Nadine Diersch
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Postdoctoral Researcher
Aging & Cognition Research Group German Center for Neurodegenerative Diseases (DZNE) Leipziger Str. 44 39120 Magdeburg Germany E-Mail: nadine.diersch@dzne.de Phone: +49 391 / 67 245 86 Twitter: @nadine_diersch Linkedin: nadine-diersch |
Research Interests
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Age-related impairments in the encoding and retrieval of spatial information
Older adults often have problems to find their way in novel environments, even after repeatedly visiting them, and studies in aged rodents and non-human primates suggest that this might be related to changes in hippocampal place cell firing patterns. In my research at the DZNE, I characterized age-related problems in learning a novel virtual environment, by measuring how well healthy older and younger adults are able to retrieve its spatial layout across several learning blocks, and investigated the underlying neural mechanisms using fMRI and effective connectivity analysis (DCM PEB). To estimate subject-specific learning states per block, we developed a Bayesian implementation of a state-space model. I found that although some older adults learned just as well as younger adults, the majority of them showed substantial deficits in retrieving information about the initially unfamiliar environment. While I could replicate findings from earlier studies in younger adults (i.e. learning-related activity changes in the retrosplenial cortex and the hippocampus), I found that activity in these regions does not change systematically in older adults across repeated episodes in the environment. Importantly, I further show that their learning deficits are linked to impaired spatial information processing in the hippocampus, as evidenced by an age-related reduction in the inhibitory self-connection of this region. |
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Building-up on recent findings from the lab, I will study next the functional mechanisms that underlie the reduced stability of the grid-cell-like representations in the aging entorhinal cortex. In addition, the potential of these measures as cognitive and neural markers for the progression from healthy aging to neurodegenerative disease will be investigated.
References:
Diersch, N., Valdes-Herrera, J.P., Tempelmann, C., Wolbers T. (2021). Increased hippocampal excitability and altered learning dynamics mediate cognitive mapping deficits in human aging. Journal of Neuroscience, 41, 3204-3221. [link]
Stangl, M., Achtzehn, J., Huber, K., Dietrich, C., Tempelmann, C., & Wolbers, T. (2018). Compromised grid-cell-like representations in old age as a key
mechanism to explain age-related navigational deficits. Current Biology, 28, 1108-1115. [Link]
References:
Diersch, N., Valdes-Herrera, J.P., Tempelmann, C., Wolbers T. (2021). Increased hippocampal excitability and altered learning dynamics mediate cognitive mapping deficits in human aging. Journal of Neuroscience, 41, 3204-3221. [link]
Stangl, M., Achtzehn, J., Huber, K., Dietrich, C., Tempelmann, C., & Wolbers, T. (2018). Compromised grid-cell-like representations in old age as a key
mechanism to explain age-related navigational deficits. Current Biology, 28, 1108-1115. [Link]
The spatial mapping of others in the brain’s navigation system
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In a new line of research, I am investigating the representation of others in space. To date, the vast majority of spatial navigation studies typically implement their tasks in empty environments, which overlooks one important fact: navigating in the real world rarely happens in non-social contexts. In fact, recent evidence from animal research suggests that the brain’s navigation circuit also maps spatial information about conspecifics. Moreover, successfully navigating in virtual reality (VR) settings requires a certain degree of immersion, which can be facilitated by the presence of an avatar. This might consequently support navigational learning and counteract navigational performance declines in older adults. To address these important questions, I am using realistic VR paradigms in combination with eye tracking and brain imaging to determine how we map others in space and in how far the presence of an avatar supports navigational learning in the elderly.
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References:
Diersch, N., Riemer, M., Mamsch, K., & Wolbers, T. (in prep.). The effects of biological motion information on ego- and allocentric spatial learning and visual
exploration patterns in older adults.
Diersch, N., & Wolbers, T. (2019). The potential of virtual reality in spatial navigation research across the adult lifespan. Journal of Experimental Biology, 222,
doi: 10.1242/jeb.187252. [Link]
Diersch, N., Riemer, M., Mamsch, K., & Wolbers, T. (in prep.). The effects of biological motion information on ego- and allocentric spatial learning and visual
exploration patterns in older adults.
Diersch, N., & Wolbers, T. (2019). The potential of virtual reality in spatial navigation research across the adult lifespan. Journal of Experimental Biology, 222,
doi: 10.1242/jeb.187252. [Link]
Action prediction in the aging mind
Non-verbal social interactions depend on our ability to infer and anticipate other people's actions. Theoretical accounts of motor activity during action observation suggest that the observer employs their motor system to make a prediction of the sensory consequences of observed actions. Consistent with this, many studies have shown that differences in motor expertise result in differences in performance and neural activation patterns, when experts and non-experts observe the same actions. But what happens when the observer’s brain and motor system are aging? My research in this domain shows that older compared to younger adults are less precise in anticipating the time-course of actions that are partly occluded from view. I further provided evidence that the neural implementation of predicting observed actions gets less distinctive with age and entails a shift from automatic, sensorimotor processing to a more controlled, visual processing. However, the internal representation of observed actions is sensitive to physical training and is modulated by the amount of sensorimotor experience with the observed actions, even in older age groups.
Non-verbal social interactions depend on our ability to infer and anticipate other people's actions. Theoretical accounts of motor activity during action observation suggest that the observer employs their motor system to make a prediction of the sensory consequences of observed actions. Consistent with this, many studies have shown that differences in motor expertise result in differences in performance and neural activation patterns, when experts and non-experts observe the same actions. But what happens when the observer’s brain and motor system are aging? My research in this domain shows that older compared to younger adults are less precise in anticipating the time-course of actions that are partly occluded from view. I further provided evidence that the neural implementation of predicting observed actions gets less distinctive with age and entails a shift from automatic, sensorimotor processing to a more controlled, visual processing. However, the internal representation of observed actions is sensitive to physical training and is modulated by the amount of sensorimotor experience with the observed actions, even in older age groups.
References:
Kirsch, L. P., Diersch, N., Sumanapla, D. K., & Cross, E. S. (2018). Dance training shapes action perception and its neural implementation within the young and
older adult brain. Neural Plasticity, 5459106, 1-20, doi: 10.1155/2018/5459106. [Link]
Diersch, N., Jones, A. L., & Cross, E. S. (2016). The timing and precision of action prediction in the aging brain. Human Brain Mapping, 37, 54–66.
doi: 10.1002/hbm.23012. [Link]
Diersch, N., Mueller, K., Cross, E. S., Stadler, W., Rieger, M., & Schütz-Bosbach, S. (2013). Action prediction in younger versus older adults: Neural correlates
of motor familiarity. PLOS ONE, 8, e64195. doi: 10.1371/journal.pone.0064195. [Link]
Diersch, N., Cross, E. S., Stadler, W., Schütz-Bosbach, S., & Rieger, M. (2012). Representing others' actions: The role of expertise in the aging mind.
Psychological Research, 76, 525-541. doi: 10.1007/s00426-011-0404-x. [Link]