Ricerc@Sapienza

The Attentional-SNARC effect (Att-SNARC) originally described by Fischer et al. (Nat Neurosci 6(6):555, 2003), consists of faster RTs to visual targets in the left side of space when these are preceded by small-magnitude Arabic cues at central fixation and by faster RTs to targets in the right side of space when these are preceded by large-magnitude cues.

In a series of five experiments with unimanual Go/No-Go tasks and intermixed Arabic numerical, i.e. numbers lower or higher than 5, and directional targets, i.e. arrows pointing to the left or to the right, we explored whether spatial codes used in isolation inherently evoke the left-to-right representation of number magnitudes, i.e. Space-to-Number congruency effect, and, vice-versa, whether number-magnitude codes used in isolation inherently evoke the conceptual activation of left/right spatial codes, i.e. Number-to-Space congruency effect.

The study examined whether developmental deficits in reading and numerical skills could be expressed in terms of global factors by reference to the rate and amount (RAM) and difference engine (DEM) models. From a sample of 325 fifth grade children, we identified 5 children with dyslexia, 16 with dyscalculia, 7 with a “mixed pattern,” and 49 control children.

From our very early school years we start to realize that numbers govern much of our life. The symbolic mathematical competence that characterises much human activity is grounded in phylogenetically older systems that allow approximate, but behaviourally adaptive, estimates of numerosity. During bio- logical evolution these rudimentary mathematical abilities might have been crucial for survival and adaptation. In this special issue, we offer an overview of some promising lines of ongoing research on number processing in the brain.