The organizational principles of de-differentiated topographic maps in somatosensory cortex
Abstract
Topographic maps are a fundamental feature of cortex architecture in the mammalian brain. One common theory is that the de-differentiation of topographic maps links to impairments in everyday behavior due to less precise functional map readouts. Here, we tested this theory by characterizing de-differentiated topographic maps in primary somatosensory cortex (SI) of younger and older adults by means of ultra-high resolution functional magnetic resonance imaging together with perceptual finger individuation and hand motor performance. Older adults' SI maps showed similar amplitude and size to younger adults' maps, but presented with less representational similarity between distant fingers. Larger population receptive field sizes in older adults' maps did not correlate with behavior, whereas reduced cortical distances between D2 and D3 related to worse finger individuation but better motor performance. Our data uncover the drawbacks of a simple de-differentiation model of topographic map function, and motivate the introduction of feature-based models of cortical reorganization.
Data availability
Behavioral and MRI data have been deposited in dryad (doi:10.5061/dryad.mgqnk98x8)
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The organizational principles of de-differentiated topographic maps - DataDryad Digital Repository, doi: 10.5061/dryad.mgqnk98x8.
Article and author information
Author details
Funding
Center for Behavioral Brain Sciences (ESIF/EFRE 2014-2020; FKZ: ZS/2016/04/78113)
- Esther Kuehn
German Research Foundation (KU 3711/2-1,project number: 423633679)
- Peng Liu
- Juliane Doehler
Else Kroener Fresenius Stiftung (2019-A03)
- Anastasia Chrysidou
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: All participants were paid for their attendance and written informed consent for participation and data handling was received from all participants before starting the experiment. The study was approved by the Ethics committee of the Otto-von-Guericke University Magdeburg (68/16).
Copyright
© 2021, Liu et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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