TABLE 3.
The effects of bilingualism: neurological and structural changes in the brain.
| Regions | Methods | Subjects | Alterations | References | |
| L1 | L2 | ||||
| Frontal region | fMRI | Spanish | English | Left prefrontal activation ↑ | Hernandez et al., 2000 |
| MRI | English | Different languages | Frontal lobe volume ↑ | Olsen et al., 2015 | |
| MRI, DTI | English | Different languages | Frontal–occipital and frontal–parietal connectivity ↑ | Luk et al., 2011a | |
| FDG-PET | German | Italian | Dorsolateral prefrontal cortex connectivity ↑ | Perani et al., 2017 | |
| Italian | German | ||||
| fMRI | Different languages | Different languages | Broca’s area activation ↑ | Kim et al., 1997 | |
| Parietal region | MRI | English | European languages | Inferior parietal cortex volume ↑ | Mechelli et al., 2004 |
| MRI | Cantonese | English | Inferior parietal lobule volume ↑ | Abutalebi et al., 2015a | |
| Mandarin | |||||
| FDG-PET | German | Italian | Inferior-, superior- parietal lobules, angular gyrus, posterior cingulum, and precuneus connectivity ↑ | Perani et al., 2017 | |
| Italian | German | ||||
| Temporal region | sMRI | Chinese | Cantonese | Left temporal pole volume↑ | Abutalebi et al., 2014 |
| Mandarin | |||||
| sMRI | Catalan | Spanish | Heschl’s gyri volume ↑ | Ressel et al., 2012 | |
| CT | Different languages | Different languages | Temporal horn volume ↑ | Schweizer et al., 2012 | |
| Subcortical region | fMRI | German | French | Left caudate nucleus activation ↑ | Abutalebi et al., 2008 |
| PET | French | English | Left putamen activation ↑ | Klein et al., 1994 | |
| Corpus callosum | sMRI | Cantonese | English | Anterior cingulate cortex volume ↑ | Abutalebi et al., 2015b |
| Mandarin | |||||
| MRI | Different languages | English | Corpus callosum (genu, body, and splenium) activation ↑ | Pliatsikas et al., 2015 | |
| fMRI | German | Italian | Dorsal anterior cingulate cortex density ↑ | Abutalebi et al., 2012 | |
| fMRI | German | French | Anterior cingulate cortical areas activation ↑ | Abutalebi et al., 2008 | |
L1, native language; L2, secondary language; CT, computerized tomography; FDG-PET, fluorodeoxyglucose- positron emission tomography, fMRI, functional magnetic resonance imaging; PET, positron emission tomography; sMRI, structural magnetic resonance imaging.