From Action to Cognition: Neural Reuse, Network Theory and the Emergence of Higher Cognitive Functions

The aim of this article is to discuss the logic and assumptions behind the concept of neural reuse, to explore its biological advantages and to discuss the implications for the cognition of a brain that reuses existing circuits and resources. We first address the requirements that must be fulfilled for neural reuse to be a biologically plausible mechanism. Neural reuse theories generally take a developmental approach and model the brain as a dynamic system composed of highly flexible neural networks. They often argue against domain-specificity and for a distributed, embodied representation of knowledge, which sets them apart from modular theories of mental processes. We provide an example of reuse by proposing how a phylogenetically more modern mental capacity (mental rotation) may appear through the reuse and recombination of existing resources from an older capacity (motor planning). We conclude by putting arguments into context regarding functional modularity, embodied representation, and the current ontology of mental processes.

Inhibitory Mechanisms in the Processing of Negations: A Neural Reuse Hypothesis

Negation is known to have inhibitory consequences for the information under its scope. However, how it produces such effects remains poorly understood. Recently, it has been proposed that negation processing might be implemented at the neural level by the recruitment of inhibitory and cognitive control mechanisms. On this line, this manuscript offers the hypothesis that negation reuses general-domain mechanisms that subserve inhibition in other non-linguistic cognitive functions. The first two sections describe the inhibitory effects of negation on conceptual representations and its embodied effects, as well as the theoretical foundations for the reuse hypothesis. The next section describes the neurophysiological evidence that linguistic negation interacts with response inhibition, along with the suggestion that both functions share inhibitory mechanisms. Finally, the manuscript concludes that the functional relation between negation and inhibition observed at the mechanistic level could be easily integrated with predominant cognitive models of negation processing.

Neural Reuse and Recycling

“Neural reuse” refers to the exaptation of established and relatively fixed neural circuits without loss of original function/use. Reuse arises over the course of normal development and evolution. The evidence of this phenomenon speaks most loudly against the idea of strict domain-specificity. It seems that no area of the brain is exempt from redeployment, with areas of the brain traditionally considered to be among the most domain-specific (such as sensory areas) also contributing their computational/structural resources to other domains, including those involving language. The evidence supporting reuse takes many forms, among them evolutionary and developmental considerations, computational considerations, and the neuroimaging and biobehavioral literature.

The Adaptable Mind

What conception of mental architecture can survive the evidence of neuroplasticity and neural reuse in the human brain? In particular, what sorts of modules are compatible with this evidence? This book shows how developmental and adult neuroplasticity, as well as evidence of pervasive neural reuse, force a revision to the standard conceptions of modularity and spell the end of a hardwired and dedicated language module. It argues from principles of both neural reuse and neural redundancy that language is facilitated by a composite of modules (or module-like entities), few if any of which are likely to be linguistically special, and that neuroplasticity provides evidence that (in key respects and to an appreciable extent) few if any of them ought to be considered developmentally robust, though their development does seem to be constrained by features intrinsic to particular regions of cortex (manifesting as domain-specific predispositions or acquisition biases). In the course of doing so, the book articulates a schematically and neurobiologically precise framework for understanding modules and their supramodular interactions.

The neural reuse hypothesis

In this chapter, the authors propose neural reuse as a promising unifying framework for the advance of developmental cognitive neuroscience. In order to do so, first, the authors describe the hypothesis of neural reuse and some of the evidence for its importance to and impact on the development of the brain. Then, the authors compare neural reuse with the three prominent frameworks in contemporary developmental cognitive neuroscience—maturational viewpoint, interactive specialization, and skill learning—and show how neural reuse can accommodate their virtues while avoiding their shortcomings. After that, the authors explore some of the implications of neural reuse for the developmental study of math cognition, brain dynamics, and neurodevelopmental disorders. Finally, the authors sketch some future directions of research and some specific research suggestions.