Such a correlation was found to be highly significant in children from higher grades ( r = 0.82, p = 0.0012, Fig. 4 ), surviving Bonferroni correction for multiple comparisons between the two conditions and across the three groups ( p corr = 0.007).
In the right hippocampus, the correlation between grade and the contrast of addition sign-only trials versus baseline sign-only trials, was also near significance ( r = 0.33, p = 0.056; BF 10 = 1.22). 2 The correlation between grade and the contrast of multiplication sign-only trials versus baseline sign-only trials, however, was not significant ( r = −0.18, p = 0.32; BF 10 = 0.35). 3.3 Spatial hippocampal activity in response to a ‘+’ sign relates to an addition-priming effect in children from higher grades We then tested whether the hippocampal response to a ‘+’ sign observed in children from higher grades was related to the operator-priming effect.