Cluster maxima coordinates of activations/deactivations, at the within-group one sample t test analysis of the areas which showed a significant interaction between groups and conditions (p<0.001, uncorrected).

<p>MNI = Montreal Neurological Institute, R = right, L = left, IFG = inferior frontal gyrus, ACC = anterior cingulate cortex.</p><p>Note that none of the regions shown in the table was significantly deactivated (one-sample t test).</p

Interactions between stimuli (animal/human) and groups (omnivore/vegetarian/vegan).

<p>An interaction was found in the right amygdala (A), indicating greater increase to animal negative valence picture view in omnivores and to human negative valence picture view in vegans. An interaction between “human pictures” and “vegan group” was also found in the left amygdala (A). An interaction was found in ACC (B) between the “omnivore group” and “human pictures”, as well as between “vegetarian group” and “animal pictures”; and in the right IFG between “animal pictures” and “vegan group” (C). Foci of activations are shown on a high-resolution T1-weighted image in the standard MNI space. Plots indicate activation changes detected in the three groups during the two experimental conditions in each of these regions. Images are in neurological convention.</p

Graph showing error bars of means and standard deviations of empathy quotient (EQ) score in the three groups of subjects.

<p>See text for further details.</p

Within-group analysis of activations.

<p>Cortical activations on a rendered brain from omnivore (A–H), vegetarian (I–R) and vegan (S–W) subjects during observation of pictures showing negative valence scenes of humans (A–D, I–N, S–V) or animals (E–H, O–R, Z–W) (within-group analysis, one-sample t tests, t = 3 for display purpose). Images are in neurological convention.</p

Within-group comparisons of human <i>vs</i>. animal negative valence picture view and vice versa in omnivore subjects, vegetarians and vegans (paired t test in each group, p<0.05 FWE-corrected).

<p>MNI = Montreal Neurological Institute, R = right, L = left, BA = Brodmann area, MTG = middle temporal gyrus, IOG = inferior occipital gyrus, IPL = inferior parietal lobule, MFG = middle frontal gyrus, IFG = inferior frontal gyrus, ACC = anterior cingulate cortex, PCC = posterior cingulate cortex.</p

Results of the between-group comparisons of emotional (human and animal) negative valence picture views.

<p>Results are superimposed on a high resolution T1-weighted image in the standard MNI space, at a threshold of p<0.05 corrected for multiple comparisons. Areas activated during human picture view in vegetarians and vegans <i>vs.</i> omnivores are shown in yellow. Activations specific for vegetarians are shown in blue. Activations specific for vegans are shown in red. A: human picture view; B: animal picture view. Images are in neurological convention.</p