The organizational principles of de-differentiated topographic maps in somatosensory cortex

eLife

Thomas Wolbers¹  Anastasia Chrysidou²  Peng Liu²  Juliane Doehler²  Esther Kuehn³  Martin N Hebart⁴ 

[1] German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany;Center for Behavioral Brain Sciences (CBBS) Magdeburg, Magdeburg, Germany;Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg, Germany;German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany;Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University Magdeburg, Magdeburg, Germany;German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany;Center for Behavioral Brain Sciences (CBBS) Magdeburg, Magdeburg, Germany;Vision and Computational Cognition Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany;

关键词: aging;    pRF mapping;    7 Tesla MRI;    somatosensation;    somatotopy;    touch;    Human;   

DOI  :  10.7554/eLife.60090

来源: eLife Sciences Publications, Ltd

【 摘 要 】

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.

【 授权许可】

CC BY