TY - JOUR
T1 - Spatial attention determines the nature of nonverbal number representation
AU - Hyde, Daniel C.
AU - Wood, Justin N.
PY - 2011/9
Y1 - 2011/9
N2 - Coordinated studies of adults, infants, and nonhuman animals provide evidence for two systems of nonverbal number representation: a ''parallel individuation'' system that represents individual items and a ''numerical magnitude'' system that represents the approximate cardinal value of a group. However, there is considerable debate about the nature and functions of these systems, due largely to the fact that some studies show a dissociation between small (1-3) and large (>3) number representation, whereas others do not. Using event-related potentials, we show that it is possible to determine which system will represent the numerical value of a small number set (1-3 items) by manipulating spatial attention. Specifically, when attention can select individual objects, an early brain response (N1) scales with the cardinal value of the display, the signature of parallel individuation. In contrast, when attention cannot select individual objects or is occupied by another task, a later brain response (P2p) scales with ratio, the signature of the approximate numerical magnitude system. These results provide neural evidence that small numbers can be represented as approximate numerical magnitudes. Further, they empirically demonstrate the importance of early attentional processes to number representation by showing that the way in which attention disperses across a scene determines which numerical system will deploy in a given context.
AB - Coordinated studies of adults, infants, and nonhuman animals provide evidence for two systems of nonverbal number representation: a ''parallel individuation'' system that represents individual items and a ''numerical magnitude'' system that represents the approximate cardinal value of a group. However, there is considerable debate about the nature and functions of these systems, due largely to the fact that some studies show a dissociation between small (1-3) and large (>3) number representation, whereas others do not. Using event-related potentials, we show that it is possible to determine which system will represent the numerical value of a small number set (1-3 items) by manipulating spatial attention. Specifically, when attention can select individual objects, an early brain response (N1) scales with the cardinal value of the display, the signature of parallel individuation. In contrast, when attention cannot select individual objects or is occupied by another task, a later brain response (P2p) scales with ratio, the signature of the approximate numerical magnitude system. These results provide neural evidence that small numbers can be represented as approximate numerical magnitudes. Further, they empirically demonstrate the importance of early attentional processes to number representation by showing that the way in which attention disperses across a scene determines which numerical system will deploy in a given context.
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U2 - 10.1162/jocn.2010.21581
DO - 10.1162/jocn.2010.21581
M3 - Article
C2 - 20961170
AN - SCOPUS:79960112305
SN - 0898-929X
VL - 23
SP - 2336
EP - 2351
JO - Journal of cognitive neuroscience
JF - Journal of cognitive neuroscience
IS - 9
ER -