Multisensory integration (MSI) is an integral aspect of functioning and mobility in everyday life and ability to function well in the real world requires intact MSI. MSI is not fully understood in aging, and its relation to cognitive and motor function has not been comprehensively evaluated. The main objective of my research is to investigate the behavioral, functional, and structural correlates of MSI in older adults and to determine whether multisensory processes are associated with specific cognitive and motor outcomes.  Our recent work in older adults has linked the magnitude of visual-somatosensory integration to important cognitive (attention) and motor (balance, gait, and falls) outcomes. We have highlighted the adverse effect of Mild Cognitive Impairment (MCI) and dementia on these relationships, but the underlying functional and neuroanatomical networks remain unidentified.

Growing evidence suggests that Alzheimer’s pathology manifests in sensory association areas well before appearing in neural regions involved in memory function. Identification of novel, non-cognitive, non-invasive markers of Alzheimer’s disease and related dementias are a national priority identified by the National Alzheimer Plan and the NIH.  Our most recent NIA funding affords us an opportunity to determine whether visual-somatosensory integration is a novel marker for Alzheimer’s disease. Our central hypothesis is that preclinical Alzheimer’s disease is associated with neural disruptions in subcortical and cortical areas that concurrently modulate multisensory, cognitive, and motor functions, resulting in mobility decline. Our proposed study, strategically designed to examine the interplay of multisensory, cognitive, and mobility processes, will: 1) provide a deeper understanding of the functional neural networks involved in MSI processes in preclinical Alzheimer’s disease; 2) determine whether functional multisensory activation in prefrontal cortex predicts future mobility decline and falls in preclinical Alzheimer’s disease; 3) assess the validity of multisensory integration as an early marker for preclinical Alzheimer’s disease; and 4) provide insights into the neurobiology of Alzheimer’s disease. Results from this project will guide future multisensory-based interventions aimed to alleviate disability and maintain functional independence of older adults at-risk for Alzheimer’s disease that can significantly augment existing interventions. Although admittedly speculative, we believe that optimizing integration of visual-somatosensory inputs may ultimately provide the framework for successful interventions that will reduce falls, improve mobility, and help maintain functional independence in older adults.

As well, we have made significant strides with regards to identifying a novel quantitative multisensory fall-risk screening tool called CatchU® Before you Fall... Falls are a significant burden to the U.S. healthcare system with over $50B spent annually on fatal and non-fatal falls. Nearly 30% of Americans aged 65 years and over (~16M) experience a fall every year. Falls are the leading cause of injury and injury-related death in older adults. Alzheimer’s disease, the most-common cause of dementia, affects nearly 6M older Americans. Besides cognitive impairment, older adults with Alzheimer’s disease are at high-risk for mobility declines and falls. The main objective of our novel multisensory fall-risk screener is to assist healthcare professionals in predicting and preventing falls in older adults with preclinical Alzheimer’s disease. Long-term goals include preventing serious injury and death in older adults, while offsetting the accelerating economic burden of falls in the United States.

1. Mahoney, J.R., George, C.J., Verghese, J., Introducing CatchUTM: A Novel Multisensory Tool for Assessing Patients’ Risk of Falling. Journal of Perceptual Imaging, 4 (3), 2021.
2. Mahoney, J.R. Multisensory integration, mobility, and risk of falls in older adults. Research Features. October 2021.
3. Verghese, J., Mahoney, J.R., Ayers, E., Ambrose, A., Wang, C., & Holtzer, R. Computerised cognitive remediation to enhance mobility in older adults: a single-blind, single-centre, randomised trial. Lancet Healthy Longevity. 2021; 2(9): e571-e579.
4. Mahoney, J.R., Verghese, J., & George, C.  The influence of diabetes on multisensory integration and mobility in Aging. BrainSciences, 11(3): 285, 2021.
5. Malcolm, B.R., Foxe, J.J., Joshi, S., Verghese, J., Mahoney, J.R., Molholm, S. & De Sanctis, P. Aging-related changes in cortical mechanisms supporting postural control during base support and optic flow manipulations. European Journal of Neuroscience, 2020 [Epub ahead of print]. PMID: 33047390
6. Mahoney, J.R. & Verghese, J. Does Cognitive Impairment Influence Visual-Somatosensory Integration and Mobility in Older Adults? Journal of Gerontology, Medical Sciences, 75(3):581-588, 2020. PMID: 31111868 
7. Mahoney, J.R. & Barnett-Cowan, M., Introduction to the Special Issue on Multisensory Processing and Aging: Links to Clinically Meaningful Outcomes. Multisensory Research 32(8):665-670, 2019. PMID: 31648200 
8. Basharat, A., Mahoney, J.R. & Barnett-Cowan, M., Temporal Metrics of Multisensory Processing Change in the Elderly. Multisensory Research 32(8):715-744, 2019. PMID: 31648192
9. Mahoney, J.R. & Verghese, J. Using the Race Model Inequality to Quantify Behavioral Multisensory Integration Effects. Journal of Visualized Experiments, 147: e59575, 2019.PMID: 31132070  
10. Mahoney, J.R., Cotton, K., & Verghese, J.  Multisensory Integration Predicts Balance and Falls in Older Adults. Journal of Gerontology, Medical Sciences, 74(9):1429-1435, 2019. PMID: 30357320 
11. Mahoney, J.R. & Verghese, J. Visual-Somatosensory Integration and Quantitative Gait in Aging. Frontiers in Aging Neuroscience, 10: 377, 2018. PMID: 30538628
12. Marusic, U., Verghese, J., & Mahoney, J.R. Cognitive Based Interventions to Improve Mobility: A Systematic Review and Meta-Analysis. JAMDA, 19: 484-491, 2018. PMID: 29680203
13. Santos, D., Mahoney, J.R., Allali, G., & Verghese, J. Physical Activity in Older Adults with Mild Parkinsonian Signs: A cohort study. Journal of Gerontology, Medical Sciences, 73 (12); 1682-1687, 2018. PMID: 29931236
14. Mahoney, J.R., Oh-Park, M., Ayers, E., & Verghese, J.  Quantitative Trunk Sway and Prediction of Incident Falls in Older Adults. Gait and Posture, 58: 183-187, 2017. PMID: 28797962
15. Chen, M., Pillemer, S., England, S., Izzetoglu, M., Mahoney, J.R., & Holtzer, R. Neural Correlates of Obstacle Negotiation in Older Adults: An fNIRS Study.  Gait and Posture, 18 (58): 130-135, 2017. PMID: 28778021
16. Holtzer, R., Schoen, C., Demetriou, E., Mahoney, J.R., Izzetoglu, M., Wang, C., & Verghese, J. Stress and gender effects on prefrontal cortex oxygenation levels assessed during single and dual-task walking conditions. Eur J Neurosci., 45 (5): 660-670, 2017. PMID: 28028863
17. Holtzer, R., Yuan, J, Verghese, J., Mahoney, J.R., Izzetoglu, M., & Wang, C. Interactions of Subjective and Objective Measures of Fatigue Defined in the Context of Brain Control of Locomotion. Journal of Gerontology, Medical Sciences, 72(3):417-423, 2017. PMID: 27567110
18. Verghese, J., Ayers, E., Mahoney, J.R., Ambrose, A., Wang, C., Holtzer, R. Cognitive remediation to enhance mobility in older adults: the CREM study. Neurodegener Dis Manag, 6(6):457-466, 2016. PMID:27813452
19. Dumas, K., Holtzer, R., & Mahoney, J.R. Visual-Somatosensory Integration in Older Adults: Links to Sensory Acuity and Balance. Multisensory Research, 29 (4-5): 397-420, 2016. PMID: 29384609
20. Holtzer, R., Verghese, J., Allali, G., Izzetoglu, M., Wang, C., & Mahoney, J.R., Neurological Gait Abnormalities Moderate the Functional Brain Signature of the Posture First Hypothesis.Brain Topography, 2015. PMID: 26613725 
21. Mahoney, J.R., Holtzer, R., Izzetoglu, M., Zemon, V., Verghese, J., & Allali, G. The role of the prefrontal cortex in postural control in Parkinsonian syndromes. Brain Research, 163: 126-138, 2015. PMID: 26551767 
22. LeMonda, B., Mahoney, J.R., Verghese, J., & Holtzer, R. The Association between High Neuroticism-Low Extraversion and Dual-Task Performance during Walking while Talking in Healthy Older Adults. J Int Neuropsychol Soc., 21 (7):519-530, 2015. PMID: 26527241
23. Mahoney, J.R., Molholm, S., Butler, J.S., Sehatpour, P., Gomez-Ramirez, M., Ritter, W. & Foxe, J.J.  Keeping in Touch with the Visual System: Spatial Alignment and Multisensory Integration of Visual- Somatosensory Inputs. Frontiers in Psychology, 5 (6): 1068, 2015. PMID: 26300797
24. Mahoney, J.R., Verghese, J., Dumas, K. & Holtzer, R. Visual-Somatosensory Integration is linked to Physical Activity Level in Older Adults. Multisensory Research, 28 (1-2): 11-29, 2015. PMID: 26152050
25. Holtzer, R., Mahoney, J.R., Izzetoglu, M., Wang, C., England, S., & Verghese, J. Online Fronto-cortical Control of Simple and Attention-Demanding Locomotion in Humans. Neuroimage, 112: 152-159, 2015. PMID: 25765257
26. England, S., Verghese, J., Mahoney, J.R., Trantzas, K., & Holtzer, R. Three level rating of turns while walking, Gait and Posture, 41(1):300-3, 2015.  PMID: 25282258
27. Lee, S., Verghese, J., Holtzer, R., Mahoney, J.R., & Oh-Park, M. Trunk Sway during Walking among Older Adults: Norms and Correlation with Gait Velocity. Gait & Posture, 40(4):676-681, 2014. PMID: 25155693
28. Mahoney, J.R., Holtzer, R., Dumas, K., & Verghese, J. Visual-Somatosensory Integration & Balance: Evidence for Psychophysical Integrative Differences in Aging. Multisensory Research, 27(1): 17-42, 2014. PMID: 25102664
29. Mahoney, J.R., Verghese, J., Holtzer, R. & Allali, G. The evolution of mild parkinsonian signs in aging. Journal of Neurology, 261(10):1922-1928, 2014. PMID: 25047763
30. Allali, G., Verghese, J. & Mahoney, J.R.  Contributions of Parkinsonian features to Gait in the Elderly. Age (Dordr), 36:9678, 2014. PMID: 24981115
31. Holtzer, R., Epstein, N., Mahoney, J.R., Izzetoglu, M., & Blumen, H.M. Neuroimaging of Mobility in Aging: A Targeted Review. Journal of Gerontology, Medical Sciences, 69(11):1375-88, 2014. PMID: 24739495
32. Mahoney, J.R., Verghese, J., Dumas, K., & Holtzer, R. Visual-Somatosensory Integration in Aging: Does Stimulus Location Really Matter? Visual Neuroscience, 31(3):275-83, 2014. PMID: 24698637
33. Shapiro, M, Mahoney, J.R., Peyser, D., Zingman, B. & Verghese, J.  Cognitive Reserve Protects Against Apathy in Individuals with Human Immunodeficiency Virus. Archives of Clinical Neuropsychology, 29(1):110-120, 2014. PMID: 24021844
34. Holtzer, R., Mahoney, J.R., Verghese, J. Intraindividual variability but not speed of processing or conflict resolution predicts performance differences in gait speed in older adults. Journal of Gerontology: Medical Sciences, 69(8): 980-986, 2014. PMID: 24285744
35. Parihar, R., Mahoney, J.R., & Verghese, J.  Relationship of Gait and Cognition in the Elderly.  Current Translational Geriatrics and Experimental Gerontology Reports, 2:167-173, 2013. PMID: 24349877
36. Shapiro, M., Mahoney, J., Zingman, B, Pogge, D, & Verghese, J.  Apathy Correlates with Cognitive Performance, Functional Disability, and HIV RNA Plasma Levels in HIV-Positive Individuals. Journal of Clinical and Experimental Neuropsychology, 35(9):934-945, 2013. PMID: 24090038
37. Oh-Park, M., Holtzer, R., Mahoney, J., Wang, Raghavan, P. & Verghese, J. Motor dual-task effect on gait and task of upper limbs in older adults under specific task prioritization: pilot study.  Aging Clinical and Experimental Research, 25(1):99-106, 2013. PMID: 23740639
38. Mahoney, J.R., Verghese J, Dumas K, Wang C, Holtzer R. The effect of multisensory cues on attention in aging. Brain Res. 1472, 63-73, 2012. PMID: 22820295
39. Oh-Park, M., Holtzer, R., Mahoney, J., Wang, C., & Verghese, J.  Effect of treadmill training on specific gait parameters in older adults with frailty: case series. J Geriatr Phys Ther. 34(4), 184-188, 2011. PMID: 22124418
40. Mahoney, J.R., Li, P., Oh-Park, M., Verghese, J., & Holtzer, R. Multisensory Integration Across the Senses in Young and Old Adults. Brain Research, 426, 43-53, 2011. PMID: 22024545
41. Holtzer, R., Shuman, M., Mahoney, J., Lipton, R., & Verghese, J. Cognitive Fatigue Defined in the Context of Attention Networks. Neuropsychol Dev Cogn B Aging Neuropsychol Cogn., 18, 108-128, 2011. PMID:21128132
42. Holtzer,R., Mahoney, J.R., Izzetoglu,M., Izzetoglu,K., Onaral, B., & Verghese, J.  fNIRS Study of Walking and Walking While Talking in Young and Old Individuals. J Int Neuropsychol Soc., 16(5), 877-89, 2011. PMID:21593013
43. Mahoney, J., Verghese, J. Goldin, Y., Lipton, R. & Holtzer, R.  Alerting, Orienting, and Executive Attention in Older Adults. J Int Neuropsychol Soc., 16(5), 877-889, 2010. PMID: 20663241
44. Verghese J., Mahoney J., Wang C., Ambrose A.F., & Holtzer, R. Effect of cognitive remediation on gait in sedentary seniors. J Gerontol A Biol Sci Med Sci.,65(12), 1338-1343, 2010. PMID: 20643703
45. Katz, R., De Sanctis, P., Mahoney, J.R., Sehatpour, P., Murphy, C., Gomez-Ramirez, M., Alexopoulos, G.A., & Foxe, J.J.  Cognitive Control in Late-Life Depression: Response inhibition deficits and dysfunction of the Anterior Cingulate Cortex. Am J Geriatr Psychiatry, 18(11), 1017-1025, 2010. PMID: 20808083
46. Sehatpour, P., Molholm, S., Schwartz, T.H., Mahoney, J.R., Mehta, A., Javitt, D., Stanton, P.K., & Foxe, J.J. A human intracranial study of long-range oscillatory coherence across a frontal-occipital-hippocampal brain network during visual object processing. Proc Natl Acad Sci U S A., 105(11), 4399-4404, 2008. PMID:18334648
47. Gomez-Ramirez, M., Higgins, B.A., Rycroft, J.A., Owen, G.N., Mahoney, J., Shpaner, M., &  Foxe, J.J. The deployment of intersensory selective attention: A high-density electrical mapping study of the effects of Theanine. Clin Neuropharmacol., 30 (1), 25-38, 2007. PMID: 17272967
48. Butler, P.D., Martinez, A., Foxe, J.J., Kim, D., Zemon, V., Silipo, G., Mahoney, J., Shpaner, M., Jalbrzikowski, M., &. Javitt, D. C.  Subcortical visual dysfunction in schizophrenia drives secondary cortical impairments. Brain, 130, 417-430, 2007. PMID: 16984902