Figure 4 : ERP data of the memory test session.

From: Generalization of word meanings during infant sleep

Figure 4

The infant ERPs at individual electrode sites, the spatial distributions of the ERP differences between correct and incorrect pairings in the relevant time ranges, and the ERP responses averaged over anterior sites (anterior) or over midline sites (midline). (a) No evidence for the retention of specific word meanings in the no-nap group (P>0.1). (b) No evidence for the creation of general word meanings in the no-nap group (P>0.1). (c) N200-500 word form priming effect indicating long-term memory for the object–word associations in the nap group (anterior: T43=2.421, P=0.020; central: T43=2.259, P=0.029). (d) N400 semantic priming effect indicating the existence of newly created general word meanings in the long-term memory of the nap group (midline: T43=−2.540, P=0.015). Note that the N400 is commonly calculated as difference between unprimed and primed conditions, but to visualize the different polarity of the infant priming effects (that is, N200-500 increase and N400 decrease) we uniformly used the difference between correct and incorrect pairings for the illustration of the spatial distributions.