A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans.
Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition.
Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.|Department of Cognitive Neuroscience, University Hospital Leipzig, Leipzig, Germany.|Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
Burkhard
B
Pleger
Institute for Neuroinformatics, Neural Plasticity Lab, Ruhr-University Bochum, Bochum, Germany.
Claudia
C
Wilimzig
Department of Radiology, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
Volkmar
V
Nicolas
Institute for Neuroinformatics, Neural Plasticity Lab, Ruhr-University Bochum, Bochum, Germany.
Tobias
T
Kalisch
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
Patrick
P
Ragert
Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.
Martin
M
Tegenthoff
Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany.|Institute for Neuroinformatics, Neural Plasticity Lab, Ruhr-University Bochum, Bochum, Germany.
Hubert R
HR
Dinse
D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity / Q000502:physiology; D010812:Physical Stimulation / Q000379:methods; D012684:Sensory Thresholds / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*; D055815:Young Adult