Voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) are the most implemented methodologies to detect alterations of both gray and white matter (WM). However, the role of WM in mental disorders is still not well defined. We aimed at clarifying the role of WM disruption in schizophrenia and at identifying the most frequently involved brain networks. A systematic literature search was conducted to identify VBM and DTI studies focusing on WM alterations in patients with schizophrenia compared to control subjects. We selected studies reporting the coordinates of WM reductions and we performed the anatomical likelihood estimation (ALE). Moreover, we labeled the WM bundles with an anatomical atlas and compared VBM and DTI ALE-scores of each significant WM tract. A total of 59 studies were eligible for the meta-analysis. WM alterations were reported in 31 and 34 foci with VBM and DTI methods, respectively. The most occurred WM bundles in both VBM and DTI studies and largely involved in schizophrenia were long projection fibers, callosal and commissural fibers, part of motor descending fibers, and fronto-temporal-limbic pathways. The meta-analysis showed a widespread WM disruption in schizophrenia involving specific cerebral circuits instead of well-defined regions.

We introduce the concept of “neurobiological foundation” of Rorschach interpretations as an extension of the concept of behavioral representation as a foundation for interpretation of R‐PAS variables. Here, we propose that if there is a parallelism between the mental, verbal and perceptual behaviors occurring within the microcosm of the Rorschach task and those occurring in the external environment [behavioral foundation], then the same brain regions engaged by the test‐taker when producing of a given code, should be engaged also when reproducing, in the external environment, the same psychological processes underlying that specific Rorschach code [neurobiological foundation]. To investigate this concept, we used archival, fMRI data and tested whether producing Oral Dependency Language (ODL) responses would associate with increased activation in brain regions associated with dependency‐related, psychological processes. Results from a sample of 21 non‐clinical volunteers partially confirmed our hypothesis, providing some support to the neurobiological foundation of the ODL code.

Recently, Ales et al. (2019) reported on an eye-tracking study showing that Complexity and other R-PAS variables located in the Engagement and Cognitive Processing domain are correlated with a proxy marker for cognitive effort and engagement. The goal of the current study was to test the robustness and validity of Ales et al.'s (2019) findings by inspecting fMRI data. We hypothesized that the greater the level of engagement and cognitive effort put in place by a Rorschach test-taker, the greater the engagement of his/her cortical areas reflecting ongoing top-down attentional processes should be. We re-analyzed archival fMRI data from 26 healthy participants exposed to the Rorschach inkblots with the instruction to think of what they might be. The association of various Engagement and Cognitive Processing R-PAS scores to increased BOLD signals in the Dorsal Attention Network of the brain was examined. As expected, Complexity showed the strongest effect size across all R-PAS variables under investigation (d = 0.43), followed by Synthesis (d = 0.32) and Human Movement (d = 0.21). Noteworthy, the correlation between the effect sizes found in the current fMRI study and those found in Ales et al.'s (2019) eye-tracking study consists of an impressive r = .80.

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