Cortical-basal ganglia imbalance in schizophrenia patients and unaffected first-degree relatives.

Structural brain changes are amongst the most robust biological alterations in schizophrenia, and their investigation in unaffected relatives is important for an assessment of the contribution of genetic factors. In this cross-sectional morphometry study we investigated whether volume changes in SZ are linked with genetic vulnerability and whether these effects are separated from secondary illness effects. We compared density of grey and white matter using high-resolution 3D-anatomical MRI imaging data in 31 SZ patients, 29 first-degree relatives and 38 matched healthy controls, using Voxel-Based Morphometry (VBM) with SPM8. Volume of basal ganglia was also compared by manual segmentation. We found increased grey matter in the striatum, globus pallidus internus and thalamus and decreased grey matter in the parahippocampal and cingulate gyri both in SZ patients and relatives. Additionally, SZ patients had decreased volume of temporal, frontal and limbic grey and white matter in comparison with relatives and controls. Relatives showed intermediate values in many of these areas. Increased volume in the thalamus and parts of the basal ganglia and decreased volume of cortical areas and underlying white matter were thus associated with schizophrenia and its genetic vulnerability. These results suggest that brain morphological changes associated with SZ are in part determined by genetic risk factors and are not entirely explained by effects of medication or changes secondary to illness.

Animated brain: a functional neuroimaging study on animacy experience.

Previous research used animated geometric figures to investigate social cognitive processes involved in ascribing mental states to others (e.g. mentalizing). The relationship between animacy perception and brain areas commonly involved in social cognition, as well as the influence of particular motion patterns on animacy experience, however, remains to be further elucidated. We used a recently introduced paradigm for the systematic variation of motion properties, and employed functional magnetic resonance imaging to identify the neural mechanisms underlying animacy experience. Based on individual ratings of increased animacy experience the following brain regions of the "social neural network" (SNN), known to be involved in social cognitive processes, were recruited: insula, superior temporal gyrus, fusiform gyrus, parahippocampal gyrus and the ventromedial prefrontal cortex bilaterally. Decreased animacy experience was associated with increased neural activity in the inferior parietal and inferior frontal gyrus, key constituents of the human "mirror neuron system" (hMNS). These findings were corroborated when analyses were based on movement patterns alone, irrespective of subjective experience. Additionally to the areas found for increased animacy experience, an increase in interactive movements elicited activity in the amygdala and the temporal pole. In conclusion, the results suggest that the hMNS is recruited during a low-level stage of animacy judgment representing a basic disposition to detect the salience of movements, whereas the SNN appears to be a high-level processing component serving evaluation in social and mental inference.