Search

Neuroimaging studies have indicated that people with alexithymia show structural and functional alterations in brain areas associated with emotional awareness, as amygdala, insula, anterior cingulate cortex, fusiform gyrus and parahippocampal gyrus, and only occasionally alterations in the cerebellar activity were reported. The main goal of the present study was to investigate the associations between gray and white matter cerebellar macro- (Voxel-Based Morphometry) and micro- (Mean Diffusivity and Fractional Anisotropy) structural measures (evaluated by means of a 3-T high-resolution structural Magnetic Resonance Imaging and a Diffusion Tensor Imaging scan protocol) and the presence of alexithymia (evaluated by means of 20-item Toronto Alexithymia Scale), in a sample of 60 healthy subjects having low, borderline or high alexithymia. As a corollary aim, the associations between volumes of amygdala, insula, anterior cingulate cortex, fusiform gyrus or parahippocampal gyrus and alexithymia scores have been investigated. Cerebellar gray matter volumes were positively associated with alexithymia scores. The subjects with high alexithymic traits had larger volumes in the bilateral Crus 1 in comparison to the remaining subjects. Volumes of right amygdala, left insula and left parahippocampal gyrus were negatively associated with the alexithymia scores. Thus, alexithymia scores were linked directly with cerebellar areas and inversely with limbic and para-limbic system, proposing a possible functional modality for the cerebellar involvement in emotional processing. The increased volumes in Crus 1 of subjects with high alexithymic traits may be related to an altered embodiment process leading to not-cognitively interpreted emotions. [ABSTRACT FROM AUTHOR]

Novelty Seeking (NS) and Harm Avoidance (HA) temperamental traits are related to approaching or avoiding motivational circuits relying on the integrity and functionality of distributed brain areas implicated in arousal and action. The present study verified whether and how macro- and micro-structural variations of basal ganglia are correlated with scores obtained in the NS and HA temperamental scales of the Temperament and Character Inventory by Cloninger. To this aim, 125 healthy adults aged 18-67 years of both sexes completed the Temperament and Character Inventory and underwent a high-resolution T1-weighted magnetic resonance imaging and a diffusion tensor imaging using a 3T scanner. The scores obtained in the temperamental scales were associated with volumes, mean diffusivity and fractional anisotropy measures of basal ganglia of both hemispheres separately, by using linear regression analyses. We found increased bilateral caudate and pallidum volumes associated with higher NS scores, as well as increased mean diffusivity in the bilateral putamen associated with higher HA scores. Macro- and micro-structural variations of basal ganglia regions contribute to explain the biological variance associated with NS or HA personality phenotype. The present findings evidencing some brain-temperament relationships highlight the importance of obtaining macro- and micro-structural measures in relation to individual differences. [ABSTRACT FROM AUTHOR]