Norouzi, E., Vaezmosavi, M., Gerber, M., Pühse, U., & Brand, S. (2019). Dual-task training on cognition and resistance training improved both balance and working memory in older people. The Physician and Sportsmedicine, 47(4), 471–478. https://doi.org/10.1080/00913847.2019.1623996
   PubMed Web of Science ®Google Scholar
• Ottersen, J., & Grill, K. M. (2015). Benefits of extending and adjusting the level of difficulty on computerized cognitive training for children with intellectual disabilities. Frontiers in Psychology, 6, 1233. https://doi.org/10.3389/fpsyg.2015.01233
   PubMed Web of Science ®Google Scholar
• Özkan, Z., & Kale, R. (2021). Investigation of the effects of physical education activities on motor skills and quality of life in children with intellectual disability. International Journal of Developmental Disabilities, 2. https://doi.org/10.1080/20473869.2021.1978267
   Web of Science ®Google Scholar
• Paillard, T., & Noé, F. (2015). Techniques and methods for testing the postural function in healthy and pathological subjects. BioMed Research International, 2015, 1–15. https://doi.org/10.1155/2015/891390
   Web of Science ®Google Scholar
• Pastula, R. M., Stopka, C. B., Delisle, A. T., & Hass, C. J. (2012). Effect of moderate-intensity exercise training on the cognitive function of young adults with intellectual disabilities. Journal of Strength and Conditioning Research, 26(12), 3441–3448. https://doi.org/10.1519/JSC.0b013e318270fc83
   PubMed Web of Science ®Google Scholar
• Pellecchia, G. L. (2005). Dual-task training reduces impact of cognitive task on postural sway. Journal of Motor Behavior, 37(3), 239–246. https://doi.org/10.3200/JMBR.37.3.239-246
   PubMed Web of Science ®Google Scholar
• Pineda, R. C., Krampe, R. T., Vanlandewijck, Y., & Van Biesen, D. (2022). Cognitive–motor multitasking in athletes with and without intellectual impairment. Scandinavian Journal of Medicine & Science in Sports, 32(2), 424–434. https://doi.org/10.1111/sms.14088
   PubMed Web of Science ®Google Scholar
• RI, M. L., & CL, A. P. (2020). Effects of a physical exercise programme on the risk of falls, balance, and walking speed in older people with intellectual disabilities. Rehabilitacion, 54(1), 19–24.
   PubMedGoogle Scholar
• Richardson, J. T. (2011). Eta squared and partial eta squared as measures of effect size in educational research. Educational Research Review, 6(2), 135–147. https://doi.org/10.1016/j.edurev.2010.12.001
   Web of Science ®Google Scholar
• Ruthruff, E., Johnston, J. C., & Van Selst, M. (2001). Why practice reduces dual-task interference. Journal of Experimental Psychology: Human Perception and Performance, 27(1), 3–21. https://doi.org/10.1037/0096-1523.27.1.3
   PubMed Web of Science ®Google Scholar
• Ruthruff, E., Van Selst, M., Johnston, J. C., & Remington, R. (2006). How does practice reduce dual-task interference: Integration, automatization, or just stage-shortening? Psychological Research, 70(2), 125–142. https://doi.org/10.1007/s00426-004-0192-7
   PubMed Web of Science ®Google Scholar
• Silsupadol, P., Shumway-Cook, A., Lugade, V., van Donkelaar, P., Chou, L. S., Mayr, U., & Woollacott, M. H. (2009). Effects of single-task versus dual-task training on balance performance in older adults: A double-blind, randomized controlled trial. Archives of Physical Medicine and Rehabilitation, 90(3), 381–387. https://doi.org/10.1016/j.apmr.2008.09.559
   PubMed Web of Science ®Google Scholar
• Sobera, M., Siedlecka, B., & Syczewska, M. (2011). Posture control development in children aged 2–7 years old, based on the changes of repeatability of the stability indices. Neuroscience Letters, 491(1), 13–17. https://doi.org/10.1016/j.neulet.2010.12.061
   PubMed Web of Science ®Google Scholar
• Söderqvist, S., Nutley, S. B., Ottersen, J., Grill, K. M., & Klingberg, T. (2012). Computerized training of non-verbal reasoning and working memory in children with mental retardation. Frontiers in Human Neuroscience, 6, 271. doi: https://doi.org/10.3389/fnhum.2012.00271
   PubMed Web of Science ®Google Scholar
• Spaniol, M., & Danielsson, H. (2022). A meta‐analysis of the executive function components inhibition, shifting, and attention in intellectual disabilities. Journal of Intellectual Disability Research: JIDR, 66(1-2), 9–31. https://doi.org/10.1111/jir.12878
   PubMed Web of Science ®Google Scholar
• Strobach, T., & Torsten, S. (2017). Mechanisms of practice-related reductions of dual-task interference with simple tasks: Data and theory. Advances in Cognitive Psychology, 13(1), 28–41. https://doi.org/10.5709/acp-0204-7
   PubMed Web of Science ®Google Scholar
• Tait, J. L., Duckham, R. L., Milte, C. M., Main, L. C., & Daly, R. M. (2017). Influence of sequential vs. simultaneous dual-task exercise training on cognitive function in older adults. Frontiers in Aging Neuroscience, 9, 368. https://doi.org/10.3389/fnagi.2017.00368
   PubMed Web of Science ®Google Scholar
• Van Biesen, D., Jacobs, L., McCulloch, K., Janssens, L., & Vanlandewijck, Y. C. (2018). Cognitive-motor dual-task ability of athletes with and without intellectual impairment. Journal of Sports Sciences, 36(5), 513–521. https://doi.org/10.1080/02640414.2017.1322215
   PubMed Web of Science ®Google Scholar
• Vuillerme, N., Isableu, B., & Nougier, V. (2006). Attentional demands associated with the use of a light fingertip touch for postural control during quiet standing. Experimental Brain Research, 169(2), 232–236. https://doi.org/10.1007/s00221-005-0142-7
   PubMed Web of Science ®Google Scholar
• Wechsler, D. (2003). Wechsler intelligence scale for children–fourth edition: Technical and interpretive manual. Psychological Corporation.
   Google Scholar
• Weterings, S., Oppewal, A., van Eeden, F. M., & Hilgenkamp, T. I. (2019). A resistance exercise set for a total body workout for adults with intellectual disabilities, a pilot study. Journal of Applied Research in Intellectual Disabilities: JARID, 32(3), 730–736. https://doi.org/10.1111/jar.12552
   PubMed Web of Science ®Google Scholar
• Wollesen, B., Janssen, T. I., Müller, H., & Voelcker-Rehage, C. (2022). Effects of cognitive-motor dual task training on cognitive and physical performance in healthy children and adolescents: A scoping review. Acta Psychologica, 224, 103498. https://doi.org/10.1016/j.actpsy.2022.103498
   PubMed Web of Science ®Google Scholar
• Wollesen, B., Wildbredt, A., van Schooten, K. S., Lim, M. L., & Delbaere, K. (2020). The effects of cognitive-motor training interventions on executive functions in older people: A systematic review and meta-analysis. European Review of Aging and Physical Activity, 17(1), 1–22. https://doi.org/10.1186/s11556-020-00240-y
   PubMed Web of Science ®Google Scholar
• Woollacott, M., & Shumway-Cook, A. (2002). Attention and the control of posture and gait: A review of an emerging area of research. Gait & Posture, 16(1), 1–14. https://doi.org/10.1016/s0966-6362(01)00156-4
   PubMed Web of Science ®Google Scholar
• Wu, T., Liu, J., Hallett, M., Zheng, Z., & Chan, P. (2013). Cerebellum and integration of neural networks in dual-task processing. NeuroImage, 65, 466–475. https://doi.org/10.1016/j.neuroimage.2012.10.004
   PubMed Web of Science ®Google Scholar
• Zenebe, K., Legesse, K., Mandal, S., Mahmud, M., & Aragaw, K. (2020). Effects of sixteen week of resistance exercises on some selected cognitive variables development in adolescents with intellectual disabilities. Turkish Journal of Kinesiology, 6(1), 26–31. https://doi.org/10.31459/turkjkin.682436
   Google Scholar
• Zhu, X., Yin, S., Lang, M., He, R., & Li, J. (2016). The more the better? A meta-analysis on effects of combined cognitive and physical intervention on cognition in healthy older adults. Ageing Research Reviews, 31, 67–79. https://doi.org/10.1016/j.arr.2016.07.003
   PubMed Web of Science ®Google Scholar