Plasticity versus stability across the human cortical visual connectome

Koen V Haak,Christian F Beckmann

doi:10.1038/s41467-019-11113-z

Abstract

Whether and how the balance between plasticity and stability varies across the brain is an important open question. Within a processing hierarchy, it is thought that plasticity is increased at higher levels of cortical processing, but direct quantitative comparisons between low- and high-level plasticity have not been made so far. Here, we address this issue for the human cortical visual system. We quantify plasticity as the complement of the heritability of resting-state functional connectivity and thereby demonstrate a non-monotonic relationship between plasticity and hierarchical level, such that plasticity decreases from early to mid-level cortex, and then increases further of the visual hierarchy. This non-monotonic relationship argues against recent theory that the balance between plasticity and stability is governed by the costs of the “coding-catastrophe”, and can be explained by a concurrent decline of short-term adaptation and rise of long-term plasticity up the visual processing hierarchy.

Highlights

Whether and how the balance between plasticity and stability varies across the brain is an important open question
For primary processing nodes plasticity may be defined as a change in response to external stimulation, for higher-order processing nodes it ought to be defined as a change in response to the signals these nodes receive from lower-level processing stages
To quantify the balance between plasticity and stability across human visual cortex, we determined the functional connectivity between 48 cortical visual areas based on the publicly available resting-state functional MRI data of twins provided by the WU-Minn Human Connectome Project (HCP)[15,22]

Summary

Introduction

Whether and how the balance between plasticity and stability varies across the brain is an important open question. It is thought that plasticity is increased at higher levels of cortical processing, but direct quantitative comparisons between low- and high-level plasticity have not been made so far. We address this issue for the human cortical visual system. Valid approach is to assess the current state of configuration with respect to a state where the configuration was free of environmental influence Such a state of zero-change corresponds to the configuration of neural circuits that is completely determined by the genetic blueprint, and plasticity can be quantified as the complement of the amount of phenotypic variance that can be explained by genetic factors. Plasticity is not limited to anatomical changes, as evidenced by, for instance, adaptive neural tuning changes in response temporarily altered image statistics[8] and the existence of long-term potentiation (LTP) to facilitate learning and memory by synaptic strengthening[16]

Methods

Results

Conclusion