Coronal view of voxel-wise subtractions (converted to Z-score maps) showing differential FDG uptake by proficiency during the post-training scan. Vertical blue lines separate the high- vs low-proficiency (n = 7 crows), low- vs high-proficiency (n = 7 crows), and medium- vs high-proficiency (n = 11 crows) comparisons. Hp hippocampus, B nucleus basorostralis, Cb cerebellum, HA hyperpallium apicale, MVL mesopallium ventro-lateralis, M mesopallium. Z-score map is superimposed atop a composite (n = 4 scans) structural MRI of the American crow brain. Slices are arranged within each comparison from most rostral to most caudal, and slice coordinates refer to an established jungle crow atlas 64 , although the peak activity within the cerebellum is more caudal than the atlas border (it is to scale). Bottom: individual normalized (global) uptake values from all crows (n = 14 crows) obtained from VOI’s centered on peak activation coordinates. Horizontal lines indicate group means for birds in the low (orange), medium (yellow), and high (green) proficiency groups. Note that the nucleus basorostralis, hyperpallium apicale, mesopallium ventro-lateralis, and mesopallium did not exceed the Z-threshold for statistical significance. Source data are provided as a source data file.
