Contents lists available at ScienceDirect Cognitive Development journal homepage: www.elsevier.com/locate/cogdev Editorial Introduction to Special Issue: “Current Perspectives on Neuroplasticity” In the past two decades, a wealth of evidence has accumulated that supports a neural constructivist approach to characterizing human development. This approach, in which learning and individual experiences play a central role in constructing mental representations and their corresponding neural changes, is of course one of the central themes of Piaget's theory. This special issue, based on the annual meeting of the Jean Piaget Society held in Toronto in June, 2015, brings together reports from researchers who examine neural plasticity in a variety of ways, across varied domains of development. It provides an overview of the state-of-the- science in examining how experiences and biology interact to shape brain development, and we hope it stimulates discussion of the implications of this neuroscience-based research for the broader understanding of child development. The importance of neural plasticity has long been recognized (e.g., Hebb, 1949), and the role of expectable environmental input (and its absence) on brain development is well known (e.g., from sensory deprivations studies; Hubel & Wiesel, 1962). An early demonstration of the way in which behavioral adaptations to more idiosyncratic (i.e., experience-dependent) aspects of the environment co-occur with neural adaptations appeared in the work of Greenough and colleagues (e.g., Greenough, Black, & Wallace, 1987), who examined rats raised in “enriched,” or relatively complex environments that included other rats and the opportunity to explore and play (see also Rosenzweig et al., 1962). Compared to rats raised in captivity as usual, these rats showed better learning and memory (e.g., on maze learning) as well as effects on brain development, including heavier and thicker cortices, more dendrites per neuron, and more spines per dendrite. The implications of these and other findings subsequently became more widely appreciated in light of several well-publicized studies with adults. For example, Maguire et al. (2000) examined brain regions related to spatial memory in a sample of taxi drivers in London, England. Taxi drivers, who have to pass a rigorous test demonstrating knowledge of London streets, were found to have larger posterior hippocampi (and smaller anterior hippocampi) than age-matched controls. In addition, the number of years they had been driving a cab was positively related to the volume of their posterior hippocampi and negatively related to the volume of their anterior hippocampi. Although correlational, this finding suggests that engaging regularly in navigation (and relying heavily on spatial memory) leads to the reshaping of relevant regions of the brain. Similar findings have been obtained for white matter and also for measures of brain function. Elbert et al., (1995), for example, used magnetoencephalography (MEG) to measure cortical representations of fingers in violin players and found larger representa- tions in sensorimotor cortex of the digits of the left (fingering) hand (but not the thumb), as would be expected if experience produced these changes. In addition, the number of hours spent practicing the piano (especially as a child) has been found to be related to myelination, with different neural regions being implicated at different ages (Bengtsson, Nagy, Skare, Forsman, Forssberg, & Ullén, 2005). Findings like these, which are increasingly supported by experimental research involving human beings, suggest that we grow our brains by using them, and that we grow our brains in particular ways by using them in particular ways (Zelazo, 2013). Our understanding of cognitive development has grown enormously with the advent of new tools and techniques for examining processes operating at many levels of analysis (e.g., for studying complex interactions among genes and environment, for measuring neural activity in young children, and for modeling developmental change using sophisticated computational techniques). This research has made it clear that there is plasticity at all levels of analysis, and in particular it has sharpened out understanding of the influence of specific early experiences on subsequent cognitive and brain development. The current special issue of Cognitive Development is designed to provide cutting edge theoretical and empirical contributions on developmental neuroplasticity. Lisa Oakes provides for this special issue a theoretical piece examining neuroplasticity in development. Rather than using a canonical framework to explore this topic, where plasticity is discussed in terms of the ways in which experience is changed by differences in brain structures, processes or input, this paper discusses the idea that developmental plasticity, itself, also effectively changes input into the system. In this way, plasticity is not only seen in the structures and processes that result from differences in http://dx.doi.org/10.1016/j.cogdev.2017.05.003 Cognitive Development 42 (2017) 1–3 0885-2014/ © 2017 Published by Elsevier Inc. MARK